MUSCULOSKELETAL SYSTEM 1 (MUSCLES)

Question 1

4 types of tissue

Answer 1

Epithelial, connective, muscular and cardiac

Question 2

Muscle cells

Answer 2

Cell that have long, thin fibres that have the ability to contract.

Question 3

What happens when Muscle cells contracts

Answer 3

When they contract, they reduce distance between the parts they are connected and decrease space they surround.

Question 4

What are some examples of connective tissues
how to they work with muscles and how are they separated.

Answer 4

-Bone, cartilage and tendons, which work with muscles to create movement
(these cells are separated by a non-cellular matrix)

Question 5

3 types of muscle tissues

Answer 5

1. smooth
2. skeletal
3. cardiac

Question 6

Skeletal Muscles

Answer 6

Muscles that move bones, they can carry out a wide range of voluntary physical activities, under conscious control.

Contractions of these skeletal muscles bring about movement of the joints, also gives body its from and maintain posture

Question 7

Smooth Muscles

Answer 7

• Muscles that are found in the alimentary canal, used for movement, they are involuntary.

Question 8

Cardiac Muscles

Answer 8

• also known as the heart muscle, as it contracts it reduces space in the heart chambers and pushes blood into a blood vessel

Question 9

Properties of Muscles

Answer 9

1. contractibility - able to shorten.
2. Excitability - able to stimulated by a nerve impulse
3. Extensibility - Able to be stretched.
4. Elasticity - Return to its original shape after being stretched.

Question 10

Structure of skeletal muscles

Answer 10

• Muscles are held in bundles

Question 11

Perimysium

Answer 11

A sheathe of connective tissue surrounds the bundle allowing it to function as an individual unit.

This allows adjacent pairs of bundles to slide past each other during contraction

Question 12

Epimysium

Answer 12

• Sheath of connective tissue that holds bundles of muscles together, towards the end of the muscle they taper and form a tendon

Question 13

Increase and decrease of connective tissue

Answer 13

The amount of connective tissue increases as age increase,

Increasing amount of connective tissue, decrease in muscular strength.

Question 14

Structure of muscle fibres

Answer 14

• Each muscle cell is called a muscle fibre and is multi nucleated.
• Around the cell is a thin plasma membrane known as the sarcolemma, containing cytoplasms known as sarcoplasms
• Sarcomere

Question 15

Structure of myofibril

Answer 15

• Within the sarcoplasm, there are thread like - myofibrils, these lie parallel to each other and run in the length of the fibre.
• Tubular network called the sarcoplasmic reticulum surrounds the myofibril.
• Each myofibril consists of smaller myofilaments

Question 16

Myofilaments

Answer 16

• found in myofibril
• Made of proteins which are involved in muscle contractions

2 types:

• Thick, Myosin
• Thin, Actin

Question 17

Sliding filament theory Def

Answer 17

When muscles contract, the sarcomere shortens, the theory suggests that this occurs as actin and myosin filaments slide across each other.

Question 18

I ate Home made zebras

Answer 18

I zone - distance between successive thick filaments

A band - Length of myosin

H zone - Middle zone of A band, contains thick filaments only

M line - Holds thick filaments

Z line - Middle of thin filament, contains protein disks (attaches thin filaments).

Question 19

Sliding Filament theory Steps 1 to 8

Answer 19

1. Arrival of the action potential causes the sarcoplasmic reticulum to release Ca2+ into the cells
2. The Ca2+ binds to troponine and displaces tropomyosin on the actin filament, exposing myosin binding sites.
3. ATP (already bonded to the myosin heads) hydrolyses to ADP and P, which allows myosin heads to bond to actin forming a cross-bridge.
4. ADP and P are removed from myosin head, this will allow the power- stroke to occur.
5. A new ATP molecule binds to myosin and allows the detachment from actin.
6. Steps 3 and 4 are repeated so that actin slides/ move closer to the centre of the sarcomere causing contraction.
7. Contractions continues until nerve impulse ends (or lack of ca2+ and ATP occurs).

Question 20

Tendons

Answer 20

Connective, inelastic, fibrous tissue that allows muscles to attach to bones.

Question 21

Bridging of joints

Answer 21

When muscles contract, bones move.

Question 22

Antagonistic pair

Answer 22

Pairs of muscle producing movement of muscle in one direction and the other in the opposite direction

Question 23

Origin

Answer 23

The end of muscle fixed to a stationary bone

Question 24

Insertion

Answer 24

Muscle attachment to the movable bone.

Question 25

Belly

Answer 25

The fleshy portion of the muscle between the tendons of the origin and insertion

Question 26

Agonist/ Prime mover

Answer 26

Muscle that causes desired movement/action

Question 27

Antagonist

Answer 27

Muscle that effects opposite to the agonist

Question 28

Synegist

Answer 28

Muscles that help the prime mover, may steady a join during a particular movement so that unwanted movement is prevented and the agonist can function more efficiently.

Question 29

Fixator

Answer 29

Muscle that acts as a stabiliser of one part of the body during movement of another part. - example: Holding the scapula firmly as it is only attached to the axion skeleton via the rib cage.

Question 30

Interactions of all 3

Answer 30

Makes very fine and precise movements possible

Question 31

Muscle Tone

Answer 31

Partial contraction of skeletal muscles. Some muscle fibres are contracted while other are relaxed. Such partial contractions tightens a muscle, but not enough fibres are contracting at one time to produce movement.

Question 32

WHOLE MUSCLE PROPERTIES

Answer 32

- epimysium - surrounds the entire skeletal muscles. - perimysium - surrounds each bundle of muscle fibres known as fasicles - fasiculous - string around the bundle of - fasicles - muscle fibre that surrounded by a sarcolemma that consists of sarcoplasms - muscle fibres contains thousands of myofibrils - sarcomere are a repeating unit that forms muscle fibres - muscle fibres break contain filaments