GCU BIO-201 Exam 3 With complete verified solutions + Rationales

synarthroses

immovable joints, found in places such as the sutures of the skull

Amphiarthrosis

slightly movable joint in places like the innervertebral discs

diarthroses

freely movable joints, found in places such as the shoulder

synovial joints

freely movable joints that connect bones with a sack of fluid to prevent rubbing and breakdown of bone

synchondroses

bones united by hyaline cartilage (cartilaginous joints); are NOT freely moveable; in places such as the epiphyseal line

symphysis

limited movement of joints due to the covering of articular surface of joints with hyaline cartilage. ex. pubis symphysis in os coxa

fibrous joints

consists of inflexible layers of dense connective tissue, holds the bones tightly together (3 Types)

Suture Joints

fuse bones together, such as in the skull

Syndesmosomes

bones connected to ligaments, such as the ligaments that connect the radius and ulna

Gomphoses

peg-in-socket fibrous joint, such as teeth in the alveolar socket

Menisci

Pads of cartilage that lie between the articular surfaces of the bones, especially between the knee and mandible

Bursae

flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluid

Tendon Sheaths

Elongated bursa wrapped completely around tendon subjected to friction

Plane/Gliding joints

Flat articular surfaces, bones slide over each other

Usually biaxial joints

Examples: between carpal bones of wrist; between tarsal bones of ankle; also between articular processes of vertebrae

hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

Pivot joints

Pivot joints allow rotation arround an axis. The forearms have pivot joints.

condyloid joints

Oval articular surface of one bone fits into a complementary depression in another; found in the joint at the metacarpals and proximal phalanx.

saddle joints

Only one pair exists and is between the thumb and wrist; biaxial

ball and socket joint

shoulder and hip; multiaxial joints

origin bone

the proximal end of bone where a muscle attaches. It cannot move.

first class lever

The fulcrum is positioned between the effort and resistance

second class lever

the load is between the fulcrum and the effort

third class lever

the input force is between the fulcrum and the load

sprain

An injury in which the ligaments holding bones together are stretched too far and risk tearing

strain

A condition resulting from damaging a muscle or tendon

Meniscal injury

a tear is incurred upon the meniscus, especially at the knee joint

luxation

total dislocation of a joint

subluxation

partial dislocation of a joint

Bursitis

inflammation of a bursa

Tendonitis

inflammation of a tendon sheath due to overuse

Insertion

The attachment of a muscle tendon to a moveable bone or the end opposite the origin

Actin

thin filaments

Myosin

thick filament

Myofiber

entire muscle cell

Myofibril

tightly packed filament bundles found within skeletal muscle fibers

Sarcoplasm

cytoplasm of a muscle cell

Sarcolemma

muscle cell membrane

sarcoplasmic reticulum

specialized endoplasmic reticulum of muscle cells that stores calcium for muscle movement

T (transverse) tubules

membranous channel that extends inward toward sarcoplasmic reticulum

terminal cisternae

dilated end-sacs of SR which cross the muscle fiber from one side to the other

Endomysium

Surrounds individual muscle fibers

Perimysium

Connective tissue surrounding a fascicle

Epimysium

covers the entire skeletal muscle

aponeurosis

a sheet-like tissue that functions as a tendon, connecting muscle to bone. it is sheet-like, compared to a coil-like tendon

Sarcomere

contractile unit of a muscle fiber

cross bridges

myosin head, which connects thick filaments and thin filaments during a contraction

titin protein

spans from tip of thick filament to Z line; helps maintain alignment

Z line

A dark thin protein band to which actin filaments are attached in a striated muscle fiber, marking the boundaries between adjacent sarcomeres.

I band

thin filaments only (#2 on picture)

A band

dark area; extends the length of the thick filaments (#6 on picture)

H zone

thick filaments only

M line

supporting proteins that hold the thick filaments together in the H zone

motor unit

A motor neuron and all of the muscle fibers it innervates

fine control

small motor units contain as few as 20 muscle fibers per nerve fiber (ex. eye muscles)

strength control

large motor units where up to 1,000 connect to a muscle (ex. gastrocnemius)

Recruitment (Muscle)

It is the process of increasing the number of motor units contracting within a muscle at a given time.

unfused tetanus

type of wave summation with partial relaxation observed between twitches

fused tetanus

when stimulus frequency is so high that no muscle relaxation takes place between stimuli

wave summation

One stimulus immediately follows the next; stimulus continually gets hit. Muscles doesn't quite return to resting state.

Treppe

Phenomenon in which each successive twitch contracts with similar amount of stimulus before.

isotonic contraction

A muscle contraction that pulls on the bones and produces movement of body parts.

isometric contraction

Muscle contracts but there is no movement, muscle stays the same length

concentric contraction

shortening of muscle ex. flexing biceps

eccentric contraction

muscle lengthens ex. extending biceps

yes

Are skeletal muscles striated?

yes

Are cardiac muscles striated?

No

Are smooth muscles striated?

no

Are cardiac and skeletal muscles regenerative?

yes

Is smooth muscle regenerative?

cardiac muscle

Which muscle type has intercalated discs?

myofibrils stretched too far

does not allow myosin and actin to touch, therefore muscle cannot form cross bridges to contract.

myofibrils too close together

actin and myosin are intertwined deeply, allowing for there to be no tension for muscle to preform contraction movement

phosphagen system

supplies energy very quickly and is the primary source of energy for very high-intensity exercise

myokinase/creatine kinase

transfers Pi from one ADP to another, converting the latter to ATP

anaerobic respiration

Respiration in the absence of oxygen. This produces lactic acid. It is used for short term exercise

aerobic respiration

Respiration that requires oxygen; is used for long term exercise

slow twitch fibers

red muscle fibers that are slow to contract but have the ability to continue contracting for long periods of time (many mitochondria, small diameter)

fast twitch fibers

muscle fibers that contract rapidly and forcefully but fatigue quickly (few mitochondria, large diameter)

calmodulin

A cyoplasmic Ca2+-binding protein. Calmodulin is particularly important in smooth muscle cells, where binding of Ca2+ allows calmodulin to activate myosin light-chian kinase, the first step in smooth muscle cell contraction.

myosin light chain kinase

enables myosin heads to attach to actin

no

does smooth muscle have sarcomeres?

Phosphorylation

The metabolic process of introducing a phosphate group into an organic molecule.

Astrocytes

contributes to and regulates Blood Brain Barrier (BBB); regulates composition of fluid in the brain; converts glucose to lactate for the brain to use as energy; secretes chemicals that stimulate nerve maintenance

Microglia

Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system

Oligodendrocytes

Form myelin sheath in CNS

ependymal cells

produce and circulate cerebrospinal fluid (ciliated for this movement)

satellite cells

protect neuron cell bodies

Schwann cells

produce myelin in PNS

Nissl bodies

RER and free ribosomes that make neurotransmitters

initial segment of axon

Area of the axon having the lowest threshold for stimulation, so the action potentials begin at this point

axoplasm

cytoplasm of axon

Axolemma

plasma membrane of axon

axon collaterals

Side branches of the axon, carry signal to other cells.

Axon telodendria

branches on axon terminal propagating signals towards post synaptic cell

Endoneurium

delicate connective tissue around individual nerve fibers in nerve

Perineurium

surrounds each neuron fascicle

Epineurium

surrounds the entire nerve bundle