nerves and muscle histology

Question 1

what are the 3 types of muscle cells

Answer 1

striated/skeletal
cardiac
smooth

Question 2

what is another way to describe skeletal muscles

Answer 2

striated

Question 3

describe skeletal/striated muscles

Answer 3

allows us to speak, move, swallow
stripy
parallel + regular stripes
cells = singly unit, no branching, nuclei at sides
each fibre = single cell/muscle fibre
many nuclei in fibre
fused to form 1 cell + multiple nuclei syncytium

Question 4

what are t tubules

Answer 4

little channels
continuous
with pits

Question 5

what is a repeating unit known as

Answer 5

sarcomere

Question 6

what points show a contractile unit

Answer 6

Z disc to Z disc

Question 7

I band is made from ….

Answer 7

actin

Question 8

A band is made from ….

Answer 8

mysoin

Question 9

describe smooth muscles

Answer 9

dilate = relaxes
constrict = contract
involuntary
spindle shape
cigar shaped
single cells, single nuclei
indistinct cell membrane
no striations
no distinct SER
dense bodies = z discs
- move inwards to make whole cell shrink

Question 10

what does the CNS consist of

Answer 10

brain
spinal cord
neural parts of the eye

Question 10

describe bipolar neurons

Answer 10

dendrites merge as one
sensory neurones of the retina, olfactory mucosa, inner ear
special sensory systems = single dendrite from the soma opposite the axonal pole
special sensation = smell

Question 10

what does the PNS consist of

Answer 10

peripheral ganglia
nerves

Question 11

what are the 4 types of neurones

Answer 11

multipolar
bipolar
unipolar/psuedounipolar
anaxonic

Question 11

describe multipolar neurons

Answer 11

dendrites meet the body separately
all motor neurons
-CNA interneurons
-extensive dendritic tree

Question 12

describe unipolar/psuedounipolar neurons

Answer 12

short stem inserts both afferent/peripheral and efferent/central pathways into the body, transmit general sensation
all other sensory neurones
general sensation = touch, hot/cold, pain

Question 13

describe anaxonic neurons

Answer 13

dendrites only present
in CNS - don’t produce action potential
regulate local electrical charges of adjacent neurons

Question 14

what is the synapse

Answer 14

region where the message is delayed from one neuron to the next structure that follows

Question 15

describe the synapse

Answer 15

where the message is delayed
consists of pre/post synaptic terminals with intervening synaptic cleft neurotransmitters stored in synaptic vesicles released + act - into synaptic cleft

Question 16

what is the function of satellite cells

Answer 16

electrically insulate PNS cell bodies
regulated nutrient and waste exchange for cell bodies in ganglia

Question 17

what are the segments of internodes called in the axon that cause is to be separated

Answer 17

nodes of ranvier

Question 18

what is another name for unipolar neurons

Answer 18

pseudounipolar

Question 19

what is the function of schwann cells

Answer 19

surround and insulate PNS axons and myelinate those with large diameters
allows for faster action potential - propagation along axon in PNS

Question 20

what is another name for schwann cells

Answer 20

neurolemmocyte

Question 21

where are cardiac muscles found

Answer 21

muscle

Question 22

smooth muscles are .... and ....

Answer 22

involuntary visceral

Question 23

thickness of the myelin sheath is proportional to .....

Answer 23

the diameter of the axon

Question 24

a bands are ... ....

Answer 24

dark stripes

Question 25

i band is ... ...

Answer 25

light stripes

Question 26

z discs are in the middle of the ... ....

Answer 26

i band

Question 27

a band is always the same .... in the ....

Answer 27

length sacromere

Question 28

the z band doesn't change .....

Answer 28

length -anchors

Question 29

what are satellite cells involved in

Answer 29

muscle damage repair

Question 30

what are cardiac muscles used for

Answer 30

heart to pump involuntary

Question 31

describe cardiac muscles

Answer 31

striations more haphazard arrangement = less striated than skeletal branches darker pink, thicker, more obvious lines cell periphery in the middle single, separated by dark pink walls = INTERCALATED DISCS

Question 32

what are the dark pink walls known as in cardiac muscles

Answer 32

intercalated discs

Question 33

what is the difference between cardiac and skeletal muscles

Answer 33

cardiac = central nuclei not peripheral cardiac = no triads - DIADS instead cardiac myofibrils - branched skeletal myofibrils - cylindrical cardiac = less pronounced sarcoplasm intercalated discs in cardiac

Question 34

longer node = longer .... distance

Answer 34

internode

Question 35

nerve fibre is the main structure in ..... nerves

Answer 35

peripheral

Question 36

neurons in both the PNS and CNS

Answer 36

- body (stoma) - 2 important substances (nissl = rough endoplasmic reticulum - form cluster, like granules in staining) - contains nucleus - dendrites - transmission - axon - single, terminal portion has branches, each has a synaptic ending - cell bodies can also receive info

Question 37

what does epinerium do

Answer 37

covers the entire nerve

Question 38

what does perineurum do

Answer 38

separates the nerve into fascicle and consists of neuroepithelial perineuriral cells

Question 39

what does endoneurium surround

Answer 39

the individual axons and their associated schwann cells

Question 40

what are ganglion

Answer 40

collection of nueronal bodies of somata

Question 41

what does the microgial act as

Answer 41

macrophage of the cell

Question 42

what is the difference between schwann cells and oligodendrocytes

Answer 42

S = PNS O = CNS

Question 43

what is a motor unit

Answer 43

motor neurone and the muscle fibres that it supplies

Question 44

what does a nerve fibre consist of

Answer 44

consists of axons, myelin sheath + shwann cells

Question 45

what do oligodendrocytes form

Answer 45

the myelin sheath

Question 46

what is the connective tissue sheaths that group nerve fibres into fascicles called

Answer 46

perineurium

Question 47

nerve fibre - full

Answer 47

consists of axons, myelin sheath and shwann cell grouped into fasicles by connective tissue sheaths - perineurium - formed by perineurim cells - fascicle contains both myelinated and unmyelinated nerve fibres - in turn are surrounded by basal lamina - network of fine reticular fibres to form the endoneurium - epinerurim covers the entire nerve - perineurum separates n=the nerve into fascicle and consists of neuroeptihelial perineuiral cells - endoneurium surrounds individual axons and their associated schwann cells

Question 48

what does the fascicle contain

Answer 48

myelinated + unmyelinated nerve fibres

Question 49

what are the 4 types of neurons define by

Answer 49

the location/presence of axons

Question 50

myelinated cells have .... around them

Answer 50

rings