Micro anatomy of muscle

Question 0

What serves as attachment for actin myofilaments

Answer 0

Z disk

Question 1

What is a z disk

Answer 1

Filamentous network of protein

Question 2

Describe the beginning and end point of the I band

Answer 2

From the end of one myosin to the beginning of the next

Question 3

A bands are the length of the

Answer 3

Myosin myofilament from end to end

Question 4

Describe the H zone

Answer 4

A portion of the a band where actin and myosin don’t overlap

Question 5

What denotes the middle of the h zone and is the delicate filaments that hold what in place

Answer 5

M line holds myosin myofilaments in place

Question 6

Which section of the sarcomere contains only actin?

Answer 6

I band

Question 7

The A band contains

Answer 7

The actin and myosin overlap

Question 8

Where would you find only myosin?

Answer 8

H zone

Question 9

Titin filaments

Answer 9

Elastic chains of amino acids

Question 10

What is responsible for making muscles extensible and elastic

Answer 10

Titin filaments

Question 11

A ______ is an axon terminal resting in an invagination of the ________

Answer 11

Synapse – sarcolemma

Question 12

Name the three components of a neuromuscular junction

Answer 12

Presynaptic terminal
Synaptic cleft
Post synaptic membrane

Question 13

An axon terminal with presynaptic vesicles is called

Answer 13

Presynaptic terminal

Question 14

The space between the presynaptic terminal and the post synaptic membrane is called

Answer 14

Synaptic cleft

Question 15

The post synaptic membrane is aka

Answer 15

Motor end plate

Question 16

______ in the presynaptic terminal form and release the neurotransmitter _______

Answer 16

Synaptic vesicles

Acetylcholine (Ach)

Question 17

A degrading enzyme in the synaptic cleft is

Answer 17

Acetylchoninesterase

Question 18

How does the sliding filament model work?

Answer 18

Actin and myosin don’t shorten, the sarcomeres do=skeletal muscle cntx
Actin myofilaments slide over the myosin to shorten sarcomeres

Question 19

Sarcomeres

Answer 19

Z disk to z disk

Question 20

During relaxation, what causes the sarcomeres to lengthen

Answer 20

Some external force like cntx of antagonistic muscles

Question 21

How does the nervous system control the muscle cntx

Answer 21

Action potentials and release of neurotransmitter chemical

Question 22

Describe resting membrane potential

Answer 22

Because more + charged particles exist immediately outside the cell membrane and more - charged particles exist immediately inside the cell membrane, there is a voltage difference btwn the inside and outside of the membrane

Question 23

What is the resting membrane potential of skeletal muscle cells

Answer 23

~-85 mV

Question 24

What are the types of ion channels

Answer 24

Ligand gated and voltage gated

Question 25

The neurotransmitter chemical binds to what type of receptor

Answer 25

Ach (acetylcholine) binds to ligand-gated ion channels

Question 26

What causes voltage-gated Na+ channels to open

Answer 26

Small voltage changes across the plasma membrane

Question 27

name the 7 functions of the muscle system

Answer 27

``` maintenance of posture heart beat movement respiration production of body heat communication constriction of organs and vessels ```

Question 28

what are the four properties of muscle

Answer 28

contractability excitabiltity extensibility elasticity

Question 29

describe muscle elasticity

Answer 29

the ability to stretch and recoil to its original resting length

Question 30

describe muscle excitability

Answer 30

capacity to respond to stimulus

Question 31

describe contractility

Answer 31

ability of muscle to shorten

Question 32

describe extensibility

Answer 32

muscle can be stretched to its normal resting length and beyond to a limited degree

Question 33

what is a muscle fiber?

Answer 33

a muscle cell

Question 34

what is the connective tissue that surrounds individual muscles and groups of muscles

Answer 34

muscular fascia

Question 35

deep to the fascia is a layer of connective tissue called the

Answer 35

epimyseum

Question 36

a muscle is composed of numerous visible bundles of _____ called _____ which are surrounded by a layer of connective tissue called _____

Answer 36

fibers fasciculi perimyseum

Question 37

an _______ and 1 or 2 _______ extend together with a ______ through the connective tissue layers of skeletal muscles

Answer 37

artery veins neuron

Question 38

what supplies blood to and surrounds the muscle fibers?

Answer 38

capillary beds

Question 39

what types of multinucleated cells produe muscle fibers

Answer 39

myoblasts

Question 40

hypertrophy

Answer 40

enlargement of muscles after birth in children and adults

Question 41

the plasma membrane of the muscle fiber

Answer 41

sarcolemma

Question 42

what is the superior layer of the sarcolemma called?

Answer 42

endomysium

Question 43

transverse tubules

Answer 43

t tubules, invaginations of the sarcolemma

Question 44

myofibril

Answer 44

bundles of myofilaments that extend from one end of the muscle fiber to the other