Muscle

Question 1

origin vs insertion

Answer 1

point of attachment closest to middle of body vs point of attachment distant from body

Question 2

bicep and tricep are

Answer 2

antagonistic muscles

Question 3

tendon, what contraction does to it

Answer 3

strong connective tissue made of collagen - contraction brings tendons together

Question 4

movements of joint: flexing, extending, abducting, adducting

Answer 4

flexing: reduce angle of joint
extending: increase angle of joint
abducting: move away from midline
adducting: move toward midline

Question 5

synergistic muscles

Answer 5

muscles that move joint in same direction

Question 6

muscle held together by

Answer 6

fascicle

Question 7

name of muscle cell, type of cell it is, name of membrane of cell

Answer 7

myofiber
multinucleate synctia (fusion of multiple cells), surrounded by cell membrane sarcolemma

Question 8

muscle innervated by ____ nerve ending onto the ____ through a ____ with ___

Answer 8

single

onto motor end plate through NMJ with ACh

Question 9

sarcomere A band, H zone, I band

Answer 9

A band: length of thick filament
H zone: part of thick filament without thin overlapping (innermost section)
I band: part of thin filament without thick overlapping (outer most section)

Question 10

sarcomere structure of myosin and actin

Answer 10

coming out from middle M line

coming in from Z lines

Question 11

steps of power stroke

Answer 11

1. crossbridge formed of myson head on actin w ADP w phosphate
2. powerstroke, ADP released
3. myson head binds to an ATP
4. ATP hydrolyzed to ADP

Question 12

role of Ca2+ in power stroke

Answer 12

when Ca2+ increases, troponin moves tropomyosin out of the way on actin so myosin can bind

Question 13

NMJ mechanism, starts with action potential

Answer 13

1. action potential arrives at axon triggering voltage gated Ca2+
2. increase in Ca2+ leads to release of ACh vessicles
3. postsynaptic has ACh receptors which are ligand gated Na+ channels (acetyl cholinesterases eat up the rest)
4. Na+ influx depolarizes postsynaptic membrane, this is known as end plate potential, which is a combination of MEPPs (mini)

Question 14

what is a motor unit, motor pool, how does depolarization spread

Answer 14

skeletal muscle fibers and neuron that innervates it
T tubules ensure entire myofiber depolarizes
motor pool: group of motor units used to contract a single muscle

Question 15

frequency summation, what happens if second contraction happens before refractory period

Answer 15

if second contraction happens immediately after first

no time for SR to uptake Ca2+, leads to stronger, short contraction

Question 16

length tension relationship

Answer 16

muscle contracts most forcefully at optimum length

Question 17

type 1 and type 2 skeletal muscle fibers

Answer 17

type 1: slow twitch, high myoglobin/oxygenation
type 2A: fast twitch oxidative fiber, somewhat fatigue resistant
type 2B: fast twitch, explosive force

Question 18

cardiac vs skeletal muscle

regarding nucleus, Ca2+, how ACh affects, muscle structure

Answer 18

cardiac cells each have a nucleus connected by intercalated disks
gets some Ca2+ from extracellular
ACh released by vagus nerve is parasympathetic
skeletal muscle has multinucleated synctia, Ca2+ only comes from sarcoplasmic reticlum, ACh stimulates contraction
both have striated sarcomeres and T tubules

Question 19

smooth muscle size, connections, striation, Ca2+, what they use instead of troponin, how it depolarizes

Answer 19

narrower and shorter than skeletal, no need for T tubules
connected by gap junctions like cardiac
no striation thick and thin not organized
no troponin/tropmyosin - calmodulin binds to Ca2+ and activates MLCK which phosphorylates myosin to activate
uses extracellular Ca2+
relies on slow channels to depolarize (no Na+)
fluctuating resting potential
innervated by autonomic motor neurons

Question 20

bone is made of

Answer 20

connective tissue

Question 21

fibroblast can become, found in

Answer 21

collagen (fibrous), elastin (stretch), osteocyte, adipocyte, chondrocyte)
found in bone

Question 22

round part vs long part of bone

Answer 22

epiphysis, diphysis

Question 23

bone substance made of

Answer 23

bone matrix and ground substance (mostly proteoglycans)

made of collagen + hydroxyapatite

Question 24

loose vs dense connective tissue is used for

Answer 24

loose: packing tissue
dense: tendon, ligament, bone.

Question 25

flat vs long bones used in

Answer 25

flat: protection
long: support

Question 26

cartilage secreted by, how does it get nutriets

Answer 26

chondrocytes, not vascular so gets nutrients from surrounding fluid

Question 27

3 cartilage types, where they’re used

Answer 27

hyaline: strong/flexible, used in larynx/trachea
elastic: support/more flexible, outer ear
fibrous: rigid, used in pelvis

Question 28

parts of compact bone

Answer 28

central canal with lemellae around (concentric rings) make up an osteon unit (fundamental unit of compact bone)
sprinkled with osteocytes in lacunae spaces (between lamellae)
lacunae linked by canaliculi which provide routes by which nutrients can reach the osteocytes and waste products can leave them

Question 29

bone to bone join by

Answer 29

ligament, called a joint

Question 30

bone to muscle join by

Answer 30

tendon

Question 31

synarthroses, amphiarthroses, diarthroses

Answer 31

fused joint, slightly mobile, freely mobile

Question 32

freely mobile joint components

Answer 32

articular cartilage of synovial capsule keeps contact smooth

filled with synovial fluid

Question 33

how bones grow from the ends (during development), when it stops

Answer 33

endochondral ossification at epiphyseal plate (discs of hyaline cartilage, which is made then turned to bone), once plate fuses, it’s done growing

Question 34

how flat bones grow

Answer 34

intramembranous ossification from embryonic mesenchyme

Question 35

osteoblast, osteocyte, osteoclast

Answer 35

osteoblast secretes matrix for bone formation
osteocyte is osteoblast trapped and dead inside bone, becomes lacuna (hole)
osteoclasts degrade/remodel bones depending on hormone

Question 36

hormones that affect osteoclast

Answer 36

calcitonin inhibits
calcitriol increases absorption of Ca2+ and P
PTH stimulates calcitrol