Respiratory System

Question 1

epiglottis

Answer 1

small leaf shaped flap of elastic fibre covered with mucous membrane. Tapered inferior end is attached to thyroid cartilage, other end moves up and down. During swallowing the pharynx and Larynx rise causing the epiglottis to cover larynx so food goes down the esophagus.

Question 2

Glottis

Answer 2

The true vocal chords with the slit between them. Air moving between them causing sounds producing vibrations.

Question 3

Trachea- SFL

Answer 3

S- a mucous membrane lined stack of 16-20 C shaped hyaline cartilage rings. Connected to cricoid cartilage by ligaments, rings connected by ligaments, 2 sides are connected to muscle
F- flexible tube of cartilage that allows the esophagus to expand during swallowing, solid parts of C rings= rigid air passage that prevents over-expansion and collapse
L- below the larynx

Question 4

Trachea lining

Answer 4

Pseudostratified ciliated columnar epithelium. Contains ciliated cells, goblet cells, and basal cells. Cilia and mucous move particles up towards the pharynx.

Question 5

Pleural membrane of the lungs

Answer 5

2 layered, lining the pleural cavity. Parietal pleura is attached to the chest wall and diaphragm, visceral is attached to the lungs. The membranes secrete fluid into the ‘pleural space’ between them so they slide easily over one another during contraction/expansion of the lungs.

Question 6

Division of the lungs

Answer 6

One on either side- with three lobes on the right and two on the left, these lobes are divided by fissures

Question 7

Alveoli (s. alveolus)

Answer 7

cup-shaped out-pouching of an alveolar sac. Where gas exchange occurs (type I alveolar cells- simple squamous epithelium). Covered in network of elastic fibres (important in expiration)
other cells: Type II A cells excrete fluid- keeps air and cell surface moist. Alveolar macrophages- phagocytes that remove fine dust particles and other debris. Surfacant secreting cells- secrete a fluid (w phospholipids) that prevent collapse of alveoli

Question 8

Respiratory membrane

Answer 8

very thin membrane made up of alveolar and capillary walls- CO2 and O2 diffuse across.
Cells: Type I alveolar cells, Epithelial basement membrane (alveoli), Capillary basement membrane(fused to epithelial), Endothelial cells of capillary wall.

Question 9

Pulmonary Ventilation

Answer 9

Consists of inspiration and expiration. Flow of air in and out of lungs.

Question 10

Quiet inspiration (breathing at rest)

Answer 10

Contraction of the outer intercostals(up and out) and diaphragm(flattens) expand the thoracic cavity pulling the lungs open with it and decreasing the pressure(alveolar press) inside the lungs. When lung pressure falls below atmospheric pressure air rushes into the lungs.

Question 11

Expiration

Answer 11

passive process- intercostals and diaphragm relax, lungs compress due to elastic recoil- presence of surfactant in alveoli prevent total collapse.

Question 12

Total lung capacity

Answer 12

made up of the tidal volume (volume of one breath) + inspiratory reserve volume(extra air inhaled-deep breath) and expiratory reserve volumes(normal inhale; exhale as forcibly as possible) + residual volume(volume of air left in lungs after expiration)

Question 13

Larynx- SFL

Answer 13

S- short tube of cartilage lined w a mucous membrane. Made up of thyroid cartilage(anterior), cricoid cartilage(inferior), arytenoids & corniculate(posterior & lateral.- all hyaline C
F- to provide a patent(open airway), produce sounds, switching mechanism to direct food and air.
L- Between the pharynx and trachea.