Physiology Test 3

Front 1

how much of body weight is muscle mass

Back 1

40-50%

Front 2

three types of muscle tissue

Back 2

cardiac

smooth (nonstriated)

skeletal

Front 3

autorhythmiticity

Back 3

contracts on its own without nervous signal

Front 4

functions of muscle

Back 4

thermogenisis, movement, storing and moving substances in body, stabilizing body movements

Front 5

properties of muscle

Back 5

excitability, contractibility, extensibility, elasticity

Front 6

muscle cells

Back 6

runs the entire length of the muscle

lots of nuclei because a lot of cells come together to form the muscle

Front 7

connective tissue wrappings

Back 7

extensions of the tendon

(side note: muscle is connected to bone by tendons)

Front 8

connective tissue components

Back 8

epimysium (surrounds the entire tissue)

perimysium (surrounds fascicles 10-100)

endomysium (surrounds individual muscle fibers)

Front 9

fascicle

Back 9

bundles of fiber

Front 10

what are muscle fibers

Back 10

made up of myofibrils which are protein rods

Front 11

what are the three layers of connective tissue wrappings known as

Back 11

parallel elastic component (have elasticity)

Front 12

sarcolemma

Back 12

plasma membrane of a muscle cell

Front 13

transverse (t) tubules

Back 13

invaginations of the sarcolemma

(allows for action potential to trigger the whole cell at once)

Front 14

sarcoplasm

Back 14

cytoplasm of the muscle fiber

no calcium, high glycogen

Front 15

myoglobin

Back 15

oxygen binding protein that diffuses oxygen into the muscle fibers

Front 16

sarcoplasmic reticulum

Back 16

membranous sac that goes all throughout the muscle cell, filled with calcium

action potential causes calcium to be released through voltage gated calcium channels

Front 17

neuromuscular junction

Back 17

synapse between somatic motor neuron (motor end plate) and skeletal muscle fiber

motor end plate has 30-40 million receptors

the bigger the motor unit, the more control you have

Front 18

Myofibril makeup

Back 18

Myofilament, M Line, Z Line, Actin

Myosin lines up at M line, Actin lines up at Z line

Front 19

Basic functional unit of muscle

Back 19

Sarcomere

Z line to Z line

What gives the cell the striated appearance

Front 20

Myosin

Back 20

Converts chemical energy into mechanical energy

Thick filament anchored at the M line

Has heads that have 2 binding spots: Acting binding site and ATP binding site

Front 21

Actin

Back 21

Thin filament

Anchored to Z lines

Myosin binding sites

Proteins around thin filaments: troponin and tropomyosin

Front 22

Tropomyosin

Back 22

Wraps around the myosin binding sites. Only lets go when ATP is hydrolyzed into ADP on the myosin.

Front 23

Troponin

Back 23

Binds calcium so it pivots and pulls off tropomyosin from the myosin binding site.

Front 24

what do you need for a muscle to keep contracting

Back 24

calcium and ATP

Front 25

calcium active transport pumps

Back 25

on the sarcoplasmic reticulum. they are always working so they are always taking in the calcium.

these use ATP

Front 26

Calsequestrin

Back 26

help the sarcoplasmic reticulum and the calcium active transport pump by binding calcium and keeping it in the sac.

Front 27

what stop ACh activity

Back 27

Acetylcholinasesterase terminates the ACh signal by hydrolyzing it.

Botulinum toxin blocks exocytosis of synaptic vesicles like ACh (very toxic, stops breathing)

Curare block ACh receptors

Front 28

electromyography

Back 28

measures the electrical activity in a muscle

(no activity in resting muscle)

Front 29

3 ways to produce ATP

Back 29

creatine phosphate, glycolysis, oxidative metabolism

Front 30

Creatine Phosphate

Back 30

at rest, the muscle produces creatine phosphate

during activity, the phosphate group can quickly be produced into ATP

only lasts about 15 seconds of output

body synthesizes it from things we eat

Front 31

creatine supplement

Back 31

whether it helps or not is inconclusive

body may stop making it permanently if you are eating it

Front 32

glycolysis

Back 32

hydrolyze 1 glucose molecule into pyruvate molecules and 2 ATP

pros: very fast and can be anaerobic

cons: very little ATP

provides about 2 minutes of output (what you use when you sprint)

Front 33

oxidative metabolism

Back 33

slow and aerobic but large ATP output.

pyruvate goes into mitochondria, goes through kreb cycle, goes through electron transport chain, and gets about 30-32 ATP.

Front 34

length-tension relationship

Back 34

the more myosin heads overlap over actin sites,

Front 35

muscle fatigue

Back 35

physical inability to maintain force of contraction after prolonged activity

Front 36

central fatigue

Back 36

Before muscle fatigue, tiredness happens when the CNS doesn't want to send muscular contracting signals anymore

Front 37

muscle twitch

Back 37

sending out one action potential to make a muscle do something

there are three periods: latent, contraction, relaxation

Front 38

latent period

Back 38

indicates when action potential got triggered to the muscle membrane

Front 39

contraction period

Back 39

the time from the start of contraction to the peak force generation

Front 40

Relaxation period

Back 40

all calcium is back in the sarcoplasmic reticulum so there is no more contraction

Front 41

what does the length of the muscle twitch depend on

Back 41

length of muscle fiber

Ex: eyes twitch fast and legs twitch slow

Front 42

what determines the strength of a muscle contraction

Back 42

action ptoential is still a one size fits all principle so it depends on the frequency. if another signal is sent fast enough then more calcium is released, more heads can bind, and the stronger the contraction is.

recruitment can also happen.

Front 43

twitch/wave summation

Back 43

when a second stimulus happens after the refractory period but before the muscle is relaxed.

Front 44

Tetanus

Back 44

sustained muscle contraction

Front 45

unfused tetanus

Back 45

oscillations are observed in graph

Front 46

fused tetanus

Back 46

contractions are so close together that you can't observe any fluctuations

Front 47

motor unit

Back 47

1 nerve innervates several muscle cells and each muscle cell is innervated by one neuron

muscle fibers are not bunched together, they are dispersed throughout the muscle, they overlap other units in bundles of 3-15

one unit is about 80-100 myofibrils

Front 48

motor unit recruitment

Back 48

recruits the least amount of motor units as possible. starts with the weaker ones then goes to the stronger ones. whatever motor unit is recruited first varies.

makes sense cause if you just want a small increase then you only recruit one motor unit, if you want a large increase then you recruit a lot

Front 49

muscle tone

Back 49

even at rest, muscles maintain a certain tuatness due to a low rate of muscle impulses

ex: the muscles in your neck are constantly contracting to keep your head up

the motor units take turns to prevent fatigue

muscle only contracts when the brain tells it to, not on their own so when the pathway is blocked, the muscle goes flaccid -- bad news!

Front 50

floppy baby syndrome

Back 50

when the muscle pathway is interrupted so the baby has no muscle tone

Front 51

hyptonia

Back 51

decreased muscle tone

Front 52

concentric contractions

Back 52

muscle length shortens, angle decreases, force generated by muscle is greater than force generated on muscle

Front 53

eccentric contractions

Back 53

muscle lengthens, angle increases, tension is less than

Front 54

isometric contraction

Back 54

muscle is contracting but not moving, holding a muscle in place

muscle force equals force of resistance on muscle

Front 55

isotonic contraction

Back 55

length of muscle changes but muscle tone stays the same

general theory because technically impossible

Front 56

isokinetic contraction

Back 56

speed of muscle contraction is the same throughout movement

Front 57

ways muscle fibers can be different

Back 57

contraction and relaxation speeds

Front 58

fast vs slow muscle fiber

Back 58

differs in speed of the myosin hydrolyzes the ATP

Front 59

slow oxidative fibers

Back 59

appears dark red due to myoglobin, mitochondria, and dense capillary supply

hydrolyzes ATP slowly

keeps pace with oxidative metabolism

fatigue resistant

posture, endurance type activities

Front 60

Fast Oxidative-Glycolytic fibers (FOG)

Back 60

uses both glycogen supply and mitochondria

lots of myoglobin, capillaries, glycogen

ATPase hydrolyzes ATP quickly

general purpose skeletal muscle fiber

Front 61

Fast Glycolytic

Back 61

Depends on glycolysis for ATP supply

low myoglobin and mitochondria

anaerobic so not many blood capillaries

lots of glycogen for glycolysis

contracts strong but fatigues quickly

Front 62

Single Unit Smooth muscle

Back 62

Nerve fiber goes close to the cells causing gap junctions and the NT are released in varicosities. Found in small vessels and walls of hollow organs.

Contract in unison.

Front 63

Multiunit Smooth Muscle

Back 63

Each muscle cell is stimulated individually so there are no gap junctions. Found in large arteries, airways to lungs, and eye muscles.

Front 64

Endocrine glands

Back 64

Thyroid, parathyroid, pituitary, pineal, adrenal

(TPPPA)

Front 65

Because circulating hormones can last for hours, what deactivates them?

Back 65

Liver and kidneys