The Respiratory System

Question 1

Nasal Cavity Structure and Function

Answer 1

• lined with cells which release mucus, which consists of lysozymes to kill bacteria
• lined with nose hairs, which are coated with mucus to collect particles which form boogers and prevent these particles from travelling further.

Question 2

Paranasal Sinuses Structure

Answer 2

Made up of 4 sinuses, which are air-filled spaces around the bones in the nose.

Question 3

Paranasal Sinuses Function

Answer 3

• Help the air become warm and moist
• Amplify sound of voice (hence the clogged sound when you get a cold)

Question 4

What are the names of the 4 paranasal sinuses?

Answer 4

1. Frontal
2. Ethmoid
3. Sphenoid
4. Maxilliary

Question 5

Pharynx Structure and Function

Answer 5

Also known as the throat
- Nasopharynx - connects pharynx to the nasal cavity
- Oropharynx - connects pharynx to oral cavity
- Valve - formed by the soft palette and uvula to close nasal pharynx when eating to prevent food travelling up.
- Laryngopharynx - connects to epiglottis and is continuous with the larynx (voice box).

Question 6

Epiglottis Function

Answer 6

Acts as a lid sealing larynx airway when eating. Cough reflex if anything other than air gets in the airway.

Question 7

Trachea Structure

Answer 7

Also known as the windpipe. Connected to the Right bronchus and left bronchus. Where they split is called the carina. Use cartilage rings for support

Question 8

Right Bronchus Structure

Answer 8

Wider and more vertical. Connects to right lung. Use cartilage rings for support.

Question 9

Right Lung Structure

Answer 9

Upper lobe
Middle Lobe
Lower Lobe

Question 10

Left Bronchus Structure

Answer 10

connected to left lung. Use cartilage rings for support.

Question 11

Left Lung Structure

Answer 11

Upper Lobe
Lower Lobe

Question 12

Cross Section of Trachea Structure and Function

Answer 12

• Layer of smooth muscle - containing sympathetic nerves and parasympathetic nerves from the autonomic nervous system.
• Smooth Muscle and the first few branches of the bronchi have Beta 2 adrenergic receptors. The sympathetic nerves stimulate the receptors causing the diameter of the airways to increase.
• Also have musocarinic receptors which are stimulated by parasympathetic nerves and decrease the diameter of airways and less air comes through.

Question 13

Airways Structure and Function in the Trachea

Answer 13

• Lined with ciliated columnar cells - moves mucus towards pharynx so that it can be spit out or swallowed (mucociliary escalator)
• Goblet cells - secretes mucus to trap particles.

Question 14

Three types of bronchioles

Answer 14

Happens when airways narrow.
Conducting bronchioles
Terminal bronchioles
Respiratory bronchioles

Question 15

Structure and Function of Conducting Bronchioles

Answer 15

Receives oxygenated blood from bronchial arteries
Walls lined with ciliated columnar cells, goblet cells and club cells. Club cells secrete glycosaminoglycans to protect epithelium and regenerates and replaces columnar cells.

Question 16

Structure and Function of Respiratory Bronchioles

Answer 16

• Alveoli on the walls
• Alveolar ducts (final destination of the inhaled air) - Walls lined with pneomocytes which secrete surfactant to decrease the surface tension and keep alveoli open

Question 17

Capillary function and structure

Answer 17

• Contains endothelial cells
• deoxygenated blood goes to capillary from pulmonary arteries

Question 18

Basement Membrane Structure

Answer 18

• Formed by the pneuomocytes and capillaries.

Question 19

Blood-Gas Barrier Structure

Answer 19

Formed by the capillary wall, basement membrane and alveoli wall to ensure that only O2 and CO2 are allowed in and out.

Question 20

What happens with the CO2 and O2 in the alveoli and capillaries?

Answer 20

The CO2 diffuses from the capillary to the alveoli to be breathed out.
The O2 diffuses into capillary from alveoli to enter the blood.
Oxygenated blood then travels through the pulmonary veins to the heart and the body.