Respitory System

Question 1

Gaseous exchange

Answer 1

• the process in the lungs whereby oxygen is delivered to the bloodstream while carbon dioxide is removed from it , takes place in the alveoli

Question 2

The importance of the alveoli

Answer 2

1. Large surface area - maximises contact between gases and blood
2. Thin walls - one cell thick, so gases can pass through easily
3. Moist lining - helps gases diffuse more freely
4. Capillary walls - ensure hood blood supply
5. Well ventilated - air can reach them easily

Question 3

The mechanics of breathing

Answer 3

Diaphragm - muscular sheet at the base of the chest cavity dividing it from the abdomen

Intercostal muscles - the muscles between the ribs that raise and lower the ribs

Question 4

The mechanics of breathing inspiration

Answer 4

Rib cage - moves upwards and outwards as the intercostal muscles contract and lengthen

Diaphragm - contracts and becomes flatter

Effect - the lungs draw in oxygen

Volumes of lungs - increases

Pressure of lungs - reduces

Question 5

The mechanics of breathing expiration

Answer 5

Rib cage - moves inwards and downwards as the intercostal muscles relax

Diaphragm - relaxes and domes upwards

Effect - Air containing CO2 is forced out the body

Volumes of lungs - reduces

Pressure of lungs - increases

Question 6

Short term effects of exercise

Answer 6

Submaximal - is an activity with a steady increase in work load or intensity working at 85% of the maximum heart rate

Maximal - an activity where the intensity is constant throughout a short period of time

Question 7

Tidal volume

Answer 7

The volume of air you inhale with each breath during normal breathing

Question 8

Minute ventilation

Answer 8

The volume of air in lites that you breath per min

Minute Ventilation = tidal volume (ml) x number of breaths (per min)

Question 9

Vital capacity

Answer 9

Vital capacity is the maximum volume of air you can breath out

Measured by spirometer

Question 10

Residual volume

Answer 10

Residual volume is the volume of air left in your lungs after breathing out

Prevents lungs from collapsing

This air cannot be breathed out

Question 11

Effects of exercise on breathing volumes

Answer 11

Tidal volume - increases

Minute Ventilation- increases

Residual volume - stays the same

Vital capacity- stays the same

Question 12

Pathway of gaseous exchange

Answer 12

• oxygen enters the raspatory system through the nasal passage and mouth
• travels down the trachea which divides into bronchi
• airways begin to narrow and branch of into bronchioles
• oxygen reaches alveoli where gaseous exchange occurs