Chapter 8 - musculoskeletal system

Question 1

Contractile proteins
- refers to
- size
- example

Answer 1

Refers to myofilament proteins within muscle cells that are responsible for muscle contraction. They never get smaller they just change how over lapped they are which contracts the myofibril.
Myosin and Actin

Question 2

Agonist

Answer 2

Muscle that causes the desired action. Referred to as the prime mover.

Question 3

Antagonist - example

Answer 3

Muscle that has an action opposite to the prime mover. Antagonist to the triceps is the biceps

Question 4

Antagonist pair

Answer 4

Muscles are always grouped in pairs called antagonists as they have opposite actions to enable them to produce coordinated and controlled movements around joints.

Question 5

Belly

Answer 5

Fleshy portion in the middle of a muscle

Question 6

Cardiac muscle
- function

Answer 6

Muscle that forms the wall of the heart. Heart beating that pumps the blood in the heart

Question 7

Connective tissue

Answer 7

Tissue that provides support for body organs

Question 8

Characteristics of skeletal muscle

Answer 8

Excitable – stimulated to do something through nerve impulses
Contractible – able to shorten to generate force
Extensible – can be stretched out of shape without damage
Elastic – after stretched out of shape it will return to original length

Question 9

Fixator

Answer 9

Type of synergist. It is a Muscle that contracts to immobilize a joint

Question 10

Flexion

Answer 10

Movement that decreases the angle between articulating bones.

Question 11

Insertion

Answer 11

End of a muscle fixed to a movable bone

Question 12

Involuntary muscle

Answer 12

Not under conscious control

Question 13

Joint

Answer 13

Connection between two bones

Question 14

Ligament

Answer 14

Fibrous tissue that attaches one bone to another

Question 15

Muscle tone
- maintains posture

Answer 15

Maintaining partial contraction of skeletal muscles. At any time some muscle fibres are contracted while others are relaxed. Fibres take turns to contract which means the contractions can be kept up for long periods of time. Posture is maintained by the muscle tone in the back and neck.

Question 16

Myofibril
- made up of
- striations
- allows

Answer 16

Long cylindrical structures made up of repeating units called sarcomeres. The arrangement of thick and thin myofilaments gives myofibrils stations with allows it to be divided into sarcomeres

Question 17

Myofilament
- referred to as
- size

Answer 17

Referred to as the contractile proteins within muscle cells- Threads of protein that are the actual units involved in the contraction of muscles
They never get smaller they just change how overlapped they are.

Question 18

Origin

Answer 18

End of a muscle that is fixed to the stationary bone

Question 19

Posture

Answer 19

Way a person holds their body when sitting or standing

Question 20

Sarcolemma

Answer 20

Cell membrane of muscle cells

Question 21

Sarcomere
- responsible for
- bounded by

Answer 21

Responsible for the contraction and relaxation of muscles. Shorted in muscle contractions from the overlap of thick and thin filaments sliding past one another. Bounded by Z lines.

Question 22

Sarcoplasm

Answer 22

Cytoplasm of muscle fibres

Question 23

Skeletal muscle
- function

Answer 23

To attach to the bones in the skeleton through tendons to provide movement

Question 24

Sliding filament therory

Answer 24

Theory that explains muscle contractions. When muscles contract the sarcomeres shorten as the actin and myosin filaments slide over one another. The sarcomeres length corresponds to the relaxed position, semi contracted or maximally contracted.

Question 25

Smooth muscle
- function

Answer 25

Not under conscious control, found in the walls of internal organs.
- to move the organs to perform function like churning of the stomach

Question 26

Synergist

Answer 26

Assist action of the agonist by STABILISING a joint in a particular movement OR producing the same movement as the agonist.

Question 27

Tendon

Answer 27

Fibrous tissue that attached muscle to bone

Question 28

Extension

Answer 28

Lengthening of a muscle

Question 29

Role of connective tissue in muscles

Answer 29

The bundles of muscle fibres are surrounded by various types of connective tissue that provide support. At the end of the muscle, the connective tissue layers merge to form dense fibrous band called tendon.

Question 30

Muscle bundles

Answer 30

Make up the muscle. Bundles of muscle fibres.

Question 31

Cross bridges

Answer 31

Structures formed by the heads of the myosin filaments interacting with the actin filaments to bind and pull along during muscle contraction

Question 32

Z lines

Answer 32

Structural proteins that separate sarcomeres within a myofibril

Question 33

H zone

Answer 33

Region where there is no overlap of myofilaments. Central zone in A band where there is just myosin

Question 34

A band

Answer 34

Length of myosin filament. A band length does not change as the length of myofilaments dont change. Makes up dark band.

Question 35

I band

Answer 35

Distance between successive thick filaments which contains only actin. Light bands. In shortening of the sarcomere the band size decreases.

Question 36

Myofibril

Answer 36

Long cylindrical structures within the sarcoplasm of each muscle fibre. Arrangement of thick and thin myofilaments within myofibrils gives myofibrils striations, which allows it to be divided up into its repeating units called sarcomeres

Question 37

Thick myofilament

Answer 37

Myosin

Question 38

Thin myofilament

Answer 38

Actin