Anatomy 11 - Histology of Muscles Flashcards Preview

Second Year - Anatomy CA21007 > Anatomy 11 - Histology of Muscles > Flashcards

Flashcards in Anatomy 11 - Histology of Muscles Deck (50):
1

What is a muscle

A band or bundle of fibrous tissue that has the ability to contract

2

What are the three types of muscle

Skeletal muscle, cardiac muscle and smooth muscle

3

Characteristics of skeletal muscle

Striated, voluntary, and contains multiple nuclei

4

Where do the nuclei of skeletal muscle lie

At the periphery of the fibre, just under the cell membrane

5

What is the cell membrane known as in uncle cells

The sarcolemma

6

Groups of muscle fibres are known as

Fascicles

7

Connective tissue surrounding the muscle as a whole is known as

The epimysium

8

Connective tissue around each individual fascicle is known as

The perimysium

9

Connective tissue around each single muscle fibre is known as

The endomysium

10

What are the smallest contractile fibres in a muscle

Sarcomeres

11

Hundreds of thousands of sarcomeres join together to form

A myofibril

12

What does cardiac muscle form

The major parts of the walls of the heart chambers and origins of the great vessels

13

Characteristic of cardiac muscle

Striated (but not as prominent as skeletal), branch to form a complex network and have a single nucleus

14

Where is the nucleus of cardiac cells found

Near the centre of the fibres

15

What do cardiac myocytes have

An intrinsic rhythmic contraction

16

What do gap junctions allow for

Synchronisation of contraction between cells and allow for waves of electrical excitation to sweep through the tissue

17

Characteristics of smooth muscle

It is involuntary, visceral, has no visible striations and has a single nucleus

18

Where is smooth muscle predominantly found

In organs

19

What are the fibres of smooth muscle like

They are elongated, spindle-shaped cells

20

The nucleus of smooth muscle

Is cigar-shaped and lies in the centre of each fibre

21

What muscle fibres allow for contraction

Actin and myosin

22

The specialised smooth ER in muscle cells is known as

Sarcoplasmic reticulum

23

What ion is in high concentration in the sarcoplasmic reticulum

Ca++

24

What neurotransmitter is release in muscle cells

Acetylecholine

25

What are the tubules within muscle cells known as

Transverse tubules or T-tubules

26

What lies on either side of the T-tubules

The sarcoplasmic reticulum

27

What is collectively known as a triad

T-tubule and the two branches of sarcoplasmic reticulum on either side

28

What does acetylcholine cause to be released in the muscle cell

An action potential

29

What does the action potential in the muscle cell cause the release of

Ca++

30

What does the release of Ca++ cause within the muscle fibres

It cause the myosin fibrils to ratchet across the actin fibrils

31

What are muscles normally connected to bone by

A tendon

32

The college of the tendon joins the muscle fibres to form a

Myotendinous junction

33

What anchors the muscle fibres to the tendon

Complex interdigitations

34

A tendons blood supply is

Poor, which means it is difficult to heal

35

What provides information on how much stretch/tension there is within the muscle

Specialised sense organs

36

What are the specialised sense organs in muscles known as

Muscle spindles

37

What do muscle spindles contain

Special muscle fibres

38

What are normal contractile muscle fibres known as

Extrafusal fibres

39

What makes up a motor unit

The motor neurone and all of the muscle fibres it innervates

40

How does the number of muscle fibres in a motor unit relate to the control

The fewer the number of muscle fibres in a motor unit, the finer the control

41

What is the synapse of a motor neurone called

The motor end plate

42

Which type of muscle tissue retains a population of myoblasts

Skeletal

43

What are myoblasts within skeletal muscle tissue known as

Satellite cells

44

Where are satellite cells found

Pressed against the outer surface of the sarcolemma, under the surrounding basal lamina

45

What is the function of satellite cells

Following damage they become active and proliferate to form new muscle fibres

46

What competes with the newly formed muscle fibres of satellite cells

Scar tissue

47

In what type of muscle tissue is there only a small population of stem cells

Cardiac muscle tissue

48

Where is skeletal muscle found

It composes the gross skeletal muscle of the muscular system

49

Function of skeletal muslce

Too move or stabilise bones and other structures

50

Where is smooth muscle found

In the walls of the tubes: the gut, respiratory tract, blood vessels and the uterus
It is also found in the iris of the eye