repiratory

Question 1

external internal and cellular respiration

Answer 1

• gas exchange between blood capillaries and air sacs of the lungs
• gas exchange between blood caplaaries and body cells
• the breakdown of organic molecules in the cell to release energy

Question 2

nose and mouth

Answer 2

nose - is supported by bone and cartilage lined with mucous membrane, containing fine hairs which filters air and moistens it
the pharynx is a common passageway for air and food
larynx- made up of cartilages and located on the trachea
prevents particles from entering the trachea removed by the coughing reflex
epiglottis closes the trachea during swallowing

Question 3

trachea

Answer 3

located in the mediastinum
cartilige that is C shaped to allow the oesophagod to expand during swallowing
lined with mucus membrane composed of cilliated epithelium with many goblet cells mucus traps particles

Question 4

lungs

Answer 4

spongy cone shaped organs
seperated medially by the mediastinum, and enclosed by diagram and thoracic cage
the visceral pleura is attached to the surface of the lungs and the parietal pleura lines the thoracic cavity

Question 5

microscopic structure of the lungs

Answer 5

the bronchi divide repeatedly to form bronchioles that lead to the alveolar ducts open into the alveoli
alveoli have thin walls of simple squamous epithelium and rich supply of blood capillaries
oxygen passes into the blood where it combines with haemoglobin where co2 diffuses out of the blood into alveoli

Question 6

diaphram ribs and intercostal muscles

Answer 6

the diaphram is a large, attached to the base of the ribs and the vertebral column
ribs protect the heart and lungs and are used in breathing
moved by intercostal muscles

Question 7

ventilation

Answer 7

the movement of air in and out of the lungs, is composed of inspiration and expiration

Question 8

inspiration

Answer 8

diaphram contacts and moves downwards
external muscles contract to raise the ribs and sternum
as the thoracic cavity becomes larger, the lungs enlarge and the air pressure in the alveoli drops
causes fresh air to enter the lungs

Question 9

expiration

Answer 9

diaphram relaxes and moves back upwards
intercostal muscles relx to allow the ribs to move downwards and inwards
as the chest cavity becomes smaller, the air presssrue in the alveoli increases
air forced out

Question 10

breathing rate

Answer 10

controlled by the brain and is mainly involunatry. breathing will be faster during and after exercise to remove extra carbon dioxide from the blood

Question 11

4 factors affecting diffusion

Answer 11

• membrane thickness
  surface area of membrane
  diffusion coeffiecnt of gas
  pressure diffrence of gases across membrane

Question 12

chemical contol

Answer 12

there are peripheral and central chemoreceptors central are in the medulla are sensetive to change in blood co2 or ph

Question 13

intra-pulmonary rectors

Answer 13

these are found in lung. cough stretch and c fibres send afferent neutral infromation to the medulla and can change the pattern of breathing