Anatomy 11 - Histology of Muscles

Question 1

What is a muscle

Answer 1

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

Question 2

What are the three types of muscle

Answer 2

Skeletal muscle, cardiac muscle and smooth muscle

Question 3

Characteristics of skeletal muscle

Answer 3

Striated, voluntary, and contains multiple nuclei

Question 4

Where do the nuclei of skeletal muscle lie

Answer 4

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

Question 5

What is the cell membrane known as in uncle cells

Answer 5

The sarcolemma

Question 6

Groups of muscle fibres are known as

Answer 6

Fascicles

Question 7

Connective tissue surrounding the muscle as a whole is known as

Answer 7

The epimysium

Question 8

Connective tissue around each individual fascicle is known as

Answer 8

The perimysium

Question 9

Connective tissue around each single muscle fibre is known as

Answer 9

The endomysium

Question 10

What are the smallest contractile fibres in a muscle

Answer 10

Sarcomeres

Question 11

Hundreds of thousands of sarcomeres join together to form

Answer 11

A myofibril

Question 12

What does cardiac muscle form

Answer 12

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

Question 13

Characteristic of cardiac muscle

Answer 13

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

Question 14

Where is the nucleus of cardiac cells found

Answer 14

Near the centre of the fibres

Question 15

What do cardiac myocytes have

Answer 15

An intrinsic rhythmic contraction

Question 16

What do gap junctions allow for

Answer 16

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

Question 17

Characteristics of smooth muscle

Answer 17

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

Question 18

Where is smooth muscle predominantly found

Answer 18

In organs

Question 19

What are the fibres of smooth muscle like

Answer 19

They are elongated, spindle-shaped cells

Question 20

The nucleus of smooth muscle

Answer 20

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

Question 21

What muscle fibres allow for contraction

Answer 21

Actin and myosin

Question 22

The specialised smooth ER in muscle cells is known as

Answer 22

Sarcoplasmic reticulum

Question 23

What ion is in high concentration in the sarcoplasmic reticulum

Answer 23

Ca++

Question 24

What neurotransmitter is release in muscle cells

Answer 24

Acetylecholine

Question 25

What are the tubules within muscle cells known as

Answer 25

Transverse tubules or T-tubules

Question 26

What lies on either side of the T-tubules

Answer 26

The sarcoplasmic reticulum

Question 27

What is collectively known as a triad

Answer 27

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

Question 28

What does acetylcholine cause to be released in the muscle cell

Answer 28

An action potential

Question 29

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

Answer 29

Ca++

Question 30

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

Answer 30

It cause the myosin fibrils to ratchet across the actin fibrils

Question 31

What are muscles normally connected to bone by

Answer 31

A tendon

Question 32

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

Answer 32

Myotendinous junction

Question 33

What anchors the muscle fibres to the tendon

Answer 33

Complex interdigitations

Question 34

A tendons blood supply is

Answer 34

Poor, which means it is difficult to heal

Question 35

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

Answer 35

Specialised sense organs

Question 36

What are the specialised sense organs in muscles known as

Answer 36

Muscle spindles

Question 37

What do muscle spindles contain

Answer 37

Special muscle fibres

Question 38

What are normal contractile muscle fibres known as

Answer 38

Extrafusal fibres

Question 39

What makes up a motor unit

Answer 39

The motor neurone and all of the muscle fibres it innervates

Question 40

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

Answer 40

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

Question 41

What is the synapse of a motor neurone called

Answer 41

The motor end plate

Question 42

Which type of muscle tissue retains a population of myoblasts

Answer 42

Skeletal

Question 43

What are myoblasts within skeletal muscle tissue known as

Answer 43

Satellite cells

Question 44

Where are satellite cells found

Answer 44

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

Question 45

What is the function of satellite cells

Answer 45

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

Question 46

What competes with the newly formed muscle fibres of satellite cells

Answer 46

Scar tissue

Question 47

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

Answer 47

Cardiac muscle tissue

Question 48

Where is skeletal muscle found

Answer 48

It composes the gross skeletal muscle of the muscular system

Question 49

Function of skeletal muslce

Answer 49

Too move or stabilise bones and other structures

Question 50

Where is smooth muscle found

Answer 50

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