Muscle Tissue

Question 1

What are the three types of muscle tissue?

Answer 1

-striated muscle
-smooth muscle
-cardiac muscle

Question 2

Where can skeletal and striated muscle be found ?

Answer 2

Found attached to bones

Question 3

Where can cardiac muscle be found?

Answer 3

Found only in the heart

Question 4

Striated muscle

Answer 4

Question 5

The sarcolemma of individual muscle fibres is in direct contact with an external lamina the ………….

Answer 5

Endomysium

Question 6

What does the endomysium do?

Answer 6

This joins groups of muscle fibre to each other and supports the capillaries and nerve axons which run between the fibres.

Question 7

Larger groups of muscle fibres are bound together by …….. (connective tissue) into…….

Answer 7

1.perimysium
2. Fascicles

Question 8

An anatomical muscle is composed of many fascicles surrounded by a stronger connective tissue fascia - the …….

Answer 8

Epimysium

Question 9

What is hypertrophy?

Answer 9

Where muscle fibres increase in size

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 16

The contractile unit of skeletal muscle is the ………… .This passes from the centre of one actin group to the next, in the resting state it is about ……..um long.

Answer 16

1.sacromere
2. 2.2

Question 17

A length of sarcomeres constitutes a myofibril, this is about …….um in diameter.

Answer 17

1-2

Question 18

Several myofibrils are grouped together by a cell membrane, termed the …………, to form a muscle fibre, typically ………..um in diameter and up to …….cm long.

Answer 18

1-sarcolemma
2. 50-60
3. 10

Question 19

Answer 19

Question 20

Explain the banding pattern to be seen in myofibrils

Answer 20

● I-bands - light bands containing only thin actin filaments
● A-bands - dark bands containing thick myosin filaments (and some actin filaments)
-H zone contains only myosin
-Darkest region contains overlapping actin and myosin

Question 21

Give an overview of muscle contraction

Answer 21

● Myosin heads slide actin along myosin causing the sarcomere to contract
● Simultaneous contraction of many sarcomeres causes myofibrils and muscle fibres to contract
● When sarcomeres contract (shorten)…
- H zones get shorter
-I band get shorter
-A band stays the same
-Z lines get closer

Question 22

Draw a contracted sarcomere

Answer 22

Question 23

Which muscle type is this, its description, function and location.

Answer 23

-smooth muscle
-description: spindle shaped (elongated) cells with central nuclei; no striations; cells arranged closely to form sheets
-function: propels/ pushes substances or objects ( foodstuffs, urine, a baby) along internal passageways; involuntary control
-location: mostly in the walls of hollow organs

Question 24

Which type of muscle tissue is this under the microscope?

Answer 24

Smooth muscle

Question 25

Smooth muscle

-Each smooth muscle cell is spindle-shaped. Cells may be ……um long in small blood vessel walls and up to ………um long in the uterus.

-There is a single nucleus centrally placed. Cells are surrounded by an external ………….. which is attached to the cell membrane.

-There is no regular arrangement of actin and myosin in the cell. The …………… proteins crisscross the cell and insert into anchoring points on the cell membrane.

-Contraction of the proteins is transmitted through the cell membrane to the surrounding external lamina. Adjoined cells contract as one unit.

Answer 25

1.20
2. 400
3. Lamina
4. Contractile

Question 26

Answer 26

Question 27

Which muscle tissue type is this, its description, function and location?

Answer 27

-cardiac muscle
-description: branching, striated, generally uninucleate cells that interrogate at specialised junctions ( intercalated discs)
-function: as it contracts, it propels blood into the circulation; involuntary control
-location: the walls of the heart

Question 28

Which type of muscle tissue is this under the microscope?

Answer 28

Cardiac muscle

Question 29

CARDIAC MUSCLE

-Cardiac muscle cells are also mononucleated. Each cells is about …..um in diameter and 100um long.

-The cells are ……………. and form long chains with neighbouring cells.

-Intercellular junctions can be seen as dark lines, these are intercalated discs which contain …………..for strength and gap junctions for cell-cell communication.

-The ……………proteins actin and myosin are arranged in a specific way which creates bands within the cell - striations. Mitochondria are prominent throughout the cells.

Answer 29

1. 15
   2.branched
   3.desmosomes
   4.contractile