Muscle and Nerve Histology

Question 1

Hierarchy of muscle fibers starting with epimysium (1) and ending with myofilaments (8)

Answer 1

Epimysium (1) Perimysium (2) Fasciculus (3) Endomysium (4) Muscle fibers (5) myofibrils (6) sarcomeres (7) myofilaments (8)

Question 2

increasing myofibril length does …. and ….

Answer 2

increases rate and extent of contraction

Question 3

increasing myofibril number …..

Answer 3

increases force

Question 4

thick filament

Answer 4

myosin wound together

Question 5

thin filament (3 different protein classes)

Answer 5

actin with tropomyosin and troponin

Question 6

these 3 bands/line distance shorten

Answer 6

HIZ

Question 7

this band stays the same

Answer 7

A

Question 8

what makes up a triad in a muscle

Answer 8

one t-tubule being sandwiched by two terminal cisternae of sarcoplasmic reticulum

Question 9

what is a motor unit

Answer 9

motor neuron and all the muscle fibers it innervates

Question 10

all or none response of motor unit means

Answer 10

when one muscle fiber contracts, it means all the others innervated by the same motor neuron do as well

Question 11

type I muscles have …. rate of contraction, get energy via ……, and have ….fatigability

Answer 11

slow….aerobic oxidative phosphorylation….low fatigability

Question 12

type IIa muscles have …. rate of contraction, get energy via ……, and have ….fatigability

Answer 12

rapid….oxidative phosphorylation and some anaerobic glycolysis…..medium fatigability

Question 13

type IIb muscles have …. rate of contraction, get energy via ……, and have ….fatigability

Answer 13

very rapid….anaeroic glycolysis….high fatigability

Question 14

eye muscles and finger muscles are …. type muscles

Answer 14

IIb

Question 15

limb muscles are often ….. type muscles

Answer 15

IIa

Question 16

postural back muscles are …. type muscles

Answer 16

I

Question 17

motor neurons can innervate …..

Answer 17

multiple muscle fibers

Question 18

a muscle fiber is innervated by …. motor neuron(s)

Answer 18

only one

Question 19

a single schwann cell is associated with sections of (single or multiple)# unmyelinated nerve(s)

Answer 19

multiple (protection fxn)

Question 20

a single schwann cell is associated with sections of (single or multiple)# myelinated nerve(s)

Answer 20

single

Question 21

discrete structures (worms snaking through) and more nuclei are both characteristic of which of the following: nerves or connective tissue?

Answer 21

Nerves

Question 22

characteristics of neuron cell bodies include

Answer 22

Nissl bodies Large nucleus prominent nucleoulus prominent cytoskeleton

Question 23

are dendrites myelinated?

Answer 23

no

Question 24

spinal motor neurons are examples of ….polar neurons

Answer 24

multipolar note: multiple dendrites. one axon.

Question 25

neurons of olfactory epithelium and retina are examples of ....polar neurons

Answer 25

bipolar note: one dendrite. one axon.

Question 26

sensory neurons of dorsal root ganglia are examples of ....polar neurons

Answer 26

pseudounipolar (one axon split in half)

Question 27

action potential begins at .... part of neuron

Answer 27

initial segment

Question 28

Cell type: Metabolize glucose into lactate (the energy substrate for neurons) (CNS)

Answer 28

astrocyte

Question 29

Cell type: create the myelin sheath. (CNS)

Answer 29

oligodendrocyte

Question 30

create csf

Answer 30

ependymal cells

Question 31

surround cell bodies of neurons in ganglia (PNS)

Answer 31

satellite cells

Question 32

what is name of structure that allows saltutary conduction

Answer 32

nodes of ranvier

Question 33

what creates a nerve blood barrier?

Answer 33

perineurium

Question 34

what does the perineurium surround?

Answer 34

a fascicle

Question 35

what covers individual nerve fiber (axon)?

Answer 35

endoneurium

Question 36

what is outside covering of entire nerve/filling space b/w fascicles?

Answer 36

epineurium

Question 37

is connective tissue present in ganglia, nerves, or both?

Answer 37

both

Question 38

what surrounds a muscle fiber?

Answer 38

endomysium

Question 39

what surrounds a fascicle?

Answer 39

perimysium

Question 40

label HIZ and A bands

Answer 40