Anatomy Quiz 2 - Muscles and Bones of the Axial Skeleton
Curvatures of the vetebral column increase resilence and flexibility of the spine but sometimes have irregularities. Name three common irregularities of the spine.
Scoliosis - abnormal lateral curve often in thoracic Kyphosis (hunchback) - exaggerated thoracic curvature Lordosis (swayback) - accentuated lumbar curvature. Often seen in pregnant women as they attempt to preserve their center of gravity toward the end of the pregnancy
What is the major function of the axial skeleton?
provide central support for the body and protect internal organs
What is the function of the Risorius muscle of facial expression?
pulls the angle of the mouth laterally, also a smiling muscle
This muscle of the neck that moves the head works in synergy with the sternocleidomastoid
semispinalis capitis
What are the three major regions of the axial skeleton?
skull, vertebral column, thoracic cage
Muscles of facial expression: what does the corrugator supercilia do?
small, narrow, pyramidal muscle close to the eye that wrinkles the eyebrows
A major muscle that flexes and lterally rotates the head is ______ and another major muscle group that does this is _________
sternocleidomastoid, scalenes
What is tetanus?
sustained and continuous muscle contraction
What bone forms the inferolateral aspects of skull and parts of cranial base and contains the zygomatic process (cheek bone)?
temporal bones
This part of the spine forms posterior wall of pelvis and articulates with L5 superiorly, and with auricular surfaces of hip bones
the Sacrum
The body of the sternum articulates with costal cartilages of ribs 2 through 7, what is it called?
the body
What the cavities and depressions in the skull called?
Fossae
What are the 14 facial bones?
2 nasal bones 2 maxillary bones 2 zygomatic bones 1 mandible 2 palatine bones 1 vomer 2 lacrimal bones 2 inferior nasal conchae
How does the body use energy during short duration exercise?
1. ATP stored in muscles is used first (6 sec) 2. ATP is formed from CP and ADP (10 sec) 3. Glycogen stored in the muscles is broken down into glucose, which is oxidized to produce ATP (anaerobic) (40 sec - end of exercise)
What are the 4 parts that make up the structure of the vertebrae?
1. Body or centrum - Anterior weight-bearing region 2. Vertebral arch - Composed of pedicles and laminae that, along with centrum, enclose vertebral foramen 3. Vertebral foramina - Together make up vertebral canal for spinal cord 4. Intervertebral foramina - Lateral openings between adjacent vertebrae for spinal nerves
What are the charcteristics of C2, also called the axis?
1. Dens of the axis projects superiorly into anterior arch of atlas to lock both C1 and C2 together 2. Dens is a pivot for rotation of atlas
What are the characteristics of the occipital bone?
*Forms most of skull's posterior wall and posterior cranial fossa *Articulates with 1st vertebra *Contains the foramen magnum which is the outlet for the brainstem out of the brain and to the spinal cord - the hole in the base of the skull
What are the functions of the facial bones?
*Framework of face *Cavities for special sense organs for sight, taste, and smell *Openings for air and food passage *Sites of attachment for teeth and muscles of facial expression
What are the paranasal sinuses?
-Mucosa-lined, air-filled spaces -Warm and humidify air -Found in frontal, sphenoid, ethmoid, and maxillary bones -enhance the resonance of the voice and lighten the skull.
What are the 7 processes of the vertebrae?
1 spinous process, 2 transverse processes, 2 superior articular processes, 2 inferior articular processes
C1, also called the atlas, has a special name because it holds the cranium, what are the other characteristics of C1?
1. It has no body or spinous process 2. consists of anterior and posterior arches, and two lateral masses 3. superior surfaces of the lateral masses articulate with the occipital condyle
What are the components and functions of the thoracic cage?
1. Thoracic vertebrae (posteriorly) 2. Sternum and costal cartilages (anteriorly) 3. Ribs (laterally) It does the following: 1. Protects vital organs of thoracic cavity 2. Supports shoulder girdles and upper limbs 3. Provides attachment sites for muscles of neck, back, chest, and shoulders
Describe the anaerobic method of ATP production
A single glucose molecule breaks down to form 2 ATPs and 2 pyruvic acid molecules and 2 water molecules by glycolysis. The pyruvic acid molecules are converted to lactic acid as a by-product (making muscles hurt day after workout)
How is ATP regenerated?
ATP is regenerated by direct phosphorylation of ADP by creatine phosphate (CP). the creatine phosphate functions in the muscle cell by storing energy that will be transferred to ADP to resynthesize ATP. ***Oxygen not used in this process
What are two mechanisms by which ATP is produced?
Anaerobic (absense of O2) and aerobic pathways
Which cranial nerve are all of the muscles of facial expression inervated by?
Cranial nerve VII (facial nerve)
Which of the following is NOT a part of the ribs: A. Head (posterior end that articulates with facets on bodies of two adjacent vertebrae) B. Neck (constricted portion beyond the head) C. Tubercles lateral to the neck that articulate posteriorly with the transverse costal facet of thoracic vertebra D. A fossa for nerve passage E. Shaft making up most of the rib
D.
Which of the following is NOT a characteristic of the thoracic vertebrae? a. T1 to T10 have transverse costal facets that articulate with tubercles of ribs b. 11 & 12 do NOT have facets that articulate with tubercles of ribs c. Long, spinous process that points inferiorly d. Circular vertebral foramen e. all of the above are characteristics of the thoracic vertebrae
E
What is the purpose of the cranial bones?
Enclose the brain in the cranial cavity Provide sites of attachment for head and neck muscles
These muscles are deep back muscles that work to move the back and allow trunk extension and lateral bending.
Erector spinae (sacrospinalis) group ´Semispinalis and quadratus lumborum—synergists in extension and rotation
The roof, lateral walls, and floor of the nasal cavity are formed by the parts of what four bones?
Ethmoid, palatine, maxillary, and inferior nasal conchae
Which of the following does NOT apply to the lumbar vertebrae? A. Receives most stress by bearing most of the weight of the body. B. Short, thick pedicles and laminae C. Flat hatchet-shaped spinous processes point posteriorly D. Vertebral foramen triangular E. Orientation of articular facets locks lumbar vertebrae together to prevent rotation F. All of the above apply
F. All
True or False: All of the cervical vertebrae share the following features: 1. Oval body 2. Spinous processes are bifid (except C7) 3. Large, triangular vertebral foramen 4. Transverse foramen in each transverse process - for blood vessels and nerves
False - only C3 through C7 share these features
True or False: Prolonged exercise is fueled by the anerobic pathway, whereas short duration exercise is fueled by the aerobic pathway.
False: Prolonged exercise is fueled by aerobic pathway
True or False: the central indentation on the superior border of the manubrium of the sternum is called the sternal angle.
False: it is called the jugular notch
True or False: the skeletal system makes up 40% of our body mass
False: it makes up 20% of our body mass
There are 85 named cavities in the skull, what are they for?
Foramina, canals, fissures, including the nasal cavities, the orbits, the ear cavities. They are for the passage of blood vessels and nerves from heart through neck and into the brain and nerves for the brain to communicate with the rest of the body
What are neuromuscular junctions?
Formed by the branching axon terminals of motor neurons, which extend from the spinal cord to the muscle. Muscle fibers are scattered throughout the muscle and there is one NMJ per muscle fiber
What are the three erector spinae muscles that move the back?
Iliocostalis - bends the vertebral column to the side Longissimus - extends and laterally flexes the vertebral column Spinalis - extends vertebral column The semispinalis and the quadratus lumborum are synergists in extension and rotation
What is the visual cortex and where is it located?
In the occipital bone, it is where the optic nerves connect
What is wave summation?
Increasing tension or summation of twitches Repeated stimulations before the end of relaxation phase, leads to contraction of greater force. Additional Ca2+ is released and 2nd stimulus creates more shortening
These straplike muscles depress hyoid and larynx as swallowing ends and during speaking and lie beneath the hyoid
Infrahyoid muscles - sternohyoid, sternothyroid, thyrohyoid, and omohyoid.
What does it mean to innervate a muscle?
Innervation is the nerve supply to the muscle. Each muscle served by at least one motor nerve and the motor nerve contains axons of up to hundreds of motor neurons, axons branch into terminals
1. Genioglossus 2. Hyoglossus 3. Styloglossus
Label 1-3 on the diagram
Why is lactic acid formed and what happens to it once created?
Lactic acid is formed when there is insufficient O2 to break down pyruvic acid for energy. It diffuses into bloodstream and is used as fuel by liver, kidneys, and heart. It is converted back into pyruvic acid or glucose by liver
What facial bone is medially fused to form the upper jaw and central portion of the facial skeleton? It contains sinuses and is a keystone bone, meaning it articulates with all other facial bones except the mandible.
Maxillary bones
The pterygoid process
Name the part of the sphenoid bone pictured
1. Ethmoid bone 2. Crista galli 3. Cribriform plate 4. Sella Turcica 5. Spenoidal sinus 6. Palatine bone 7. Palatine process of maxilla 8. Frontal sinuses 9. Nasal bone 12. Vomer
Name the parts of the diagram
B. orbital plate of frontal bone D. greater wing of sphenoid bone O. orbital plate of ethmoid bone N. frontal process of maxilla M. lacrimal bone L. orbital process of palatine bone J. zygomatic bone I. infraorbital foramen
Name the parts of the diagram
styloid process
Name this part of the temporal bone
There are 12 pairs (24 total) of ribs that attach posteriorly to bodies and transverse processes of the thoracic vertebrae. Which ones are considered "true (vertebrosternal) ribs and what does that mean?
Pairs 1 through 7, because they attach directly to the sternum by individual costal cartilages
Which bones form the majority of the top of the skull (superior and lateral aspects of the cranial vault)?
Parietal bones
These muscles of the neck work to create head extension, rotation, and lateral bending.
Splenius capitis and cervicis
What are the muscles that move the neck?
Sternocleidomastoid, Scalenes, Splenius capitis and cervicis, Semispinalis capitis
Deep muscles involved in swallowing by moving the hyoid bone and larynx, they lie superior to the hyoid bone, anchor the tongue, and help form the floor of the oral cavity.
Suprahyoid muscles
What are the two groups of muscles involved in swallowing in the neck and the throat?
Suprahyoid muscles (Digastric, stylohyoid, geniohyoid, mylohyoid) and Infrahyoid muscles (Sternohyoid, sternothyroid, thyrohyoid, omohyoid)
T or F: As the intensity of a stimulus increases, the proportion of motor units excited also increases, but the strength of muscle contraction only increases to the point maximum contraction
T
What are the four pairs of muscles involved in mastication?
The Temporalis and masseter (prime movers of jaw closure) (Masseter raises the mandible) The Medial and lateral pterygoids (grinding movements) Buccinator - (holds food between teeth and compresses the cheek)
What do the anterior and posterior longitudinal ligaments of the spine do?
The anterior ligament prevents hyperextension The posterior ligament prevents hyperflexion
What are the muscles of the scalp?
The epicranius muscle consisting of the epicranius aponeurosis, frontal belly, and occipital belly.
What is the cause of loss of height in old age?
The flattening of the intervertebral discs
What are the bones that attach the extremities to the axial skeleton called?
The girdles
What three parts make up the nasal septum of bone in the nasal cavity?
The perpendicular plate of ethmoid, the vomer and the anterior septal cartilage
What is the pituitary gland and where it is located?
The sella turcicia is located in the sphenoid bone and houses the pituitary gland - which is the starting point for the endocrine system (all hormones originate here)
How does the body use energy during sports?
Through Aerobic (endurance) and Anaerobic threshold (strength), which is the point at which muscle metabolism converts to anaerobic. The threshold is the initial point in the beginning of the exercise, before switching over to Aerobic activity. For prolonged exercise the body will switch to Aerobic state after first 60 seconds of activity
What is the purpose of the vetebral column?
Transmits weight of trunk to lower limbs Surrounds and protects spinal cord
T of F: Contraction produces muscle tension, force exerted on load or object to be moved, the same principles apply to a full muscle or a single muscle fiber
True
T or F: Anaerobic respiration yields only 5% as much ATP as aerobic respiration, but produces ATP 2½ times faster. It produces ATP to last about 30-40 seconds
True
True or False: A suture is a type of joint
True
True or False: The bones of the cranium start off as membranes and fuse together in adulthood. Sutures are the areas where the membranes fuse together
True
True or False: the cervical and lumbar curvatures are concave posteriorly and the thoracic and sacral curvatures are convex
True
True or False: the following are movements of the vertebral column: flexion, extension, lateral flexion and rotation
True
True or False: the outer collar of the vertebral disc that is composed of collagen and fibrocartilage is called the anulus fibrosus
True
True or False: the point where the sternal body and the hiphoid process of the sternum fuse is called the Xiphisternal joint
True
True or False: the site for muscle attachment on the vertebrae is the spinous process, which projects posteriorly
True
True or False: the sternum consists of three fused bones called the manubrium, the body, and the xiphoid process.
True
True or False: the transverse processes of the thoracic vertebrae articulate with the ribs
True
True or False: In a muscle cell we can have 100,000 of mitochondria.
True well-conditioned muscles will generate more mitochondria
What are the two major parts of the skeletal system and what is the skeletal system composed of?
Two major parts are axial and appendicular - it is composed of bones, cartilage, joints, ligaments
The sella turcica of the sphenoid bone
What is pictured here?
The mastoid process of the temporal bone
What is pictured in the diagram?
the crista galli - provides dura attachment for the brain
What part of the ethmoid bone is pictured?
palatine bone
Which bone is pictured here?
the vomer
Which bone is pictured here?
Squamous suture - between parietal and temporal bones
Which suture is pictured here?
coronal suture - between frontal bone and parietal bones
Which suture is pictured here?
lambdoid suture - between the parietal bones and the occipital bone
Which suture is pictured?
sagittal suture - between the left and right parietal bones
Which suture is pictured?
What is the function of the Platysma muscle of facial expression?
a broad sheet of muscle fibers extending from the collarbone to the angle of the jaw - it opens the mouth and pulls the corners of the mouth out to the side and down, involved in frowning
What is a Motor unit?
a motor neuron and all (four to several hundred) of the muscle fibers it supplies
What are the two sets of bones that form the skull?
cranial bones and facial bones
What is the function of the Zygomaticus muscle of facial expression?
draws the angle of the mouth superiorly and posteriorly to allow one to smile
Which of the following is NOT true about muscle metabolism and energy (ATP) needed for contraction? a.) ATP only source used directly for contractile activities and is required for myosin to bind to actin filament b.) Available stores of ATP are depleted in 4-6 seconds c.) ATP is the gasoline that drives the body d.) The most distinguishing characteristic of muscle tissue is its ability to transform chemical energy into mechanical energy. e.) all are true
e.) all are true
What happens if muscle relaxation does not occur?
eventually muscle fatigue develops because the number of mitochondria in the cell is limited and they can no longer make ATP fast enough
The smaller the number of muscle fibers that a motor neuron controls, the _______ the movement.
finer
What are the three muscles that anchor and move the tongue?
genioglossus, hyoglossus, styloglossus (all are innervated by cranial nerve XII, the hypoglossal nerve)
What happens when the anulus fibrosus pushes up and against the spinal nerve?
herniation of the disc
What do the small dark spots in the cranial fossae represent, for example, olfactory nerves in the nose?
holes in the bones that are designed for the passage of blood and nerves
What is the purpose of the ligamentum flavum
it connects adjacent vertebrae
How can the cranial bones form joints if they do not move?
joints are two bones fused together - the term "joint" does not necessarily imply movement or space. A suture is an articulation between bones
These bones form the medial walls of the orbits and house the glands where tears come from. Name the bones and the glands.
lacrimal bones and the lacrimal fossa housing the lacrimal sacs
What are the three phases of muscle twitch?
latent period, period of contraction, period of relaxation
What are the functions of the depressor labil inferioris and levator labil superioris muscles of the face?
lowers the bottom lip and lifts the upper lip, respectively
What is isotonic contraction?
muscle shortens because muscle tension exceeds load, ex. normal movement thin filaments slide
What is a motor unit's response to a single action potential of its motor neuron?
muscle twitch
What are the two groups of muscles in the head?
muscles of facial expression and, muscles of mastication and tongue movement
Which bone forms the bridge of the nose?
nasal bone
What is a motor nerve?
nerve that carries a nerve impulse (action potential) to a muscle for contraction
What is isometric contraction?
no shortening; muscle tension increases but does not exceed load (trying to pick up 500 lbs and cannot move it) ´Cross bridges generate force but do not move actin filaments
What is the function of the Orbicularis oculi muscle of the face?
originates from the nasal portion of the frontal bone and closes the eyelids
What is the function of the Mentalis muscle of facial expression? ´Buccinator ´Platysma
paired central muscle of the lower lip, situated at the tip of the chin - pouting or sticking out the lower lip
Another term for rib pairs 8 through 12 is "false ribs". What is different about pairs 8-10? And pairs 11-12?
pairs 8-10 are called vertebrochondral ribs because they attach to the sternum by joining costal cartilage of the rib above pairs 11-12 are called vertebral (floating) ribs because there is no attachment to the sternum
These bones form the posterior one-third of the hard palate and the posterolateral walls of the nasal cavity. They make up the small part of the orbits.
palatine bones
This part of the spine consists of 3-5 fused vertebrae and articulates superiorly with sacrum
the coccyx
What are the functions of the Depressor anguli oris and Orbicularis oris muscles of facial expression?
the depressor anguli oris is associated with frowning, it originates from the mandible and inserts into the angle of the mouth. The orbicularis oris encircles the mouth and controls movements of the mouth and lips (closing the mouth)
This skull bone contributes to medial wall of orbits, has a perpendicular plate that forms the superior nasal septum and 2 cribiform plates that form the roof of the nasal cavaties.
the ethmoid bone
Which is the deepest bone in the skull?
the ethmoid bone
Which bone is the movable base for the tongue and the site of attachment for muscles of swallowing and speech? It is unique because it does not articulate with any other bone of skull
the hyoid bone
This fissure is located in the orbit between the sphenoid and the maxilla
the inferior orbital fissure
What is the major function and components of the intervertebral discs?
the major function is to absorb shock and the parts are the nucleus pulposus and the anulus fibrosus
Which bone is the largest and strongest in the face, forms the lower jaw and contains the TMJ (the only freely moveable joint in the skull)?
the mandible
This portion of the sternum is superior and articulates with the clavicle and ribs 1 and 2
the manubrium
this part of the intervertebral disc is gellatinous and gives disc its elasticity and compressibility
the nucleus pulposus
Which muscle has the alternate actions of pulling the scalp forward and backward and producing horizontal wrinkles in the forehead?
the occipital belly of the epicranius
These bones are formed by parts of 7 bones: frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal, ethmoid. They are sites of attachment for the eye muscles and encase the lacrimal glands. They are:
the orbits
Which bone in the skull articulates with all other cranial bones but not the facial bones?
the sphenoid bone
What are the parts of the sphenoid bone?
the superior orbital fissure, foramen rotundum, ovale, spinosum. Contains three pairs of processes: Greater wings Lesser wings Pterygoid processes
What two bones or parts of bones form the zygomatic arch (prominence of the check)?
the temporal process of the zygomatic bone and the zygomatic process of the temporal bone form the zygomatic arch
This bone is plow shaped and forms the inferior part of the nasal septum.
the vomer
This inferior part of the sternum is not ossified until age 40 and is a site for muscle attachment
the xiphoid process
What is the function of the buccinator muscle of facial expression?
thin quadrilateral muscle occupying the interval between the maxilla and mandible, it is known as the "kissing" muscle, also for whistling, blowing or sucking air
What are sutural bones?
tiny irregular shaped bones that appear within sutures
What is the purpose of wave summation?
to produce smooth, continuous, muscle contractions
lacrimal bone
which bone is pictured in the photo?
What is muscle tone?
´A state of sustained partial contraction. ´Reflex type of mechanism within the body, usually a learned process ´Due to spinal reflexes ´Groups of motor units alternately activated in response to input from stretch receptors in muscles ´Keeps muscles firm, healthy, and ready to respond ´The more we exercise the greater the muscle tone we will have
What are the characteristics of the frontal bone?
´Anterior portion of cranium ´Most of anterior cranial fossa ´Superior wall forms part of the orbits ´Contains air-filled frontal sinus ´Makes up the forehead
What happens during the period of relaxation?
´Ca2+ reentry into SR and waits for another action potential; tension declines to zero
What the two types of isotonic contraction?
´Concentric contractions—muscle shortens and does work ´Eccentric contractions—muscle generates force as it lengthens ***Muscle tension remains relatively constant during isotonic contractions
Name the eight cranial bones
´Frontal bone ´Parietal bones (2) ´Occipital bone ´Temporal bones (2) ´Sphenoid bone ´Ethmoid bone
What allow us to sit upright, hold things, walk, etc.?
´If stimuli are given quickly enough, muscle reaches maximal tension and fused (complete) tetany results.
What is the size principle as it related to muscle recruitment?
´Motor units with smallest muscle fibers recruited first ´Motor units with larger and larger fibers recruited as stimulus intensity increases ´Largest motor units activated only for most powerful contractions ´Motor units with larger, less excitable neurons would be recruited later in muscle stimulation when contractile strength increases.
How does the muscle respond to stimulus?
´Muscle contracts more vigorously as stimulus strength increases above threshold ´Beyond maximal stimulus no increase in force of contraction
What is the latent period of muscle twitch?
´Occurs following the arrival of the AP and is a short period during which Ach is released and diffuses across the cleft and binds to the receptors. ´As the Ach migrates across the cleft and begins to propagate across the surface of the muscle. Transitionary period between
What is muscle fatigue?
´Physiological inability to contract despite continued stimulation - stimulation itself is not the issue. ´Fatigued muscle cells that recover rapidly are the products of intense exercise of short duration
What is the aerobic pathway of ATP production (Kreb's cycle)?
´Produces 95% of ATP during rest and light to moderate exercise ´Series of chemical reactions that require oxygen; occur in mitochondria ´Breaks glucose into CO2, H2O, and large amount ATP ´Fuels - stored glycogen, then bloodborne glucose, pyruvic acid from glycolysis, and free fatty acids ´38 ATP yield per glucose molecule - very efficient (only 2 with anaerobic) ´Waste products from aerobic pathway are CO2 and urine
What controls the force of contraction?
´Recruitment (multiple motor unit summation) - activates more and more muscle fibers to engage to produce movement
What is the period of contraction in muscle twitch?
´cross bridge formation; tension increases - sliding filament mechanism takes place
