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Flashcards in Chapter 10 Study Deck (44)
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1
Q

Three types of muscle tissue in the body

A

Smooth
Skeletal
Cardiac

2
Q

Types of muscle cells that are referred to as “Muscle fibers”

A

Smooth

Muscle

3
Q

Which characteristic about Muscle fibers give them this name

A

They both have myofilament
Actin - Thin
Myosin - Thick

4
Q

Two types of myofilament

A

Actin - Thin

Myosin - Thick

5
Q

Define “Sacrolemma” and “Sarcoplasm”

A
Sacrolemma 
- Plasma membrane, 
-t-tubules
Sacroplasm
-stores oxygen
-glycogen
6
Q

Prefixes of muscle

A

Myo-
Mys-
Sarco-

7
Q

Characteristics of skeletal muscle

A
  • Longest Cells
  • Voluntary
  • Multinucleate
  • -Syncytium
  • overall body mobility
  • Adaptable force
  • Rapid contraction but tires easily

Their force production is adaptable and they contract rapidly. They are formed from the fusion of cells that work together for a common function, so they act as a syncitium. Movement of body or things in the enviroment

8
Q

Characteristics of Smooth muscle

A
  • Walls of hollow organs
  • moves substance through internal body passageways
  • No striations
  • Involuntary
  • Slow and sustained contractions

No striation, one central nucleus and involuntarily controlled. Found in the walls of hollow organs for movement of substances. contract slowly

9
Q

Characteristics of Cardiac

A
Walls of heart 
Pumps blood
Striated 
Involuntary
Nervous control

striated, single nucleus, short, fat and branched cells with lots of mitochondria. Involuntarily controlled and found in the walls of the heart. Moves blood.

10
Q

List and describe the functional characteristics of muscle tissue in general.

A

1- Can receive and respond stimuli. Stimulus is the neurotransmitter from neurons and the response is the contraction and generation of force
2 - Contractility - Ability to shorten forcibly
3 - Extensibility - Ability to be stretched beyond resting length
4 - elasticity - Ability to return to resting length after being stretched

11
Q

Functions of muscle

A

1 - Movement - locomotion, manipulation of the environment for skeletal. movement of a substnace through a hollow organ for smooth and movement of blood for cardiac
2 - Posture
3 - Stabilizing joints
4 - Generating heat

12
Q

Different kind of tissues found in skeletal muscle (4)

A

Skeletal muscle tissue
CT Sheaths
Nervous tissue
Blood

13
Q

The three muscle connective tissue shealths

A

Endomysium - Surrounds each muscle fibers
Perimysium - Surrounds grouping of muscles called fascicles
Epimysium - Out covering of the entire muscle and is continuous with the tendon of the muscle

14
Q

Describe the nervous and blood supply to the skeletal muscle

A

There is one nerve that brings electrical signal to each muscle, one artery bringing blood (oxygen and nutrients) to each muscle and there may be more than one vein thaking blood (carbon dioxide and wastes) away from each muscle

15
Q

Can you define “origin” and “insertion” of skeletal muscle

A

Origin - End of the muscle that is on the bone that will move least in the action

Insertion - End of the muscle on the bone that will move most in the action

The insertion will always move toward the origin in the action

16
Q

Describe the general microscopic anatomy of a muscle fiber

A

Muktinucleated cell with a specialized plasma membrane called a sacrolemma and cytoplasm called sacroplasm (contains glycosomes and myoglobin) they are also bery long (several centimeters) and not very wide (several micrometers)

17
Q

Why are muscle fibers cinsidered a “syncytium”

A

Cells fuse together during fetal development to form muscle fibers so they “work together” = Syncitium

18
Q

what is the cytoplasma of a muscle cell called

A

Sacroplasm

19
Q

Myofibril

A

A cylindrical unit packed with myofilaments (actin and Myosin) and fll the muscle fibers

20
Q

What is considered the smallest contractile unit of a muscle

A

sarcomeres

21
Q

the general structure of a sarcomere?

A

Defined from z-disc to z disc and contains overlapping actin and myosin proteins for contraction

22
Q

What attaches actin and myosin to the z discs?

A

Actin - attached by nebulin

Myosin - attached by titin

23
Q

what are actin and myosin referred to as?

A

Actin is thin filaments

Myosin thick filaments

24
Q

What is the sacroplasmic reticulum of a muscle cell is? what is its special function ion muscle fibers?

A

it is modified smooth endoplasmic reticulm. it specifically stores and releases calcium into the sarcoplasm for muscle contraction

25
Q

What are terminal cisternae?

A

the ends of the sarcoplasmic reticulim (SR) that are coupled to the t-tubule to form triads. The calcium is released from this part, which is triggered by electricity coming dowwn the t-tubule

26
Q

Describe T-Tubule and its function in a muscle cell

A

Indentations of the sacrolemma. it carries the electric signal deep into the muscle fiber and trigger the SR to release its calcium for muscle contractions

27
Q

Triad

A

Two terminal cisternae and one t-tubule between them at the A-I junctions of the myofibrils.

28
Q

How do the components of the triad work together in muscle contraction?

A

the t-tubule carries the electric signal to the terminal cisternae, which then are triggered to release calcium into the sarcoplasm for muscle contraction

29
Q

describe the “sliding filament model of contraction”?

A

during muscle contraction, actin is pulled by myosin towards the center of the sacromere. so actin “slides” Past myosin

30
Q

How so the actin and myosin interact in the sliding filament model?

A

the myosin heads “grab” actin to form a crossbridge. Then the myosin heads change shape in a way that pulls towards the center of the sarcomere. This action is called a power stroke.

31
Q

What type of neuron stimulate skeletal muscle?

A

Motor

32
Q

describe the structure of a neuromuscular junction

A

the motor neuron ending contains vesicles filled with the neurotransmitter acetylcholine. The portion of the muscle sarcolemme across from the motor neuron ending is called the motor plate and contains receptors from acetylcholine. The space between the motor end place and the motor neuron is called the synaptic cleft

33
Q

What is a synaptic vesicle?

what neurotransmitter wil always stimulate skeletal muscle?

A

a Lipid “bubble” formed by a phospholipid bilayer

Acetylcholine

34
Q

What is the space between the axonal ending and the motor end plate of the muscle cell is called

A

Cleft

35
Q

What process releases the neurotransmitter from the axonal terminal?

A

exocytosis

36
Q

How are neurotransmitter destroyed? why do they need to be destroyed.

A

an enzyme called acetycholinesterase
As long as it is in the cleft it can bind to the receptors and cause muscle contraction to be able to relax the muscle the neurotransmitter must be removed

37
Q

define a motor unit

A

a motor neuron and all of the muscle fibers that it innervates

38
Q

General structure, location, arrangement and charateristics of smooth muscle fibers

A

Spindle shaped cells with only one nucleus. Not striated even though it still has actin and myosin. The actin and myosin are arranged in a cris-cross pattern. There is only a little but of endomysium

39
Q

Compare and contrast the structure and function of a smooth muscle cell and a skeletal cells

A

Skeletal muscle cells are cylindrical and centimeters long whereas smooth muscle cells are spindle and a couple of hundred micrometers long. Skeletal muscle cells contract to move the body and things in the enviroment whereas smooth muscle cells contract to move substances through them

40
Q

Peristalsis

A

wave-like contractions of smooth muscle in the walls of hollow organs to move substances through them

41
Q

how do smooth muscle receives neurotransmitter since they lack a neuromuscular junction

A

bulbous swelling called varicosities release neurotransmitter over many smooth muscle cells at once

42
Q

How are the actin and myosin arranged in a smooth muscle cell

A

in cris-cross pattern through the cell. This pattern allows the cells to twist and shorten during contraction

43
Q

do you know what the intermediate filaments and dense bodies are in a smooth muscle cell?

A

Intermediate filaments are actin and myoin and dense bodies hold them together when they cross in the cell

44
Q

Can you list and describe the unique characteristics of smooth muscle?

A

SR is less developed. Indentations called calveoli hold calcium from extraceular fluid for contraction. There are no Z-disks or satcomeres. Smooth muscle responds to stretch by relaxing, this allowing a hollow organ to fill wiith a aubstance, such as in the stomach urinary bladder or uterus.