Chapter 17: Movement in humans

Question 1

Bones

Answer 1

• Tissue formed by living cells
• Consists of minerals (e.g. CaSO4, make the bone rigid), proteins (e.g. collagen) and water

Compact bone
- Outer shell of all bones, shafts of limb bones
- Dense and rigid -> providdes great strength for supporting the weight of the body
- Yellow bone marrow fills the shafts of limb bones

Spongy bone
- Head of limb bones
- Porous -> absorb shock and resist stress
- Red bone marrow fills the cavities of spongy bones

Question 2

Bone marrow

Answer 2

Yellow bone marrow:
- fills shafts of limb bones
- fatty tissue, stores fat

Red bone marrow:
- fills cavities of spongy bones
- produces blood cells

Question 3

Cartilage

Answer 3

• tissue formed by living cells
• contains fewer minerals → softer and more elastic

Question 4

Neuromuscular junction: transmission of neurotransmitters

Answer 4

• Arrival of nerve impulse at the nerve ending of a motor neurone stimulates the synaptic vesicles to release neurotransmitters into the NMJ between th e nerve ending and the muscle fibre
• Neurotransmitter relaeed from the vesicle difffuses across the neuronmscular junction and binds to specific receptors sites on the membrane of the muscle fibre. This binding triggers the generation of an electrical impulse. This impulse is transmitter along the muscle fibre and triggers muscle contraction.