ZOO 3731 Exam 2 Ch 9 - 15

receptors are going to be the ones that are going to receive the sensory input and depending on where they are going to be located we can classify them into three different groups.

Receptors are monitored by the sensory neurons: - Exteroceptors -proprioceptors -interoceptors

White matter can be divided into regions

The *posterior white columns* are located between the posterior horns and the posterior median sulcus. The *anterior white columns* are located between the anterior horns and the anterior median fissure, and they are interconnected by the anterior white commissure. *Lateral white columns*, between the anterior and posterior columns, are composed of white matter.

thin filaments are composed of

Troponin Active site Tropomyosin G actin molecules

G actin molecules

-each individual actin molecule is a G actin -each actin molecule has an active site. (the yellow portion) that wants to bind to the thick filaments

Interoceptors

Interoceptors = internal environment: -Digestive, respiratory, cardiovascular, urinary, and reproductive systems -Sensations of deep pressure and pain (Viscera) internal organs

contractions is triggered by the presence of

calcium ions

Neck muscles

Mylohyoid Digastric Stylohyoid Sternocleidomastoid (cut) Omohyoid sternohyoid scalenes

Extensor pollicis longus

Origin:Ulna Insertion:Thumb Action: *Extension at joints of thumb* and abduction at wrist

Gluteus Medius

Origin: iliac crest and other areas of the ilium Insertition: Greater trochanter of femur Action: *Abduction and medial rotation at hip*

Vastus Lateralis

Origin:Close to greater trochanter and along linea aspera Insertion:Tibial tuberosity Action: Extension at knee

so remember how we had sensory information and sensory input that would arrive up here in the ______ so motor information is going to be exiting through the _________

thalamus hypothalamus

A muscle that flexes the knee would originate on the:

femur or coxal bone

NEURONAL CONTROL OF MUSCLE RELAXATION

passive form of movements in the muscle

1st order type of neuron

pseudounipolar

A patient is experiencing pain on the posterior part of his thigh. what nerve may be implicated?

sciatic nerve

Red contains

sensory , 1st order

posterior gray horns contain

sensory information;The posterior (dorsal) horns contain somatic and visceral sensory nuclei

Serial processing:

serial processing is when they are all lined up so you would call it serial processing you have one neuron sending information to one more neuron that's sending in information to one more neuron but they're all linear so all in series.

Skeletal Muscles can be classified based on

shape or the arrangment of their fibers

Transversus Abdominis:

beneath the oblique muscles is the transversus abdominus this muscle gets a special name because the fibers run transversely or horizontally it is the deepest muscle of all the anterior wall abdominal muscles.

The meniges will wrap up not only the spinal cord but the .....

brain

The afferent division of the PNS ......

brings sensory information to the CNS. such as touch, pressure, pain

Group 3: Superficial posterior leg compartment

called calf muscles

Where does the spinal cerebellar tract end?

cerebellum

Lateral gray horns contain

contain visceral motor neurons

When a muscle is relaxed these active sites on the thin filaments are

covered up

Latissimus dorsi

covers up the majority of the inferior portion of the back it actually originates on this the vertebral column but it also attaches to the scapula here on the very bottom so it's really both and then it inserts on the humerus on the inside this is important on the medial portion of the humerus. this muscle has two actions depending on the original location of the arm if the arm is already flexed at the shoulder. This is a lateral view so the arm is actually at a in this example it's at 90 degrees relative to the body so if the arm is already flexed at the shoulder this muscle because it's in the back and it's attached to the humerus will extend it or bring it back down into anatomical position but if the arm is already ABducted this is a front so if the arm is already abducted this muscle will pull and bring the arm back down or adducted. by the way ignore the 2 X's on them that's a different muscle.

The further you go down the spinal cord the larger the ........

cut section of your spinal cord at different areas and one thing that you can notice from these different areas is that the further you go down the larger the gray matter becomes compared to the white matter okay so the larger you go down the bigger the gray matter compared to the white matter.

Sarcoplasm

cystol of the cell are specific to muscle fibers

Brachialis

deep to the biceps brachii is a muscle that crosses over the elbow joint it doesn't go all the way up and cross the shoulder joint like the biceps brachii does so it can only perform flexion of the forearm at the elbow this is called brachialis.

Flexor retinaculum

dense fibrous connective tissue that covers up those tendons . (holds everything in place)

multiple sclerosis

disease that's called multiple sclerosis where these myelin sheets or oligodendrocytes are actually affected and they don't produce the myelin as efficiently as they're supposed to and so it sort of destroys the connection and it breaks the isolation of the transmission of the information.

The perimysium is a layer of connective tissue that

divides the muscle into a series of internal compartments, each containing a bundle of muscle fibers called a fascicle

The cell body of a first order neuron will be located in the

dorsal ganglion

Sensory nerve goes through the _______ root

dorsal root

Trapezius:

down here lower in the neck you can see the trapezius muscle which is actually not an axial muscle it moves the upper limb but I play that's why it's not bolded here but I wanted to show it because it's often confused with the sternocleidomastoid so keep that in mind this trapezius muscle is on the back of the neck.

dura mater

dura means hard mater means mother so this is going to be the toughest of the membrane layers. ( Lateral support of the spinal cord is provided by the connective tissues within the epidural space and by the extensions of the dura mater accompanying the spinal nerve roots as they pass through the intervertebral foramina )

1. A muscle that aids in chewing without moving the mandible is: A. mentalis B. buccinator C. levator anguli oris D. zygomaticus E. temporalis

B. buccinator

Spinocerebellar tract number of neurons involved when does decussation occur? Location of pathway in SC

- 2 neurons -pons (meduall obloongata) -lateral

Skeletal Muscle Fiber Characteristics

- are the cellular component of muscles they are individual muscle cells. -unqiue feature is that they are multinucleated. So each muscle cell has hundrends of these nuclei -incredibly long; 30 to 40 cm in length, little over a foot long. They can be as long as the muscle itself -some of the biggest cells in our body - have striated or striped appearance actually caused by the contractile proteins with in the myofibrils.

Pseduounipolar has the the dentrites in the ________ and a cell body in the ______ and the terminal butouns in the______

- denrites: effector area (skin organ, muscle) -cell body located in the dorsal ganglion (PNS) -terminal butouns are the in spinal cord

Four anterior wall muscles for the abdominal muscles

- internal oblique -external oblique -rectus abdominis -transversus abdominis

function of the 2 openings in the diaphragm

- only way in and out because everything is closed off by muscle fibers - 2 openings that allow for passage of arteries, veins, nerves, and structures like the esophagus to transport substances between the thoracic cavity and the abdominal cavity.

Excitability

- responds to stimuli from the nervous system (skeletal) & hormones (smooth). (depending on the type of muscle this stimulation can either come from the nervous system which excites skeletal muscle or circulating hormones which influences smooth muscles.)

Contractility

- shortens actively & exerts tension (pull) on what it's attached to

the part of the meninges between the dura mater and the arachnoid mater there is a space that's called a

- subdural space

Third-Order Neuron:

- which leaves the *thalamus and it's going to go to specific areas of your cerebral cortex* and this third order neuron now depending on where it arrives in your cerebral cortex it's sort of going to give you the *different sensations that you feel* and it's going to and be related to specific areas of your body and if you look up here you can see that we have a little guys sort of all distributed out.

What trunks give rise to the lateral cord?

-*superior* is going to give rise to the lateral cord the *middle* is also going to give rise to the lateral cord.

Lateral spinothalamic tract number of neurons involved when does decussation occur? Location of pathway in SC

-3 neurons - spinal cord -lateral

Neuroglias Functions AKA

-AKA glial cells (give support to neurons) -Providing the framework for the neural tissue. (give all the support the neurons need) -Maintaining the intercellular environment (making sure all the waste is removed that everything is balanced) -Acting as phagocytes (if their is a pathogen not suppose to be there they will act as a phagocyte and remove these pathogens) -100 billion neuroglia, or glial cells Roughly five times the number of neurons. (20 billion neurons)

Plantaris action

-Also a PROPRIOCEPTOR (senses spatial position of foot) but plantaris is a special muscle it is called a proprioception what this means is that it contains specialized nerve cells that have a role in sensing spatial position of the foot walking bipedally or upright requires a lot of spatial recognition of where exactly to place the lower limb it's incredibly important to know exactly where the lower limb is going to be planted during walking because walking on two feet you've got a balanced more of the body weight onto a smaller segment of the body the plantaris muscle sends information to the brain allowing us to know exactly where our foot is at any point during walking

Nerve cells, or neurons:

-Are responsible for the transfer and processing of information in the nervous system -the neurons are the ones that are going to process all the information so the information that's received by the receptor which is a type of neuron then it takes to the central nervous system connecting to another neuron then it takes to the effector organ through another neuron so all this has to do with neuron activity.

Astrocytes

-Are the largest and most numerous glial cells. Have a variety of functions: -Maintaining the blood-brain barrier. -Creating a three-dimensional framework for the CNS. (microfilaments) -Performing repairs in damaged neural tissue. -Guiding neuron development. -Controlling the interstitial environment.

Efferent Division

-Begins inside the CNS & ends at an effector -So your efferent division it's always going to begin inside the central nervous system now a lot of you guys get confused with the central nervous system so when I say central nervous system what comes to your mind so what should come to your mind is two things brain and spinal cord so does this mean that information can begin only at the level of the spinal cord instead of having to start at the level of the brain yes that's true so information can start at the level of the spinal cord instead of having to go all the way up to the brain.

Superior trunk is formed by

-C5 and C6

Motor Tracts

-CNS issues motor commands in response to information provided by sensory systems Commands distributed by: -Somatic nervous system -Direct contractions of skeletal muscles Autonomic nervous system -Innervates visceral effectors, such as smooth muscles, cardiac muscle, and glands

Two anatomical subdivisons of the nervous system

-Central nervous system (CNS) -Peripheral nervous system (PNS)

Efferent divison Somatic nervous system (SNS):

-Controls skeletal muscle contractions. -May be voluntary or involuntary. so the afferent receptors receive the information they take it all the way to the central nervous system which can go all the way to your brain or stay at the level of the spinal cord this information then is taken back to an effector organ in this case for the somatic nervous system is going to be a skeletal muscle so this mean that the skeletal muscle is going to contract this response can be voluntary so when you the side that you're going to pick up the pen to write it's voluntary when you have to do things like a reflex that you don't have to think about then it's going to be involuntary.

Unipennate muscles

-Extensor digitorum muscle - pennate mean that the muscle fibers are at an oblique angle to the tendon. - unipennate muscles the muscle fibers are on one side of the tendon you can see that here this is where the tendon is and all the muscle fibers are on one side

The effernt divison Autonomic Nervous System

-Is also called visceral motor system. -Regulates smooth muscle, cardiac muscle, and glands. -Is involuntary. (autonomic nervous system or ans which is also called visceral motor system so this has to do with your internal organs so it's going to regulate the smooth muscle of several of your organs things like your respiratory organs your cardiac muscle your glands and luckily all this is involuntary so you don't really have to think about your heart pumping blood through your body or your lungs inflating with air and things like that because it's all done involuntarily.)

Motor neurons:

-Most are multipolar neurons -Somatic nervous system (involuntary or voluntary)- send info to muscles to contract the muscle in response to a stimulus. -Autonomic nervous system (involuntary)- have affet occuring in a certain organs

Interneurons or association neurons:

-Most are multipolar neurons. smaller neurons located between two neurons. usually between a neuron in the PNS and neuron in the CNS

Sensory neurons

-Most are pseudounipolar neurons Form the afferent division of the PNS: -Somatic sensory neurons -Visceral sensory neurons

Neural tissue contains two distinct cell types:

-Nerve cells, or neurons: -Supporting cells, or neuroglia

Pia mater

-Pia mater- Pia means delicate so delicate mother it really is a very very delicate membrane that hugs not only the spinal cord but also hugs the brain and you can see it right over here this membrane.

Neurons have three functional groups:

-Sensory neurons -Motor neurons -Interneurons or association neurons:

Number of synapses varies from one tract to another

-Sensory tract ending in cerebral cortex involves 3 neurons -Sensory tract ending in cerebellum involves 2 neurons so there is a difference in the number of neurons depending on where the information is going to be going to.

Functions of Skeletal Muscle (5)

-Skeletal movement -Maintain posture/body position -Support /protect soft tissues ex. Abdominal wall muscles & pelvic floor muscles -Regulate entrance/exit of material ex. Orifices of digestive & urinary systems -Maintain body temperature

Sensory tracts: Complexity of response depends on:

-Where processing occurs -Where motor response is initiated

Multipennate muscle

-deltoid - the muscle fibers still run oblique to the tendon but the tendon branches within the muscles there are actually multiple tendons within the muscle and a good example of this is the deltoid muscle which is coming off of your shoulder and attaching to your humerus

central canal

-down the middle you have a little opening -Central canal now is going to be important because you're going to have your CSF cerebral spinal fluid passing through it.

Intermediate Tendon

-each is divided by a small tendon - the alteration of the muscle belly to tendon is what gives us our 6 pack -Ex: rectus abdominis has a series of separate muscle bellies (between the muscles bellies)

lateral flexion in the torso (bending)

-external oblique (anterior part) -internal and external oblique (lateral part) -quadratus lumborum -internal oblique (anterior part)

Fasciulus gracilis and cuneatus (posterior columns)

-if you notice here when we're talking about the posterior column it can be subdivided into what we call a fasciculus gracilis and a fasciculus cuneus. you don't need to know these specific terms for the posterior column but it's just important that you know that they have different areas and basically it's going to start at different areas of the spinal cord so it you can see because it's posterior column it's going to start on the posterior region the spinal cord and basically the fasciculus gracilis is going to be more medial than the fasciculus cuneus. -they will go all the way up the thalamus

Rotation

-iliocostalis and longissimus -internal oblique -external oblique

Smooth Muscle

-involuntary movement -found in a digestive tract highlight the esophagus and the stomach. Push the fluid and solids through the digestive tract.

Anterior spinothalamic tract number of neurons involved when does decussation occur? Location of pathway in SC

-neurons 3 -spinal cord -anterior

Medial-Lateral Rule Example

-okay so here they give an example so if you have information that's leaving from or arriving from t11 is going to be more medial because it's more inferior than information that's going to be arriving from c4 so that means if it's more superior it's going to run more lateral on your spinal cord okay so we can say maybe medial would be here so this would be information from t11 and lateral would be here so information from c4 so this is just saying the medial lateral rule is just saying that information that is more inferior runs medially and information that's more superior runs laterally.

Circular muscle

-orbicularis oris muscle and oculi -the muscle fibers form concentric rings around some sort of opening and these are also called sphincter muscles

Aponeurosis

-some muscles that have long sheets of tendon when they elongate like that they are called this -connect muscles to other muscles (unlike tendons) -reason you cant see the abdominal muscles. Covers the muscles belly

Triceps Brachii

-there's only one muscle in the posterior portion of the arm - notice how all these heads come together into one tendon that inserts on the ulna here because the insertion is on the forearm this serves to extend the forearm and because there's a portion that attaches to the scapula if the arm is already abducted this will help pull it closer to the body and adduct it that's only if the long head is contracting.

Nervous system

-things that occur in the nervous system are very very fast so you need a fast response you need a substance that's going to be released fast so you can get that fast response. -nervous system releases hormone or chemicals known as neurotransmitters they're going to be excitatory or inhibitory. -excitatory: meaning that it's going to make sure that the action occurs so that the signal is going to be transmitted. - inhibitory it means that it's going to block that signal from occurring.

The nerve branching off of C5 can belong to both the _________ and ________ plexuses.

. cervical; brachial

The glial cells that destroy microorganisms in the CNS are:

. microglia

Anatomy of Peripheral Nerve connective tissue layers

1) Epineurium covering the peripheral nerve (alot of fascicles grouped together) 2) Perineurium (around one fascicle) (collection of nerves) 3) Endoneurium (axon or each fiber)

Erector Spinae Group:

1) Spinalis: the spinalis is closest to the spine it's the skinny muscle right here next to the spinous processes of the vertebrae. 2) longissimus is the one in the middle and you can't see this from this slide because the splenius capitis is in the way but it's the longest of all of them hence longus. 3) the iliocostalis is the most lateral one and it's named that because it originates on the ilium and inserts on the ribs.

Neuronal control of Muscle Contraction step 1

1) exactly how does the nervous system control muscular contraction what we can see here is the end of a *motor neuron coming in contact with the sarcolemma* of one of the muscle fibers this is defined as a neuro muscular synapse or where a neuron and a muscle meet

Function of the neck muscles

1) position and move the mandible, hyoid, and larynx or voice box 2) they form a foundation for muscles of the throat and tongue

chemical synapse step 1

1) so first you need to have an action potential that's going to be coming down this axon right over here once it reaches the axon then it's going to travel down all the way to your terminal button.

The three layers of Meninges are

1)Dura mater: like I said we have what we call the outermost layer 2)Arachnoid mater: middle layer is what we call the 3)Pia mater: the most internal one.

Three main sensory tracts that deliver somatic sensory information to the sensory cortex of the cerebral or cerebellar hemispheres

1)First-order neuron 2)Second-order neuron 3)Third-order neuron

Intrinsic Muscle of the Back layers

1)Superficial layer -Splenius (splenius capitis and splenius cervicis) 2)Intermediate layer -Spinalis group -Longissimus group -Iliocostalis group 3)Deep layer -Semispinalis -Multifidus -Rotators -Interpinalis -intertransversarii

The superior trunk originates from the branches of which cervical nerve?

C5 and C6

Multipolar neurons are found in the

CNS

Arm: Muscle Compartments Groups?

Contains muscles from Groups 2 & 3 -POSTERIOR COMPARTMENT (EXTENSORS) -ANTERIOR COMPARTMENT (FLEXORS)

the third thoracic muscle that is most important in terms of breathing .

Diaphragm

Extensor pollicis longus & brevis:

Extends phalanges of the pollex

Orbicularis oris:

I already covered the action of the orbicularis Oris when discussing the buccinator but here is an image showing what it would do without the air in the cheeks without the bucciantor working as well, so it purses the lips.

Group 1: Medial thigh compartment

* anterior compartment removed to see inside the thigh

PNS

Peripheral nervous system (PNS): -Neural tissue outside the CNS -Provides sensory information to the CNS -Carries motor commands to peripheral tissues functions of the peripheral nervous system: basically is going to be to receive the sensory information that arrives in the periphery carry it to the central nervous system and then be the highway to receive whatever information is going to be processed in the central nervous system back to the periphery. so it's just like a highway of nerves.

Muscles can be grouped according to their primary actions into four types:

Prime movers (agonists) Antagonists Synergists Fixators

Proprioceptors

Proprioceptors = internal environment: (plantaris) -Position and movement of skeletal muscles and joints -Information carried in somatic sensory neurons so these are going to be located close to joints and by being located close to joints it sort of gives you your body that sensation of where your body is localized in time and space. but basically even though proprioceptors are internal and interceptors are both internal make sure that you differentiate interceptors for being part of your major organs and the proprioceptors has to do with more of position and movement of skeletal muscles and therefore it's going to be located at joints.

Rotator cuff muscles

SUPRASPINATUS INFRASPINATUS SUBSCAPULARIS TERES MINOR

While doing yoga, Ann noted that when she sat with her legs crossed, she felt a sharp pain in her thigh. The muscle that allows Ann to cross her legs is called:

Sartorius

Muscle of mastication

Temporalis Masseter Buccinator

Action

The function of the muscle upon contraction

Neuronal control of Muscle Contraction step 5

5)contraction within the sarcomere will happen all the sarcomeres are contracting along the myofibril and therefore the muscle itself will shorten in length.

it's motor information it's going to be leaving on the__________ part of your brain if it's sensory information it's going to be arriving in the ________ part of your brain.

anterior posterior

Transverses abdominus in posterior wall

as being this innermost layer of anterior wall muscle.

now you notice as we go over muscles in group 5 that there are usually separate muscles involved with moving the thumb and it'll be one muscle that moves the fingers this is because....

as humans our thumbs are highly specialized for certain types of movement so the flexor digitorum profundus for example has separate tendons each one will go to a different finger but there's a separate muscle entirely called the flexor pollicis longus

The glial cells that guide migrating neurons in the developing fetal brain are:

astrocytes

quadrates lumborum muscles:

attached from the *iliac crest to the lumbar vertebrae* there are several quadratus muscles in the body and anytime you see a muscle called quadratus it's rectangular in shape it's got four sides so quadratus lumborum is indicating to you there's a quadrates muscle that happens to be associated with the lumbar vertebrae.

Group 2 & 3: Biceps brachii

ACTIONS: *Flexes forearm* *Flexes arm* *Helps hold humeral head in glenoid fossa (long head only)* Origin:Scapula Insertion: Radial tuberosity (Actions:Flexion at elbow and shoulder; supination)

Group 2: Deltoid

ACTIONS: Abducts humerus Origin: *Clavicle and spine of scapula* Insertion: Deltoid tuberosity of *humerus* Other Actions -Anterior muscle: flexion and medial rotation of humerus -Posterior part: extension and lateral rotation of humerus

All together what dorsiflexes the foot

Action all together (tibialis anterior, Extensor digitorum longus, and extensor hallucis longus)

1. Which of the following muscles is NOT involved with moving the jaw? a. temporalis b. sternocleidomastoid c. masseter d. digastric

b. sternocleidomastoid

Properties of Muscle (listed) (4)

1)Excitability 2)Contractility 3)Elasticity 4)Extensibility

The afferent division carries information from

: -Somatic sensory receptors: Skeletal muscles, joints, and the skin -Visceral sensory receptors: Smooth muscle, cardiac muscle, and glands -Special sense organs: Eye, nose, tongue, and ear

Which of the following is a main characteristic of skeletal muscle fiber? A.straited apperance B. incredibly short C. presence of intercalated disc D. Single nucleated

A. straited appearnce

Path of flexor tendons

Flexor digitorum longus and flexor hallucis longus cross over each other. (hallucis goes over the digitorum)

Lumbar region

L1-L5

Vastus Medialis

Origin:Entire length of linea aspera of femur Insertion:Tibial tuberosity Action: Extension at knee

Thoracic region

T1-T12

Somatic motor tracts always involve

a upper motor neuron a lower motor neuron

Why does skeletal muscles have striated apperance?

because the sarcomere is set up in alternating bands of mylofilaments both thick and thin

The cell body of a second order neuron will be located in the:

spinal cord

Sliding Filament theory

when a muscle contracts these actin filaments are going to slide toward each other over the thick filaments.

fulcrum

fixed point, joint in the skeletal system

In addition to flexing the knee, the sartorius is responsible for:

flexes and laterally rotates the hip joint

Internal intercostal muscles:

inter means between costal means ribs so these muscles run between each of the ribs one set of muscles. just deep to the external intercostals are another set of muscles called the internal intercostals (*depress the ribs*)

The large areas wrapped in myelin are called

internodes

Muscle Fascicle

is a bundle of muscle fiber cells

2nd order type of neuron

multipolar

skeletal muscles are stimulated by the

nervous system

Which cord is formed by all trunks?

posterior

Troponin is responsible for

regulating when tropomyosin moves away. when tropomyosin will allow or not allow the active sites to be exposed

between the Pia mater and the arachnoid mater we do have a space and the space does exist which is called

subarachnoid space

Quadriceps femoris tendon

tendon that the patella bone forms inside of

Myofibrial

with in each musch fiber

Soleus

* looks like gastrocnemius shape but it does not have two heads.* Origin:Head of fibula and posteromedial shaft of tibia Insertion:Calcaneus via calcaneal tendon Action:(*Plantar flexion at ankle*;) postural muscle when standing

Gluteus Minimus

* this is deep to the gluteus medius (smallest) Origin: Lateral surface of ilium between inferior and anterior gluteal lines Insertition: Great trochanter of femur Action: *abduction and medial rotation at hip*

Flexor Hallucis longus

*(flex big toe) the muscle is lateral* origin:Posterior surface of fibular insertion:Inferior surface, distal phalanx of hallux action:(Flexion at joints of hallux); plantar flex ankle

Gastrocnemius

*(most prominent two head)* Origin:Femoral condyles of femur Insertion:Calcaneus via calcaneal tendon Action:(*Plantar flexion at ankle*;) flexion at knee

Plantaris

*(tiny)(small muscle belly very short) * -*majority of it is the long thin tendon goes all the way down into the plantar part of the foot* Origin:Lateral supracondylar ridge of femur Insertion:Posterior portion of calcaneus Action: (*Plantar flexion at ankle*;) flexion at knee

All other muscles in the gluteal compartment action

All other muscles: Laterally rotate thigh Steady head of femur in the hip joint

Tendon

At the ends of the muscle. Type of connective tissue that connects the muscle to their bone or skin or another muscle. - dense connective tissue

Which of the following is a main characteristic of a skeletal muscle fiber? A. smooth apperance B. incredibly long C. presence of intercalated discs D. single nucleated

B. Long

sensory and motor tracts are

Communication between CNS and PNS

Muscles of facial expressions

Frontal belly of occipitofrontalis occipital belly of occipitofrontalis orbicularis oculi zygomaticus minor zygomaticus major orbicularis oris platysma epicranial aponeurosis levator labii superioris buccinator depressor anguli oris

What Bone FEATURE does Gluteus Maximus insert on?

Gluteal Tuberosity

Gluteus Maximus functions

Gluteus maximus muscle actually has quite a lot of actions but we're only going to discuss two of them it has to because it depends on exactly the location of the femur and the angle of the hip when this muscle contracts. if the thigh or femur another way of saying that is it already flexed meaning it's drawn close to the torso contraction of the gluteus maximus will extend the thigh and bring it back posteriorly however if the femur or thigh is an anatomical position as this picture is showing contraction of the gluteus maximus would abduct the thigh again. the tensor fasciae latae tenses the fasciae latae surrounding the thigh muscles.

FIVE UPPER LIMB MUSCLE GROUPINGS

Group 1: move the pectoral girdle Group 2: move the arm at the shoulder Group 3: move the forearm at the elbow Group 4: move the hand at the wrist Group 5: move the digits

Teres major

originates on the scapula down here at the bottom and inserts on the front part of the humerus. why is that important because it's that location of insertion that allows it to medially rotate the arm because it's attached to the anterior part of the humerus it can rotate it this way medially if it were attached to the back it would do the opposite it would laterally rotate. this concept will be reinforced again when we talk about lateral rotators of the arm which are attached to the posterior aspect of the humerus.

There is no muscles that move or stabilize ____ ______

os coxa; part of the pelvis is held tightly bound to the sacrum via joints and ligaments. In addition, it is also not meant to be moved like the scapula and clavicle are

Damage to the_____________ nerve will interfere with ones diaphrag which may be deadly, this nerve originates between ____ and _____. (vertebral nerves)

phrenic C3,C5

Cervical Plexus

plexus is just going to be a group of nerves okay so that's when we're talking about cervical plexus is going to be a group of nerves that are located in the cervical area. now these are going to contain branches that are cutaneous so they come from the skin and also muscular but in specific areas of the cervical region.

Flexor digitorum superficialis

Origin:Medial epicondyle of humerus; coronoid process of ulna and radius Insertions: Bases of middle phalanges 2-5 Actions: Flexion at proximal interphalangeal, metacarpophalangeal and wrist joints (*Flexes phalanges of digits II-V (not thumb*)

Flexor Carpi Ulnaris

Origin:Medial epicondyle of humerus; olecranon on ulna Insertion: Pisiform, hamate, base of metacarpal V Action: Flexion and adduction at wrist

Obturator Internus

Origin:Obturator foramen Insertion: Greater trochanter of femur Action: *Lateral rotation* and abduction of hip. *Help to maintain stability and integrity of the hip* * named that because it covers the obturator foramen and is inside the pelvis basically the internal obturator muscle*

adductor longus

Origin:Pubis Insertion:Linea aspera of femur Action: *Adductionat thigh*, flexion, and medial rotation at hip

Extensor pollicis brevis

Origin:Radius Insertion: Thumb Action: *Extension at joints of thumb* and abduction at wrist

Subcapularis

Origin:Subscapular fossa of scapula Insert: Lesser tubercle of humerus Action: Medial rotation at shoulder

Pseudounipolar are found in the

PNS

Name the Neuroglia that are found in the PNS and CNS

PNS: - Satelliate cells -Schwann cells CNS: -Oligodendrocytes -Astrocytes -Microglia -Ependymal cells

Parallel Processing:

Parallel Processing: parallel is when you have one neuron that sort of diverges initially into three different neurons but then you're going to have a serial processing again so they run parallel to each other. .

Relaxation passive or active? contraction passive or active?

relaxation is a passive form of movement in the muscle whereas contraction is an active form we say it's passive because in order for relaxation to occur there's no impulse when the impulse is present that is actively initiating the muscle to contract.

The endomysium is a layer of connective tissue that

surrounds each skeletal muscle fiber and therefore binds each muscle fiber to its neighbor, and supports capillaries that supply individual

Inferior Oblique

takes inferior portion of eye rotates it medially. (extorsion) external rotate eye

most muscles in the body has this type of organization? (2)

tendon and muscle belly (head)

Skeletal muscles are organs that include?

that include 4 basic tissue types but consist primarily of skeletal muscle tissue.

common fibular nerve

that's why it's called common because after it branches it gives two separate branches a deep and a superficial fibular nerve.

carpal tunnel

the carpal tunnel is a passageway between a bend and the carpals this is a right hand from a palmar view this line right here is representing a cut that we've made and now we're viewing from a different angle the carpals almost like we are the radius and we're looking into the carpals so the carpals bend here and create this passageway through which the flexor tendons pass and what's forming the superior part of the carpal tunnel is that flexor retinaculum tissue.

sarcolemma

the cell membrane of each muscle fiber. This surrounds the muscle cell and regulates transport of substances.

Muscle fibers are considered

the cells of the muscle

perimysium

the connective tissue fibers of the perimysium (per-i-MIS-ē-um; peri-, around) divide the muscle into internal compartments. Each compartment contains a bundle of muscle fibers called a fascicle (FAS-i-kul; fasciculus, bundle). The perimysium contains collagen and elastic fibers, and numerous blood vessels and nerves supply each fascicle.

superior oblique has a tendon that attaches to the eye the muscle belly is posterior to that

trochlea (ligamentous sling)

as soon as these nerves they branch out the first thing that they do is that they come together to form what we call ______

trunks

Myofibril Surrounded by? Consists of ?

Surronded by: sarcoplasmic reticulum consists of: Sacromeres (z line to Z line) (if all the sacromere lined up end to end within the myofibril or contracting the myofibril will shorten and therefore the muscle will shorten)

Synergists:

Synergists: or additional muscles that will help a prime mover or an agonist and performing a particular action the best example that I can think of is there's a muscle in your back called the latissimus dorsi and there's another smaller muscle in that same region called the teres major and these two muscles both adduct the arm the the agonist is the larger latissimus dorsi and the synergist it's helper buddy is the teres major .

The motor command leaves through the:

ventral root

motor nerve is exiting through the _________ root

ventral root

Nerves that directly control the motility of the stomach or rate of the heartbeat would belong to the:

visceral motor division

Active sites

wants to bind to the thick filaments. it's the binding of the active site on these actin molecules to the thick filaments that causes muscular contraction therefore when a muscles relaxed these active sites are covered up

Frontal Belly of Occipitofrontalis:

we can see here right above the frontal bone is called the frontal belly of the occipital frontalis this is actually one muscle that has two parts one that's on the frontal and one that's on the occipital and so that would be the occipital belly of the occipitofrontalis. These two bellies of the same muscle are connected by the epiccranial aponeurosis. (the epicranial aponeurosis connects the two bellies which are part of the same muscle so as an entire muscle it's called the occipital frontalis the entire muscle is composed of the two bellies and the epic cranial aponeurosis)

Polysynaptic

we're going to have inter neurons that are going to be involved in this process so you're going to have a sensory neuron over here you can have in this case they're showing two inter neurons but if you have inter neurons it's already called polysynaptic and then they're going to sort of synapse with other motor neurons and in this case they're showing two skeletal muscles okay so that's your polysynaptic -*you're going to have inter neurons that are going to connect to motor neurons* and it can be one or several motor neurons depending on how many interneurons you have. -A polysynaptic reflex has more than one synapse between the stimulus and response

Medial-Lateral Rule

what the medial lateral rule is is just saying that information that is coming from more inferior areas of your body are going to run more medial an information that is going to be coming from more superior areas of your body is going to be running more lateral.

The ___________________________is a deep crease on the anterior surface of the cord

anterior median fissure

Epicranial Aponeurosis:

aponeurosis is a type of connective tissue tendon that connects two muscles together and epi cranial just means it's above the cranium

ganglions

are big cluster of neuronal cell bodies

How can skeletal muscle be distinguished from the other 2 types?

because it exerts a pulling force on the skeletal elements. This pulling force can either stabilize a joint and prevent movement or it can create movement at that joint.

Why can the adductor magnus perform opposite actions at the same joint?

because of the two insertions 1) linea aspera on the back of the femur 2) the one little bit more anterior on the medial epicondyle thats why it can flex and extend thigh

When a muscle contracts why does it shorten in length?

because the sarcomeres that are lined end to end shorten. Its the interactions between both the thick and thin filaments that contracts the sarcomere.

why is it called the cross bridge cyle?

because the specific connection point between the thick and thin filaments is called a cross bridge

Why are skeletal muscles unique?

cause they are voluntary ( you have conscious control over most of the skeletal muscles in your body)

Pectineus:

Origin: superior ramus of pubis Insertion: pectineal line inferior to lesser trochanter of the femur. Action: flexion and adduction at hip

Piriformis

Origin:Anterolateral surface of sacrum Insertition: Greater trochanter of femur Action: (*Lateral rotation*) (*Help to maintain stability and integrity of the hip*) and abduction of hip.

Brachioradialis

Origin:Epicondyle of humerus Insertion:Styloid process of radius Action: *Flexion at elbow (flexes forearm)*

Tensor Fasciae Latae

Origin:Iliac crest and iliac spine Insertion:Iliotibial tract Action:Abduction* and medial rotation at hip (*Tenses the fascia latae surrounding the thigh muscles*)

Sartorius

Origin:Iliac spine Insertion:Near tibial tuberosity of tibia Action: *Flexion at knee; abduction, flexion, and lateral rotation at hip* (thigh) *crosses over from lateral side to the medial side of the lower limb. (thin muscle)

iliopsoas muscle

Origin:Iliacus (iliac fossa) Psoas major (vertebrae T12-L5) Insertion: Lesser trochanter of femur Action:Flexion at hip and/or lumbar intervertebral joints ACTIONS: *Flexes thigh* *Psoas major also is a postural muscle when lower limb is fixed*

Superior Gemellus

Origin:Ischial spine Insertition: Greater trochanter of femur Action: *(Lateral rotation) (Help to maintain stability and integrity of the hip)* and abduction of hip.

Semitendinosus

Origin:Ischial tuberosity Insertion:Proximal, medial surface of tibia Action: Flexion at knee; extension and medial rotation at hip *Extends thigh and flex leg* *(long thin tendon that runs from the muscle belly all the down onto tibia)*

Inferior Gemellus

Origin:Ischial tuberosity Insertition: Greater trochanter of femur Action: *(Lateral rotation) (Help to maintain stability and integrity of the hip)* and abduction of hip.

Teres Minor

Origin:Lateral border of scapula Insertion: Greater tubercle of humerus Action: Lateral rotation and adduction at shoulder

extensor carpi ulnaris

Origin:Lateral epicondyle of humerus Insertion:Metacarpal V Action:*Extension and adduction at wrist*

Extensor digiti minimi

Origin:Lateral epicondyle of humerus Insertion:Posterior phalanx V Action:Extension at joints of digit V and extension at wrist (*Extends phalanges of digit V (pinky*)

Extensor carpi radialis brevis

Origin:Lateral side of humerus Insertion:Metacarpal III Action:*Extension and abduction at wrist*

Extensor digitorum

Origin:Lateral side of humerus Insertion:Phalanges 2-5 posterior Action:Extension at finger joints and wrist (*Extends phalanges of digits II-V(not thumb*)

Flexor digitorum profundus:

Origin:Medial and posterio surfaces of ulna, medial surfaces of coronoid process; interosseous membrane Insertion: Bases of distal phalanges of digits 2-5 (Flexes phalanges of digits II-V (not thumb))

Flexor carpi radialis

Origin:Medial epicondyle of humerus Insertion:Bases of metacarpal II and III Action: Flexion and abduction at wrist

Palmaris Longus

Origin:Medial epicondyle of humerus Insertion:Flexor retinaculum Action:Flexion at wrist

Pronator teres

Origin:Medial epicondyle of humerus and coronoid process of ulna Insertion:Lateral surface of radius Action: *Pronates forearm*; (flexion at elbow)

Cross bridge

connection between the myosin head and the actin molecule

The spinal cord tapers at a conical tip called the:

conus medullaris

The following helps prevent lateral and inferior movement of the spinal cord:

denticulate ligaments

What are muscles? What are the types of muscles?

muscles are organs that create movement in the body. Humans rely on muscles for many physiological process and virtually all of our dynamic interactions with the environment. Main function: Movement 3 types of muscle tissue: Skeletal Muscle, cardiac muscle, and smooth (each is based on its histological structure and function)

Sacral region

from S1 it goes all the way to S5

The spinal cord and the brain: Have

functional independence.

Vertebral Column and Spinal Nerves

give you an idea of how the nerves are going to exit your vertebral column so you can see that there they are going to be paired you're going to exit on both sides of the body once they exit they can form like several branches and these branches when we get to the spinal nerves they're going to form what we call plexuses so you have four different plexuses we have the cervical the brachial the lumbar and the sacral plexus so these plexuses are just groups of nerves that get together after they branch off from your vertebral column.

What is characterized through out the sectional anatomy of the spinal cord ?

gray matter forms like an H right down the middle over here and that's usually how it's going to be characterized throughout the spinal cord independent of what level it's at the other structure

Antagonists:

in the same example there would be a muscle that opposes that action so there's an antagonist that opposes the biceps brachii action and will do the opposite it will extend the forearm as I said that's the triceps brachii.

splenius capitis:

muscle is in the posterior part of the neck it -Origin: *originates on some of the cervical and thoracic vertebrae* Insertion:* inserts on the occipital bone* - this is another muscle kind of like the sternocleidomastoid where the action depends on whether both sides of the muscle but the right and left side are contracting at the same time or if only one side is contracting. - if both sides are contracting at the same time follow the action arrow it's going to *extend the neck* because it will pull on the occipital bone and pull it toward the back of the spine - if only one side contracts however it's going to pull the head to that side so if the right splenius capitis muscle contracts that would be *lateral flexion.*

The ________ trunk stems from C7 which gives rise to the ________ and _________ cords

middle, lateral,posterior

Sensory receptors

monitor conditions inside the body and in the external environment

The efferent division carries....

motor commands to muscles and glands (carrying info to gland its either going to secrete more or activate the gland to secrete more substance or stop the gland from secreting what ever substance it usually secretes)

3rd order type of neuron

multipolar

Each muscle contains several bundles of ______

muscle fascicle

Each muscle fascicle is composed of many_____

muscle fibers

Muscle fascicle is composed of several

muscle fibers

Sarcomere has alternating bands of thick and thin filaments these filaments are referred to as?

mylofilaments, to differentiate they are parts of the muscles

Each muscle fibers has hundrends to thousands of these _____

myofibrils

Which protein forms the thick filaments of a skeletal muscle fiiber?

myosin

Temporalis:

named for the fact that *originates on the temporal bone this muscle also inserts on the mandible* youcan't see that here but it goes up underneath here and inserts on the mandible and it has the *exact same function as the masseter muscle so it also will elevate and retract the mandible depending on the original position of the mandible*.

Gray matter contains alot of

which contains lots of neuronal cell bodies

Phrenic Nerve

-this nerve is going to be going down all the way to your diaphragm and it's called the phrenic nerve so basically it's going to provide sensory information from and also motor innervations from the diaphragm okay so the phrenic nerve is important because it innervates the diaphragm. -cervical plexus

Nerve Regeneration After Injury Step 2

2) to occur so your axon is sort of going to start to *emit little processes that are going to allow them to grow in the direction of the distal stump and to help remove the debris that's present in this area you're going to have specific macrophages that are going to chew up whatever is left over in terms of that's being degenerated or certain types of Debris.*

CNS

Central nervous system (CNS): -Brain and spinal cord -Integrating, processing, and coordinating -Intelligence, memory, learning, and emotion function of central nervous system: is basically to receive the information that is felt inthe peripheral nervous system so the information comes from the peripheral nervous system is taken all the way to the spinal cord so they sort of integrate whatever happens on the peripheral nervous system sends it to the brain and the brain it's processes it and then it's they can come back down to your peripheral nervous system.

Distinct characteristics between the nervous system and Endocrine

Nervous system: Relatively swift but brief responses Endocrine: Slower but they often last much longer

Rectus Femoris

Origin: Iliac spine and superior acetabular rim of ilium (pelvic girdle or coxal bone) Insertion:Tibial tuberosity Action: *Extension at knee; flexion at hip or flexes thigh* *origin not in femur like the other muscles in the quadriceps femoris group. crosses both hip and knee joint.*

Adductor Brevis

Origin: Inferior ramus of pubis Insertion: Linea aspera of femur Action: *adduction at thigh*and flexion at hip

Calcaneal/Achilles Tendon

Shared by the gastrocnemius and soleus. Attaches to the calcaneous which is going to allow these muscles to plantar flex the foot because it will draw upon the calcaneal bone.

MUSCULAR ORGANIZATION IS HIERARCHICAL

Skeletal Muscle -----> Muscle Fascicle -----> Muscle Fiber * all 3 of these connective tissues reach the ends of the muscles. Where there is no longer any skeletal muscle fibers and they converge to form tendons or aponeurosis

Step 3 of the cross bridge cycle

Step 3: once the active sites have been exposed those purplish blue myosin heads (of adjacent thick filaments) have an affinity to the active site and they're going to bind to the active site this connection between the myosin head and the actin molecule is called a cross bridge.

Step 1 of the cross bridge cycle

Step 1:so step one the cycle begins with a series of electrical events( in the sarcolemma) that initiates the sarcolemma to trigger a release of calcium from the terminal cisternae of the SR or the sarcoplasmic reticulum that was that blue network that surrounded each of the myofibrils. these calcium ions are going to enter into the zone of overlap or that area where the thin and the thick filaments overlap with one another.

Step 2 of the cross bridge

Step 2: *calcium ions bind to the troponin on the thin filaments troponin* (is depicted here as the two orange round structures in the long orange structure in step 1) once the calcium binds to the troponin *the tropomyosin the thin blue strings here will pull away from the actin molecules and that's going to expose the active sites* you can see the yellow active sites are now exposed to the external environment.

Step 5 of the cross bridge cycle

Step 5: at this point the myosin heads are still attached to the actin molecules and a molecule of ATP is required for each myosin head to break that cross bridge this is depicted here in step 5.

Muscle Fiber Surronded by? Contains?

Surronded by: Endomysium ( wrapping around each individual muscle fibers itself. This helps bind all the muscle fibers together) Contains: Myofibrils ( each muscle fiber contains hundreds to thousands of myofibrils)

Gray matter contains

There is a central, H-shaped mass of gray matter containing the cell bodies of neuroglia and neurons

Forearm: Anterior compartment ( groups 4&5)

These that are highlighted here in the anterior compartment of the forearm their tendons will come in either insert here the carpals or the metacarpals and that's how they would affect the wrist or the tendons will continue all the way down into the digits and perform some action on the fingers or the thumb because of the location of these muscles on the anterior side they're going to perform mostly flexion.

white matter is going to contain

White matter is going to contain the axons that are wrapped up with oligodendrocytes (and since myelin is a lipid rich substance it sort of gives that aspect that is sort of a whitish color that's why we call it a white.)

Where the does spinothalamic tract end?

cerebrum

When is it that an impulse does not have to reach the brain?

in a reflex arc

black contains

lower motor, motor

Occipitofrontalis:

which raises the brow and furrows the forehead

Lateral cord will give rise to the

your *musculocutaneous nerve and median nerve.*

Sciatic Nerve

• see how your sciatic nerve is going to have nerve that come all the way from l4, l5, s1, s2, and s3 all of them come together to form this huge nerve that's your sciatic nerve -*L4-S3* - largest nerve in the body - originates from the ventral rami pf L4-S3 -innervates the semimembranosus,semitendinosus and adductor magnus

Short head and long head

• short head: attaches to the coracoids process • long head the tendon of it runs up through the intertubercular groove or the bicipital groove that we when we did the skeletal system and it inserts on the scapula crossing the shoulder joint. the reason that this is called the long head in the short head is that the long head has a longer tendon so it's in reference to the length of the tendon and how it has to go further to get to its attachment point these two attachment points that we just identified are the origins there's an insertion on the humerus and there's an insertion down here on the radial tuberosity so therefore if the arm is being held at anatomical position this muscle will flex the forearm or it could also flex the arm at the shoulder additionally the long head of the biceps brachii helps to hold the humeral head in the glenoid fossa it helps stabilize the shoulder joint.

Conus medullaris:

• structure right over here at the end. Conus means bone of the medulla. so basically your spinal cord is going to taper into this conical tip which is going to be located right below you lumbosacral enlargement and it's basically the end of your spinal cord

iliotibial tract

(*Band of collagen fibers that extends along the lateral surface of the thigh and inserts upon the tibia*) the fasciae latae extends all the way down the lateral side of the thigh and attaches to the tibia thus this portion of the fasciae latae is called the iliotibial tract you may have heard this referred to as the IT band because it connects the ilium to the tibia and crosses over the knee joint this is important for stabilizing the knee. iliotibial tract injuries are really common in running and hiking and cycling. anything that involves repetitive flexion and extension of the knee this injury is caused by repetitive motion that creates inflammation in the IT band.

Extensor Hallucis Longus

(*extends the big toe*) Origin:Anterior surface of fibula Insertion:Superior surface, distal phalanx of hallux Action:*Extension at joints of hallux*; dorsiflexes ankle

Motor Tracts Carrying Subconscious Motor Commands

(4 motor tracts) - rubrospinal tract -reticulospinal tract -tectospinal tracxt -vestibulospinal tract

How many extrinsic eye muscles ?

(6) 1) superior rectus- pulls eye up 2) lateral rectus - pulls the eye lateral 3) medial rectus-pulls medially toward the nose 4)inferior rectus- pulls down 5)superior oblique 6)inferior oblique

EXTRINSIC MUSCLES

(Appendicular) (most superficial) they either support or move the pelvic girdle or upper limbs so - Originate from vertebrae or ribs -Insert on bones of the upper limb - Move/stabilize the upper limb

INTRINSIC MUSCLES

(Axial) (deeper) -Originate from vertebrae or ribs - Insert on vertebrae or ribs -Move/stabilize the axial skeleton

THREE CLASSES OF LEVERS: Third Class

(In a third-class lever, the force is applied between the resistanceand the fulcrum. This arrangement increases speed and distancemoved but requires a larger applied force.) in the third class of levers the force is applied between the resistance and the fulcrum a perfect example of this is flexion at the elbow or flexing the forearm here the joint that it's affected is the elbow so that's the fulcrum -the resistance is the weight of the segment of the body that's being moved and the -applied force is exerted right here between those two this is the biceps brachii muscle with the arrow pointing toward the origin so it would be pulling up on the radius.

Applied Force

(always by the muscle) the effort produced by the muscle contraction

The epimysium

(ep-i-MIS-ē-um; epi-, on, + mys, muscle) is a layer of dense irregular connective tissue surrounding the entire skeletal muscle. The epimysium separates the muscle from surrounding tissues and organs and is connected to the deep fascia.

Gluteus Maximus

(largest of gluteus muscles) Origin:iliac crest and other areas of the ilium; sacrum, coccyx Insertion: Iliotibial tract and gluteal tuberosity of femur Action:Extension and lateral rotation at hip; helps stabilize the extended knee; abduction at hip (*Extends thigh and Abducts thigh*)

Restistance

(load) the weight that opposes the effort

semimembranosus

(membrane broad and flat) *deep to semitendinosus and wider.* Origin:Ischial tuberosity Insrtion:Medial tibial condyle Action:Flexion at knee; extension and medial rotation at hip *extend thigh, flex leg*

Dermatomes

(we're talking about the distribution of the sensory fibers so all of this is sensory so we're not talking about motor.) -*Each pair of spinal nerves supplies a specific region of the skin, an area known as a dermatome (Figure 14.6). Dermatomes are clinically important because damage to either a spinal nerve or dorsal root ganglion will produce a characteristic loss of sensation in specific areas of the skin.* -but we're going to have pairs of spinal nerves like we see them over here to your left so we have a spinal nerve on one side and a spinal nerve on the other side and these pairs so each of them they're basically going to be monitoring a specific region of the body surface and the specific region and the mapping of these specific regions in terms of sensory input is called dermatome.

Group 3: Lateral leg compartment

* both insert on the lateral side of foot

Adductor Magnus

* deep to adductor longus and largest addcutor* Origin:Pubis Insertion:Linea aspera of femur Action:The whole muscle produces adduction at the hip *adducts thigh, flexes, extends thigh* (tendon attaches or inserts right on the medial epicondyle of the femur)

tibialis anterior

* does not go to toes its a tendon. Runs and insert on the medial part of the foot near the 1st metatarsal. inserts on medial side of foot it will pull it inward.* Origin:Lateral condyle and proximal shaft of tibia Insertion:Base of first metatarsal and medial cuneiform Action:Dorsiflexion at ankle; *inversion of foot*

fibularis longus

* has a long tendon that runs down and inserts on the lateral side of the foot.* Origin:Head and proximal shaft of fibula Insertion:Base of metatarsal I and medial cuneiform Action: (*Eversion of foot*) and plantar flexion at ankle

Extensor Digitorum longus

* has individual tendons that go to each of the toe digits 2-5* Origin:Lateral condyle of tibia, anterior surface of fibula Insertion: superior surfaces of phalanges 2-5 Action:*Extension of joints of toes 2-5*; dorsi flexes ankle

Fibularis brevis

* is deep to the longus and has a shorter tendon* Origin:Fibula Insertion:Base of metatarsal V Action:(*Eversion of foot* and plantar flexion at ankle

Supinator

*supinates forearm* Origin: Lateral epicondyle of humerus and ridge near the radial notch of the ulna Insertion: Anterolateral surface of radius distal to the radial tuberosity.

Anterior & Lateral spinothalamic tract *1st order* Dendrites: Cell body: Terminal bouton: *2nd Order* Dendrites: Cell body: Terminal bouton: *3rd order* Dendrites: Cell body: Terminal bouton:

*1st order* Dendrites: receptor Cell body: dorsal root ganglion Terminal bouton: spinal cord *2nd Order* Dendrites: spinal cord Cell body: Medulla oblongata Terminal bouton: thalamus *3rd order* Dendrites:thalamus Cell body:thalamus Terminal bouton: cerebrum

Posterior Columns *1st order* Dendrites: Cell body: Terminal bouton: *2nd Order* Dendrites: Cell body: Terminal bouton: *3rd order* Dendrites: Cell body: Terminal bouton:

*1st order* Dendrites: receptor Cell body: dorsal root ganglion Terminal bouton: spinal cord *2nd Order* Dendrites: spinal cord Cell body: Medulla oblongata Terminal bouton: thalamus *3rd order* Dendrites:thalamus Cell body:thalamus Terminal bouton: cerebrum

Spinocerebellar tracts *1st order* Dendrites: Cell body: Terminal bouton: *2nd Order* Dendrites: Cell body: Terminal bouton: *3rd order* Dendrites: Cell body: Terminal bouton:

*1st order* Dendrites: receptor Cell body:dorsal root ganglion Terminal bouton: spinal cord *2nd Order* Dendrites:spinal cord Cell body: spinal cord Terminal bouton: cerebellum * 3rd order* Dendrites: no 3rd neuron Cell body: Terminal bouton:

abductor pollicis longus

*Abducts phalanges of pollex * Origin:Ulna and radius Insertion:Metacarpal I and trapezium Action: Abduction at joints of thumb and wrist

step 4 reflex arc

*Activation of a motor neuron*. When a motor neuron is stimulated to threshold, it conducts an action potential through the ventral root of a spinal nerve to the peripheral effector organ.

Step 2 of reflex arc

*Activation of a sensory neuron*. Information is carried in the form of an action potential along an afferent fiber. In this case, the axon conducts the action potential into the spinal cord through one of the dorsal roots.

Extensor indicis

*Extends phalanges of digit II (index finger)* origin: posterior surface of ulna insertion: posterior surface of promximal action :phalanx of index finger, with tendo of extensor digitorum

Step 3 of reflex arc

*Information processing in CNS*. Information processing begins when the neurotransmitter released by the axon terminals of a sensory neuron reaches the postsynaptic membrane of a motor neuron or interneuron. In the simplest reflexes, this processing is performed by the motor neuron controlling the peripheral effectors. In more complex reflexes, one or more interneurons are located between the sensory and motor neurons, and both serial and parallel processing occur. This type of information processing selects the appropriate motor response through the activation of specific motor neurons.

Step 5 reflex arc

*Response by effector*. Activation of the motor neuron causes a response by a peripheral effector, such as a skeletal muscle or gland. Reflexes play an important role in opposing potentially harmful changes in the internal or external environment.

Step 1 of reflex arc

*Stimulation and activation of receptor*. There are many types of sensory receptors (the general categories of sensory receptors were introduced in Chapter 13). Each receptor has a characteristic range of sensitivity; some receptors, such as pain receptors, respond to almost any stimulus. These receptors, which are the dendrites of sensory neurons, are stimulated by pressure, temperature extremes, physical damage, or exposure to abnormal chemicals. Other receptors, such as visual, auditory, or taste receptors, are specialized cells that respond to only a limited range of stimuli.

Axon Hillock

*between the axon and the cell body* there's the structure that's called axon hillock. the axon hillock is *where your axon is going to start and the signals that are transmitted from your dendrites so the signals that are transmitted from your dendrites through your cell body and all the way to your axon they're going to pass the axon hillock and once they pass the axon hillock then they can't return the signal* cannot return so once the signal passes the axon hillock it has to run its course all the way through to the terminal button. so the axon hillock we say it's the point of no return the terminal buttons basically they here is where your synapse is going to occur and synapse just means that the information is going to be passed from one cell to another cell what cell is this going to be it can be another neuron or it can be a muscle or it can be a gland it all depends on the location of this specific neuron.

Tibialis posterior

*deepest one (tendon goes on the medial side of the foot)* *Extra info* Origin:Interosseous membrane and adjacent shafts of tibia and fibula Insertion: Navicular, all three cuneiforms, cuboid, metatarsals II, III, IV Action: (*Inversion of foot*); plantar flexion at ankle

First-Order Neuron:

*going to be the neuron that's going to be arriving from your peripheral nervous system* it's arriving right over here from your peripheral nervous system and *taking this information to the central nervous system at the level of the spinal cord* so it arrives and by now you guys should know it *arrives through the dorsal root ganglion* and you can see right over here in red it's going to go all the way up to the brainstem so this is your first order neuron so it's the first neuron that comes in and you can see how in this example this neuron is going to be coming in at the *level of the spinal cord* and then it goes directly to the brainstem okay so this red neuron here is your first order neuron once it gets to the brainstem it's going to synapse with another neuron which is called the second order neuron.

What trunk gives rise to the medial cord?

*inferior trunk* is the only one that's going to give rise to your medial cord

reflex

*is just going to be an immediate involuntary motor response to a specific stimulus so things that you don't think about but that your body moves* and so this happens because sometimes you have certain conditions that occur either inside or outside of your body that changes rapidly and unexpectedly and then your body has to adjust by sending a motor response and usually in these conditions you want it to be pretty fast so therefore *you don't want it to have to go all the way the information you don't want it to have to go all the way up to your brain to be processed* so you want it to be processed at the level of the spinal cord and by it being processed at the level of the spinal cord it can occur pretty quickly so usually the response is not very variable so you're always going to probably produce the same type of motor response independent of what type of stimulus it is.

Both the fibularis brevis and longus

*pull on the lateral side and turn the foot outward

eccentric contraction:

*the force generated is insufficient to overcome the external load on the muscle and the muscle fibers lengthen as they contract* a good example of this is when you slowly lower something heavy rather than simply letting it drop and what that's doing is it's a means of decelerating a body part so let's use this example again this person has just lifted a heavy weight and now they're slowly going to extend their elbow and put the weight back down this movement is not actually being caused by the biceps brachii muscle that we just talked about before it's being caused by the triceps brachii muscle which is back here in the back of the arm however the biceps brachii muscle is actually still doing something it's elongating and that elongation serves as a means of decelerating that body part in other words if the biceps brachii didn't do this the forelimb would fall down too quickly in a jerky motion.

Masseter:

*the masseter lies right on the portion of the mandible just anterior to the mandibular condyle it also attaches superiorly to the zygomatic bone and part of the temporal bone* -*Origin: zygomatic bone and part of temporal* -*Insertion: mandible* - the masseter is a good example of how you can infer the origin and insertion of some of these muscles quite easily. so I posed you the question where do you think the origin of this muscle is and where do you think the insertion is. well you already know that this muscle is involved with mastication or chewing so that's going to move the mandible in some way so the insertion has to be down here on the mandible it can't be the part up on the cranium because you can't move the cranium in relation to the mandible and keep the mandible stationary that's not how we chew right does it make any sense so the part up here on the zygomatic bone and the temporal has to be the origin this down here has to be the insertion therefore when the muscle contracts and shortens it will pull towards the origin pulling the mandible up closer to the cranium.well how in words would we explain that action well it depends on where the mandible is to begin with. -if the mandible is depressed in other words it's moved inferiorly and more inferior than an anatomical position then that contraction is going to cause elevation *so it's going to elevate the mandible.* however if the mandible is protracted meaning it's pushed anteriorly relative to anatomical position then when this muscle contracts is going to pull it closer to the cranium which would be retraction *so it will retract the mandible*. (so this brings up a theme that we're going to be seeingover and over again when we do muscles which is the action of the muscle depends on the position of the bony element that's going to be moved)

Platysma:

*which is a very thin muscle right under the skin* *that covers up all the muscles of the anterior neck* so you can see here on this side are these muscles that we're going to talk about when we move on to the neck and the platysma is on top of those - *it originates down here near the clavicle and inserts up here on the mandible and a little bit on the corner of the mouth * -so again just for visualization if the *origin is down in the clavicle and the insertion is on the mandible* in the corner of the mouth and the muscle shortens it's going to pull toward the origin so what do you think that would do. (platysma down here being cut and reflected back so that you can see that it is superficial to all of the deeper muscles in the anterior portion of the neck)

Motor Tracts Carrying Conscious Motor Commands

- (2 motor tracts) -anterior corticospinal tract -lateral corticospinal tract (cerebral cortex to spinal cord)

Posterio column tract number of neurons involved Where does decussation occur? Location of pathway in SC

- 3 neurons -medulla obloongata -posterior

Flexor carpi muscles:

- The next two muscles kind of go hand-in-hand there the flexor carpi muscles. there's a flexor carpi radialis on the radius side and a flexor carpi ulnaris on the ulnar side each of these inserts on the carpals hence the name carpi. they both flex so they're going to flex the wrist is what the beginning of the words tell you and there's a differentiation between the one that's on the radius side the one on the ulnar side. -the last two I wanted to clarify here because the name tells you what it does when it's contracting along with its pair in other words when both the flexor carpi radialis and the flexor carpi ulnaris muscles contract at the same time the wrist is going to be flexed because you've got this side pulling and this side pulling however abduction and adduction at the wrist is going to involve only one of these contracting at once. the one on the radial side on the thumb side contracts by itself that's going to abduct the wrist so the flexor carpi radialis contracts by itself that's going to pull the hand outward away from the body. if just the flexor carpi ulnaris contracts is going to do the opposite it'll pull the hand toward the body.

Posterior Wall of abdominal muscles

- psoas major -iliacus - quadtratus lumborum -transversus abdominis' * anterior wall muscles do warp all the way to the back

NEURONAL CONTROL OF MUSCLE RELAXATION step 8

8)therefore contraction ends the thin filaments will go back and spread from each other and therefore the sarcomeres lengthen and thus the entire muscle lengthens

Nervous and endocrine systems function shared characteristics

-Control and adjust the activities of other systems.when we think about the nervous system sometimes we like to compare it to the endocrine system basically because both of them are going to sort of control other systems not only in terms of what substances it releases but how the other systems are going to work and how they're going to be able to adjust to certain activities -Shared characteristics: Chemical communication with targeted tissues

Microglia

-Smallest glial cell -Stem cells that produce microglia also produce monocytes; are going to produce macrophages Act as phagocytic cells by engulfing: -Cellular debris -Waste products Pathogens -Represent 5% of population of glials cells (however if there is an injury it can actually triplicate the number but basically you have five percent of the population normally of microglia but if you do have an infection this population will increase dramatically.)

Supporting cells, or neuroglia:

-Support and isolate the neurons -neuroglia or glial cells- they're basically going to give the support that the neurons need to be able to do their function properly so the only function of the glial cells basically is to help the neurons perform their function to the optimal best.

What are the different parts of the skeletal muscle system?

-Tendon -Muscle belly (head) -Intermediate Tendon - Aponeurosis

In general tracts are

-Tracts are paired (bilaterally and symmetrically along the spinal cord) -Axons within each tract are grouped according to the body region innervated (now these tracks are always going to be paired so because you have a spinal cord right over here you're going to have sensory information arriving on both sides and then you're going to have motor information exiting on both sides okay so it's always going to be bilateral and it's always going to be symmetrical.)

The PNS is subdivided into two divisions

-afferent divison -efferent divison

Second-Order Neuron:

-basically the *cell body of the neuron is going to be located right over here on the brainstem* and sometimes it can also be located here on your spinal cord further down depending on where it's going to synapse okay now the second order neuron once it gets to your thalamus is going to synapse with another neuron which is called the third order neuron

The lateral gray horn is only located Anterior and posterior gray horns are located

-between T1 and L2 - throughout the spinal cord

Trapezius

-called this because its shaped like a trapezoid -muscle extends all the way from the occipital bone onto the scapula and then on to the spine because of its broad attachments it really has multiple actions -wraps around to the front the anterior side and *attaches to the clavicle* so that's how it's able to elevate the scapula and the clavicle. -so it has two insertion points so when this part of the muscle contracts it would lift up those two pectoral girdle bones but there's also a part to the muscle here in the posterior side and that's why there's two arrows that when it contracts because it's located here on the back of the scapula it can retract the scapula. so if it's already protracted the scapula is already facing anteriorly this would contract and pull it back into anatomical position

Thick Filaments

-composed of myosin - are stationary and its the thin filaments that are going to move in releation to the thick filaments -titin protein holds the thick filaments in place. - each blue band is composed of many individual myosin protein. -head of myosin is going to attach to the active site on the actin molecule

Parallel muscle

-have parallel muscle fascicles in other words they're parallel to the longitudinal axis of the muscle the majority of muscles in your body are parallel muscles - biceps brachii muscle

Oligodendrocytes

-important because they are going to be the ones that are going to produce what we call the myelin sheet. -the importance of the oligodendrocytes is to basically make sure that the information that's received by the cell bodies of the neurons the information actually gets passed on from one neuron to the other and so the myelin actually isolates the information and make sure that it goes from one neuron to the other neuron

Cardiac Muscle

-involuntary movement ( no conscious ability to control these muscle contractions) - found in the heart. Its main role is too pump the heart so that it pushes blood through the arteries and the veins.

Biceps brachii

-it can perform action at the shoulder joint and at the elbow joint and that's because the muscle actually crosses both joints.

Brachial Plexus

-more complex than the cervical plexus and if you look here it also is larger than the cervical plexus so that's why it's a little bit more complex because you have more nerves that are going to be branching from your brachial plexus the brachial plexus. - *is going to be important for innervations of the pectoral girdle and upper limb* -therefore it's going to receive the innervations from c5 and remember I said it's only part of c5 and you can see that there's another part of c5 that's actually going to be going up to your cervical plexus. so *C5 all the way to T1* is what comprises your brachial plexus and again it's only part of c5 and not the whole c5.

external intercostals muscles

: are on the outside between each rib.. (Elevate the ribs) They both have opposing actions.

Maintain posture/ body position

-muscles dont always have to move a joint. They can also maintain the posture in the body. By stabilizing those joints. If your standing or sitting there are muscles active in your torso keeping your spine erect. These muscles are continually contracting but they are causing stabilization of the skeleton not movement of the skeleton.

femoral nerve

-originates from the ventral rami of *L2-L4* -innervates the quadriceps femoris, sartorius, pectineus, and iliopsoas. It recieves information from the skin of the anteromedial surface of the thigh and medical surface of the leg and foot - *stops at the level of the femur*

Genitofemoral Nerve

-originates from the ventral rami of L1 and L2. It recieves sensory information from the skin over the anteromedial surface of the thigh and portions of genitalia. - femoral branch - genital branch

Convergent Muscle

-pectoralis muscles -the muscle fibers form a broad area on one end that then come together at a common point to form a tendon on the other end and a good example of this would be the pectoralis muscles

structures by the central canal are called ?

-posterior gray commissure -Anterior gray commissure these structures are basically going to contain fibers or nerves that are going to be passing from one side of the spinal cord to the other;basically this is a highway for nerves that are passing from one side to the other. (The gray commissures (commissura, a joining together) contain axons decussating (crossing) from one side of the cord to the other)

Elasticity

-rebounds to original length after contraction (i.e., resting phase) -all muscles have a resting phase where they are not actively contracting and they are not exerting a pull or tension on another structure.

Flexion involves which torso muscle (hyperextension)

-rectus abdominis -psoas major

Parallel muscle with tendinous bands

-rectus abdominis muscle -special type of parallel muscle that has those tendons bands in it

Bipennate Muscle

-rectus femoris muscle -muscle fibers run obliquely on either side of a tendon that runs down the middle a good example of this is the rectus femoris which is the quadriceps muscle right in the middle of your thigh

Sensory Neurons Arrangement

-sensory modality arrangment -medial-lateral rule -somatotopic arrangment

Sacromere

-smallest functional unit. smallest part of the muscle that can still function. If you were to break it down into its individual parts those parts cannot function on their own. - is an arrangment of alternating thick and thin filaments that are types of protein. These proteins slide against one another and contract the sacromere

Arachnoid mater

-so the arachnoid mater basically is going to be the one that's going to be squished between the dura and the PIA mater.

afferent division

-so these are all different types of receptors that are located in these areas they're going to receive the information carry it over to the central nervous system where this information is going to be processed after its process it's going to be leaving the afferent division so it's going to be exiting or leaving through the efferent division. - for it to arrive to CNS you need to have specific receptors that are going to recieve this information and be able to carry it to the cns

Extensibility

-the ability to continue to contract over a series of resting lengths. - example: smooth muscle cells can be stretched several times more than their original length and they still contract when stimulated.

Why is it that we are able to perceive different sensations if all of the information is sent by one cell type: the neuron? Through the same mechanism that is called: action potential?

-this is sort of by mapping this out this way that it did right over here sort of gives you an idea of the different pathways that our brain or our central nervous system has and that's what we were talking about we're depending on the sensation and where the information is coming from is going to have a different path and that's how we're able to perceive different types of sensation because it all depends so if you have a muscle sensation you can see how it's going to synapse right over here if you have a visceral it's going to synapse over here at a different location so these different locations is sort of what gives you the different sensations and you can sort of map out your brain to have different areas of your brain being responsible for specific sensation or specific motor functions.

How muscles move limbs?

-when talking about muscles that move the limb joints the majority of the time the muscle is going to originate on a proximal segment and insert on a distal segment. -let's look at an example here on the left with the upper limb if this is an anterior view and we're in anatomical position a muscle that originates on the humerus and inserts on the forearm or the radius and ulna can only do one thing if the origin is here and the insertion is here is going to pull on the insertion and flex the elbow there's no way it can extend the elbow. to do that it would have to be on the posterior side of the upper limb because remember muscles only pull they cannot push.

Which of these is NOT a region of the spinal cord? Selected Answer: A. pelvic B. lumbar C. thoracic D. cervical E. sacra

A

The diaphragm also has non respiratory functions

1)the first is that it prevents acid reflux by pressing on the esophagus remember how there are those passageways in the diaphragm that allow things to pass through one of them is for the esophagus and so this muscle is important for preventing acid from refluxing from the abdomen up into the thorax. 2) the second function is that the diaphragm increases intra-abdominal pressure or the pressure inside the abdomen this is important for helping to expel vomit, feces, and urine.

Nerve Regeneration After Injury Step 1

1)with regards to regeneration after injury neurons usually have very limited ability to recover after an injury but there's a lot of study being done on regeneration and so I thought it was a good idea to include this section on our lecture. but basically if you have this occurring in the peripheral nervous system then you will have Shwan cells that are going to help to catch up this broken nerve. okay so here we're just showing where the site of injury is occurring right over here everything that's part of the main structure so the axon and here you will have your *cell body is what we call the proximal stump and everything that's lost is what we call the distal stump.1* and you can see here is going to be your Schwann cell that's producing the myelin around this axon.

Flexor digitorum superficialis

: flexor tells you the action. digitorum refers to the fingers not the thumb but the fingers. so this would be all the digits except for the thumb. the superficialis part just refers to the fact that there's another muscle deeper to it so this is the one that is more superficial so if you trace out the tendons of the flexor digitorum superficialis they go to the tips of the phalanges .

Neuronal control of Muscle Contraction step 2

2) transverse or t tubules those were indentations in the sarcolemma that projected into the sarcoplasm and met with and touched the sarcoplasmic reticulum. the purpose of the *t tubule is to transmit the action potential or the electrical impulse that the neuron is bringing to the synapse and initiating a response in the sarcoplasmic reticulum from that action potential.*

chemical synapse step 2

2) when it reaches the terminal button something needs to happen you need to have influx of calcium. so calcium channels open up and calcium enters into this terminal button.

White contains

2nd order, interneuron, sensory

Neuronal control of Muscle Contraction step 3

3) so when the electrical impulse reaches the sarcoplasmic reticulum it will release a store of calcium so that's one of its functions it stores and releases calcium

Nerve Regeneration After Injury Step 3

3)and then you're going to have new Schwann cells that are going to migrate and sort of occupy this area right over here and these new Shwann cells are going to wrap up the new external process that's growing from the main axon and

chemical synapse step 3

3)calcium after it enters the terminal button it's going to send these little green dots right over here that are called synaptic vesicles. the synaptic vesicles are the ones that contain the neurotransmitters so when calcium enters this is going to cause the membrane of these synaptic vesicles to sort of fuse. so if you have your membrane of your terminal button here and your synaptic vesicles right over here and calcium entering.

Neuronal control of Muscle Contraction step 4

4) from the steps of muscular contraction that calcium is required to bind to the troponin and allow the tropomyosin to expose those active sites and the actin molecules so that's what you're seeing here calcium ions flooding in and allowing cross bridge formation between the thin and the thick filaments thus here's cross bridge formation.

chemical synapse step 4

4)so this is going this process of calcium entering is going to cause the synaptic vesicles to migrate to the end right over here so if we would correspond it would be right over here on this other finger and the migration of these synaptic vesicles to this portion down here is going to cause the membrane of this synaptic vesicle to fuse with the membrane of the terminal button right over here so there's a fusion of the membrane of the synaptic vesicles with the membrane of the terminal button. and by fusing it's going to release the neurotransmitters to the outside.

Nerve Regeneration After Injury Step 4

4)you can see that the shwann cells are able to cover this new axon that was formed but you can see that the new axon is going to be thinner the *shwann cells are not going to be as effective as the original ones so there is a little bit of regeneration but this regeneration is not as efficient as what like the function is not as efficient as if you had a normal type of neuron without having any injury* okay but it's a good ways it's better than not having any sort of regeneration

chemical synapse step 5

5) now if this neurotransmitter is an excitatory neurotransmitter the best example of an excitatory neurotransmitter is acetylcholine that's your best example most common one so if you have an excitatory neurotransmitter this neurotransmitter is going to bind to specific receptors on this other structure. what structure can this be you guys should be thinking about what structre could the synaptic terminal or the terminal button be contacted .

How many classification there are for the Neuroglia?

6

How many steps in the cross bridge cycle?

6

chemical synapse step 6

6) so we know that it can contact a neuron or a muscle or gland right so that's what this second structure can be so this second structure is going to have specific receptors that are going to bind to the neurotransmitters so you're going to have receptors on the wall and the membrane of this second structure which again can be a neuron a muscle or gland and

NEURONAL CONTROL OF MUSCLE RELAXATION step 6

6)so how exactly does the muscle then relax well the neuron will stop emitting the impulse and if there's no impulse that impulse cannot be transmitted through the t tubules and so the action potential or the electrical impulse ceases.

chemical synapse step 7

7)once the neurotransmitters bind to these specific receptors they're going to cause sodium channels you're going to cause sodium channels to open up. sodium channels to open up and allowed sodium to enter

NEURONAL CONTROL OF MUSCLE RELAXATION step 7

7)when that impulse ceases the sarcoplasmic reticulum is going to recapture or reabsorb the calcium ions it previously released therefore of calcium is not present no cross bridges can form because the active sites will be covered up again by the tropomyosin

skeletal muscle system consist of more than _______ skeletal muscles

700

Group 2: Teres major

ACTION: *Medially rotates arm* Originates: Inferior angle of scapula Inserts:medial lip of the intertubercular groove of humerus (*front part of the humerus*) (Extension and medial rotation at shoulder)

Group 1: Serratus Anterior

ACTION: Protracts scapula Origin:Anterior and superior margins of ribs 1-8,1-9,1-10. Insertion: Anterior surface of vertebral border of scapula

Group 2: Coracobrachialis

ACTIONS: *Adducts arm* *Flexes arm* Origin: on the coracoid process of the scapula Inserts: shaft of humerus (the first muscle that's located in the arm region is the Coracobrachialis this crosses the shoulder joint it originates on the coracoid process of the scapula and inserts on the humerus)

Group 2: Pectoralis major

ACTIONS: *Adducts arm* *Medially rotates arm* Origin: *sternum and clavicle* ( cartliages of ribs 2-6, body of sternum and inferior,meadial portion of clavicle) Inserts: *humerus* ( crest of greater tubercle and lateral lip of interrubercular sulcus of humerus)

Group 1: Pectoralis Minor

ACTIONS: *Depresses scapula* *Protracts scapula* Origin: Anterior surfaces and superior margins of ribs 3-5 or 2-4 and the fascia covering the assoicated external intercostal muscles. Insertion: Coracoid process of scapula

Group 2: Latissimus dorsi

ACTIONS: *Extends arm* *Adducts arm* Origin: Spinous processes of inferior thoracic and all lumbar and sacral vertebrae, ribs 8-12, and thoracolumbar fascia ( *bottom of scapula and vertebral column*) Insertion: floor of intertubercular sulcus of the humerus ( *on medial portion of the humerus*)

Group 2 & 3: Triceps brachii

ACTIONS: *Extends forearm* *Adducts arm (long head only)* Origin:Humerus and scapula Insertion:Olecranon of ulna Action:Extension at elbow Long (adduction at shoulder)

Group 1: Trapezius Action

ACTIONS: Elevates scapula & clavicle Retracts scapula Origin: Occipital bone, ligamentum nuchae, and *spinous processes of thoracic vertebrae.* Insertion: Clavicle and scapula (*acromion and scapular spine*)

Gluteus medius & minimis: Actions

Abduct thigh Medially rotate thigh

Group 3: Brachialis

ACTIONS: Flexes forearm Origin:Anterior surface of humerus Insertion:Ulnar Action:Flexion at elbow

Rotator cuff muscles Actions

ACTIONS: HOLD HUMERAL HEAD IN GLENOID FOSSA Lateral rotators: supraspinatus, infraspinatus, teres minor Medial rotator: subscapularis

Group 1: Rhomboids & Levator Scapulae

ACTIONS: Levator: *Elevates scapula* Origin: Transverse processes of first four cervical vertebrae Insertion: Vertebral border of scapula near superior angle and medial end of scapular spine Rhomboids: *Retracts scapula* Origin: Rhomboid major: Ligamentum nuchae and the spinous processes of vertebrae T2 to T3 Rhomboid minor: Spinous processes of vertebrae C2-T1. Instertion: Major: vertebral border of scapula from spine to inferior angle Minor: Vertebral border of scapula

Group 2: Posterior thigh compartment AKA?

AKA hamstrings 2 on medial and one on lateral crosses two joints: hip and knee joint

contractions also requires the presence of?

ATP

Anatomical snuff box

Another cool thing about your body that you may not have realized is that you have a area perfectly designed for sniffing snuff now here in South Florida this isn't a very popular time but snuff is a very finely ground tobacco product that is snorted through the nose it was very popular especially among women several hundred years ago because it was considered dainty and is actually sort of almost made a comeback in some circles because of the backlash against smoking in public but one typical way that snuff is snorted is is it's placed in this depression betweenthe thumb and the wrist this depression doesn't exist unless you fully extend the thumb so if everybody takes their thumb and extends it and kind of actually abducts it so pulls it away from the wrist as this woman is doing in the image two tendons pop out the two tendons that are involved with extending the thumb *extensor pollicis longus and extensor pollicis brevis and between those two tendons is this great big space* so the skin sinks down into that space and it makes a nice little cavity for the snuff so you can add this to your category of random useless knowledge still kind of interesting though

Tendon sheaths and ligaments at the wrist

Anterior: Flexor retinaculum Flexor tendon sheath Posterior: Extensor retinaculum extensor tendon sheath

Middle Trunk

C7 exits to form the middle trunk

Inferior Trunk

C8 come together with T1 form the inferior trunk.

1. Amanda has dimples. Dimples are an inheritable trait caused by a shortened muscle which leads to a small depression in the flesh, either one that exists permanently or one that forms in the cheeks when one smiles. Which muscle causes this effect? A. orbicularis oris B. depressor anguli oris C. levator labii superioris D. zygomaticus major E. masseter

D. zygomaticus major

Motor tract: Upper motor neuron Dendrites: Cell body: Terminal bouton:

Dendrites: cerebrum Cell body: cerebrum Terminal bouton: spinal cord or brain stem

Motor tract: Lower motor neuron Dendrites: Cell body: Terminal bouton:

Dendrites: spinal cord or brain stem Cell body: spinal cord or brain stem Terminal bouton: skeletal muscle

Divergence:

Divergence: so you can have one neuron which is called divergence. *one neuron sending information to two neurons so it's sort of diverging and splitting it up and then these two neurons are going to split up the information and send it.* In this example to 3 other neurons each so you're sort of diverging the information from one to six total neurons.

Example of the Intermediate Tendon in rectus abdominis

Example: rectus abdominis each bump is definded on a person beacuse those are muscle bellies which have been worked out to an extent so they have increased in size. The tendon are between the muscle bellies they cannot increase in size because they do not have skeletal muscle fibers. They end up staying as ridges or lines that define those muscles bellies

Exteroceptors

Exteroceptors = external environment: -Touch, temperature, and pressure sensations -Special senses of sight, smell, and hearing

Flexor digitorum profundus:

Flexes phalanges of digits II-V (not thumb) (Profundus means deep like profound if somebody's very profound they have very deep thoughts that's how I remember that this has the exact same action as a flexor digitorum superficialis so the name gives it away it flexes the digits.)

Group1 Upper Limb

Group 1: move the pectoral girdle -Origin: Axial skeleton / Insertion: Clavicle or Scapula these muscles do not cause actions at the shoulder this is a common misconception these move the clavicle and scapula the upper limb may go with it but that movement is not occurring at the shoulder joint.

FOUR LOWER LIMB MUSCLE GROUPINGS

Group 1: move the thigh at the hip (where femoral head meets the acetabulum of the os coxa.) -Origin: Pelvic bones / Insertion: Femur Group 2: move the leg at the knee -Origin: Pelvic bones or Femur / Insertion: Tibia or Fibula Group 3: move the foot at the ankle -Origin: Femur, Tibia, or Fibula / Insertion: Tarsals or Metatarsals Group 4: move the digits -Origin: Tibia or Fibula / Insertion: Phalanges

Group 2 Upper Limb

Group 2: move the arm at the shoulder -Origin: Clavicle or Scapula / Insertion: Humerus

Group 3 upper limb

Group 3: move the forearm at the elbow -Origin: Humerus - Insertion: Radius or Ulna

Group 4 upper limb

Group 4: move the hand at the wrist -Origin: Humerus, Radius, or Ulna / Insertion: Carpals or Metacarpals

Group 5 Upper Limb

Group 5: move the digits -Origin: Radius or Ulna / Insertion: Phalanges

Muscle Groupings Head & Neck Torso

Head & Neck: Muscles of facial expression Muscles of mastication Extra-ocular muscles Muscles of the tongue Muscles of the pharynx Muscles of the neck Torso: Thoracic cage muscles Back muscles Abdominal muscles

Muscles can be named for:

Most muscle names provide clues to their identification or location -Specific body regions or location -Shape of the muscle -Orientation of the muscle fibers -Specific or unusual features -Its origin and insertion points -Primary function -References to occupational or habitual action

Skeletal Muscle Fiber Anatomy

Myofibril Sarcolemma Sarcoplasm Nuclei Mitochondria T tubules Sacroplasmic reticulum

Infraspinatus

Origin: Infraspinous fossa of scapula Insertion:Greater tubercle of humerus Action: Lateral rotation at shoulder

gracilis

Origin: Pubis Insertion:Medial surface of tibia inferior to medial condyle Action:Flexion and medial rotation at knee; adduction and medial rotation at hip *long thin muscle on the inside *adducts thigh*

Supraspinatus

Origin: Supraspinous fossa of scapula Insertion: Greater tubercle of humerus Action: Abduction at shoulder

Insertion

Point of muscle attachment that is movable (muscle attachment location on the bone that is moving during a particular movement)

Origin

Point of muscle attachment that remains stationary (its a muscle attachment site on the bone of the joint that is not moving)

Step 4 of the cross bridge cycle

Step 4: after the cross bridge has been formed energy is released and the myosin heads are going to pivot and pull the thin filaments toward the M line in other words toward the center of the sarcomere .( Myosin head must be activated before a cross bridge cycle can begin. This occurs when the *ATP binds to the myosin head and is hydrolyzed to ADP and inorganic phosphate*. The energy liberated from the hydrolysis of ATP activates the myosin head,* forcing it into the cocked position.* The activated myosin head binds to actin forming a cross bridge. *In organic phosphate is released and the bond between myosin and actin become stronger*. ADP is then released and the activated myosin head pivots)

Step 6 of the cross bridge cycle

Step 6: ( when another ATP binds to the myosin head the link between the myosin head and actin weakens, the mysoin head detaches. ATP is hydrolyzed to ADP and inorganix phosphate . The energy released during hydrolysis reactivates the myosin head returning it to the cocked position) myosin heads return to a cocked position or in other words in a position that they can attach and form another cross bridge again this brings us back to the very beginning and the entire cycle can then be repeated again as long as enough calcium and ATP is available to continue these interactions between the thick and the thin filaments one thing you should keep in mind is that we were focused on one cross bridge in one sarcomere of one myofibril of one muscle cell of one muscle fascicle so what I'm trying to get at here is that trillions and trillions of these cross bridges are being formed anytime you perform some sort of action with your muscles.

endomysium

The endomysium (en-dō-MIS-ē-um; endo-, inside, + mys, muscle) surrounds each skeletal muscle fiber (individual skeletal muscle cell), binds each muscle fiber to its neighbor, and supports the capillaries that supply the individual fiber. The endomysium consists of a delicate network of reticular fibers. Scattered myosatellite cells that lie between the endomysium and the muscle fibers are stem cells that repair damaged muscle tissue.

What is the retinaculum function and what causes carpal tunnel syndrome?

The fascia of the forearm thickens on the posterior surface of the wrist to form a wide band of connective tissue, the extensor retinaculum. The extensor retinaculum holds the tendons of the extensor muscles in place. The fascia also thickens on the anterior surface, forming another wide band of connective tissue, the flexor retinaculum, which holds the tendons of the flexor muscles in place. Inflammation of the retinacula and tendon sheaths restricts movement and irritates the median nerve, a sensory and motor nerve that innervates the hand. This condition, known as carpal tunnel syndrome, causes chronic pain.

The Lumbar and Sacral Plexuses

The lumbar plexus and the sacral plexus originate from the lumbar and sacral segments of the spinal cord. *The ventral rami of these nerves innervate the pelvis and lower limb*. Because the ventral rami of both plexuses innervate muscles of the lower limb, the lumbar and sacral plexuses are often referred to as the lumbosacral plexus. L1-s4

white matter contains

The peripheral white matter contains myelinated and unmyelinated axons organized into tracts and columns

The spinal cord:

The spinal cord: -Is more than just a highway for information. -Integrates and processes information. (brain it can actually process information at the level of the spinal cord a lot of information does go up to the brain but a lot of it can also be processed at the level of the spinal cord and it doesn't have to go up to to our brain.)

Anterior gray horns contain

anterior (ventral) horns contain somatic motor neurons.

Thoracolumbar Fascia

Two sets of muscles are divided by this. -connective tissue on top of the deep muscles and prevent us from being able to see them

QUADRICEPS FEMORIS group

VASTUS INTERMEDIUS VASTUS LATERALIS VASTUS MEDIALIS RECTUS FEMORIS

Orbicularis oculi

a circular muscle that surrounds the eye and each one of these you can break down the words and they pretty much make sense orbicularis means to orbit or encircle and so this is a circular muscle where we went over the shapes of muscles so it's a circular muscle. orbicularis oculi is the one in the ocular region associated with the eye. (opening and closing)

Where does neuron synapse with another neuron?

a neuron can synapse with either another neuron like we see right over here on the first example so you have this multipolar typical neuron that has an axon. so this is your typical neuron and you can see that the end of this typical neuron is going to be synapsing right over here with another neuron and where does it synapse on another neuron so it's synapses on the dendrite of another neuron. you

Synaptic cleft

a space right over here between the membrane of the terminal button and the membrane of the next structure which this space is called a synaptic cleft.

which statement defines excitability

ability to respond to stimulation

Thin Filaments mostly composed of

actin

Tropomyosin

active sites are covered in a blue stringy material or protein when muscle is at rest. (each thin filament contains 2 strinds of actin molecules that are twisted around eachother)

What forms the posterior cord?

all of the trunks forms the posterior cord

Groups 4 & 5: Superficial anterior compartment

all of these originate on the medial epicondyle of the humerus

Actions of all : plantaris soleus gastrocnemius calcaneal tendon

all plantar flex foot when they contract together

omohyoid:

also has two bellies; a superior belly and inferior belly. however it's below the hyoid so its action is slightly different. omo means shoulder so *this connects the scapula to the hyoid.* the insertion is on the hyoid *therefore this muscle depresses* or pulls the hyoid inferiorly

isometric contraction:

and in *this the muscle remains the same exact length* so an example would be holding an object up without moving it the force precisely matches the load and no movement results so again in this example there is no movement this person is simply holding this heavy weight parallel to his forearm and what that would require is the biceps brachii muscle to contract however it's not going to shorten.

What forms the lateral cord?

and then the *superior trunk* will form part of the lateral cord then the *middle trunk* will also form part of the lateral cord so we have a little bit of the superior and a little bit of the middle trunk forming the lateral cord.

motor information it's going to be leaving on the _______ part of your brain if it's sensory information it's going to be arriving in the ______part of your brain.

anterior posterior

Schwann Cells

are important and they have the same function as the oligodendrocytes in the central nervous system so the main function of the schwann cells is to also *produce myelin* and you can see right over here how they're going to produce myelin now we usually say that if you have a neuron that's going to be surrounded by myelin we call it a myelinated axon if we have a cell that's not going to be surrounded by myelin then we call it an unmyelinated axon so the cells there are the neurons and more specifically the axons that the oligodendrocytes cover with the myelin sheath we always consider these to be myelinated axons with regards to the Schwann cells we can have what we called them mylinated axons which is this one right over here on the left or the unmyelinated axon and you can see right over here that even though the *unmyelinated axon still has a Schwann cells that produces myelin but basically you have one cell one Schwann cell that's covering several axons and by doing this we can see there is unmyelinated axon meaning that even though it does have a little bit of a myelin sheet but it's not enough to make sure that it protects the signal that goes from the cell all the way down to the effector organ* in this case here you can see that you have one Schwann cell wrapping up one axon and therefore we can say that this is a myelinated axon here in the peripheral nervous system .

primary movers or agonists:

are muscles that are responsible for producing a particular movement and I keep using this example because it's easy but at the elbow the biceps brachii flexes the forearm so that's an example of an agonist.

Central tendon

at the very superior part of the diaphragm

Zygomaticus Minor and Major:

attached in some way to the zygomatic bone so they start with the word zygomaticus there's a zygomaticus major and a zygomaticus minor and if you refer to those muscle terminology tables that I stress that you look at major means larger and minor is smaller so anytime you have a muscle that's named the same thing but the only difference is at the end it's a major or a minor that means that those muscles perform similar actions but one happens to be bigger you. so both of these muscles *originate on the zygomatic bone* right here and they *insert somewhere around the upper lip* so knowing that you could infer that it's going to pull toward the origin and *then lift the upper lip.*

Neuron Structure

axon hillock with your initials axon segment right over here in this case it's showing axons that's unmyelinated this one has no myelin but it can be myelinated so if it were to be myelinated you would have your myelin sheath bone that over here from one end to the other and you would have these little spaces between the myelin sheets and you guys should recall that these spaces are called node of ramvia. so the signal would actually jump from one another ramvia to the other node of ramvia and the importance of the myelin is to actually not only protect the signal so it doesn't get lost but also to make the signal run faster. other things that you can see on this line is the staining right over here it's a typical what we call a Nissle staining that's going to stain the organelles of the cell body and we are able to detect a neuron using this type of staining .

neurons are another name for

axons or fibers

Which of the following branched patterns of nerves is part of the brachial plexus? A. superior trunk, lateral cord, axillary nerve B. superior trunk, lateral cord, musculocutaneous nerve C. middle trunk, posterior cord, medial nerve D. inferior trunk, posterior cord, ulnar nerve

b

Somatotopic arrangement:

basically the ascending sensory fibers they're going to be arranged within individual tracks according to their site of origin in the body okay so if you have a specific area of your body for example your big toe so most of the information coming from your big toe is going to be running through the same pathways through the same tract or information that's going to be arriving or from your upper limbs or from your shoulder they're going to be running through the same tract information that's going to be coming from your nose it's going to be running through the same track information that's coming from your gluteus maximus it's going to be running through the same track. okay so topic place that means *place of origin similar tracks* okay.

Endocrine

basically things occur way slower sometimes it not only takes a while for it to occur but it can whatever the activity is going to be produced it can last for a few hours or a few minutes ,a few days, a few weeks ,even a few years. . endocrine system basically it's going to release a lot of different hormones mainly and we're not going to get into the endocrine system because we don't even cover in this course

Sarcoplasmic Reticulum

each myofibril is surronded by this blue structure

each of the spinal cord regions will have?

each of these regions they're going to have tracts that are going to be involved in movements or sending messages from that particular area and if we have areas where they're going to be controlling especially sensory and motor function of your limbs you're going to have an enlargement of the spinal cord.

flexor tendon sheaths

each tendon each individual tendon is wrapped with connective tissue in these sheets that are called flexor tendon sheaths and those are there to reduce friction and help with the structures rubbing up against one another

Pectoralis major

entirely the pectoralis major muscle lies under the breast and it *originates on the sternum and the clavicle and inserts on the humerus*. if the arm is already abducted this will act to add it back to the body adduction if however the arm is already in anatomical position as in this case it's already adducted it can't be adducted anymore. this muscle will act to medially rotate the arm in other words going to take the humerus and rotate it toward the body.

The glial cell that helps to form cerebrospinal fluid is the:

ependymal cell

1. The prime mover of spinal extension is the:

erector spinae

Extension involves which torso muscle

erector spinae

The prime mover of spinal extension is the:

erector spinae

Support /protect soft tissues example?

ex. Abdominal wall muscles & pelvic floor muscles -reason your abdominal organs dont spill out in front of you is that there is a series of abdominal wall muscles on the anterior part of your abdomen that hold those organs into the abdominal cavity. Series of muscles at the bottom of the pelvis called pelvic floor which support and protect soft tissues inside of the pelvis. Series of muscles that pregnant women are told to workout in prepartion for child birth.

Regulate entrance/exit of material

ex. Orifices of digestive & urinary systems Skeletal muscles encircle the opening or orifices of the digestive and urinary tracts exterting a voluntary control over swallowing, defecation, and urination.

Compared to the endocrine system, the nervous system is:

faster and more specific

The superficial fibular nerve runs on top of the ________ while the deep fibular nerve runs on top of the _____

fibula , tibia

THREE CLASSES OF LEVERS: First Class

first class of lever the fulcrum or the joint lies between the applied force and the resistance or the opposed force so for example this joint here between the -Atlas and the occipital condyles is the fulcrum that's the fixed point about which the lever is going to move - the applied force is always exerted by the muscle so here in this example this muscle is contracting shortening that's why the arrow is pointing down to show you that this is the insertion this is the origin so it's going to be pulling the back of the head down which will be lifting the entire cranium what action is this extension but this muscle has to work against the resistance or the -opposing force which in this example is the weight of the head so these arrow pointing down represents the weight of the head by which the applied force has to work against. In a first-class lever, the applied force and the resistance are on oppositesides of the fulcrum. This lever can change the amount of force transmittedto the resistance and alter the direction and speed of movement

Pectoralis Minor

first time we really get an understanding of how a muscle can perform more than one action depending on the original location of the joint to be prior to the movement so if your scapula is already elevated this muscle will pull and depress the scapula likewise if the scapula is already retracted this muscle being on the anterior side if it were to shorten and pull toward the origin is going to protract the scapula or pull it anteriorly.

External intercostals function

for each pair of ribs the fibers of the external intercostals run diagonally like putting your hands in your pockets put your hands in your pockets and notice the orientation of your forearms they run from superior lateral to inferior medial because the external intercostals elevate the ribs, -* the origin has to be on the inferior border of the superior rib while the insertion is on the superior border of the inferior rib.*

Reverberation:

form like a feedback loop so you have one neuron sending information to another neuron that can either send information to a third neuron or can send the information back to the original place so that's why we call it a feedback loop or reverberation

superior oblique

has a tendon that attaches to the eye and then the muscle belly is actually posterior to that and right here where it bends it's being tethered on the medial side of the bony orbit by this ligament called the trochlea. trochlea is a pulley to review that really quickly a pulley is a wheel or an axle that helps support movement and changes the direction of a cable or some sort of rope that pulls something up and lifts the load so for example in this hypothetical situation if you wanted to lift this heavy box a pulley is a wheel attached to some sort of support and some sort of cable or rope would be used around that pulley and you could pull that cable and it changes the direction of the movement and allows you to lift a heavy weight up thus the eyeball is the box the trochlea is the pulley and the muscle is the rope.

Anaxonic Neurons :

here basically they're small, it's hard for you to distinguish where the dendrites are and where the axon is. it looks like a little astrocyte these are only found in the central nervous system and more specifically in special senses organs so your olfactory your visual and things like that they don't really understand the function of this type of neuron but it is classified as an annex sonic neuron.okay so the neurons that you can't differentiate a dendrite from an axon. - special senses -CNS

How are they formed and where does the diaphragm attach?

here you can see on the right exactly what the diaphragm looks like* it attaches from the front part on the inside of the ribcage and both the ribs and the costal cartilages and also attaches at the very back of the ribcage behind the abdominal organs* - due to these attachments the diaphragm is *dome shaped* it arches all the way from the anterior part of the ribcage the posterior part. - there are two peaks in the dome a right and a left. on the *right side of the body the dome is taller than that of the left* this is because the liver which sits right here just inferior to the diaphragm in the abdominal cavity takes up more room than organs on the left side of the abdominal cavity and so it actually sits up higher and there's less space on the right side of the thorax because of that. - attaches from the anterior internal aspect of the ribcage to the posterior internal aspect of the ribcage and also the spinal cloumn

gray matter has these projections called

horns - posterior gray horn -lateral gray horn -anterior gray horn

Skeletal movement

how muscles move joints explain which muscles are acting on the joints causing those movements

Sternocleidomastoid:

if you break it down it tells youexactly what it attaches to sterno for sternum cleido for clavicle mastoid for mastoid process. The sternocleidomastoid has two heads one that *originates on the clavicle and one that originates on the sternum both of these heads insert on the mastoid process* one thing to mention at this point is that all these muscles are found on both sides of the neck it's just that in this image they've chosen to show some present and some not depending on what side you're looking at so the sternocleidomastoid has two actions depending on whether both the left and right sides are contracting at the same time or if only one side contracts at a time because the insertion is on the mastoid process if *both contract at the same time it's going to flex the neck or pull the chin closer to the chest if only one side contracts however it's going to pull that side laterally and that would be lateral flexion at the neck *these aren't the only muscles that flex and laterally flex the neck there are others that assist

spinocerebellar

in spinal thalamic you're telling you exactly where you're starting and where would you're going to end okay so the spinocerebellar is going to start at the spinal cord and it's going to end in the cerebellum -involve 2 neurons

Zygomaticus major + minor:

in the next image we can see the action of the zygomaticus muscles that are lifting the corner of the upper lip laterally almost an Elvis impression.

THREE CLASSES OF LEVERS: Second Class

in the second class of levers the resistance is located between the applied force and the fulcrum a good example of this is the action of standing on your tiptoes in this example the fulcrum or the joint that's being affected is this joint right here between your metatarsals and your toes the resistance is the weight of your body and -the applied force are the calf muscles here in the posterior part of the leg so notice these calf muscles are attaching to the calcaneus so when they shorten and notice the arrow is pointing up in educating that this is the insertion and this is the origin so when the muscles shorten and pull on the calcaneus they have to oppose the resistance or the weight of the body however what's going to happen is the action is going to occur all the way over here at the fulcrum which in the previous example was between the applied force and the resistance but here is on the far left side. In a second-class lever, the resistance lies between the applied force andthe fulcrum. This arrangement magnifies force at the expense of distanceand speed; the direction of movement remains unchanged.

Route of tendons in foot

in this image you can see the tendons of a series of muscles run through this structure called the sustantivo groove the tendons that are involved are all the flexor tendons and the tibialis posterior tendon this is how these tendons pass from the leg into the bottom or the plantar part of the foot.

information that's going to be carrying pain and temperature are going to leave

information that's going to be carrying pain and temperature are going to leave lateral part of the spinal cord

information that's going to having to deal with crude touch is going to leave from the

information that's going to having to deal with crude touch is going to leave from the anterior part of the spinal cord.

Motor Neuron

initiating a stimulus causing the skeletal muscle to contract. stimulus is in an form of an electrical impulse

Buccinator

is a muscle here right in the *cheek* (In the cheek with its muscle fibers running horizontally between all the muscles that are associated with the lips andthis big muscle here that we're going to name in a second called the masseter)

medial cord is going to give rise too

is also going to give rise to your *Ulnar nerve*

The _________ cord and the ______ cord merge to form the median nerve

medial and lateral

Denticulate ligament-

is going to be an *extension of your spinal Pia mater and it's going to connect the PIA mater to the spinal arachnid mater and to the dura mater so you can see that it's sort of a ligament like the name says that it's going to provide a lot of the stability of your spinal cord so it helps to hold it in place.* this next figure is basically just to show you exactly how then the Pia mater is so it's a very very thin membrane and you can see that the Denticulate ligaments over here and they're going to help the pia to sort of attach to the arachnoid mater and to the dura and givethat stability so this is just for you to refer to. are located along the length of the spinal cord. These structures, which are found between the dorsal and ventral roots of the spinal nerves, are extensions of the spinal pia mater, and they connect the pia mater and arachnoid mater to the dura mater of the spinal cord. The denticulate ligaments begin at the foramen magnum of the skull, and *they prevent side-to-side and downward movement of the spinal cord*. At the inferior tip of the conus medullaris, the connective tissue fibers of the spinal pia mater form the filum terminale

diaphragm:

is one single sheet of muscle that separates two major cavities of the body it's an important anatomical landmark because it is the division point between all of the structures and the thorax or the thoracic cavity and all the structures and the abdomen or abdominal cavity.

Orbicularis Oris:

is the circular muscle that's associated with the oral region around the mouth if you remember back to when we talked about circular muscles circular muscles regulate openings in the body so these would be associated with opening and closing the eyes and mouth.

rectus abdominis:

is the one responsible for the 6-pack appearance of some people's abdomens and again there's also a right rectus abdominis muscle and a left rectus abdominis muscle on either side of the belly button. superficially the aponeurosis of the external oblique muscle covers the rectus abdominus muscles so here on the left side of this person the only reason that you're able to see the rectus abdominis is that the external oblique and it's aponeurosis have been cut away.

Depressor Anguli Oris:

is the opposite of elevate so it depresses anguli because it runs at an angle and Oris oral referring to the mouth this muscle *originates on the mandible and inserts at the corner of the mouth* therefore it must draw the corner of the mouth down.

concentric contraction:

is what we have been mentioning up until this point *the force generated by the muscle is sufficient enough to overcome the resistance and the muscle shortens as it contracts* so in this scenario here an individual lifting weights and we're using the elbow again it's a great example flexing the elbow. his biceps brachii muscle is creating enough force to lift up his forearm and the weight that he has in his hands and what that's going to do is allow for shortening.

Astrocytes :Controlling the interstitial environment.

it can control the interstitial environment and again it has to do with the significant number of processes that it has and by having these several processes it actually increases the surface area of the cell and if it *increases the surface area* you can see how it's going to facilitate the exchange of certain ions and other molecules within the extra cellular fluid and the central nervous system and by doing this it's actually going to be able to control the chemical content that's present inside the central nervous system.

Pseudounipolar neuron

it sort of has continuous dendrite and the cell body and the axon so it doesn't really pass through the axon like we see for example on the bipolar right over here see how it the axon and the dendrite the information sort of passes through the cell body. here on the pseudounipolar it looks like it's one Pole right because if you notice the information it goes from the dendrite doesn't have to pass directly through the cell body. but you do see a distinguish dendrite from a distinguished axon these *neurons are found in your peripheral nervous system and basically they're the ones that are going to send for example sensory information all the way to the central nervous system* but these axons they are going to be myelinated because you want to make sure that you maintain the information and that information runs fast . -PNS -myliented

Tensor Fasciae Latae:

just lateral to the gluteus maximus muscle is this very small muscle here right on the side of the hip called the tensor fasciae latae it's kind of ordd term but it makes sense if you understand that this muscle is inside of this fascia tissue this connective tissue that surrounds some of the muscles in the thigh and this fascisia called fasciae latae. the tensor fasciae latae the muscle that's inside tenses or tightens this fasciae latae.

Extensor carpi radialis

lateral view of the forearm showing those muscles that are considered functionally to be part of the posterior compartment that are actually on the lateral side this includes the two extensor carpi radialis muscles and here I have a better way of showing you that the extensor carpi radialis longus is on top of the extensor carpi radialis brevis. anterior to these two muscles is the brachioradialis muscle if you break down this term brachio means arm or humerus radius means radius so this tells you exactly what it attaches to the origin is on the humerus and the insertion is on the radius. extensor carpi radialis muscles are going to do the opposite of the flexor carpi radialis muscles when both contract together along with the extensor carpi ulnaris muscle the hand at the wrist will be extended when only these contract by themselves and the extensor carpi ulnaris is not contracting this will abduct the hand at the wrist .

The musculocutaneous nerve stesm from the __________ cord, which stes from __________ and _______ trunks

lateral, superior , middle

1. Which of the following muscles raises the upper lip? A. buccinator B. masseter C. levator labii superioris D. depressor labii superioris E. orbicularis oris

levator labii superioris

Levator Labii Superioris

levator means to elevate anytime you see that and a muscle it means it elevates something labii comes from labium which means lip. superioris superior so in other words the superior muscle that *elevates the lip this is located between the nose and the zygomaticus minor.*

most of the time when a muscle contracts it of course is going to cause some sort of action this action is applied to a bone otherwise known as a ___________ this _______ moves a fixed point or a point of rotation called the _________ and every _______ in a skeletal system is a joint anytime this action is exerted on the lever there's going to be an opposing force acting in the opposite direction.

lever, lever,fulcrum, fulcrum

How many nerves form the cervical plexus?

nerves that are going to be forming this cervical plexus they're going to be coming from these five nerves over here so c1 all the way through c5 now c5 is only part of c5 okay so c5 is going to be split into cervical plexus and brachial plexus. but all the others c1 through c4 all of them are going to be forming the cervical plexus

Cell body

neuron is going to have a cell body like all other cells within this cell body which can also be called a soma or a perikaryom all the same thing so this typical cell body is going to contain all the organelles that other cells regular cells have like a nucleus a nucleus mitochondria Golgi apparatus I'm sure you can see them by your and the plasmic reticulum with your ribosomes.

upper motor neuron

neuron that's going to be exiting your cerebral cortex so it's going to be exiting the cerebral cortex it's going to be coming down through the brainstem and once it gets to the brainstem we have information that goes directly down to your spinal cord or we can have information that leaves through your brain stem. - now about 85% of the information that's coming down to your spinal cord is actually going to shift come down cross over to the other side and be able to exit your spinal cord through the motor tract. -15% actually comes down straight - 85% crosses to the other side and 15% maintains the same side of the track. - upper motor neuron it can either excite or it can inhibit your lower motor motor nerve okay so if it excites that the information continues to move on if it inhibits and it sort of blocks that information.

Levator Labii sup. + depressor labii:

next is levator labii superioris which we said were those just lateral to the nose and they are lifting the upper lip straight Up. So like zygomaticus major which lifts it laterally these lifts it superiorly.

The space between the mylein sheets that are produced by adjacent oligodendrocytes is called

nodes of ranvier (is actually an empty spot where you don't have myelin sheet.)

digastric

now notice that this term does not have hyoid in it so that tells you something that means it's not directly attaching to the hyoid .digastric means to bellies: gastric for stomach di: two. So bellies so this muscle has two parts to it one in the most anterior portion here and one that goes more posteriorly. Digastrics: *has two bellies an anterior belly that attaches to the mandible and a posterior bellythat attaches to the mastoid process these two bellies are connected by a tendon that is attached to the hyoid bone through a ligament* -you can see that easily on the previous slide sort of like the trochlea and the eye. this ligament changes the direction of the muscle and so that's why you have the digastric and this L shape so if I told you that the *origin is on the mastoid.process and the insertion is on the mandible * -insertion: hyoid -origin: mandible or mastoid -can you infer what action it has exactly *it depresses the mandible* - on top of the digastric is the stylohyoid.

Median nerve is going to be made up of what cords

now your median nerve is going to be made up of not only the *lateral cord* but also part of your *medial cord* it's going to be coming right in here so the median nerve is made up of the lateral and the medial cords.

forced exhalation:

occurs when coughing for example or blowing out a candle or during intense exercise this is a very quick action that depresses the ribs and forces the air out of the lungs.

one of the muscles that's helping the torso stay upright over the lower limb is the?

one of the muscles that's helping the torso stay upright over the lower limb is the psoas major it's going to contract at a steady rate and prevent the torso from falling in any direction so in other words it holds it upright just above and balances it just above the lower limb again this occurs when the lower limb is fixed meaning it's not moving.

Each skeletal muscles has?

one or several bellies which contain the portions of the muscle that contracts the skeletal muscle fibers.

when flexing the elbow origin? Insertion?

orgin: humerus Insertion: radius flexion of forearm bicep brachii muscles cause flexion at the elbow

A muscle's action can often be inferred from its

origin & insertion

Flexor pollicis longus:

origin: Radius and interosseous membrane Insertion: Base of distal phalanx of pollex Action: Flexion at joints of pollex (flexes pollex) (and it's tendon goes to the thumb the word pollicis refers to Pollux and remember that is the two phalanges that make up the thumb.)

Vastus intermedius

origin: on femur Insertion: tibiial tuberosity by the quadriceps tendon, patella, and patellar ligament Action: extend the knee

Group 1: Gluteal compartment (deeper)

origin: os coxa insertition: on proximal part of the femur

Group 1: Gluteal compartment

origin: pelvis Insertion: femur

Extensor carpi radialis longus

origin:Lateral side of Humerus Insertion:Metacarpal II Action: *Extension and abduction at wrist*

Flexor digitorum longus

origin:Posterior medial surface of tibia Insertion:Inferior surface of phalanges 2-5 Action:(*Flexion of joints of toes 2-5*); plantar flexes ankle (*more medial*)

Lateral Femoral Cutaneous nerve

originates from the ventral rami of L2 and L3. It recieves sensory info from the skin over the anterior, lateral, and posterior thigh.

Popliteus

popliteus unlocks the fully extended knee you've probably heard that if your knees are extended and you lock them in place that that can cause you to pass out you don't want that to happen so you bend your knee slightly that movement involves like popping your knee out a little bit. (*Unlocks fully extended knee*) *right on back side of the proximal part of the tibia or back of knee*

The _________________ cord is formed by the merging of the superior, middle, and inferior trunks.

posterior

Posterior cord gives rise to

posterior gives rise to axillary nerve and radial nerve

Pronator Teres:

pronates so hence the name and it's this one here and it's the only one that we're going to discuss that inserts somewhere in the forearm and does not continue down into the wrist or fingers and thumb.

Which type of neuron has a tract that goes from the effector organ to the spinal cord?

pseudounipolar

Contraction phase is active, resting phase is passive -Muscles can only

pull, they can't push

The posterior cord gives rise to which nerves?

radial and axillary

the posterior cord gives rise to the _______ and the _____ nerves, while the medial cord gives rise to the _________ and ______

radial, axillary, ulnar, median

Depressor anguli oris:

remember was that one that depresses the corners of the mouth this is easy to remember because when you're depressed what do you do you're sad right so you have a frowny face now this is a simplification because there are several other muscles that help you frown so I wouldn't technically say that this is your frown muscle but it is one that does pull the corners of the mouth down.

superior oblique

rotates top of the eye inward (intorsion) AKA internal rotation

What is the smallest functional unit of a skeletal muscle?

sarcomere

Myofibrils are basically tens of thousands _______ lined up end to end

sarcomeres

myofibrils are made up of?

sarcomeres which are structures that cause contraction in muscles

T tubules

series of tubes these yellow structures called transverse or T tubules. these wrap around some parts of the myofibril but they are all connected to eachother. they communicate to outside of the sarcolemma.

Biceps Femoris (long head and short head)

short head is below touching the femur* Origin:Ischial tuberosity and linea aspera of femur Insertion:Head of fibula, lateral condyle of tibia Action:Flexion at knee; extension and lateral rotation at hip *Extend thigh, flex leg*

Mitochondria

significant number of mitochondria in this section so you can imagine how many there are through out the muscle fiber. Contraction of the muscle fiber requires significant amount of energy or ATP. That why you have so many mitochondria in each muscle fiber.

Muscle Fascicle surronded by? contains?

surronded by: Perimysium ( wraps around each muscle fascicle individually) Contains: Muscle Fibers (many muscle fibers are bound together into each muscle fascicle)

subarachnoid space

so between the arachnoid mater and the PIA mater and this space does exist it will contain CSF so the fluid that's present in your brain which is your cerebral spinal fluid and this fluid is very important for shock absorber for diffusion of dissolved gases nutrients waste products and things like that

What happens during breathing?

so how this works during breathing is the external intercostals muscles are responsible for contracting during inspiration or taking in a breath this draws the ribs up elevates them expanding the thoracic cage and allowing for the lungs to expand as they fill with air when air is then released when breathing out during expiration and the lungs deflate what's happening is the external intercostal muscles are relaxing and allowing the ribs to return to anatomical position. *so when external intercostal muscles are active they elevate the ribs *when they contract they depress them but that you can't say the external intercostals act to depress the ribs. the internal intercostal muscles do that so then your question is well when do they do that if they're not doing it during normal breathing and the answer is there's an action called *forced exhalation*.

What does the neurotransmitter dictate?

so in case it synapses with an neuron it can be excitatory or inhibitory depending on the neurotransmitter and same thing for muscles you can have an excitatory or an inhibitory effect depending on the neurotransmitter and same thing with glands side excitory or inhibitory depending on the neurotransmitter. so the type of neurotransmitter that's being released by this first neuron here which we call a pre synaptic neuron. presynaptic neuron because it's a neuron before the synapse. so whatever this presynaptic neuron releases in terms of neurotransmitter is going to dictate if it's going to stimulate by releasing an excitatory neurotransmitter or if it's going to inhibit the action by releasing an inhibitory neurotransmitter.

Autonomic Nervous System Tracts

so information that's not going to be going to skeletal muscle for motor command it's going to be going to your organs and if it's going to be going to organs then we have the autonomic nervous system you can see how it starts a little bit lower mostly it's going to start here at the level of the hypothalamus. so remember how we had sensory information and sensory input that would arrive up here in the thalamus so motor information is going to be exiting through the hypothalamus and going to specific organs now we don't have to know exactly which how this mechanism works we just have to know from this line that if it's motor and it's going to your organs it's going to be leaving through your hypothalamus and then can leave through initially at the base of your brain so your brainstem or you can also go down to your spinal cord and leave through your spinal cord but all of them if it's autonomic is going to affect organs so it can affect smooth muscle terms of your heart on your respiration it can affect glands so if you're going to secrete less or more glands and it can affect your adipocytes where you're going to be storing more or less energy.,

Sensory modality arrangement:

so sensory modality so that means different types of sensory information is going to be coming from specific areas of your spinal cord. okay so you can see right over here these blue arrows right over here that are coming towards the posterior side of the spinal cord you can see how all of these are going to be carrying information like: • Touch • Pressure • Proprioception • vibration

Astrocytes : Maintaining the blood-brain barrier

so the first function has to do with the maintenance of the blood-brain barrier but basically you can see how the astrocytes they *have these end feets here towards the end of the cytoplasmic process and these end feets are sort of going to wrap up the central nervous system and they're going to isolate the central nervous system from the rest of the circulation and by doing this they protect the central nervous system from the outside and creates what we call this blood-brain barrier*. okay so this is done through these feets that are present at the end of these cytoplasmic processes right over here.

So the main type of synapse is called

so the main type of synapse is what we call chemical synapse chemical because you're going to have a specific chemical that's going to be released and depending on what type of chemical is released then you're going to have an Neuron stimulating another structure or a neuron inhibiting another structure

Carpal tunnel syndrome

so the problem with this setup is that you have a whole bunch of structures going through the same passageway and those structures are being held in place by this dense fibrous connective tissue when there is *constant pressure on this area as when typing or using a mouse this can cause inflammation inside the carpal tunnel* in these structures. this inflammation causes pressure to build up in the region and *puts pressure on the median nerve* and that is what causes the tingling sensation that occurs in thehand due to having carpal tunnel syndrome. so when there's built-up pressure there's nowhere for the structures to expand because the flexor retinaculum is not a very giving tissue this is why one of the therapies for severe carpal tunnel syndrome because you wouldn't want to do this if it wasn't severe enough is to surgically cut into the flexor retinaculum just enough so that it can expand

Quadriceps Femoris Function

so the quadriceps femoris muscles when they all contract together as a group all four of them they extend the leg that's because most of them originate on the femur somewhere and they insert via the quadriceps femoris tendon onto the patella which inadvertently remember had that patellar tendon that connects it to the tibia so even though the quadriceps femoris tendon actually comes through and ends here and it's a patellar ligament that connects the patella to the tibia it's still going to draw up and cause tension and pull the tibia closer anteriorly or extend it the leg.

Where does the synapse occur?

so the terminal button is where it does synapse is going to occur

Stylohyoid:

so this muscle *attaches from styloid process to hyoid (insertion)* this is the muscle that I referenced when speaking about the hyoid being the only bone in the body that doesn't directly articulate with another bone. Stylohyoid: or that's the one that goes from the styloid process to the hyoid so I'm what this does is crosses over that location where the digastric attaches to the hyoid via that ligament so the belly of the stylohyoid is actually superior and a little bit anterior to the posterior belly of the digastrics. Action: Elevates larynx

Actions of the Hamstrings

so we're generalizing and we're just going to say that as a group of muscles the hamstrings *extend the thigh and flex the leg* so how does this work exactly well the *origin is on the ischial tuberosity and depend on which muscle it is it's either going to insert on the tibia or on the fibula* either way that means the muscle is crossing two joints it crosses over the hip joint here and it crosses over the knee joint therefore if your hip is already flexed and these muscles contract it will extend and pull the femur more posteriorly and place it back into anatomical position likewise if the leg is extended and these muscles contract it will pull the tibia and fibula posteriorly which will cause flexion of the leg

Rotator cuff muscles (Anterior)

so what exactly do these muscles do well the insertions kind of help you out first we've already mentioned it helps hold the humeral head and the glenoid fossa that's just a fancy way of saying it stabilizes the shoulder joint right. lateral rotators are the ones on the posterior side and the only medial rotator is the one that's anterior so to reiterate again these are lateral rotators because they insert on the posterior side so they're going to pull in the posterior side and turn the humerus away from the body and the subscapularis because it inserts on the anterior side will pull the humerus toward the body.

Dermatome example

so you can see right over here is how you have for example your l3 coming down right over here L3 and it sort of wraps around but it also continues right over here and right over here. so one nerve that's leaving at this area right over here is actually going to be controlling several different areas or relying sensory input of several different areas of your body now clinically this is very important because by sort of tapping the skin of an individual in different areas of the body the physician can actually diagnose or try to diagnose what nerves are going to be affected okay so that's the importance of dermatomes.

How is the spinal cord protected?

so your vertebral column together with your ligaments and tendons and muscles they're going to make sure they're going to protect the spinal cord from the external environment and not only these structures but there is also a very specialized membrane that has three layers that's going to be called the meninges they're also very important for not only providing protection but they also provide physical stability and they're also very important for absorbing shock so they're going to be important for protecting not only the spinal cord but also the brain since this membrane which is called collectively the meninges does wrap up your brain

The efferent division is further divided into two divisions:

somatic nervous system (SNS) (muscle) autonomic nervous system (ANS) (viscera or internal organs)

Maintain body temperature

some of the energy used for contraction is converted to heat. So contracting muscles lose a little bit of heat that actually keeps our body temperature in the range required for normal functioning and homeostasis

How many segments is the spinal cord divided into?

spinal cord can be divided into 31 different segments these segments are going to receive the name according to their area where their at

stretch reflex

spinal reflex it's going to be characterized as a monosynaptic type of reflex because basically that's exactly what it's showing right over here so it's going to activate your sensory neuron that's going to produce stimulus through your motor neuron okay so your stretch reflex is your monosynaptic type of input .

Cardiac muscles and Skeletal muscles are __________ where as smooth muscles are not

striated

Superior trunk branches to form

superior part of it is going to form what we call the *lateral cord* and the inferior part is going to form part of the *posterior cord.*

Skeletal Muscle surronded by? Contains?

surronded by: Epimysium - (above the muscle this connective surrounds all the muscle fascicles.) Contains: Muscle Fascicles (many muscle fascicles are bound together to form the organ level skeletion)

deltoid

the deltoid muscle is this muscle in the shoulder right on the lateral part of the shoulder and if you look at it from a lateral view which I don't actually have a picture of it's shaped like a triangle or a delta the Greek letter and so that's how it gets its name deltoid this muscle *originates on the spine of the scapula and then wraps around and does attach to a clavicle on the anterior side and it inserts on the humerus* because of its lateral location and how it inserts on the lateral side of the humerus when it shortens toward the origin is going to abduct the humerus thus the arm and anything attached to it distally will be drawn further away from the body.

dorsal ramus and the ventral ramus this just means

the dorsal ramus and the ventral ramus this just means that information can be arriving from different areas of the body so if it's located dorsally it's going to be coming through the dorsal ramus and if it's located ventrally it's going to be coming in through the ventral ramus which is this one right down here. You can see how the information from both parts your anterior or posterior they're going to combine. The dorsal (posterior) ramus of each spinal nerve receives sensory innervation from, and sends motor innervation to, the skeletal muscles of the back. The relatively large ventral (anterior) ramus supplies the ventrolateral body surface, structures in the body wall, and the limbs.

Groups 4 & 5: Posterior compartment

the extensor digitorum is this one right here with the tendons going to each individual digit and then unlike the flexors there is this separate little bitty muscle here going to the pinky and that's called the extensor digii minimi the way I remember this is mini-me from Austin Powers was small and this is going to your smallest digit which is your pinky.

extrinsic eye muscles

the extrinsic eye muscles are the skeletal muscles outside of the eyeball that move the eye around in the bony orbit. these are referred to as extrinsic because there are intrinsic eye muscles within the eye that have completely different functions t

Buccinator + orbicularis oris:

the first is the Buccinator which *compresses the cheek* so the reason that he's able to hold air inside of his cheeks. well one is his mouth is shut but the second is that the *Buccinator is compressing the cheek around that air but the buccinator doesn't just help make this facial expression it's also a muscle of mastication because it compresses the cheek it helps move food towards the teeth when chewing it's also used for sucking substances through the mouth so this muscle is very important in infants for example since that's the primary way through which they obtain nutrients* getting back to this image the orbicularis Oris is closing the mouth and helping hold the air in.

Which structure binds to the active site of the thin filament to cause muscle contraction?

the head of the myosin

Fixators:

the last grouping or fixators and these are agonist and antagonist muscles that contract at the same time to stabilize a joint rather than move it so as an example if you stretch your hand out as if to get something from somebody there are flexor and extensor muscles in your upper limb that contract at the same time to help stabilize your outstretched hand.

Serratus Anterior

the last muscle group one inserts on the scapula but it does so on the anterior side or the portion that's adjacent to the ribcage notice how eachindividual segment of this muscle inserts on one of the ribs and it causes it to have this jagged appearance that's why the muscle is called serratus. it's serrated like a knife and it gets named anterior because there's a posterior one as well thus based on its position and where it's inserting this would also protract the scapula and just to clarify you'll notice that the anterior muscles that we just covered originate on the ribcage and the posterior ones were originating on the vertebral column.

What forms the medial cord?

the medial cord we only have the *inferior trunk* forming the medial cord

reflex arc

the neural "wiring" of a single reflex is called a reflex arc. A reflex arc begins at a receptor and ends at a peripheral effector, such as a muscle or gland cell.

Palmaris Longus:

the next one I want to point out is this one here in the middle called palmaris longus is a skinny one where the tendon ends right here at the base of the palm. not everyone has one of these actually if you take your thumb and your ring finger and you make an okay sign put them together and then bend or flex your wrist towards you the palmaris longus tendon will pop out right in the center it will be most prominent however if you perform this action and all you see are two tendons side by side and there's not a third one sticking out in the middle that means you do not have the palmaris longus. -:it flexes the wrist those of you that don't have it you're probably wondering well does that mean I can't flex my wrist well clearly that's not the case right it is one of several muscles that flex the wrist and it's small so not having it doesn't have a significant influence on your ability to flex your wrist.

Bipolar Neuron

the next one is what we call the bipolar neuron and basically the bipolar neuron is going to have several dendrites that fuse to form this one single major structure but then when it gets to the end sort of branches out like your regular dendrite and you can see that it will have an axon that can be differentiated from the dendrites and at the end you will have the terminal button like we usually do on a regular neuron now these bipolar neurons they're sort of rare type of neurons they're going to play an important role in sensory information for your special senses so things like sight smell and hearing and these axons aren't going to be unmyelinated axons. so special senses and unmyelinated axons . - special senses - unmyelinated axons

Astrocytes :Guiding neuron development.

the next one which has to do with guiding neuronal development this is very interesting so astrocytes like I said they have these long filaments and by providing these long filaments here we have a filament they're going to allow neurons to actually use these *fibers as guidance to migrate from one area to the other* and if you guys copy this link over here that's what you're going to be able to see you're going to be able to see a neuron that's going to be moving on top of this glial process and sort of using the *glial process as a guidance to get from one location to the other.*

Neuroglandular synapses

the next synapse is what we call the neuroglandular synapse where you're going to have a neuron that's going to synapse with a gland.

Internal intercostal muscles function

the opposite is true of the internal intercostals they run the opposite diagonal direction from superior medial to inferior lateral because the internal intercostal muscles depress the ribs the origin insertion is switched compared to the externals the *origin is on the superior border of the inferior rib and insertion is on the inferior border of the superior rib*

Convergence:

the opposite is what we call a convergence so you have four neurons here all of them trying to contact the same neuron so they're converging the information so it's called a convergence.

The posterior surface of the spinal cord has a shallow longitudinal groove called

the posterior median sulcus

Sensory fibers carrying fine touch, pressure, proprioception, and vibration is going to leave from

the posterior side of the spinal cord

Astrocytes: BBB

the processes of these astrocytes over here they're going to wrap around this capillary and by wrapping around the capillary it isolates the blood that's passing through the capillary forming what we were talking about your blood brain barrier.

Posterior cord will give rise to the

the radial nerve and axillary nerve

Why is there no Anterior cord?

the reason for this is that or the way that they nominate these cords basically the lateral is going to be more lateral the medial is going to be more medial and then the posterior since this is two dimension it's hard for you to see but the posterior is actually going to be moving more dorsally.

Iliacus:

the same is true of the iliacus which is in the iliac fossa hence its name and also attaches to the femur .

Satellite Cells

the satellite cells they're going to be present in specific areas of the periphery that we call ganglions and ganglions are just a big group of cluster of neuronal cell bodies .so this figure shows right over here this is a ganglion you can see these big structures here are going to be your neuronal cell bodies and you can see how the satellite cells which are these little dots over here are going to be surrounding the cell bodies of these neurons so basically they're going to *give support to the neurons that are present in these ganglion or ganglia plural and by doing this they're going to help to regulate the exchange of nutrients and waste products that occur between the neuronal cell bodies that are present in the ganglia and the extracellular fluid*. (Satellite cells surround neuron cell bodies in peripheral ganglia (Figure 13.8). Satellite cells regulate the exchange of nutrients and waste products between the neuronal cell body and extracellular fluid. They also isolate the neuron from stimuli not intended to pass from neuron to neuron.)

neuromuscular synases

the second type of synapse is what we call the neuromuscular synapse and we did talk about this when we were covering muscle so basically you're going to have a neuron that is going to synapse with a skeletal muscle and that's the neuromuscular synapse.

The central nervous system (CNS) consists of

the spinal cord and the brain.

How far is the spinal cord going to extend?

the spinal cord it's going to extend from your foramen magnum right over here all the way down to your first lumbar vertebra so it goes all the way down to L1.

spinothalamic

the spinothalamic is going to start on the spinal cord and it's going to end in the thalamus. -involve 3 neurons

Scalense:

then between the sternocleidomastoid and the trapezius are three muscles called the scalene there's an anterior one a middle one and a posterior one these as a group *laterally flex the neck* so if the scalenes on the left side of the person's head contract then the head will be pulled down toward the shoulderso these are the muscles that assist the sternocleidomastoid in that movement.

Axon

then on the other end you're going to have this long process that's called an axon now neurons have only one axon and several dendrites. and the axon is what's going to conduct or transmit the nerve impulse and the nerve impulse always goes in this direction here so it always runs from the cell body all the way to the end of the axon on these little structures that we call terminal buttons or end feet.

The medial cord is going to give rise to

then your medial cord is going to give rise to your ulnar nerve.

Rotator cuff muscles (posterior)

there are four muscles that make up the rotator cuff the rotator cuff muscles help stabilize the shoulder joint three of the muscles are named after bone features that you've already identified and those are the supraspinous fossa and infraspinous fossa and subscapular fossa. for each of these the muscle has a similar name it just ends in tus which indicates that it's a muscle and not a bone feature so the supraspinatus is in the supraspinous fossa. the infraspinatus is in the infraspinous fossa and not visible on the slide there's a subscapularis on the subscapular fossa. and as you can see from the image they're named for their origins so the supraspinatus originates on the supraspinous fossa and and so forth. The only one not named for a fossa is the teres minor which is this thin one here on the bottom. notice that all three of these in the posterior side are inserting on the posterior part of the humerus. on the anterior aspect is the subscapularis in the subscapular fossa and and it inserts on the anterior portion of the humerus.

Group 5: Posterior compartment - deeper

there is a muscle up here called the supinator and that tells you exactly what it does itsupinate the forearm and then here is the abductor pollicis longus underneath the abductor pollicis longus is the extensor pollicis brevis. One thing you will notice here is that all of the pollicis muscles the tendons be traced to the thumb and extensor indicas however its tendon goes to the index finger hence indicus and again the (you'll notice that at this point with all of these forearm muscles really didn't talk about the origin very much because it doesn't matter exactly where on the radius and ulna or humerus these things attach it's just important to know that the origin is proximal and that the insertion is in the name usually and it's going to be somewhere in the hand or the fingers and thumb.)

myofibrils

these are structures inside the muscle fiber call just like others they are long cylindrical structures that run the entire length of the muscle

oligodrocytes

these cells possess slender cytoplasmic extensions. However, oligodendrocytes have smaller cell bodies and fewer and shorter cytoplasmic processes (Figures 13.5 and 13.6). Oligodendrocyte processes contact the axons or cell bodies of neurons and tie clusters of axons together, improving the performance of neurons by wrapping axons in myelin, a material with insulating properties.

Oblique muscles:

these fibers run in the same direction as the external and internal intercostal muscles so the external oblique muscle fibers run diagonally like putting your hands in your pockets and then the internal oblique ones run the opposite direction also like the intercostals the external oblique is more external and the internal oblique is just deep to the external oblique.

the spinal nerve

these spinal nerves we actually call them mixed spinal nerves just because they're going to contain both the afferent and efferent fibers so as you can see if it were arriving the spinal cord is going to be afferent if it's exiting if it's exiting it's going to be efferent. this spinal nerve right over here is going to contain both the afferent and efferent fibers therefore they're called mixed spinal nerves. (Distal to each dorsal root ganglion, the sensory and motor fibers form a single spinal nerve that exits from the intervertebral foramina (Figures 14.1c and 14.2a). Spinal nerves are classified as mixed nerves because they contain both afferent (sensory) and efferent (motor) fibers. Figure 14.2a,b shows the spinal nerves as they emerge from intervertebral foramina.)

Ependymal Cell

they're going to be present in ventricles of the brain so ventricles are a sort of empty spaces where you're going to have the circulation of the cerebral spinal fluid and so *these empty spaces are going to be lined by the ependymal cells*. you can see how these cells they have cilia and *these cilia which you can see on this figure over here is going to help to circulate the CSF* within the spaces of the nervous system so not only they help with the circulation but there are specialized ependymal cells that are present in the ventricles that will actually participate in the secretion of the cerebral spinal fluid so not only it helps to secrete the cerebrospinal fluid but the cilia present in these cells helps to circulate the cerebral spinal fluid within the ventricles.

Each myofibril is composed of one or several different types of proteins. The type of proteins they are composed of differentiate _______ __________

thin and thick filaments

Mylohyoid:

this flat muscle here right under the chin is called the mylohyoid and Mylo means molar that's named that because of the location right under the molars where that muscles attaching to the mandible this muscle *creates a floor on the bottom of the mouth* that supports the structures of the tongue and other oral structures.

Multipolar neuron:

this is the most common type of neuron it is present in your central nervous system the axon is usually going to be *myelinated* right over here and this is what we classify as your typical neuron with your dendrites branching out over here big cell body and a long axon .-CNS

Sensory homunculu example

this little guy is what we call a homunculus and this specifically we call it a sensory homunculus because it's sort of showing you specific areas of your body where you're going to feel either more sensation or less sensation and this is exactly what we did in class when we are doing the little activity with the paper clip so you can see right over here how in this homunculus over here so your sensory homogeneous so let's look at the face specifically so you can see that your face has a huge lips okay so this means that your lips have more sensory receptors than for example your eyes that look very tiny compared in this figure okay same thing with your hands right so you have huge hands look at the size of your hands compared to the rest of your arm or the size of your hand compared to your back okay so that's why when you were doing the little activitywith the paper clip you notice that you have way less receptors on your back then you do on your hand so this is exactly what is showing you the other thing that this figure shows you that it's sort of interesting is that areas of your body that are more medial so right down the middle they're going to be located on the cerebral cortex more laterally

subdural space

this space appears a lot in when we do preparations or histological preparations but scientists believe that there really isn't that space or that space isn't present in real life so when the person is alive and you don't section and don't do any thing to it then there probably isn't that space over there.

Psoas major:

this very large muscle here that *attaches the femur and the lumbar vertebra* together and purposefully not saying which one's the origin which one's the insertion because in actuality they flip so this is a muscle that is both an axial muscle and an appendicular muscle depending on the particular action it's going to perform.

Erector Spinae Group: function

this word tells you exactly what they do, they erect the spine:. -when the torso is flexed or bent anteriorly these muscles will pull on the spine and pull the body up right back into anatomical position that would be called *extension of the torso* now keep in mind that this is what happens if all three of these muscles contract at the same time.

ADDUCTOR HIATUS

through which femoral artery & vein travel on their way to the leg (opening in the adductor magnus muscle)

The sciatic nerve branches into _________ and the ______

tibial and common fibular nerve

sciatic nerve is actually going to branch at the level of your knee into what we call a _________ nerve that's going to run more medially and then a _______________ neerv and this nerve is going to branch into a deep and a superficial

tibial nerve common fibular nerve

Dorsiflexion of foot involves the:

tibialis anterior, extensor digitorum longus and extensor hallucis longus

extensor carpi ulnaris

tis on the ulna side, it inserts on the carpals just as the flexor one does and it does the opposite action as the flexor carpi ulnaris so it will extend the hand of the wrist in conjunction with the extensor radialis muscles up here and if it's doing it by itself it's going to adduct the hand at the wrist.

Which protein hilds the thick filaments in place?

titin

Movement

what you're going to be doing this is what happens. so from the cerebellum it goes back to your motor primary what we call primary motor cortex from the primary motor cortex it exits through this so this would be your upper motor neuron so it's taking information to the lower motor neuron and if it originates here at the basal nuclei the same thing they can send information to the primary motor cortex or you can leave directly from the base on okay to your lower motor neurons so this is just for you to see how all this information is sort of gathered and it's put together to make sure that we perform the movements that we're supposed to perform so there are several areas of your brain that are involved.

What happens when the cross bridge ends

when calcium ions are actively transported back into the sarcoplasmic reticulum. troponin goes back to its original shape allowing tropomysin to glide over and cover the myosin binding site on actin.

Inspiration Maximum

when the diaphragm contracts it moves inferiorly, it shortens. Which increases the space in the thoracic cavity and draws air into the lungs

Expiration Maximum

when the diaphragm relaxes it returns to its orginal shape which decreases the thoracic space and forces air out of the lungs.

when the longissimus and iliocostalis contract together

when the longissimus and iliocostalis contract together they *rotate the torso* so in this example if the left iliocostalisis and left longissimus were to contract they would rotate the torso this way, this would also be called left rotation.

How many cervical regions does the spinal cord have and why?

when we're talking about the cervical region and it does go all the way down to eight because we start before your atlas right over here so that would be c1 and then between the Atlas and the axis would be C2 and that's why you go all the way to c8 even though we only have seven cervical vertebrae.

orbicularis oculi:

which controls winking. I make it a point here to say winking is not closing the eye because there's a separate muscle that blinks and shuts the eye so this is scrunching up the skin around the eye on winking.

sternohyoid:

which is right next to it just medial to the omohyoid it's called sternohyoid because it attaches to the sternum this muscle also *depresses the hyoid and larynx.*

The Planning Stage

which is showing you when you're going to plan something that you have to make a decision so you make the decision here at the frontal lobe so right at the beginning of the interior part of your brain then this information is taken to the motor Association area motor Association might take it to this structure that's called basal nuclei or might take it to the cerebellum which has to do with motor control and from here basically it's going to exit through your spinal cord so this is the planning stage so you're planning what you're going to be doing.

dorsal root ganglion

which is this enlargement over here of this section of the dorsal root and the dorsal root ganglion is basically *going to contain a lot of cell bodies of neurons so every time you have a ganglion it means that you have cell bodies of neurons* and we should also start thinking about what glial cells are found here because we did talk about the glial cells that are found in ganglions so if you guys don't remember it it's going to be your *satellite cells are going to be found here in the Ganglion so they're going to sort of give support and remove waste products and bring nutrients to the cell bodies of the nerves that are presen there at the dorsal root ganglion.*

Platysma:

which was that thin one covering up the front of the neck and *inserting on the mandible in the corner of the mouth this muscle allows you to grimace* so that is what I would describe this face as another way of saying that as a without this muscle robert de niro could not do his classicfacial expressions. in addition because of the way the platysma attaches the fact that it inserts on the mandible it also helps to press the* mandible or pull it down*. (one thing I did want to mention before we move on to muscles of mastication is that up until this point we've been talking about muscles that are not causing actions at joints most of these muscles attach to the skin and that's how they're able to move the skin and make these facial expressions.)

Buccinator:

which we already talked about as being a muscle of facial expression and again it's also a muscle of mastication during chewing the buccinator main function is to as I said compress the cheek and push the food back towards the teeth so it can be chewed up.

Astrocytes :Creating a three-dimensional framework for the CNS

with regards to creating this three-dimensional framework for the central nervous system again it has to do with these astrocytes and the end feets that produce this framework and we're going to be able to see it better on the next slide when we talk about oligodendrocytes but we can add that the astrocytes are going to have a lot of micro filaments inside of the cells and these microfilaments sort of give support to the whole structure of your central nervous system .

Astrocytes :Performing repairs in damaged neural tissue

with regards to performing repaired in damaged neural tissue if you have an area of your brain that was damaged you're going to have the astrocytes sort of come in and stabilize the tissue and actually produce a scar tissue at the injury site and this is going to allow for not the optimal repair but some sort of repair which is done by astrocytes .

Motor Tracts

you should know that the central nervous system or the information that's coming out of the central nervous system is going to be a motor command and this motor command is generated due to information that comes through sensory receptors they can be distributed to skeletal muscles if they're distributed to skeletal muscles then we say that it's a somatic nervous system remember somatic means skeletal muscle or they can be delivered to organs and if they're delivered to organs or viscera then we call it an autonomic nervous system now.

Dendrites

you're going to have these projections that are called dendrites .the dendrites are the ones that are activated when you have a stimulus arrive at the cell so the stimulus arrives right over here at the level dendrites or it can also arrive at the cell body dendrites or it can also arrive at the cell body.

Monosynaptic

you're just going to have one motor neuron so you have your sensory neuron over here and it stimulates a motor neuron and it exits through here so this is what we call a monosynaptic reflex . *A monosynaptic reflex has a sensory neuron synapsing directly on a motor neuron*

your median nerve is going to recieve input from?

your median is also going to receive input from your medial cord

pudendal nerve

• is important because this is the one that's going to become your *fibular nerve* later on. - originates from the ventral rami of *S2-S4* -It innervates muscles of the perineum, the urogenital diaphragm, and the external anal and urethral sphincters.

levator scapulae

• is this one that's more superior that originates much higher up on the spinal column and inserts on the scapula the name tells you exactly what it does anytime you see levator and a muscle it means it elevates here it's telling you what bone is elevating.

How ae we able to differentiate the different type of info?

• now these axons and we talked a little bit about this how specific information from specific region are going to be grouped in the same area of your spinal cord or in the same area of your brain and that's how we're able to differentiate the different types of information depending on which pathway or which tract it goes through and where the information is going to be arriving either at the level of the spinal cord or at the level of the cerebral cortex or even at the level of the brainstem. the brainstem being the base of the brain so the inferior part of the brain.

The rhomboid muscles

• on the other hand there's two of them a major which is larger and a minor which is smaller and their origin is more inferior on the spinal column thus this has an influence on what they can possibly do they can't lift the scapula because they're not superior enough they actually retract the scapula and the rhomboids are named that because they're shaped like rhombuses see that shape actually makes sense.

so about 95 percent of the information that arrives at the cerebral cortex it has to start right over here at the _________

• so about 95 percent of the information that arrives at the cerebral cortex it has to start right over here at the thalamus okay so all the information that arrives or ninety-five percent of the information that's arriving in your cerebral cortex is going to have to pass through the thalamus and the thalamus is going to distribute this information where it has to go.

Example of strecth reflex

• so when you go to the physician office and he gets a mallet and he bangs the mallet over here on your knee more specifically the inferior ligament that holds the patella which by now you guys should know that's your patellar ligament and therefore this stretch reflex can also be called patellar reflex. • okay so when you *stimulate the ligament it basically stretches these muscle spindles that are going to be in your quadriceps muscle so by stretching these muscles spindles that are located right over here they're going to provoke in our autonomic regulation of the skeletal muscle length and by doing this the stimulus is going to stretch this reflex muscle and by stretching it this way you can see the arrow it's sort of going to trigger the contraction of the muscle okay so you don't really have to do about this you just have to or you don't want to really have to think about this it's just an automatic response so that's why it's called a stretch reflex* • now this type of stimulus is very brief but it does produce a contraction that we call it an unopposed contraction because there's really nothing that's going to be holding this muscle from actually provoking a contraction so by doing these physicians are testing to see if there is any type of injury to your spinal cord and if you're doing it in your patellar ligament they're actually testing to see if there's any damage between *l2 and l4* so you can do this stretch reflex in several areas of your body but the most common one is the patellar reflex that's done at the level of your need more specifically in your patellar ligament okay and you can see again that it's only one sensory neuron and one motor neuron

long head lateral head medial head

• the long head of the triceps brachii is the portion that crosses the shoulder joint and actually attaches to the scapula. • lateral head on the lateral side that does not cross the shoulder joint. • medial head which is visible in the next slide underneath this lateral head.the triceps brachii with the lateral head cut so you can see that deep to it is the medial head which is shorter and is mostly on the inferior portion of the humerus.

FOREARM: Muscle compartments

• the two interior compartments are split into superficial and deep these are both anterior to the ulna and the radius

lumbarsacral enlargement

• where the innervation is going to provide information from structures of the pelvis and the lower limbs.

filum terminale

•which is the structure right over here you can see it ends at the coccygeal ligament and basically it's this thermal thread of fibrous tissue that's going to extend all the way from the tip of the conus medullaris so right over here to your coccygeal region so it goes all the way down from here all the way down to your coccygeal region and it's called the filum terminale. basically what it's going to do is going to provide this *longitudinal support to the spinal cord and it's going to be part like I said of your coccygeal ligament.*

cervical enlargement

•which you can see how your spinal cord is a little bit more enlarged and in this area the nerves are going to supply information or take information from the pectoral girdle and the upper limbs .