Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MSK Test 2 - LE > HISTOLOGY - Skeletal Muscle & Nerve Tissue Lecture > Flashcards

HISTOLOGY - Skeletal Muscle & Nerve Tissue Lecture Flashcards

1
Q

What are the three muscle types

A

Skeletal – striated and voluntary Cardiac – striated, involuntary Smooth – non striated and involuntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the following:

1) Myocytes
2) Endomysium
3) Fascicles
4) Perimysium
5) Epimysium

A

1) mytocytes - skeletal mucles cells (aka myofiber/muscle fibers)
2) endomysium - membrane that seperate monocytes
3) fascicles - groups of myocytes
4) perimysium - membrane that seperates fascicles
5) epimysium - membrane that surrounds the entire muscle

From interior to exterior = 1 –> 2 –> 3 –> 4 –> 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
A

a -Epimysium

b -Perimysium

c - Endomysium

d -Muscle fiber in middle of fascicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
A

A - transverse

B - longitudinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a sarcomere?

A

The smallest unit of a muscle

The contractile unit of muscle made of actin and myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the functions of the following sarcomere structural units?

1) Z-line
2) I-band
3) M-line
4) H-zone
5) A-band

A

Z-line = the anchor site for actin (thin) microfilaments

I-band = an area containing only actin (thin) microfilaments

M-line = anchor site for thick myosin filaments

H-zone = contains only thick myosin filaments

A-band = overlap of thick and thin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where does a sarcomere extend from?

A

One Z-line to the next Z-line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
A

a - Z-line

b -myosin filament (thick)

c - actin filament (thin)

d - I-band

e - A band

F - I-band

g - H-zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Skeletal muscle cells are…

A

multinucleated (located on peripohery of cell) and fused together from myoblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a sarcolemma? What are transverse tubules?

A
  • a plasma membrane surrounding a skeletal muscle cell
  • invaginations of the sarcolemma that play a key role in continuing and action potential to the sarcoplasmic reticulum. Also play key role in moving calcium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is sarcoplasmic reticulum?

A

A specialized type of endoplasmic reticulum in muscle cells that functions primarily to store Ca2+ ions for muscle contraction — reabsorbs Ca2+ once used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are Terminal Cisternae?

A

The distal ends of the SR that release Ca2+, triggering muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain the Sliding Filament Mechanism during contraction?

A

1) During contraction, thin and thick filaments slide past one another bringing the Z-lines closer together
2) There is no change in the size of the actin or myosin filaments during this process — ONLY THE DEGREE OF OVERLAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain the regulatory proteins 1) Tryptomyosin and 2) Tryponin and what they do

A

Tryptomyosin - lies in groove between actin filaments and muscler tissue, resposible for blocking cross-bridge sites ON ACTIN during relaxation, preventing contraction (CONTRACTION INHIBITOR)

Troponin

Troponin T - Binds troponin complex to tryptomyosin

Troponin I - inhibnits the binding of myosin heads with actin

Troponin C - Binds to Ca2+, revealing the cross-bridge sites on actimnm via conformational change in Troponin I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why are myosin heads important for muscle contraction?

A

They have ATP binding sites that start contraction and a binding site for attaching to actin cross-bridge sites

17
Q

What are the steps of muscle contraction?

A

1) Neuron gives signal to contract
2) ATP becomes bound to mysoin head and is hydrolyzed
3) Myosin head extends to attached to actin cross-bridge site once calcium reveals the sites (see calcium importance steps
4) “Powerstroke” action is initiated and the myosin head pulls the actin toward the m-line, shortening the distance between the z-lines
5) ADP released during process, another is needed to either continue contraction, increase contraction or release contraction

18
Q

Explain the importance of calcium in muscle contraction?

A

Ca2+ controls muscle contraction

1) Ca2+ is held in SR and is released following signal from neuron
2) Signal travels down the sarcolemma and the T-tubules release the Ca2+
3) Ca2+ binds to troponin C in the presence of enough ATP, which induces confirmational change that movews the tryptomyosin, exposing the cross-bridge sites

19
Q

How are muscle fibers catagorized?

A

1) Type of contraction (power, speed, duration)
2) ATP supply (anaerobic, aerobic)

20
Q

Explain:

Type I Fibers

Type IIa Fibers

Type IIb Fibers

A

Type I (slow, oxidative) —- marathon runners

-Very red due to myoglobin, many mitochondria, slow ATPase, contract slowly and for long periods without fatigue

Type IIa (oxidative-glycolytic)

-Primarily aerobic, most abundant in body, some mitochiondria, intermediate ATPase, PROVIDES POWER

Type IIb (Fast glycolytic) —- weight lifters

-Primarily anaerobic, Fast ATPase, fatigue quickly, few myoglobin and mitochondria

21
Q

Whata re the name of neurons in CNS vs PNS

A

CNS = nuclei

PNS = ganglia

22
Q

Whata re the two type of cells in nerve tissue?

A

Neurons - comnduct electrical impulses

neuroglia - neuron supporting cells (myelinate, protect)

23
Q

What is Nissl Substance?

A

A substance consiting of many granular endoplasmic reticulum and ribosomes which strongly adhere to stains in histology

Many are present in neurons becauses they need to make a lot of protein/neurotransmitters in order to span through the body

24
Q

What are the basic components of a nerve cell?

A

Cell body - processess electical info

Axon - transmits electrical info/carry signal away fromc cell body

Dendrites - recieve signal/carries toward cell body

Synapse - point where electric signals are transmitted from an axon terminal to an effector cell

Schwann cells - myelinate the axons in the PNS

25
Q

What are the three anatomical classificatiomns of neurons?

A

1) Multipolar - one axon, many dendrites (MOST COMMON)
2) Bipolar - one axon, one dendrite (Retina)
3) Unipolar - one cell process with a branch thay has one axon and one dendrite (Dorsal Root Ganglia)

26
Q

What are satellite cells

A

Cells that cover neurons and are responsible for maintaining and regulating the environmenta around the neuron

27
Q

What is the importance of myelin sheaths and the process of mylination?

A

Improves speed of signal transmission via Nodes of Ranvier (hops from node to node)

Oligodendrocytes (CNS) or Schwann cells (PNS) wrap around axons repeatedly until they form a myelin membrane

Axons can be be myelinated OR unmyelinated

28
Q

What are the three important structures of a peripheral nerve cell?

A

Endoneurium - CT between/surounding axons (COVERS AXONS)

Perineurium - CT surrounding clusters of axons, forming fascicles (COVERS FASCICLES)

Epineurium - CT surrounding several nerve fascicles (COVERS ENTIRE NERVE)

29
Q
A

A - Perinurium

B - Epineurium

C - Fascicle

30
Q

What is this?

A

A X-section of a peripheral nerve cell

31
Q

What are the 4 essential parts of a the chemical synapse?

A

1) Presynaptic knob (axon terminal) — Has vesicles that release neurotransmitter in synaptic cleft
2) Synaptic cleft - space between neurons which continues signal via neurotransmitters
3) Presynaptic membrane
4) Postsynaptic membrame

32
Q

Explain what happens are the neuromuscular junction that stimulates muscle contraction?

A

1) Nerve impulse stimulates release of Acetylcholine (ACh) into synaptic cleft
2) ACh stimulates sarcolemma which excites the muscle and iscarried down to T-tubules to initiate contraction (Ca2+ release)
3) Enzymes break down ACh to limit action to 1 muscle twitch

KEY: every skeletal muscle cell has an axon terminal but not all cardiac or smooth muscle cell is directly innervated

33
Q

What are muscle spindle receptors?

A

Monitor changes in length, rate of change (Stretch and speed)

Prevents you from overstretching the muscle and contracting too fast

SENDS REFLEX signal to spinal cord saying tnot to stretch any further

34
Q

How many schwann cells and oligodendrocytes are there comopared to neurons?

A

Schwann cells - one cell to one neuron

Oligodendrocytes - one cell to many neurons

35
Q

What are the two types of Muscle Spindle Receptors?

A

1) Intrafusal Fibers - inside muscle spindle
a) Nuclear Bag Fibers – wrapped at center by type Ia nerve fibers, monitor change in length and degree of tension
b) Nuclear chain fibers – wrapped at ends by Type II nerve fibers, detect static muscle length
2) Extrafusal Fibers - outside muscle spindle (alpha motor fibers)

36
Q

What are golgi tendon organs?

A

Located in at the origins and insertions of muscle tendons, they are proprioreceptive sensory organs that sense changes in muscle tension

When you lift weights, golgi tells how much you are exerting and will prevent further contraction to prevent injury

MSK Test 2 - LE (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions