Final Exam

NERVOUS TISSUE....

The nervous system is the body's control center, and communications network. - needed to maintain homeostasis

Conus Medullaris

end of spinal cord where it tapers off

4 Types

epithelial - cover and protect the body (creates order in body THINK: middle schoolers in lunch room on taco tuesday ... need specific lines / specific tables to make sense of the chaos) connective - provide support muscle - movement nervous - control and communication

What three organelles are necessary for protein synthesis?

nucleus, ribosomes, rough ER

How are tissues relevant to the definition of an organ?

the type of tissue defines the function of an organ

Ventricles

the ventricular system is a set of four interconnected cavities (ventricles) in the brain where the *CSF is produced*

Reticular Formation

web of grey matter running vertically through all levels of the brainstem functions*: - somatic motor control - cardiovascular control - pain modulation - sleep and conciousness - habituation ex) alarm clock going off: signals "wake up" BUT also HR/BP goes up and many other things simultaneously.

transcription

the DNA molecule unwinds, and an enzyme called RNA polymerase creates a complementary strand of RNA, using one of the strands of DNA as a template; afterwards, RNA is released and the DNA strand rejoins its complementary partner

How does the structure of the cell membrane depend on the chemistry of the phospholipids?

the amphiphilic molecules arrange themselves into a bilayer, with their *hydrophilic phosphate-containing heads facing the wate*r on each side of the membrane and their *hydrophobic tails directed twd the center*, avoiding water.

3. tentorium cerebelli

- shelf of dura - creates a covering to separate parts of the cerebellum from the cerebrum.

Articulations

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Bone Tissue

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Fissures

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Internal Anatomy of Spinal Cord

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Introduction

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LEARNING MODULE 2

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Endocrine Gland

(THINK HORMONE UNIT) lose their duct work and their secretion to the *blood* NOT the surface

2 Types of Bone

* based on texture * 1) *compact bones*: appear smooth and homogenous, densely packed bone. 2) *spongy (cancellous) bone*: composed of small spicules (trabeculae) of bone and a great deal of open space, where you find most of your bone marrow.

Pyramidal Pathways

*2 neurons in pathway* UMN / LMN 1st --> UMN: cell body in motor cortex pf pre

Muscle Metabolism

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Nervous Integration

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General Ft. of Epithilial

*Avascular* - no direct blood supply - blood vessels are in the underlying connective tissue layer - SO gets O2/nutrients w/ diffusion from connective tissue layer *Nerve supply* put higher up in epithelial so nerves sense pain RIGHT AWAY *high mitotic rate* constantly replenishing themselves bc of their location ex) stomach lining cells replenish ~ every 4 days bc under HIGH STRESS

Difference between rough and smooth ER

*Both* types of ER make phospholipids *rough ER* membrane proteins and secretory proteins are all produced on the ribosomes of the rough ER. *Smooth ER* also functions in detoxification, carbohydrate metabolism, storage of calcium ions

Draining CSF

*Draining CSF* - MUST drain CSF at same rate we produce it, too much CSF pressure in ventricular system means *intercranial pressure* so brain gets "squished out" - why brain tumors are SO BAD

Characteristics of Skeletal Muscles

*Excitability* - muscle cell membranes share this w/ nerve cell membranes - capable of conducting electrical messages ex) think muscle getting hit with taser, e- message goes out to entire body *contractibility* - can shorten / thicken *extensibility* - all can stretch NOT due to elastin fibers muscle cell ITSELF stretches

how does the Na-K pump work?

*Function:* removes 3 Na+ from the cell and inserts 2 K+ into cell *Purpose:* constantly removes Na so that Na and glucose inflow keeps going, keeps Na concentration higher and K concentration lower, regulate cell volume

STUDY STORY

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The Brain

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dense connective tissue 3 types

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Spinal Nerve Roots

*HOW ENTIRE SPINAL CORD IS SET UP* *Func. of spinal nerve roots*: For the spinal cord to perform its functions... sensory information needs to come in and motor information needs to go out *dorsal root ganglion*: - outside the CNS - cell bodies of *sensory neurons* - *dorsal roots*: the axons of neurons out of the ganglion into the dorsal horn *spinal nerve*: (look at slide)furthest outside CNS to the L of ^^ - inside are all the dendrites of sensory neurons for that segment served by that section of the spinal cord. ex) if we "clipped" these then the roots would lose all sensory information. *ventral roots*: - axons of *motor neurons* (going OUT of the ventral horns as roots) - cell bodies/dendrites are located in the ventral horns - roots go out and join w/ roots of the sensory information.

Vertebral Column Kids vs. Adults

*Kids*: - 31/32 vertebrae or cartilage models for vertebrae - 7 cervical, 12 thoracic, 5 lumbar AND - *5 sacral vertebrae / 2/3/4 coccyx vertebrae once adulthood is reached the sacral / coccyx vertebrae will file together *Adult* - 7 cervical, 12 thoracic, 5 lumbar atlas: "holds up the world" / brain axis: has process called odontoid, which the head can rotate around.

Simple Squamous

*Location* endothelium of all blood vessels, blood capillaries, endocardium (lines inside of heart), pericardium (membrane of heart), lymph capillaries. *function*: VERY THIN therefore allows diffusion/osmosis allowing RAPID transport.

skin

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2 Skin Cell Populations

*Population 1) Keratinocytes (90% of Cell Population)* - belong to the *keratinizing system*, the cells which are continually produced by cells at the deepest level of the epidermis and are pushed towards the surface. As the cells become more superficial they pass through a differentiation process known as *keratinization* that leaves the cells dead yet waterproof as they reach the outermost layer of the epidermis ^^ this "differentiation sequence leaves *5 distinct layers or strata* in the epidermis of thick skin, *4 distinct layers or strata* in the thin skin: *Population 2) Melanocytes*: - these cells comprise the *pigmentary system* - *cell type*: melanocytes, located interspersed along basement membrane with the cells of the stratum basal. - *function*: melanocytes produce the UV light absorbing pigment *melanin* and pass that pigment to the cells of the *stratum spinosum*, where the melanin is stored in this layers cells cytoplasms. Stores the melanin just above their nuclei so that the UV light si blocked from the cell DNA (light is a very powerful mutagen). As stratum spinosum cells are pushed towards the surface to become the subsequent layers the melanin is then distributed through the thickness of the epidermis.

Schematic of Sacromere

*Schematic of Sarcomere* *Iband*: actin present (light band) bc thin *Aband*: where myosin / actin overlap, light can't pass through *H-Zone*: myosin only

The Cranial Nerves

... STUDY - study face cartoon!!

Thin Myofilament

*actin - thin* - 2 strands (per side) twisted together into a double helix - on strand are *myosin binding sites* only open WHEN CONTRACTING ^^ *tropomyosin - troponin complex* - hinds binding sites when NOT CONTRACTING

adipose connective tissue

*adipose tissue* - *cell type*: adipoblast / adipocyte (as ^^ cells accumulate more fat from (+) nutrition they become more mature aka get bigger and bigger, these cells come from your *diet*. ^^ *in embryonic tissue these cells are far apart*, but in us these cells get larger and larger with the more calories that get stored as fat so that eventually they become "squished" together. - *function*: *energy storage*, (+) energy balance, body storing fat, (-) *energy balance* body can go back to these fat cells and take it out for E, *protection* from mechanical injury, *thermoregulation*, *used to pack organs in*. - *location*: underneath skin (protection, thermoregulation), heart, kidneys, eyes, etc all organs (all organs packed in this for protection).

dorsal midbrain

*all grey matter* Function: processes visual and auditory info - w/ *corpora quadrigemina*: think about visual / auditory reflexes (hearing / equilibrium reflexes) *still all unconcious / reflexive* EXAMPLES IN NOTES - boyscouts, 1 scout yells "dad" then all dads reflexively turn head towards direction of shouting child. - missing step on stairs instinctively throwing body backwards *cranial nerves* III / IV assoc w/ eyeball movements

Behavior of Whole Muscles

*all or none principle* *the force / tension of contraction dependent upon 4 factor:* 1) frequency of stimulation of muscle fibers by motion neurons 2) length of muscle fibers before they contract 3) numer of muscle fibers (motor units) contracting at any one time, structural components of the muscle itself

ventral midbrain

*all white mater*

areolar connective tissue

*areolar*: - matrix is loosely organized BECAUSE of the population of *wanderer cells* that are crawling through the tissue, WBC derived from the blood get out and escape into the loose connective tissue looking for dead, foreign, bad things in your connective tissue. This is why it MUST be loose, form follows function. - *cell type*: fibroblast (makes fibers continuously, highly mitotic) FIRST lies down ground substance THEN into that it lies down the fibers - *fiber type/function*: collagen fibers that are going in all directions (force is being put on fibers in all directions), elastin fibers (stained w/ *virhoff stain = black / purple* pulled in all directions, must stretch a little bit. - *location*: loose connective EVERYWHERE, surrounds every blood vessel, and it sits DEEP to the epithelial tissue.

Types of Receptors

*based on location in the body* *interoreceptors* (visceroreceptors): viscera *exteroreceptors*: skin, vision, etc *proprioreceptors*: every muscle you have *based on stimulus* mechanoreceptors thermoreceptors chemoreceptors photoreceptors nociceptors: specialized pain receptors baroreceptors: pressure

Principal Parts

*brainstem* (3 parts) - medulla - pons - midbrain sitting on top of this... *diencephalon* (3 parts) - thalamus - hypothalamus - epithalamus (on top of all this similar to a "mushroom cap") *cerebrum* - on top of the entire structure sitting behind this ... *cerebellum*

Features of the Neonatal Skull

*fontanel*: location where the bone hasn't yet joined / fuzed together THINK: of as a "fountain" if punctured then liquid would come out like a fountain. MAPS - mastoidal - anterior - poster - sphenoidal *2 Functions*: - allows head to change shape during birth while passing through birth canal - allows for rapid growth of the brain for the first years of life.

cartilage tissue (subtype of connective tissue)

*cartilage*: a relatively stiff connective tissue w/ a flexible, rubbery matrix. - *cell type*: chondroblasts --> secrete the matrix and surround themselves w/ it until they become trapped in cavities called *lacunae* once enclosed in lacunae they mature and become *chondrocytes* - *characteristics*: *avascular*, so nutrition and waste removal dependent upon diffusion through the stiff matrix, bc this is slow chondrocytes have a *slow metabolism rate / slow cell division rate* why injured cartilage takes forever to heal. - *how to distinguish different types (3)* Matrix is rich in glycosaminoglycans and *contains collagen fibers that range from invisibly fine to thick, differences in these fibers provides a basis for classifying cart.*

elastic connective tissue

*cell type*: fibroblast - *fiber type*: elastic fibers that branch freely, forming sheets or ligaments (LOOK FOR PURPLE BC V STAIN) - *function*:provides extensibility, elasticity to various organs that need to be stretched. - *location*: lungs, elastic arteries, trachea, bronchial tree, vocal cords, vertebral ligaments, suspensory ligaments (of the penis).

Cervical / Lumbar Enlargements

*cervical enlargement*: - between C4 and T1 larger bc of large upper extremity (more area) in need of higher nerve supply. *lumbar enlargement*: - between T9 and T12 (smaller than cervical but still large) bc of lower extremity (more area) in need of higher nerve supply. ^^ THORACIC bc remember stops at L2

Epithelial as a Barrier...

*closely packed cells* *zonula ocludens* tight junctions that are in a closely associated area of two cells whose membranes join together forming a barrier virtually impermeable to fluid *continuous sheet* *zonula adherans* protein complexes that occur at cell junctions in epithelial forming continuous sheers so that cells can *"talk"* to one another THINK: epithelial lining mouth becomes throat, esophagus, stomach, small intestine, etc ^^ all must communicate *apical vs. basal surface* apical: cell later exposed to the surface ex: stomach cells exposed to hydrochloric acid *basement membrane* (2 pts) prevents epith. tissue from "falling off" by holding cells onto the surface THINK PB & J *Part 1: basal lamina* made by epith. cells secrete it "down" *Part 2 reticular lamina* connective tissue, secretes it "up"

Synaptic Integration

*collective synapse* - filters information - integrates / interprets the situation ex) threshold: +3 excitatory: + 6 inhibitory: -4 = +2 going to post synaptic SO no AP it is the sum of what is happening at the synapse at any given time which determines what happens. *inhibitory neurons* THINK: further from threshold - bind to chem gated Cl- channels ex) what makes you not hear AC during lectures unless pointed out ADD: have problems w/ inhibitory neurons, people are more / too aware all the time. *excitatory neurons*: - bind to chem gated Na+ channels.

Protection and Coverings

*cranial bones* - well made skull, w/ plates of bone, fused together. - intact cavity w/ foramen for blood vessels - brain very well encased in this *meninges* - *dural sinuses* - dural extensions *dura mater* - unlike spinal cord NO fat pad, DIRECTLY attached to skull

Overall Spinal Cord Anatomy

*cylindrical*: flattened on anterior and posterior sides = oval shaped.

dense irregular

*dense irregular connective tissue* - *cell type*: fibroblast - *fiber type*: collagen fibers, randomly arranged. - *function*: provides strength, support, and protection - *location*: dense fascia, reticular dermis, perichondrium, periosteum, joint capsules, dura mater, membrane capsules, heart valves.

dense regular

*dense regular connective tissue* - *cell type: fibroblast - *fiber type*: collagen arranged parallel w/ squished nuclei (BC DENSELY PACKED MATRIX) - *location*: tendons, ligaments, achilles heel

Depolarization

*depolarization*: (+) ions flowing to inside of membrane - SAME TERM as action potential - carrying "all" can only carry this messsage Threshold Stimulus Voltage Gated Na+ channels: open at site of stimulus Na+ influx through channels (-70mV --> 30mV) Positive Feedback: - opens adjacent voltage gated Na+ channels - getting more and more ^^ *self-propagating system*

elastic cartilage

*elastic cartilage* - *characteristic fibers*: chondrocytes embedded in cartilage rich matrix rich in network of elastic fibers. - *function*: allows structure to be semi-rigid and extensible; structure can still return to resting shape. - *location*: epiglottis, external ear (can stretch / return easily), and auditory tubes. LOOKS LIKE HYALIN, EXCEPT DARK PURPLE ** has a higher mitotic rate THEREFORE grows continuously, why older people have large ears.

Titan

*elastic filaments* - once the muscle has contracted, pulls z lines of sarcomere back into place. - causes elasticity characteristic of muscle

Meninges / Spaces

*epidural space* space between bone of vertebrae and dural mater. - filled w/ adipose tissue aka good for shock absorption *dura mater* - first layer of meninges - the hard "tough mother" lots of collagen, very dense connective tissue *subdural space*: peel back dura mater *arachanoid membrane* middle meninges looks like spider web THINK: lab *subarachnoid space* - between arachnoid membrane and pia mater - filled w/ CSF, a water based fluid that encases the spinal cord. *pia mater*: - 3rd meninges - intimately attached to spinal cord, can't take it off - holds blood vessels directly to spinal cord surface

limbic system

*evol*: one of the earliest indications that a cerebrum was on its way *limbic system*: wrapped in / around the hypothalamus / thalamus smell passes right through cribriform plate of ethmoid bone to cranial cavity --> directly into limbic system (aka doesn't go to thalamus) - the "emotional brain": neurons associated w/ emotions, sex, rage, memory, and *smell (direct connection to smell)* this BC of memory + smell assocation ex) smelling hostess cinn cakes reminds me of childhood

fibrocartilage

*fibrocartilage* - *characteristic fibers*: scattered chondrocytes w/ hyaline cartilage matrix among bundles of collagen fibers, named for its *coarse readily visible bundles of collagen*. - *function*: provides support, fusion (between pubic bones and between vertebrae), absorbs shock in some joints, deepening of shoulder and knee joints. *resists both being compressed AND pulled apart* - *location*:pubic symphysis, intervertebral discs, and menisci of shoulders and knees. BLUE UNDER MICROSCOPE

Connective Tissue

*function* - supports the body - binds/connects its parts - mechanical framework for movement - stores materials (fluid and energy) ^^ due to the production by its cell types of intercullular deposits, nonliving fibers, and ground substance collectively called the *matrix* connective tissue in *the most widespread* tissue that we have in the body summary: bones, tendons, and cartilage bind, support, and protect your organs anf give you a skeleton so that you can *move w/ purpose*

cerebellum

*function* creates smooth motor movements, coordinates movements ^^ cerebellum "gets drunk"

Vertebral Column

*function* weight bearing portion, increases in size as you move down column bc more weight to bear (aka why lumbar vertebra bodies are SO much larger than cervical / thoracic) *3 Different Vertebrae Types and Distinguishing Feature* - *cervical*: transverse foreamen - *thoracic*: facets that articulate with rib tubercles. - *lumbar*: large body size *Major Features Common to ALL Vertebrae* - spinous process - transverse process (w/ or w/o rib facets) - vertebral foreamen - body *Spring Like Look to Vertebral Column* *fetal position* REF. IMAGE - start off in c-shaped position, brain at one end, spinal cord at the other. Still has this shape when first born. *Primary curves* - thoracic and sacral curves, still partially in originally c shape. *secondary curves* - cervical, lumbar curves brought on by *development* - more flexible -*"indentations" places you can place your hand into* *forming curves* *6/7/8 weeks*: baby starts to be able to pick up own head, now cervical vertebrae begin to need the other way forming c-shape. *6 months*: sit up / crawl, lumbar curve starts to bend *9 months - 1 yr*: walking

Receptors and Membrane Potentials

*generator potentials*: receptor cell is the same as end of dendrite (sensory neuron) - ALL skin senses work this way *receptor potentials*: theres a separate cell that receives the stimulus and releases neutron's to 2nd cell, receptor cell is DIFFERENT from sensory neuron. *1:1 Relationship* R12 attached to SN12 - when stimuli applied to receptor, it'll become directly depolarized as this gets closer to threshold IF strong enough AP in sensory neuron and that AP will go to CNS. *Amplitude of AP* - frequency of AP traveling towards CNS per s ex) 10 ap / s = kinda hot 100 ap / s = SUPER hot

glandular epithelia

*glands*: the glands of the body are derivative of epithelial tissue, most glands are going to retain a connection to that surface bc that is where they're putting their secretions.

Grey Matter

*grey matter* - nerve cell bodies , unlyelinated axons / dendritic zones *doral horns*: - every neuron associated w/ incoming sensory information is located here. *ventral horns*: - every neuron associated w/ outgoing motor information is located here. *lateral horns*: - house autonomic, motor neurons

multicellular gland

*has a duct* receives the secretion makes gastric juice and then goes out to cell *location* stomach

Naming Epithelial

*how* - how many layers - shape of the TOP layer (look at nucleus shape) *what to look for*: - uniform sheets of similar cells - closely packed cells w/ intercellular materials found in the spaces between the cells - absence of blood capillaries (avascular) simple (one layer) - sqamous - cuboidal - columnar - pseudostratified stratified - squamous (keratinized OR nonkeratinized) - cuboidal - columnar - transitional

hyaline cartilage

*hyaline cartilage*: -*characteristic fibers*: chondrocytes embedded in cartilage matrix rich in collagen fibers. Named for its clear, glassy appearance due to *invisibly fine collagen fibers*. - *function*: *resists compressive forces* (holds airways open during respirator), eases joint movement, a precursor of bone in the fetal skeleton and growth zones of long bones in children. - *location*: articular surfaces of bones, anterior ribs, nose, *

Tetany

*incomplete tetany*: - brain sending more signals faster and faster. - has a slight relaxation period between twitches (Look at graph on slides) think: holding up barbell at gym, and don't want to let it drop *complete tetany*: - brain sending more signals faster and faster but NO RELAXATION PERIOD. - real life: muscles can't handle this, so we never experience this in real life.

Difference between integral and peripheral proteins?

*integral proteins* penetrate the phospholipid bilayer *peripheral proteins* to not penetrate into the layer (but adhere to one face of the membrane instead.

Intervertebral Discs

*intervertebral discs* between EVERY vertebrae, made of fibrocartilage, divided into 2 parts (THINK JELLY DONUTS) *annulus fibrous (dough)* - round connective tissue, very collagenous THEREFORE holding 2 bones together and resisting being pulled apart *nucleus purposes (jelly)* - where hyaline cartilage sits, resists compression - some water squeezes out of cart throughout day, why you're slightly shorter at the end of the day than at the beginning - cartilage will rehydrate while you sleep, wake up taller. *ruptured disc*: dough breaks open, jelly spills out and goes straight to the vertebral canal and impends on spinal cord causing back pain, electrical pain to nerves.

Intro to Neurophysiology

*job*: communicate different parts of the body together. communication depends upon *2 basic properties of their cell membranes* 1) *RMP* e- voltage across the membrane 2) *ion channels*: neuronal cell membranes contain a variety of ion channels that may be open or closed.

epidermis

*keratinized squamous epithelium* sits upon prominent basement membrane that forms promenient layer between epidermis and dermis *avascular* cells depend upon diffusion gradient for metabolic support bc this process is slow and blood vessels are located in the dermis the superficial epidermal cells are dead. *keratinocytes* building blocks of tough protein keratin ^^ these are CONSTANTLY replenishing selves enough to *completely replace your epidermis every 4-6 weeks* *keratin* a water-proofing protein cells have accumulated and pushed to toe outside layers, keeps water / microorganisms from getting in / out.

Muscle Stretch

*length - tension relationship and muscle tone* muscle strength depends on how stretched or contracted ti is before it is stimulated too contracted = too much overlap of myofilaments too stretched = not enough overlap of myofilaments between extremes = *optimal resting length* allows for production of greatest force. *EXAMPLE*: - holding a barbell w/ biceps brachi fully extended, and asked to lift it will have MORE FORCE VS. holding a barbell with biceps half curled and asked to lift the same amount of weight. *EXAMPLE 2*: - when heart stretches more bc it takes in more blood, it pushes the blood back out to the rest of your body with GREATER FORCE.

Simple Columnar

*location* GI epithelium (mouth, esophagus, stomach, small / large intestines) *function*: secrete digestive juices/absorb nutrients ALSO in OV Ducts because they secrete nutrients for the egg as it makes its way down the uterus.

CPCE ciliated pseudostratified columnar epithelium

*location* respiratory passageways, some reproductive epithelium. *function* ciliated therefore in resp. epith., larynx to removee harmful particles / bacteria, also in lungs bc cilia moves mucus.

stratified transitional

*location* uterus, urinary bladder, female urethra *function* distention (enlargement) of organ to prevent increases in organ wall tension *apical cells will have a scalloped appearance when bladder is empty*

Nonkeratinized stratified squamous

*location* "wet" skin locations oral cavity, pharynx, esophagus, anus, vagina, etc. *function* protection from wear/tear

Keratinized Stratified Squamous

*location* skin (epidermis) *function*: barrier, protection from wear/tear

stratified cuboidal/columnar

*location*: some large ducts *function* protection

Simple Cuboidal

*location: tubules of nephrons (functional units in kidneys), secretory portion of some glands, ducts of most glands *function* modifies secretion SO used in places where that is a worry AKA kidneys.

CSF and Protection

*mechanical protection*: - water doesn't compress - shock absorption ex) when car hits tree, brain "sloshes" around hitting skull = lots of brain damage if CSF wasn't there. *chemical protection*: - pristine environment for neurons (neuronal signaling)

Typical Spinal Nerves

*mixed* bc sensory and motor component *3 layers of conn. tissue to insulate fibers* *endoneurium* - covered individual nerve fibers - allows NS to process SPECIFIC information, bc nerve fiber will carry an AP and not affect neighboring neurons. - provides INSULATION *perineruium* covers fascicles *epineurium* - covers spinal nerve

Functions of Skeletal Muscle

*motion* *stabilizing body position* - maintaining posture - hold still while contracting *regulating organ volumes* - stretching smooth muscle is going to set off a reflex (urinary bladder stretching = time to PEE) *thermogenesis* - shivering when cold

Functions of the Skeletal System

*movement* *support* - supports soft tissue - basis for external body *protection* - houses the brain - thoracic cage *hematopiesis* blood cell formation *mineral homeostasis* inside the bone, a repository for minerals, the bone matrix Ca, , and carbonates, etc that the body can store when times are good and tap into when times are bad. *energy storage* most of your bone marrow is fat

Structural Classification of Neurons

*multipolar* - basic neuron - *efferent*: away from CNS - *motor neurons: going out to make something happen *bipolar* - 2 poles - *association neurons* : multipolar neurons and bipolar neurons in special senses pathway (basic 5 SPECIAL senses sight, touch, smell) *unipolar* "t-shaped" - *central process* has axon that comes off the middle - *sensory* (afferent)* neurons all have a *receptor* at the end of dendrite sensing hot, cold, pain, tickle, etc. THINK: barney wears a "uniform" bc he suits up to hide his deep emotional SENSING side

Muscle Tone

*muscle tone* a state of partial contraction of a resting skeletal muscle, a few motor units are contracting while all the others are at rest. *produces muscle firmness* w/o producing muscle movement *non worker outer*: - low state of readiness - less muscle units are turned on - muscle less firm ex) on your muscle you have 18 motor units, 3 are contracting completely other 15 are relaxing this means that your muscle isn't contracting with maximal force but partial force. *worker outer*: - *high state of readiness* - more muscle units are turned on - makes muscle firmer ex) on your muscle 18 motor units, 6 are contracting completely, *Purpose of Going to Gym not to burn calroies with cardio BUT to gain muscle BC* ^^ why people with higher muscle tone burn more calories at rest bc utilizing more ATP to make cross bridges *Muscle Tone Functions*: - manages posture (always have to have some motor units contracting) otherwise you'd fall over - state of readiness

Saltatory Conduction

*myelinated membrane* therefore only have to depolarize at nodes of ranvier - HUGE energy conservation - fast 130 m/s PROBLEM: how can neuron kick out K+ and bring in Na+ ... it can't past all the myelin. SO *nodes of ranvier*: small gaps in myelin w/ a (-) charge - Na+ is attracted to these (-) charged spaces - within nodes of ranvier are the voltage gated na/k+ channels, and Na-K pumps so when voltage threshold stimulus applied it can reach all of these.

Thick Myofilament

*myosin - thick* - shaft with filamentous tail - globular head (golf-club shape) that binds to actin w/ head portion.

White Matter

*white matter* - myelinated axons, how we communicate. ascending / descending tracts

Structural Classification of Joints

... aka what kinds of material binds these bones together

Smooth Muscle

*non-striated* bc no sarcomeres *involuntary* *can be stimulated/inhibited by nervous and endocrine systems* found in the walls of hollow organs *2 Types* *visceral* - membranes are excitable and touching w/ many gap junctions to move things forwards (think digestion) *multi-unit* - ind. cells instead of one message that sweeps the whole thing, they get their own message (ind cells) - gets own branch of the nervous system - skin, w/ piece of hair sticking out of it = one multiunit , each piece of hair has their own multiunit

Levels of Sensations

*not necessarily conscious* *sensation*: having a receptor to get a stimulus and send information to CNS. - *spinal cord / brainstem*: solely sensations, reflex only *perception*: becoming aware / conscious of stimulus - *thalamus*: crude perception - *cerebrum (cerebral cortex)*: precise perception *Receptors / Sensory Modality*: - receptors are VERY specific, what is the particular thing that the receptor responds to. ex) receptor JUST FOR: heat, cold, deep touch, light, etc.

Making Myelin

*oligodendrocytes* - uses processes to wrap around axon - if axon dies then neuron doesn't know where to grow back. *schwann cells* - whole cell itself becomes the myelin SO if axon dies, stays in place so neuron knows where to grow back.

2 Layers to Dermis

*papillary demis* - the most superficial layer lying adjacent to the epidermis the *dermal papillae* project upwards into the epidermis (reflected in our fingertips, help us grip onto surfaces) *tissue type* loose areolar connective tissue, and elastic connective tissue *function* within papillae are specialized sensory receptors for pain and touch as well as looped capillaries that supply nutrients to the epidermis *reticular dermis* makes up 80% of dermis deep to papillary dermis *tissue type* dense irregular connective tissue w large collagen fibers and thin elastin fibers *function* contains many arteries and veins, the sweat and sebaceous glands of the skin, and nervous receptors for deep touch, pressure, and temperature.

Immediate Energy

*phosphagen system* (10-12 seconds)

Epithelial Types

*proper:* cover and line inner and outer body surfaces so it's EVERYWHERE *glandular:* forms your glands and secretes hormones / other substances

reticular connective tissue

*reticular connective tissue* - *cell type*: fibroblasts and lymphocytes - *fibertype*: very short collagen fibers arranged randomly to form a scaffolding around which the rest of the organ is built. ^^ this infrastructure is known as the *stroma* of an organ. - *function*: builds the framework of organs IN PARTICULAR (lymph nodes, spleen, liver)

Neuronal Circuits

*simple series* *diverging* - nerve impulse from a single pre synaptic neuron causes stimulation of increasing numbers of cells along the circuit THINK: telephone game, 1 piece of information ending up in MULTIPLE different places *converging* - lots of info taking to 1 common place *riverbeating* - echoing series if all threshold then circuit never stops flowing ex) long term memory - how I can remmeber that scrappy was my first pet still. *parallel circuits* - redundancy, multiple circuits that do the same job so you can lose neurons and not die. ex) breathing uses parallel circuits

Post Synaptic Potentials

*spatial* - more than one neuron talking to post synaptic neuron - neural effects of 1+2 happen at the same time and you get an AP bc threshold was met. *temproal* - 1 neuron talking to postsynaptic neuron and is sending out sub threshold stem BUT if the *rate of firing* is so fast the sub threshold stimuli can (+) together to get threshold. *Net effects of postsynaptic potentials* 1. facilitation 2. summation (AP) 3. inhibition (hyper polarization)

Components of a Sensation

*stimulation* *transduction*: relating information from receptor to nerve fiber (sensory neuron) *conduction*: process of carrying AP to CNS *translation (interpretation)*: in the CNS at synapse between neuron / associative neuron

Cardiac Muscle

*striated* *involuntary* ex) heartbeat controls its own beat *can be stimulated/inhibited by nervous and endocrine system* *cardiac muscle cells* *continuity of cardiac muscle cells due to...* *functional synctium* (ind. cells working as one unit, why they can all contract at same time to get ex: heartbeat) *intercalated discs* = gap junctions, where membranes of two cardiac muscle contact one another *one nucleus* centrally located

Features of Skeletal Muscle (3)

*striated*: light and dark bands due to myofilament arrangement *voluntary*: under conscious control *can only be stimulated by the nervous system* MUST have a branch of the nervous system, or it won't work at all. - we can only stimul w/ a *threshold stimulus* *multinucleated* have multiple just underneath sarcolemma, nuclei are pushed to the *periphery* *skeletal muscle cells size* - formed of relatively long *cylindrical* cells. HOWEVER, cells of some of the larger harder-working muscles may be up to 25cm in length (brain to leg) and can be seen w/the naked eye

What determines range of motion

*structure/shape of articulating bones* - tightness of fit between articulating surfaces *strength / tension of the joint ligaments* - positions of ligaments, muscles, and tendons around the surrounding joints *appositon of soft parts* ex) bodybuilder range of motion limited bc so much muscle around joints *hormones* (relaxin) - causes joints to release in tightness ex) pelvis

Sarcomere Overview

*the functional unit, core of how our muscles contract*

Hypodermis

*tissue type* loose connective, adipose *function* provides insulation from heat loss, protection from mech. injury, provides routes for blood vessels and nerve passages.

Protection and Coverings of Spinal Cord

*vertebral canal*: protects spinal cord, all 26 vertebral foramen *meninges*: coverings of the spinal cord, inside the vertrbral canal, 3 layers of connective tissue. *CSF*: water based fluid AKA spinal cord v. well protected w/ these layers: - bone - conn. tissue - fluid

positive feedback

*why likely to disturb homeostasis* a self-amplifying cycle in which a physiological change leads to even greater change in the same direction rather than producing the corrective effects of negative feedback. ex) birth, labor contractions, etc can often be *harmful* or even *life-threatening* bc this self-amplifying nature can quickly change the homeostatic set point.

Neuromuscular Junction

- *Synapse*: the point where a nerve fiber meets any target cells. - *Neuromuscular Junction / Motor End Plate:* when that target cell is a muscle fiber - *axon terminal*: at the end of each nerve fiber it ends in a a "bulbous" swelling called the axon terminal synaptic cleft - *synaptic cleft*: separates the axon terminal from the muscle fiber - *synaptic vesicles*: within the cleft are vesicles filled with Ach (one of many neurotransmitters) - *ACh Receptors*: to respond to Ach these receptors are located at each synapse (~ 50 million), sit at the motor end plate and recognize large amounts of Ach in axon terminal wanting to diffuse - why contains junctional folds to increase surface area to allow more Ach receptors

Sebaceous Glands

- *function*: keep hair pliable and to assist in waterproofing the skin - *location*: epithelial tissue, associated w/ hair follicles - glands produce oily *sebum* moves into hair follicle canal where it spreads and makes hair appear oily. - sebum + sweat = *acid mantle*, an antimicrobial layer covering the epidermis.

Gross anatomy of long bone

- *the epiphysis*: the head of the long bone, located at the proximal / distal ends. Each epiphysis is formed by an outer shell of compact bone that is covered in life by: - *articular cartilage*: hyaline cartilage (bc hyaline cartilage resists *compression* no bone grinding on bone.) - *medullary spaces*: within the epiphysis is spongy bone forming med. spaces, that contain *red bone marrow* responsible for blood cell formation. - *the diaphysis (bone shaft): extends from each epiphysis towards the middle of the bone. Made of a shell of compact bone surrounding the medullary cavity. - *medullary cavity*: this cavity contains *yellow bone marrow (adipose tissue)* in the adult. - *the metaphysis (epiphyseal line)*: area where epiphysis meets the diaphysis . Represents the point in growth of the long bone where the *epiphyseal growth plate of cartilage* was finally overtaken by bone tissue during endochrondral ossification . - *periosteum*: covers the bone, EXCEPT for where the art. cart. is present, divided into 2 layers: 1) *osteogenic periosteum*: - the innermost layer of the of the periosteum lies DIRECTLY on the bone matrix, consisting of the osteoprognitor cells (bone lining cell) , cells are quiescent until bone repair needed. 2) *fibrous periosteum*: - outermost layer ("sock" to the bone) - made of *dense irregular connective tissue* - where skeletal muscles attach to bones (why tendons don't detach from bones) - provides routes for blood vessels and nerves that penetrate the bone. *endosteum*: lines the medullary cavity and spaces. A single layer of osteoprogenitor cells that function like those of the osteogenic periosteum.

Diarthrosis

- ALL of our synovial joints freely movable - knee / elbow joints mostly - mostly found in limbs

Functional Classification

... how much that joint will move

REVIEW MOVEMENTS ALLOWED AT DIARTHROSIS (SYNOVIAL JOINTS)

....

Synovial Joint

- TYPICAL JOINT - freely moveable, bones held together w/ a joint cavity *Parts to a Synovial Joint* *synovial joint cavity*: - continuous w/ periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones articulating surfaces.

Dural Sinuses

- These are the cavities formed when the two layers of the dura mater separate in the cranium - These cavities are blood-filled - a veinous drainage system for bloodflow to brain itself

Asynchronous Firing

- same (3/16) motor units aren't continuously firing , they fire *asynchronously* - this is why you don't get tired quickly - controlled by *nervous system* ex) use *cerebellum*, has it all under control unconsciously and uses this asynchronous firing of motor units = same level of tone, just different muscle cells.

longitudinal fissure

- sep L/ R hempishpheres - connected w/ corpus callosum

Fibrous Joint

- bones held together w/ ligaments / fibrous connective tissue VERY TIGHT ex) - sutures

Gray Commissure

- bridges across the spinal cord, axons of neurons that cross over to the other side - how we communicate the L / R sides of the brain together.

Denticulate Ligaments (of pia mater)

- come off of pia and pierce out through the arachnoid / dura and attach all the way down the spinal cord. at the very end is the *filum terminale* which goes all the way down the v. canal to the inside of the coccyx where it anchors the end of the spinal cord down.

The skeletal system

- consists fo bony AND cartilaginous framework of the body, 50% bone (dead, mineral component) 50% cartilaginous (organic, water based, lots of blood supply)

Spinal Cord

- continuous w/ the brain - mediates spinal reflexes - site of nervous integration (contains synapses) - provides pathways to and from the brain *gray matter*: gives rise to motor neurons, receives sensory information, mediates spinal reflexes. *white matter*: provides pathways to and from the brain - ascending - descending

Dermatomes

- each band of skin associated w/ specific segment of spinal cord "bands all the way down the body" THINK: make 6 with fingers, associated w/ C6 EXCEPTION: skin of face / top of head innervated w/ C5 ALL other parts of skin innervated w/ SN's.

The Flexor (Withdrawal) Reflex

- have to contract lots of muscles to get body away from the source of pain (SO need association neurons) ex) stubbing toe on nail Pain = associated w/ a single sensory neuron correlated to single, appropriate section of spinal cord w/ appropriate spinal nerve. sensory neuron enters ^^, then diverges to appropriate association neurons, extends / descends to turn on more flexors in other parts of spinal cord reciprocal innervation goes to association neurons to turn on extensors (agonistic to flexors) THEN one of association neurons sends message to brain of PAIN. VOCAB *intersegmental*: multiple segments of spinal cord involved *polysynaptic*: multiple synapses. *ipsilateral*: same side *reciprocal innervation*

31 Segments of Spinal Cord

- have to look at nerve roots to count - each functional segment of spinal cord gives rise to a pair of spinal nerves (31 pairs)

Cartilaginous

- held directly together w/ cartilage ex) - costal cartilage (ribs) - pubic symphysis - intervertebral discs

Central Canal

- in the center of the gray commissure - part of the ventricular system (the set of 4 interconnected cavities or ventricles in the brain, where the CSF is produced)

Ampiarthroses

- joints move slightly THINK: amphibian can live on land or in the water pubic symphysis

serous membrane

- lines a body cavity that doesn't open directly to the exterior (thoracic or abdominal cavities) and covers the organs contained within that cavity. - has underlying layer of areolar connective tissue covered by mesothelium (simple squamous epith.) which secretes serous fluid allowing organs ot glide easily over another and against body cavities.

mucous membrane

- lines a body cavity that opens directly into the exterior - consists of a layer of epithelial lining and an underlying layer of connective tissue

Characteristics of connective tissue

- more than one cell type per tissue - matrix within intercellular spaces - proportionally more matrix than cells (OPPOSITE of "knit together") cells are scattered and what is *between* these cells determine the character of the tissue (matrix materials) - a blood supply

Scapula

- no bony attachments to axial skeleton - glenohumeral joint *function*: attach the upper arm to the thorax, or trunk of the body. This connection stabilizes the arm and provides for arm movement at the shoulder. - NOT very stable therefore allows a wide range of movements - has no bony attachment to actual skeleton is FREE HANGING on back of you, hanging by muscles (rotator cuff muscles --> coming off rib cage go over to invest the shoulder joint, scapula hangs there w/ no attachment

Synarthroses

- non-moving joints aka suture joints

transverse fissure

- separates cerebellum from cerebrum

lateral fissure

- separates temporal lobe from rest of cerebrum

Stretch Reflex

- the simplest reflex in the body - every motor unit in the body has an embedded *muscle spindle* *muscle spindle* - receptor inside the motor unit which constantly measures how stretches your motor unit is ^^ senses change in stretch SO needs to contract (extend) you'll kick. - every motor unit has an association w/ a spindle a *sensory neuron*, constantly feeding information back to the CNS - used to maintain *muscle tone* (optimum contractions) ex) *striking knee w/ hammer* - AP goes down a sensory pathway to motor neuron in corresponding section of spinal cord, new AP created at motor neuron and travels down efferent pathway and creates a contraction = knee flexion. ALSO AT THIS SYNAPSE *reciprocal innervation* - inhibitory neurons turned on, goes to different motor neurons in the same corresponding spinal section which turns on *antagonistic flexion* of the hamstring. At the motor neuron it releases inhibitory neurot's to hyper polarize the motor neuron for hamstring = no AP = no contraction. VOCAB *segmental*: only need ONE segment of spinal cord *monosynaptic*: one synapse, 2 neurons (1 sensory, 1 motor) *muscle spindle* *Ipsilateral*: same side of the body *Reciprocal Innervation* (inhibition) - ensures we counteract stretch w/ agonist - ensures we don't accidentally contract agonist to muscle that we want.

Essential Functions of the Nervous System

- to maintain *homeostasis* - senses changes in the internal / external environment - integrates / interprets incoming sensory information - responds if necessary to environmental changes SO how do various components of the nervous system cooperate in performing these functions? *fibers* bringing this information into the CNS to interpret / integrate it.

Transverse Tubules ASK

- tunnel like inholdings of the sarcolemma

Sarcoplasmic Reticulum ASK

- wraps up myofibrils (invests / surrounds) - stores Ca+ - voltage gated Ca+ channels (uses ATP to pump against concentration gradient / to fill tube w/ Ca+) - carries electricity (only the nervous system can stimulate e- impulses)

Nerve - Muscle Relationship

1 motor neuron + ALL the muscle cells it innervates = *1 motor unit* *levels of innervation* - all 650 muscles have different levels *gross motor movement* want motor unit to be LARGE (gluteus maximus) *fine motor movement* want motor unit to be SMALL (writing w/ a pen) *What is Recruitment?* - the brain function of "you need more motor units to get the job done" ex) think you're picking up a box full of books so recruit LOTS OF motor units, but then realize that you only need to recruit very few because the box is empty.

3 Basic Elements to Connective Tissue

1) *amorphous ground substance* - connective tissue cells are first going to lie down this *water based interstitial fluid* that is the ground substance not which we are going to put everything else. - cells then add in specific *hyaluronic acid* to give this water based fluid some consistency (think adding jello packet to water) this begins to *glue things together,* responsible for the strength and function associated with a particular connective tissue. 2) *fibers* *collagen*: - has high tensile strength, withstand being pulled apart along its long axis. - is very fragile when force is going perpendicular to long axis. *elastin* - adds extensibility (stretches) / elasticity (recoils) - where: skin / lungs - UV light breaks elastin fibers. *reticular fibers* - a specialized form of collagen, gives support to individual cells; forms the *framework* of organs; binds together smooth muscle cells. - makes the branching framework (stroma) ex) when building an organ (spleen), you first lay down the framework or the reticular fibers, like building a house, lie foundation down first. 3) *specific chemicals*(bone, cartilage, etc) *Matrix = all 3 put together*

Sudiferous sweat glands 2 Types

1) *eccrine* - simple, tubular structure that have coulee basal secretory portion deep in the dermis and a single tube that leads from it to the surface of the epidermis, opening is a *pore*. - *function*: correlated w/ a tremendous blood supply to its locations allowing for efficient *heat removal from the body*. - *location*: all over the skin - *eccrine glands stimuli*: all produce same secretion, BUT location of glands that secrete vary depending on stimuli: *emotional*: palm glands *physical*: forehead, neck, back, and trunk. ^^ *bacteria action on this sweat is what causes BO* 2) *apocrine* - no role in thermoregulation - larger glands whose secretory portions are located in the *hypodermis* but who's ducts empty out onto a *hair follicle canal* - *location*: axillary (armpit) region, external ear canal, and within the nasal passages. ^^ main contributor to *human odor* different than *BO* bc human odor is induced by emotional factors.

3 Broad Functions of Nervous System

1) *senses changes in the environment (internal / external) has special *receptors* in specific places measuring that "thing" - internal: BP, O2 levels, CO2 levels, etc - external: heat, tickle, light / deep touch, etc. *integrates / interprets* "someone knows" somewhere in body *responds* if necessary it'll send a message back out somewhere to get a response. ex) nerve signal says, "touching hot stove" so you remove your hand. ^^ the response is in your skeletal/smooth/cardiac muscles OR secretion from glands.

Organization Levels

1) *whole muscle* - a contractile organ, usually attached to bones by way of long tendons. 2) *Epimysium*: - all combined deep = deep fascia 3) *Muscle Group*: - bundle of fascicles 4) *Fasicle*: - perimysium - bundle of myofibers (muscle cells) 5) *myofibers* (muscle cells) - sacrolemma - sarcoplasm - wrapped in endomysium 6) *myofibril* - all the combined sarcomeres 7) *myofilaments* - thin : actin - thick : myosin ** make up the sarcomere REFERENCE HANDOUT FOR VISUAL

Hypothalamus

1/5 diencephalon all gray matter paired nuclei: organized by different homeostatic function function: - homeostasis = hypothalamus - controls the *pituitary gland* --> master endocrine gland senses: appetite, thirst, temperature, sleep, fight / flight, anger, sex- drive, etc.

Essential Functions of the Spinal Cord

2 essential functions - *white matter function:*get info from PNS to CNS so brain knows what is happening - *gray matter function:* mediate spinal reflexes (integrates information)

Pain

2 types of *nociceptors* *fast*: sharp pain *slow* dull pain

Spinal Nerves

31 pairs *spinal canal emergence* w/ ventral / dorsal roots distribution: 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal *differential growth*

Thalamus

4/5 diencephalon 100% grey matter *function* - every sensory nerve *except smell* goes here before cerebrum - simple (crude) consciousness *relay station* (grand central station) lots of information going in / out *crude perception* - period of time when you're first awake ex) MOSQUITO feel something on you and JUST after that you have a precise perception to look at where it is and smack it.

Parts to a Synovial Joint (ASK)

6 special features - articular cartilage that covers the opposing bony surfaces - bandlike ligaments a joint cavity - fluid filled THINK between tibia and femur (knee) synovial fluid lubricant - viscous egg-white fluid, acts like "grease on a hinge" - fibrous joint capsule sensory nerve fibers and blood vessels *synovial joint cavity*: - continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulating surfaces. *articulating cartilage*: - the smooth, white tissue that covers the ends of bones where they come together to form joints. ^^ can be damaged w/ injury or normal wear and tear. PARTS *articular capsule*: - an envelope surrounding a synovial joint. Each joint capsule has two parts 1) *outer - fibrous* - composed of white fibrous tissue - has collagen therefore this fibrous portion prevents the bone from being pulled apart. 2) *Inner - Synovial Membrane*: - a secreting layer *synoviocytes* - secrete synovial fluid SO the joint cavity becomes filled w/ this fluid. - has a lubricating function *THINK:* when you crack your knuckles, this is the fluid that is being released from changes in the bone shape. Gets released in a gaseous state = popping sound.

Epithalamus

AKA PINEAL GLAND function: - used to be able to sense light / dark (biorhythms) - sleep / wake cycles - DIRECT connection to eyes THIS IS BC used to be close to thin skull before cerebrum developed. last part of diencephalon ex) - how do bears know its time to hibernate (biorhythms) they're measuring the daylight/dark cycles.

cerebral nuclei

AKA basal ganglia control of semi-voluntary movements and muscle tone *once learned movements* --> semi-voluntary - catching a ball - driving a car - walking as we learn these voluntary movements we're "programming" the cerebral nuclei so that things become *semivoluntary*

The Reflex Arc

ALL reflexes have these to keep within homeostasis... STEPS: *receptor* 1) receptors in reflex arc are sensory neurons associated w/ a receptor device (transducer) and which relay nerve impulses to a central control center *sensory neuron* 2) sensory (afferent) neuron: if stimulus is threshold, membrane will depolarize traveling along the sensory nerve to the cell body --> 3) *integration center(s)* w/ association neurons axon into dorsal root ganglion, --> dorsal roots --> into the spinal cord through the dorsal horn. *synapse / integration center*: - synapses between sensory and motor nerve is the integration center, or the *collective synapse* (ss #1, ADD example diagram) at collective synapse either a summation or inhibition will occur depending on threshold. 4) *motor neuron* AP coming out of integration center --> axon --> ventral roots --> rejoin spinal nerve --> 5) out to effector (skeletal musc. motor unit in this case) THEN motor unit will contract or does something to try to counteract the environmental change and maintain homeostasis.

Nervous System Main Division

CNS - brain / spinal cord - takes in sensory information (integrates / interprets) PNS - everything else - connected w/ nerves ^^ 12 cranial pairs, 31 spinal pairs - receptors take info from CNS and sends it out to response units.

CSF Flow Pattern / Removal

CSF: makes ultra-filtrated blood (amber-colored) 1) CSF secreted into choroid plexus in each lateral ventricle 2) CSF flows through interventricular foramina into third ventricle. 3) choroid plexus in third ventricle adds more CSF 4) CSF flows down cerebral aqueduct to fourth ventricle 5) choroid plexus in fourth ventricle adds more CSF 6) CSF flows out of two lateral apertures and one median aperture 7) CSF fills subarachanoid space and bathes external surfaces of the brain and spinal cord. 8) at arachnoid villi, CSF is reabsorbed into venous blood of dural veinous sinuses. SUMMARY: CSF made in ventricles (I, II, III) THEN circulates CSF flows through aperatures (an opening in each lateral extremity of the lateral recess of the fourth ventricle of the human brain). FROm ventricle 4 into subarachnoid space into central canal to surround the brain / spinal cord. *Flow Pattern*: - ventricle 1,2,3,4 --> through arachnoid villi --> to the OUTSIDE *CSF Water Based Importance* - CSF barrier (chem barrier) - shock absorption - drainage LOOK AT HANDOUT

Animal Cells

Centrioles, lysosomes.

Wave Summation

DONT FULLY RELAX if a SECOND STIMULUS is applied to a muscle cell AFTER the refractory period but BEFORE the contraction is over: - muscle will respond to both the first and second stimuli, this additive effect is known as *wave summation* - when successive stimuli are applied to a muscle cell so quickly that the muscle can relax only partially between stimuli, the process of wave summation is said to have given rise to *incomplete tenany* ** this process is important in normal human physiology because most skeletal muscles actions are the result of short-term titanic contractions rather than s series of simple twitches THEREFORE the body movements are *smooth, sequential, and sustained rather than jerky.*

Treppe Contractions

FULLY RELAX BETWEEN CONTRACTIONS ^^ this allows for better / more forceful contractions

Spinal Cord Length

Foramen magnum to L2 (belly button) *differential growth*: - vertebral column outgrows spinal cord ^^ bc nerve tissue (spinal cord) stops growing early in life BUT vertebral column (bone) continues to grow until you reach adulthood.

Isotonic and Isometric Contractions

Isotonic: length of muscle can change, but force stays the same OPPOSITE = Isometric aka "same length": length stays the same, force changes think: doing a plank

Clavicle

Joints: - sternoclavicular - acromioclavicular *function*: - major strut, a structural component designed to resist longitudinal compression, braces the shoulder, keeping the upper limb away from the midline of the body. - transfers force from the arm to the axial skeleton region of the body ( like when doing push ups)

Adoption of Receptors

Most occurs at receptor level, but further adoption occurs at central processing.

Hierarchy of Human Structure

Organ system --> organ --> tissues --> tissues --> cells --> organelles --> molecules --> atoms

The Crossed Extensor Reflex

PREWIRED TO OCCUR at the same time the withdrawal reflex is occurring, the crossed extensor reflex is occurring. step on something so you pick foot up, OTHER leg must be balancing your body. L side of reflex ( literally same as flexor withdrawlal reflex) - excitatory flexors are turned on BUT THEN R side now needed for balance - inhibition extensors are turned on ^ Rec. Innervation to other side for Balance: - excitatory (flexor) neurons cross the grey commissure to the other side / go down a segment turn on extensor motor neurons on other side = extension of opposite side. VOCAB intersegmental polysynaptic *contralateral*: information came in on one side of the body BUT it;s going to affect the other side.

What is a Relfex

Reflexes are... - inborn - unlearned - unconscious *somatic* associated w/ skeletal muscles and movement. *visceral* run our organs ex) stomach churning, BP reflexes, urinal reflexes, etc.

Voltage Gated Ion Channels

Situation : 14x more Na+ outside than inside but can't flow in BC gate closed SO how to open gate??? - receptors respond to voltage - e- amount to open gate must be *threshold*

Chemically Gated Ion Gates

Situation : 14x more Na+ outside than inside but can't flow in BC gate closed SO how to open gate??? ex) chem Ach in this case - Ach receptors open gate when ach binds to receptors and changes shape of gate, Na+ ions are now flowing inside the cell = ELECTRICITY

Superficial / Deep Fascia

Superficial: hypodermis - "fatty layer around country ham deep: all the epimysium

Accessory Ligaments

THINK KNEE JOINT - separate (extra) ligaments or parts of the joint capsule, often just *thickenings* of the local dense regular connective tissue. - they are made up of bundles of *dense regular connective tissue* which are highly adapted for resisting strain. ^^ this prevents extreme movements that may damage the joint. *2 Types* *extracapsular*: connects one bone to the another, goes outside the capsule *intracapsular*: inside the capsule, to reinforce the joint ex) ACL

Bursae

THINK: *bu*rsae ... *bu*bble wrap little pads of synovial membrane stuck in areas of friction aka EVERYWHERE *interpaterallar bursar*: right underneath the patella, need bc of all the friction that goes towards knee. *bursitis* - overuse injury, too much friction going to bursae

Twitch Contractions

THINK: AP bell curve *Threshold Stimulus*: (if met) every sarcomere contracts fully and completely in the muscle cell for the existing condition. *Subthreshold*: - any stimulus less than threshold, can cause changes in muscle cell membrane BUT it won't cause a contraction. *Simple Twitch*: - a single threshold stimulus applied to a skeletal muscle 1) *latent period*: - period of time between the application of the stimulus and the beginning of actual contraction - during this time the electrical and chemical events that initiate the sliding filament mechanism are occurring. 2) *contraction period*: - there is actual shortening of the muscle cell such that force is generated 3) *relaxation period*: - during this time calcium is being removed from the sarcoplasm, actin and myosin are uncoupling, and the myofilamenvs are sliding back into resting position. *refractory period*: once the muscle cell is stimulated enough to contract, it briefly loses its ability to respond to additional stimuli.

5 Layers of Epidermis

THINK: can lucy get some beer? LOOK AT HANDOUT 1) *stratum basale*: - single layer of cuboidal to columnar cells located directly upon the basement membrane - high mitosis rate(closest to dermis) forcing cells to move towards surface. - makes *keratinocyte stem cells, melanocytes, and merkel cells*. 2) *stratum spinosum*: - 8-10 layers of polygonal (spiny looking cells) derived from *keraetinocytes* from basal layer. - layer that receives melanin from basal layer and uses it as a shield for the nuclei. 3) *statum granulsum*: - 3-5 layers of flattened cells whose nuclei are degenerating and whose cytoplasm contains granules of *keratohyalin* (precursor to making keratin), making the cytoplasm appear grainy. 4) *stratum lucidum (thick skin only): - 3 or 4 layers of almost transparent cells who have no nuclei and w/ indistinct membranes. - cells are packed w/ *eledin* a semifluid differentiated form of *keratohyalin*. 5) *startum cornem* - 25-30 layers of clear, flat dead cells. The contains *keratin*, the hardened waterproof final product of the keratinization process. - the most superficial layers of this stratum are continually shed w/ *exfoliation*

Osteogenesis

The process of building bone, in this process there are *3 different cell types* that are continuations of one another: 1) *osteoprogenator cells (bone lining cells):* - the "babies" of the system, long, thin, squamous cells SO cover a large SA / all of the bone surfaces. - they are quiescent UNTIL bone gets broken and needs to be repaired, therefore must become an osteoblast (teenage bc need mitosis to occur) 2) *osteoblast*: -"teenager" cells, mitosis RAPID, cells that make the bone. - also start to make / fill in bone matrix, now osteoblasts are pushed apart and entombed in own bone matrix SO mitosis starts to slow down becomes... 3) *osteocyte*: - once bone is made, osteoblasts mature into osteocytes the "Adults"

Plant Cells

Vacuoles, chloroplasts, cell wall

Repolarization

Voltage gated K+ channels open - same as Na+ just slightly slower - repolarization *chases* depolarization K+ efflux from cell (+30 --> -90mV) ^^ *Hyperpolarization* occurs bc passes -70 and goes to -90. - now it is HARDER to get an AP, therefore is less likely to give off an impulse. Na-K pumps restore ions to their proper places - used to "fix" levels after de/re polarization - another channel - anytime 3 Na noticed inside the cell uses 1 ATP to change shape of Na-K pump to kick them back out, same w/ 2 K sensed outside cell. - uses A TON OF ENERGY to maintain balance PUMPS PUT 3 NA PUMPS IN 2 K USES 1 ATP

choroid plexus

a network of capillaries that project from the *pia* - mater responsible for CSF formation

Long Term Energy

after ~ 40 seconds, cardiovascular and respiratory systems "catch up" and deliver sufficient oxygen so aerobic respiration meets ATP demand. activity continues until loss of glycogen, blood glucose, fluids and electrolytes, couples w/ lactic acid requires that activity ceases.

cerebral functional areas

all areas to know (front to back) - frontal lobe: what makes humans unique - pre motor cortex - primary motor area (pre central gyrus) - primary sensory area (post central gyrus) - visual primary / association area (in occipital lobe) - auditory primary / association area (in temporal lobe) *TOGETHER PRE / POST CENTRAL GYRUS* mediates conscious desire to create movement PRIMARY SENSORY AREAS *POST CENTRAL GYRUS* group of neurons where sensory pathways first take this info to cerebral cortex - primary visual (occipital lobe) - primary sensory (temporal lobe) - taste - hearing PRIMARY MOTOR AREAS *PRE MOTOR CORTEX FIRST*: - initial desire to make a movement *PRE CENTRAL GYRUS* - takes every neuron to every motor unit of skeletal muscle in the body ASSOCIATION AREAS see blue shit, BUT you don't know what it is / what color you just see it - UNTIL REACHES visual association area / auditory association area

Motor Cortex

areas of representation THINK: motor homunculus (hands, lips, tongue, etc) *1:1* motor neuron : motor unit *pre central gyrus*: has motor neurons that correspond to skeletal muscle

Somatosensory Cortex

areas of representation THINK: sensory homunculus (big hands / lips) *1:1* receptor : cortical neuron *post central gyrus*

Cauda Equina

at end of spinal cord, nerves that are hanging like "hairs" (horses tail) in vertebral column until they reach the exit point.

Skeletal Muscle

attached to skeleton (w/ EXCEPTION of muscles of facial expression, attached to the skin of the face)

Bone Shape

bones can be FURTHER classified w/ this *long bones*: - longer than wide - shaft w/ head on either end - compact bond found as a shell surrounding empty shaft w/ some spongy bone in the head of either end. - *function*: serves as rigid levers acted upon by skeletal muscles to produce bodily movements -*location:* humorous, radius, ulna, femur, tibia, etc *short bones*: - cube shaped - more spongy than compact bone - *function*: limited motion merely glide across one another - *location*: carpal bones of wrist, tarsal bones of ankle. *flat bone*: - thin / flattened - layer of spongy bone sandwiched between 2 layers of compact bone - *function*: enclose and protect soft organs, provides broad surfaces for muscle attachment - *location*: most cranial bones, ribs and sternum, os coxae. *irregular bone*: vertebrae, some skull bones

RMP

build up of ions on either side of the cell membrane *polarized membrane* positive outside, negative inside, takes a lot of energy *RMP* = -70mV bc the outside is more positive than the inside SO ions (+) / (-) are attracted. inside less positive even tho (30x K+ inside vs 14x Na outside) bc inside has intracellular inorganic phosphates HOP4 and proteins IMPERMEABLE TO MEMBRANE bc so big AND CARRY (-) charge.

Fast Adapting Receptors

can change their sensitivity levels very quickly ex hot bath (still hot) but feels warm now bc receptors adapted to heat quickly

Pectoral Girdle

clavicle scapula *functions of pectoral girdle* - no articulations w/ vertebral column - not very stable - wide range of movement

Filum Terminale

comes off of the end of the conus, continuation of the pia mater, comes all teh way down and anchors the spinal cord at the very bottom of the coccyx.

Pelvic Girdle

coxal (hip bones) - ilium - ischium - pubis sacrum

2 parts to skin

epidermis dermis

EPSP

excitatory = facilitates post synaptic potential THINK: flicking a domino, all excitatory neurot's bring membrane closer to threshold.

Pons

function: - bridges together the spinal cord, brainstem, and cerebellum. - motor control *craninal nerves* - 5,6,7,8 AKA almost entirely white matter *white matter* - bridges ascending fibers from spinal cord - bridges descending fibers from cerebrum *grey matter* - associated with cranial nerves

Medulla Oblongata

functions: contains functions we need TO LIVE - breathing nuclei in the medulla - BP gradient nuclei in medulla cranial nerves: - 12,11,10,9,8 white matter: - lateral / anterior corticospinal tract grey matter: arranged as nuclei associated with cranial nerves

Major Cranial Bones

fuzed together w/ sutures as a "case" location for the brain to sit and be protected major sutures: - saggital - squasomal - lambdoidal - coronal

Neuroglia

glia = "glue" in greek "connective tissue" cells of nervous system CNS - astrocytes: - makes blood brain barrier - scaring over wounded area of brain. CNS - oligodendrocytes makes myelin CNS - microglia eats dead stuff "munch munch" CNS - ependymal cells - lines ventricular system - makes brain CSF barrier PNS - neurolemmoytes (Schwan cells) - myelin sheath CNS/PNS - satelitte cells - stem cells

Exocrine gland

has a piece of duct work, takes secretion and puts onto designated surface

Proprioreceptive Senses

in every motor unit CONSTANTLY feeding information back to CNS about body position ex) how you know where your L foot is ALWAYS firing at some particular frequency depending on how stretched that joint / ligament is aka how contracted motor unit is.

Cutaneous Sensations

info from skin to cerebrum thermal, pain, tactile, deep touch, etc *Receptor Distribution*: - widespread, but more on front than on back THINK: fingers / lips

IPSP

inhibitory = inhibits post synaptic potential - brings you further away from threshold now even LESS likely to have an AP.

cerebral white matter

large area of cerebral cortex dedicated to associating things together ... divided into 3 fibers *association fibers*: takes function of special areas of cerebral cortex on SAME SIDE and sends message to another area ( *related areas* aka diff. gyrus , talking on the same side ) *commissural fibers* 2 gyri (same) of opposite sides that are the same. - goes through corpus callosum - SAME areas *projection fibers* leaves an area, going somewhere else --> cerebral cortex --> white matter --> brainstem / thalamus / spinal cord (DESCENDING PROJECTION FIBERS - MOTOR)

Sensory Pathways

most sensory information *desiccates* en route to cerebrum final destination = *somatosensory cortex* *perception* 3 neurons involved 1) *first order neuron* - sensory neuron dendrite attached to peripheral receptor dendritic fibers pass through spinal or cranial nerve to synapse in CNS 2) *2nd order neuron* - association neuron - in grey matter receives info from sensory - axon *ALWAYS desiccates and ascends*in medulla to thalamus where it synapses 3) *3rd order neuron* - association neuron - cell body in thalamus grey matter synapses w/ 2nd order neuron - axon passes through cerebral white matter - synapses w/ somatosensory neuron (perception occurs) ^^ somatosensory neuron (perception occurs) location of *4th neuron* which responds to the entire pathway

MUSCLE TISSUE

motion results from alternating contraction (shortening) and relaxation of muscle cells *prime function of muscle* - convert chemical energy (ATP) into mechanical energy in order to: 1) generate force 2) perform work 3) produce movements

what does it mean for a solute to move *down* its concentration gradient?

moves from an area of high concentration to low concentration to reach equilibrum

2 Cell Types of NS

neurons neuroglia - support cells

translation

once the mRNA is bound, tRNA,* carrying the appropriate amino acids, comes and base-pairs with the codons on mRNA*; then ribosome forms a peptide bond between the two amino acids; empty tRNA released and goes back to bond with another amino acid; mRNA shifts down to next codon; repeat

Mechanically Gated Channels

open w/ mech. stimulus ex) touch

Four biological criteria to life

organization cellular composition metabolism responsiveness homeostasis reproduction evolution

Articular Discs

pieces of *fibrocartilage* meant to round out the way your bones fit together - "figure 8" between knee joint bones "cradle" for femur to prevent side to side moments. *location*: KNEE: top of tibia flat, distal end of femur is round, put menisci in there that fit that bone better SHOULDER: *glenoid labrum*

Articulations

points or connections between bones and cartilage, and between bones and teeth. the structure of a joint determines its function

post central gyrus

postcentral gyrus(behind): sensory (parietal lobe)

pre-central gyrus

precentral gyrus (in front): motor (frontal lobe) THINK: taking pre workout to move a lot

Epithelial Function

protection, absorption, secretion, diffusion creates a barrier so that substances to keep fluids in / out of certain areas

After Image

receptors still responding to stimuli even after it's gone ex) camera flash

Projection

regions of somatosensory cortex (cerebrum), each neuron is linked to specific receptors via chain of neurons - cortex takes this information and projects back to point of stimulation ex) look at american flag on screen, then look at white wall

7 main functions of skin

regulation of body temperature protection sensation excretion immunity blood reservoir synthesis of vitamin D

2. falx cerebelli

sep L / R cerebellar hemispheres

1. falx cerebri

sep. L / R hemispheres

central sulcus

separates pre / post central gyri

Dural Extensions (3)

separates sections of the brain

Bottom to Top of Brain

spinal cord medulla oblongata pons midbrain diencephalon - hypothalamus - thalamus - epithalamus cerebrum cerebellum (bottom / back of brain)

Functional Classification of Glands: Holocrine

the entire cell becomes the secretory product, the cell accumulates material in the cytoplasm, when a stimulus comes to secrete it releases the entire cell and ENTIRE CELL goes into duct for duct work aka this cuts the cell off from nutrients / oxygen by doing this, now all these cells will die, secretion is released when cells die and membranes break open *uses* greasy nose crevices, release of ovum from ovary (gland released entire cell), sperm (gland released an entire cell).

cerebrum

the large cap that sits over the diencephalon / cerebrum *function* *cerebral cortex* - took grey matter inside and pushed to outside so now developing neurons can undergo rapid mitosis - folded into gyri and sulcri to increase surface area - *13 billion neurons* AKA tons of info coming to / from cerebral cortex

unicellular gland (goblet cell)

think: wine glass *Parts* *mucin*: upper portion of goblet cell, lots of mucin in the apical cytoplasm *stem* sits on the basement membrane contains all the organelles *function* when goblet cell is stimulated to secrete there is *no duct* bc the gland is already on the surface of epithelium. Instead the top of the cell simply opens and the mucin goes to the surface of that epithelium and mixes w/ water to become mucus. *location* in places we want a slick surface - GI tract

facilitated diffusion

transport solute particles through a membrane by transport proteins NO ATP, GOES DOWN CONCENTRATION GRADIENT

active transport

transport solute particles through a membrane by transport proteins USES ATP, GOES AGAINST CONCENTRATION GRADIENT

Cerebral Aqueduct

ventral / dorsal midbrain dividing line CLEAR separation of function (sensory / motor)

Continuous Conduction

when membrane is unmyelinated, EVERY single piece of membrane must be depolarized. - requires LOTS of ATP - slow 1/2 m/s *one-direction only:* message goes in 1 direction bc as you begin to depolarize the next channel the previous one is repolarizing THEREFORE you can't go back. *wave of depolarization*: can travel in all directions w/ = speed/strength BUT message is headed to the synapse.

Short Term Energy

when phosphagen gets exhausted quickly muscle cells shift to ... *anaerobic metabolism* - uses up glycogen stores provides ATP for 30-40 seconds of maximum activity

negative feedback

why are *stabilizing mechanisms* are called negative feedback the human body will typically self-restore to a state of equilibrium by itself , this is called*homeostasis* *negative feedback* a process in which the body senses a change and activates mechanisms that negate or reverse it.

Slow Adapting Receptors

won't stop sending information about those stimuli because stimulus is always there and is *important*. - things most likely to kill you - ex) cold, BP, O2 in blood,

Functional Classification of Glands: Merocrine (eccrine)

yellow cells are making red dot membrane bound vesicles, cell is storing them in the cytoplasm near teh apical surface until a stimulus comes along causing vesicles to rise and "pop" out dumping out materials going into duct for duct work. ex) champagne bubbles popping in the air *uses* salivary secretion, pancreatic secretion, neurotransmitters being secreted by neurons, etc.