Exam 2 Flashcards
what is the total number of bones in the human body?
206
which part of the body has the highest number of bones?
the hands and feet (28 in both hands and 28 in both feet)
how many axial bones are there?
80
how many appendicular bones are there?
126
what are the functions of bones?
support, protection, movement, storage (minerals, fats), hematopoiesis
what is hematopoiesis?
the formation of blood cellular components
what are the 4 bone shape classifications?
long, irregular, flat and short
describe long bones and give examples
- not necessarily long, just longer than they are wide
- ex: femur, all metacarpal and phalange bones
describe short bones and give examples
- look like little cubes, about as wide as they are long
- ex: tarsals (ankle bones) and carpals (wrist bones)
what are the two types of bone tissue?
- compact bone
- spongy bone
describe irregular bones and give examples
- irregular in shape
- vetebral bones, facial bones
describe flat bones and give examples
- bones that are flat
- ex: sternum, bones of the cranium
short and irregular bone structures are comparable to the structure of the ______ bone
long
what does compact bone look like when magnified?
like a bullseye
what does spongy bone look like when magnified?
honeycomb
a flat bone can be described as a “______ sandwich”
spongy bone
what is the trabeculae of spongy bone?
the delicate beams that give spongy bone its honeycomb-like appearance
what are the types of bone cells?
- osteogenic cells
- osteoblast
- osteocyte
- osteoclast
describe an osteogenic cell
- stem cell
- will divide to produce another stem cell and to create an osteoblast
describe an osteoblast
immature bone cell that builds bone matrix, contributing collagen to matrix
describe an osteocyte
mature bone cell (osteoblasts differentiate into osteocytes), job is to maintain the bone matrix
describe an osteoclast
multinucleate cell that degrades bone matrix, motile
______ fibers are responsible for bone’s strength and flexibility
collagen
the shaft of the bone is known as the _______
diaphysis
the epiphysis is made up of more ______ bone, whereas the diaphysis is made up of more ______ bone
spongy, compact
ends of bones are called _______
epiphyses
bone stem cells come from the ______ layer and an inner layer that’s called the ______
peritoneum, endosteum
what is the periosteum?
protective connective tissue covering around the entire outside of the bone except for the very ends
describe the epiphyseal line
the part of the long bone where growth occurs
______ cartilage is on the ends of bones and is specifically known as _____
hyaline, articular cartilage
what are the two sources of bone cells?
periosteum and endosteum
describe the medullary cavity (where is it, what is it lined by)
- lined by: endosteum
- filled with yellow bone marrow, where fat storage takes place (in adults)
in adults, spongy bone is full of ______
red bone marrow
describe the structure of the epiphysis of an adult long bone
articular cartilage > compact bone > spongy bone (red bone marrow) > endosteum lining inner portion
describe the structure of the diaphysis of an adult long bone
very thick compact bone > medullary cavity (yellow bone marrow) > spongy bone marrow on inside (lined with endosteum) > periosteum on outside, bone is highly vascularized
_______ fibers are responsible for adhering the periosteum to the bone
perforating
each ring of the compact bone is called a _______
lamella/lamellae
the _______ is the structural unit of the compact bone and is responsible for the bullseye look of the bone
osteon
describe the central canal of the compact bone
- innervated
- vascularized
_________ house the osteocytes
lacunae
___________ are tiny, hair-like canals into which the osteocyte processes move and allow for each lacuna to be connected and to connect to the central canal
canaliculi
what is ossification?
the process by which the body makes bone
describe endochondral ossification
occurs during embryogenesis, bones are first made in a hyaline cartilage model
most of the bones in the body are made by ______ ossification
endochondral
what is an articulation?
the place of contact between two bones, bone and cartilage, and bone and teeth
immovable joints are known as
synarthroses
what is the range of motion of a joint?
none to extensive (some joints allow for no movement)
bones articulate at a _____
joint
joint _____ is inversely proportional to joint stability
mobility
the more mobile a joint, the _____ stable it is
less
slightly movable joints are known as
amphiarthroses
what is the least stable joint?
the shoulder joint
what is the most mobile/movable joint?
the shoulder joint
freely movable joints are known as
diarthroses
T / F : most joints are diarthroses
true!
describe fibrous joints
- no joint cavity
- joint material consists of dense regular connective tissue that joins tissue to bones
- immovable to slightly movable
describe suture joints
- found in skull
- dense regular connective tissue
- interlocking fibers
- immovable
describe gomphosis joints
- roots of teeth in sockets of mandible, maxillae
- fibrous periodontal ligaments
- immovable
describe cartilaginous joints
- no joint cavity
- joint material: cartilage joining bones
- immovable to slightly movable
Gomphoses and suture joints are examples of
fibrous joints
describe synovial joints
- joint cavity between bones
- freely movable!
pubic symphysis and intervertebral discs are examples of
cartilaginous joints, specifically fibrocartilaginous joints
T / F : most joints of the body are synovial
true!
in order to have a significant amount of movement between bones, there must be ___________ present
a joint cavity
there are ____ different kinds of synovial joints
6
the knee joint is primarily what two bones?
femur and tibia
in synovial joints, the bones are joined and enclosed by _________
a joint capsule/joint cavity that is fluid filled
describe the articular capsule
- the “sock” of the synovial joint
- continuous with the periosteum, encloses articulating bone ends
- has inner and outer portions
the more warmed up you are, the _____ the synovial fluid is
thinner
what is the inner portion of the articular capsule? describe it
- the synovial membrane
- produces synovial fluid (has lots of capillaries)
- made out of loose areolar tissue
what is the outer portion of the articular capsule? describe it/its function
strengthens, made out of the same stuff as the periosteum
what is the synovial fluid? why is it important?
- liquid within joint cavity
- lubricates the joint, shock absorbs, nourishes
_________ is the thin hyaline cartilage responsible for reducing friction between bones
articular cartilage
what is the functions of ligaments at/in a joint?
to reinforce joint capsule
what is menisci? what is the function?
- fibrocartilage
- shock absorption
what is a bursa? what is its function?
- sac of synovial fluid where bone can rub up against soft tissue
- provides cushioning, reduces friction
what is a tendon sheath?
elongated bursa
what are fat pads? what are their functions?
- adipose tissue
- provide cushioning
what bones make up the shoulder joint? how do they fit together?
- humerus and scapula
- head of the humerus fits into the Glenoid cavity of the scapula
what is the reinforcing cartilage in the shoulder joint?
labrum
the _____ joint is the most complex joint in the body
knee
_____ is always the medial bone in the lower leg and the _____ is always the lateral bone
tibia, fibula
reinforcing ligaments on the outside of the knee joint are known as
collateral ligaments
what are the two reinforcing ligaments in the middle of the knee joint?
the ACL and PCL
describe a first degree sprain
- a mild sprain where a few fibers of the ligament are partially torn
- no loss of function
describe a second degree sprain
- a moderate sprain
- partial tearing of ligament itself
describe a third degree sprain
- most severe
- complete tear or rupture of ligament
- can have loss of function of joint
sprains are injuries to
ligaments
sprains occur by
forcible twisting of a joint
what are common joint pathologies?
- sprains
- strains
- dislocation
- tendonitis
- bursitis
- osteoarthritis
strains are due to
overstretching muscles and/or tendons
why can/do strains take a long time to heal?
tendons have very little vascularization, slowing down the healing process
a _____ will often coincide with a dislocation injury
sprain
what is a dislocation?
when bones move completely out of place
what is tendonitis? what causes it?
- inflammation of a tendon
- caused by overuse of a tendon and repetitive movements
what is bursitis? what causes it?
- inflammation of the bursa sacs
- caused by trauma to the bursa
what is osteoarthritis? what is it caused by?
- bone and joint inflammation
- typically caused by degradation of cartilage that occurs naturally over time
what are the 6 types of synovial joints?
- planar joint
- hinge joint
- saddle joint
- ball and socket joint
- pivot joint
- condyloid joint
define flexion
to decrease the angle of joint
define extension
to increase the angle of joint
define rotation
movement around a longitudinal axis
define medial rotation
anterior surface inward
define lateral rotation
anterior surface outward
moving the arm further behind your body is an example of
hyperextension
define abduction
away from midline
define adduction
towards midline
define circumduction
the movement of a limb in a circular direction (cone-shaped)
define pronation
forearm with palm posterior (down)
define supination
forearm with palm anterior (up)
define palmar flexion
hand at wrist (bending wrist downward)
define plantar flexion
foot at ankle (pointing toe up or down)
define inversion
sole of foot inward (standing on outside of feet)
define eversion
sole of foot outward (standing on inside of feet)
define protraction
jaw or shoulder girdle away from midline
define retraction
return jaw and shoulder to midline
define dorsiflexion
flexion of foot at ankle
define opposition
thumb to fingers (“okay sign”)
describe a non-axial joint (structure, function, examples and locations)
- not capable of any kind of angular movements
- example: plane joint
- structure: flat surfaces
- function: gliding
- example location: intercarpal and intertarsal
describe a uniaxial joint and give examples
- only one axis
- example: hinge joint and pivot joint
describe a hinge joint (structure, function, examples)
- uniaxial
- structure: concave/convex surfaces
- function: flexion and extension movements
- examples: elbow and knee
describe a pivot joint (structure, function, examples)
- uniaxial
- structure: rounded bone surface fits into a ringed surface
- function: rotation movements
- examples: atlantoaxial joint (C1 and C2), proximal radioulnar joint
describe a biaxial joint and give examples
- 2 planes of movement
- ex: condyloid joint and saddle joint
describe the condyloid joint (structure, function, examples)
- biaxial
- structure: oval convex bone surface fits into a concave surface of second bone
- function: flexion/extension and abduction/adduction
- examples: MCP joints 2-5 (knuckles); wrist movements
describe the saddle joint (structure, function, examples)
- biaxial
- structure: bone surface resembles a saddle
- function: flexion/extension and abduction/adduction
- ex: 1st carpometacarpal (CMC) joint (thumb)
describe a ball and socket joint (structure, function, examples)
- multiaxial
- structure: rounded head of one bone into cup-like depression of second bone
- function: flexion/extension, abduction/adduction and rotation
- ex: hip and shoulder
define articulation
a location where two or more bones meet
muscle cells are called muscle ____________, how does their structure command this name?
- fibers
- elongated and cylindrical
what gives the muscle fiber a striated appearance?
alternating light (I) and dark (A) bands
what is the unit of contraction in the muscle?
sarcomere
why are A bands dark?
there are both actin and myosin filaments there/overlapping
an entire sarcomere is the space from what to what?
Z disc to Z disc
what is the thin filament of the sarcomere? the thick?
- thin: actin
- thick: myosin
which filament looks like beads on a string?
actin
what is associated with the thick filament?
myosin + ATPase
what is associated with the thin filament?
actin + regulatory proteins
what is the function of the sarcoplasmic reticulum?
stores and releases calcium ions
_________ are the “go signal” for contraction
calcium ions
describe a neuromuscular junction
place where motor neuron ending (axon terminals) interacts with a muscle fiber
what neurotransmitter is involved in muscle contraction?
ACh
in order for calcium ions to be released, what must first occur?
neurotransmitter release + action potential
what determines the different amounts of force a whole muscle can contract with?
frequency of stimulation and number of muscle fibers
what is the difference between muscle fiber and whole muscle stimulation?
- muscle fiber is all or nothing contraction
- whole muscle contraction has a graded response
describe a muscle twitch
single stimulus, low tension/force
describe tetanus
fused peaks, continuous stimuli, no relaxation
T / F : muscles don’t always shorten when they contract but they do all generate tension
T
define/describe isotonic contraction
- the same tension
- cross-bridge formation, actin slides, muscle shortens, load is moved
- ex: squats, curls
what is the more typical type of contraction?
isotonic
define/describe isometric contraction
- the same length
- actin does not slide, but muscle tension is generated
- muscle cannot overcome the load
- ex: putting hands in front of you and pushing on a wall
contrast origin and insertion in terms of mobility
- origin: less movable, fixed bone
- insertion: more movable bone
is origin or insertion usually proximal? distal?
- origin: proximal
- insertion: distal
define/describe prime mover
the muscle(s) contracting and accomplishing most of the movement
define/describe synergist
muscle(s) contributing less to the movement
define/describe antagonist
muscle(s) producing opposite movement
when looking at the bicep region of the arm, what is the prime mover? synergist? antagonist?
- prime mover: biceps brachialis
- synergist: biceps brachii
- antagonist: triceps brachii
define/describe fixator
muscle(s) that keep other parts of the body stable so that movement can occur
Rectus femoris is an example of a muscle named for its…
fiber direction (vertical) and attachment (femur)
muscles are named based on…
action, shape, location of the bone or muscle, the attachments, fiber direction, muscle size and number of origins
what is an example of a muscle named for its number of origins?
biceps brachii and/or triceps brachii
describe the levels of organization of muscle from whole muscle to myofilaments
- myofilaments make up the myofibrils
- myofibrils within muscle fibers/myofibers
- muscle cells/fibers bundle together to form fascicles
- fascicles make up the thickness (bulk) of the muscle
describe the microscopic anatomy of the muscle fiber
- sarcolemma covering muscle fiber
- muscle fiber made up of myofibrils (100s-1,000s)
- myofibril made up of myofilaments
- two possible myofilaments: actin and myosin
describe the events that occur in the stimulation and contraction of skeletal muscle
- motor neuron sends ACh to ACh receptors on muscle fiber
- Na+ diffuses into the cell
- action potential spreads rapidly along the sarcolemma
- calcium ions released from sarcoplasmic reticulum
- actin-myosin cross-bridge formation
- sliding of the actin filaments, muscle shortening/contraction
what are the 3 pathways for ATP regeneration during muscle activity?
- direct phosphorylation
- aerobic pathway
- anaerobic pathway
describe direct phosphorylation (energy source, product, oxygen use, duration of energy provision)
- energy source: CP
- oxygen use: none
- products: 1 ATP per CP, creatine
- duration of energy provision: 15 seconds
describe the aerobic pathway (energy source, product, oxygen use, duration of energy provision)
- energy source: glucose, pyruvic acid, free fatty acids from adipose tissue, amino acids from protein catabolism
- oxygen use: required
- products: 32 ATP per glucose, CO2, H2O
- duration: hours
describe the anaerobic pathway (energy source, product, oxygen use, duration of energy provision)
- energy source: glucose
- oxygen use: none
- products: 2 ATP per glucose, lactic acid
- duration: 40 seconds or slightly more
select all of the functions of skeletal muscle
- generates heat
- maintains posture
- moves food along the gastrointestinal tract
- stabilizes joints
- transports blood
- generates heat
- maintains posture
- stabilizes joints
select all of the terms or phrases that characterize cardiac muscle
- intercalated discs
- cylindrical cells
- involuntary
- multinucleate
- forms heart walls
- striated
- intercalated discs
- involuntary
- striated
- forms heart walls
which of the following refers to one neuron and all the skeletal muscle cells it stimulates?
- synaptic cleft
- muscle fiber
- motor unit
- neuromuscular junction
motor unit
select all of the characteristics and examples of isometric contraction.
- muscle tension increases
- muscle lengthens
- muscle shortens
- no movement occurs
- lifting a baby
- holding a baby in one position
- muscle tension increases
- no movement occurs
- holding a baby in one position
select the anterior abdominal muscle.
- rectus femoris
- biceps brachii
- external oblique
- latissimus dorsi
external oblique
which special movement turns the sole of the foot medially?
- eversion
- inversion
- dorsiflexion
- plantar flexion
inversion
when comparing skeletal, cardiac, and smooth muscle, which of the following characteristics is unique to just one muscle type?
- striated appearance
- spindle-shaped cells
- under involuntary control
- uninucleate cells
spindle-shaped cells (unique to smooth muscle)
cross bridges form when __________
myosin heads bind to actin molecules on the thin filaments
which of the following is a chewing muscle?
- platysma
- orbicularis oris
- masseter
- zygomaticus
masseter
select the true statement regarding skeletal muscle attachments.
- the insertion is the immovable or less movable attachment.
- the origin is the more movable attachment.
- during contraction, the insertion moves toward the origin.
- each muscle attaches to bone or another connective tissue at no fewer than three points.
during contraction, the insertion moves toward the origin
the orbicularis oris has a _______ fascicular pattern
- circular
- parallel
- convergent
- fusiform
- pennate
circular
the pectoralis major has a ________ fascicular pattern
- circular
- parallel
- convergent
- fusiform
- pennate
convergent
the sartorius has a ________ fascicular pattern
- circular
- parallel
- convergent
- fusiform
- pennate
parallel
the biceps brachii has a _______ fascicular pattern
- circular
- parallel
- convergent
- fusiform
- pennate
fusiform
The rectus femoris has a _______ fascicular pattern
- circular
- parallel
- convergent
- fusiform
- pennate
pennate
in a skeletal muscle fiber, the sarcomere is a repetitive unit that consists of the entire region between the __________
z-discs
a fascicle is wrapped by a layer of connective tissue called __________
perimysium
when the biceps brachii acts as the __________ to flex the forearm, the triceps brachii on the opposite side of the humerus acts as the __________ by opposing this movement
prime mover, antagonist
the movement of a limb toward the midline of the body along the frontal plane is known as __________
adduction
the plasma membrane of a muscle cell is called the __________
sarcolemma
