Skeletal

Question 1

What are the functions of the Skeletal System?

Answer 1

Protection
Movement
Support/Structural
Mineral Storage
Blood Cell Formation

Question 2

Skeletal Tissue is responsible for:

Answer 2

✓ Mineral storage
✓ If 35% drop in blood calcium = convulsion
✓ Need to ‘bank’ minerals in bones
✓ Replaced approximately every 9 months
✓ Blood Cell formation
✓ Red marrow inside long bones
✓ Some white blood cells produced in yellow bone marrow
✓ At birth all marrow red, with age converts to yellow
✓ Within vertebrae, ribs, sternum & cranial bones
✓ Produces 3 types of blood cells

Question 3

Give examples of these types of bone;

Answer 3

Long Bones – e.g. in arms & legs
Short Bones – e.g. carpals in the wrist, tarsals in the ankles
Flat Bones – e.g. skull, sternum
Irregular Bones – e.g. mandible and vertebrae

Question 4

What is the function of an osteoblast?

Answer 4

To build bone (ossification)

Question 5

What is the name of the thick membrane surrounding the bone?

Answer 5

Periosteum

Question 6

What is the name for the main portion of a bone?

Answer 6

Diaphyses

Question 7

What are the epiphyses?

Answer 7

The end part of a long bone

Question 8

Where is spongy bone found?

Answer 8

The inner part of bones

Question 9

Where is compact bone found?

Answer 9

The outer “coating” of bones, a rigid coating made up of osteon and lamellae

Question 10

Osteons

Answer 10

The predominant feature of compact bone, they are cylindrical structures consisting of onion-like concentric rings of lamellae surrounding a central canal

Question 11

Central canal:

Answer 11

A channel through the core of each osteon; it permits the passage of neurovascular structures

Question 12

Endosteum

Answer 12

A fibrous layer that covers the interior of each bone; it has a rich neurovascular supply

Question 13

Periosteum

Answer 13

A fibrous layer that covers the exterior of each bone with the exception of the joint surfaces; it has a rich neurovascular supply.

Question 14

✓ Erythrocytes-

Answer 14

A red blood cell, made in the bone marrow, containing haemoglobin.

Question 15

✓ Leukocytes-

Answer 15

A white blood cell, forming part of the immune response against foreign bodies and disease.

Question 16

Thrombocytes

Answer 16

A component of the blood that promotes clotting

Question 17

✓ Process-

Answer 17

a projection or outgrowth of bony tissue from a larger body.

Question 18

Spine –

Answer 18

a column of bone, also known as the vertebral column

Question 19

✓ Tubecle

Answer 19

a round nodule

Question 20

Crest

Answer 20

a ridge or raised surface

Question 21

Facet

Answer 21

a small smooth area on a bone, usually with an articular surface.

Question 22

Fossa

Answer 22

a small depression or hollow

Question 23

Sulcus

Answer 23

a groove or furrow

Question 24

Foramen

Answer 24

an opening, hole or passage

Question 25

Meatus

Answer 25

a natural body opening or canal

Question 26

Define how much movement is provided for each of these joint classifications and provide an example.

Answer 26

-Synovial – allow a lot of movement e.g. Ball and socket – hip or shoulder joint -Hinge joints e.g. knee and elbow -Pivot joint – neck -Saddle joint - thumbs -Fibrous or synarthrosis joints – allow very little movement Bones of the skull (this is important in relation to brain injuries that can effect vision) -Cartilaginous – allow some movement, more than fibrous but not as much as synovial e.g. between vertebrae

Question 27

State four functions of the muscular system

Answer 27

Movement (Eye movement) Regulate organ volumes/maintain homeostasis Maintain posture/stabilize joints Produce heat Breathing

Question 28

What are the three types of muscle? How do they differ?

Answer 28

Skeletal, Cardiac and Smooth

Question 29

What attaches skeletal muscle to bone?

Answer 29

Tendons or connective tissue (aponeurosis)

Question 30

Smooth muscle lines what type of organ?

Answer 30

Smooth muscle controls pupil constriction Hollow organs, another example is in the digestive system

Question 31

What part of the nervous system controls smooth muscle?

Answer 31

Peripheral

Question 32

What chemical enables/causes muscle contraction?

Answer 32

Atp

Question 33

What is the name of the contractile unit only found in skeletal muscle

Answer 33

Skeletal muscle contracts fast, this is important for fast eye movements! Sliding Filament mechanism

Question 34

What type of tissue holds skeletal muscle of similar function together?

Answer 34

Fasciae

Question 35

What is the smallest contractile unit of a muscle fibre?

Answer 35

Sarcomere

Question 36

What must occur to allow the myosin head to bind to the actin filament?

Answer 36

Tropomyosin must have been removed by the binding of calcium.

Question 37

What do mitochondria do to allow the sarcomeres to contract?

Answer 37

Mitochondria produce ATP. There is an ATP binding site on the myosin head, providing energy for the myosin head to move the actin towards the Z line – causing contraction.

Question 38

What is the name of the structure where a motor neurone meets a skeletal muscle fibre?

Answer 38

Neuro-muscular junction

Question 39

What is the name of the neurotransmitter responsible for most excitatory movement of skeletal muscle?

Answer 39

Acetylcholine

Question 40

What happens when the nervous impulse reaches the axon terminal?

Answer 40

Causes the vesicles to release acetylcholine into the synaptic cleft/gap

Question 41

What is the gap between the neurone and muscle called?

Answer 41

Synaptic cleft

Question 42

What does the neurotransmitter bind to?

Answer 42

Receptors on the sarcolemma

Question 43

Once this happens, what flows into the muscle fibre?

Answer 43

Sodium ions move into the sarcolemma from the extracellular space

Question 44

What then happens to the electrical charge of the muscle fibre?

Answer 44

It becomes relatively more positive/less negative

Question 45

Once the threshold level is reached the action potential is sent through what muscular structure?

Answer 45

Along the sarcolemma to the T-tubules

Question 46

In what two ways is the neurotransmitter ‘recycled’ and returned to the motor neurone and what is the name of the enzyme responsible for one of these methods?

Answer 46

It diffuses away from the synapse It is broken down by the enzyme Acetylcholinesterase (into acetic acid and choline)