Lecture 28- Muscle Tissue

Question 1

Three types of muscle tissue

Answer 1

Skeletal muscle- large cells that have striations and are under voluntary control

Cardiac muscle- found only in heart, small striated cells under involuntary control

Smooth muscle- found in walls of hollow organs , small elongated unstriated cells under involuntary control

Question 2

Muscle functions

Answer 2

Muscles produce movement by acting on bones of the skeleton, pumping blood, forming valves or propelling substances through hollow organs.

Muscles aid in maintaining posture by adjusting the position of the body with respect to gravity.

Muscles stabilize joints by exerting tension.

Muscles generate heat as a function of their
metabolic processes.

Muscles enclose and protect internal organs.

Question 3

4 Characteristics of muscle tissue

Answer 3

Excitability- the ability to receive and respond to a stimulus.

Contractility- the ability to contract forcibly when stimulated.

Extensibility- the ability to be stretched.

Elasticity- the ability to resume the cells’ original length once stretched.

Question 4

Endomysium

Answer 4

Surrounds each muscle fibre (skeletal muscle cell)

Question 5

Perimysium

Answer 5

Surrounds group of muscle fibres (skeletal muscle cells)

Question 6

Epimysium

Answer 6

Surrounds whole muscles

Question 7

Each muscle is an organ true or false?

Answer 7

True

Question 8

What is muscle made up of

Answer 8

Muscle fibres
Blood vessels
Nerves
Connective tissue

Question 9

Fascia

Answer 9

Supports and surrounds muscle

Question 10

Muscle Insertion

Answer 10

More movable attachment

Question 11

Muscle Origin

Answer 11

Less movable attachment

Question 12

Direct muscle attachments

Answer 12

Epimysium fuses with periosteum or perichondrium

Question 13

Indirect muscle attachment

Answer 13

Connective tissue wrappings of muscle extend into rope like structure that attaches to bone,cartilage, or fascia

Most common

Question 14

Skeletal muscle fibres

Answer 14

Large cylindrical cells with multiple nuclei beneath the sarcolemma or plasma membrane

Question 15

Sarcoplasm

Answer 15

Cytoplasm of muscle cell

Large amounts of glycosomes for glycogen storage

Large amounts of myoglobin, an oxygen binding pigment similar to hemoglobin

Question 16

When do muscles function aerobically

Answer 16

When there is adequate oxygen and nutrient delivery

Question 17

What produces creatine?

Answer 17

Skeletal muscles
Cardiac muscle cells
Brain neurons

Question 18

Direct phosphorylation

Answer 18

Coupled reaction of creatine phosphate and ADP

no oxygen required

1 creatine phosphate produces 1 ATP

Question 19

Anaerobic pathway

Answer 19

Glycolysis and lactic acid formation

No oxygen required

1 glucose produces 2 ATP and 2 lactic acid

Question 20

Aerobic pathway

Answer 20

Aerobic cellular respiration of glucose, pyruvic acid, free fatty acids from adipose, amino acids from protein catabolism

Oxygen is required

1 glucose produces 30-32 ATP, CO2 and H2O

Question 21

Lactic acid fermentation

Answer 21

If oxygen is not available pyruvate converts into lactic acid.

This pathway produces only about 5% the ATP from each glucose, but ATP production occurs 21⁄2 times faster.

Most of lactic acid produced is released to the bloodstream and taken to the liver, heart, or kidneys for use, but lactic acid that remains in the muscle contributes to soreness after exercise.

Question 22

Glycolytic muscle

Answer 22

Relatively few blood vessels and good for short bursts of intense activity

Question 23

Oxidative muscle

Answer 23

Has abundant blood vessels and mitochondria for prolonged use

Question 24

Slow oxidative fibres

Answer 24

contract slowly but are very resistant to fatigue. They are used for things like standing and posture.

Question 25

Fast oxidative glycolytic fibres

Answer 25

are moderately resistant to fatigue but can also use anaerobic glycolysis. They are used for walking and sprinting.

Question 26

Fast glycolytic fibres

Answer 26

have few mitochondria and few blood vessels. They are good for short anaerobic motions like lifting and throwing. Most muscle building occurs in these fibres.