W3 Lecture 2 7/3

Question 1

3 types of muscle tissue in the body

Answer 1

Skeletal muscle - responsible for body mobility. Voluntary muscle i.e. can be controlled
Cardiac muscle - only found in the heart. Involuntary muscle i.e. contracts without stimulation from nervous system
Smooth muscle - found in the walls of organs. Involuntary like cardiac muscle.

Question 2

4 special characteristics of muscle

Answer 2

Excitability - ability to receive and respond to stimuli
Contractility - ability to shorten when stimulated
Extensibility - ability to extend
Elasticity - ability to recoil after being stretched

Question 3

4 main functions of muscle

Answer 3

Produce movement - responsible for moving our body segments
Maintain posture & body position - function to counteract gravity and maintain position
Stabilise joints - recall muscle tone was a factor of joint stability
Generate heat - contraction i.e. shivering

Question 4

Muscle cells are called…

Answer 4

Muscle fibres

Question 5

Muscles attach on to bones & the attachment points are known as:

Answer 5

Origin - end that attaches to a bone that doesn’t move. Usually the proximal end.
Insertion - end that attaches to a bone that moves. Usually the distal end.

Question 6

A sarcomere is composed of myofilaments which contain…

Answer 6

Thick filaments (myosin)
Thin filaments (actin)

Question 7

3 types of contraction

Answer 7

Isometric - contraction with on change in fibre length
Concentric - contraction with fibres shortening
Eccentric - contraction with fibres lengthening

Question 8

When a muscle contracts, it’s classified into 3 functional groups based on roles in the movement

Answer 8

Agonist/prime mover - muscle with major responsibility for causing a movement
Antagonist - muscle that opposes/controls the movement
Synergist - help agonist muscles by adding force or by eliminating movement

Question 9

Hypertrophy

Answer 9

Muscles will get stronger with loading (like bone)

Question 10

Disuse atrophy

Answer 10

Loss of muscle mass

Question 11

What is force?

Answer 11

Push or a pull on an object -> muscles pull on bones

Question 12

What do lever systems consist of?

Answer 12

Lever (rigid bar that rotates)
Fulcrum (the pivot point)
Effort force
Load force

Question 13

For/4 lever systems in the body

Answer 13

Lever = bones
Fulcrum = joints
Effort = muscle forces
Load = the bone itself + overlying tissues + anything you are trying + weight of limbs

Question 14

Levers have different advantages. A lever will allow either:

Answer 14

1. A heavier load to be moved -> power lever
2. A load to be moved further and faster but the effort will be greater than the load -> speed lever

Question 15

Anatomical power levers?

Answer 15

muscle force is less than load

Question 16

Anatomical speed levers?

Answer 16

muscle force is larger than load