Term 1 Exam: Cardiac Muscle Tissue from Chapter 10/11

Question 1

How is cardiac muscle identified? (4)

Answer 1

1. Striated
2. involuntary
3. branched
4. uninucleate

Question 2

Cardiac muscle contains intercalated discs, what are these?

Answer 2

• intercellular connections points

- contain desmosomes (structural connections) and gap junctions (electrical connections)

Question 3

Cardiac tissue is capable of autorhythmicity. What is autorhythmicity?

Answer 3

• Ability to spontaneously generate impulses that trigger contraction

Question 4

What layers are found in cardiac tissue?

Answer 4

Endomysium

LACKS perimysium and epimysium that are found in skeletal muscle (not arranged in bundles)

Question 5

What is smooth muscle tissue? (8)

Answer 5

1. Composed of short muscle fibres
2. have a fusiform shape
3. Have single centrally located nucleus
4. Non-striated (thick and thin filaments are not aligned so no visible striations)
5. No z discs
6. Sparse Sarcoplasmic reticulum
7. Transverse tubules are absent
8. Involuntary

Question 6

What are the benefits of smooth muscle having slow contraction?

Answer 6

• Resistant to fatigue

- Usually sustained for an extended period of time

Question 7

Compare the contraction and relaxation of skeletal muscle and smooth muscle?

Answer 7

Smooth muscle takes longer to contract and relax

Question 8

What is the visceral (single unit) nerve for?

Answer 8

skin, walls of hollow viscera (stomach, intestine, uterus, urinary bladder)
-signal triggers contraction of multiple fibres

Question 9

What is a multi-unit nerve

Answer 9

signal triggers contraction of a single fibre

eg: arrector pili of hair, iris