Respiratory and skeletal systems

Question 1

What happens during inspiration?

Answer 1

• diaphragm and external intercostals contract
• volume of thoracic cavity increases
• pressure decreases
• air enters the lungs

Question 2

What happens during inspiration while exercising?

Answer 2

• recruitment of sternocleidomastus and pectoralis minor
• further increases the volume of the thoracic cavity
• creating a pressure gradient
• air enters the lungs more quickly

Question 3

What happens during expiration?

Answer 3

• passive process where diaphragm and external intercostals relax
• volume of thoracic cavity is reduced
• air pressure increases
• air is expelled from the lungs

Question 4

What happens during expiration while exercising?

Answer 4

• recruitment of external intercostals and abdominals
• decrease the volume of the thoracic cavity further
• increase the pressure more
• air forced out of the lungs more quickly

Question 5

What is breathing rate and give a maximal and resting value?

Answer 5

the number of times we breathe in or out per minute

resting value = 12-15

maximal value = 40-60

Question 6

What is tidal volume and give a resting and a maximal value?

Answer 6

volume of sir inhaled or exhaled per breathe

resting value = 5.5-7.5L

maximal value = 15-20L

Question 7

How are the alveoli designed for gas exchange?

Answer 7

• thin walls result in a short diffusion pathway
• extensive capillary network provides a good blood supply
• large SA results in a greater O2 uptake

Question 8

Describe the partial pressure of O2 in the body?

Answer 8

• PP of O2 is higher in the alveoli than capillaries as O2 has been removed by working muscles
• O2 concentration is lower in the blood therefore PP is lower
• difference in PP is called concentration/diffusion gradient
• the steeper the difference the faster diffusion is

Question 9

How does capillary and alveoli PP equalise?

Answer 9

• O2 will diffuse from the alveoli to the blood until pressure is equal in both
• PP of CO2 in the blood entering entering alveolar capillaries is higher than in the alveoli
• CO2 therefore diffuses into the alveoli from the blood until pressure is equal in both

Question 10

What is a joint?

Answer 10

where two or more bones meet and are classified by how much movement is allowed

Question 11

What is the function of articulating cartilage and bursa?

Answer 11

cartilage = coves bones at a joint and prevents friction

bursa = fluid filled sac located between a bone + tendon reducing friction

Question 12

What is the structure and function of a joint capsule?

Answer 12

• fibrous layer of tissue encasing a joint
• strengthens and protects the joint
• synovial fluid fills the joint capsule nourishing cartilage and preventing friction

Question 13

What is a synovial membrane and what does it do?

Answer 13

• inner lining to a joint capsule secreting synovial fluid
• a pad of fat acts as a shock absorber

Question 14

What is a ligament and what does it do?

Answer 14

fibrous connective tissue connecting bone to bone, holding structure keeping them stable

Question 15

What is a tendon and what does it do?

Answer 15

fibrous connective tissue connection muscle to bone facilitating movement around a joint