1. Anatomy of the respiratory system

Question 1

describe the development of the respiratory system

Answer 1

develops as a diverticulum from the pharynx

Question 2

what are the adaptations of the lateral nasal cavity to maximise warming and moistening inspired air?

Answer 2

Inferior middle and superior conchae increase the surface area of the nasal cavity – this increases the amount of inspired air that can come into contact with the cavity walls. They also disrupt the fast, laminar flow of the air, making it slow and turbulent. The air spends longer in the nasal cavity, so that it can be humidified.

Question 3

what is the function of the nasal cavity?

Answer 3

induce turbulent flow
warm and moisten inspired air 
recover water from expired air 
speech production (phonation)
olfaction

Question 4

what are the paranasal sinuses?

Answer 4

The paranasal sinuses are air-filled extensions of the nasal cavity.

Question 5

what is the function of the paranasal sinuses?

Answer 5

Lightening the weight of the head
Supporting immune defence of the nasal cavity
Humidifying inspired air
Increasing resonance of the voice

Question 6

why are the cartilages of the trachea incomplete?

Answer 6

as the oesophagus runs posterior to the trachea and needs space to expand when swallowing a food bolus.

Question 7

what form the conducting airways?

Answer 7

trachea
primary bronchi
secondary (lobar) bronchi
tertiary (segmental) bronchi
bronchioles
terminal bronchioles

Question 8

what is meant by the conducting airway?

Answer 8

sections of the respiratory tract which do not directly participate in gas exchange and instead simply allow bulk flow of air to areas which are responsible for gas exchange.

Question 9

how many true ribs do we have?

Answer 9

12

Question 10

how many false ribs do we have?

Answer 10

5 pairs

Question 11

what are the boundaries of the thoracic cavity?

Answer 11

walls = sternum, ribs and vertebrae
roof = superior thoracic aperture 
floor = diaphragm, inferior thoracic aperture

Question 12

where do the ribs articulate on the vertebrae?

Answer 12

on the demifacets. each rib articulates with 2 vertebrae

Question 13

what is the mediastinum?

Answer 13

The mediastinum is a division of the thoracic cavity; it contains the heart, thymus gland, portions of the esophagus and trachea, and other structures. It is the septum between the pleural cavities

Question 14

how does the chest wall move on inspiration?

Answer 14

increase in the lateral dimension of the chest as ribs ascend
sternum moves up and outwards to increase the anteroom posterior dimension of the thorax

Question 15

what pressure change occurs to allow inspiration?

Answer 15

the volume of the thoracic cavity increases, dropping intrapleural pressure
alveolar pressure must be lower than atmospheric pressure for air to enter the alveoli

Question 16

describe the structure of intercostal muscles?

Answer 16

3 layers. external intercostals, internal intercostal and innermost intercostal

Question 17

what vessels are associated with the ribs?

Answer 17

below the ribs = intercostal artery, vein and nerve

above the ribs = collateral branches

Question 18

what innervates the diaphragm?

Answer 18

phrenic nerve - c3 c4 c5

Question 19

what are the 3 major openings of the diaphragm?

Answer 19

vena cava T8
oesophagus T10
aortic hiatus T12

Question 20

what muscles are accessory muscles of ventilation?

Answer 20

pectoral muscles

SCM

Question 21

intercostal arteries have a dual blood supply, what are they?

Answer 21

aorta

internal thoracic artery

Question 22

where are chest drains inserted?

Answer 22

above the ribs

Question 23

what drains into the azygous vein?

Answer 23

thoracic cage - drains blood from the level of the heart so that it doesn’t go straight into the right atrium

Question 24

describe the variation in the structure of the left and right lobes?

Answer 24

the left lung has 2 lobes separated by the oblique fissure. It is indented by the heart
the right lung has 3 lobes. the superior and middle lobe are separated by the transverse fissure. the middle and the inferior lobe of the right lung are separated by the right oblique fissure

Question 25

why is it more common to inhale objects into the right bronchus than the left?

Answer 25

as the right bronchus sits at a straighter angle than the left bronchus

Question 26

what is the hilum of the lung?

Answer 26

the hilum is on the medial surface of the lung and is the area where vessels run in and out . Contains bronchi, pulmonary arteries and veins

Question 27

at what level is the hilum of the lung?

Answer 27

T3/T5

Question 28

what are the divisions of the mediastinum?

Answer 28

the anterior the superior the middle the posterior

Question 29

what is the difference between the visceral and parietal pleura?

Answer 29

visceral pleura is adhered to the organ, parietal is in contact with the thoracic wall. parietal = rich innervation, somatic pain visceral = no somatic innervation, do not feel pain as sharply, more of an ache.

Question 30

what is the pleural cavity?

Answer 30

a potential space between the visceral and parietal serous membranes. Contains a small amount of serous fluid

Question 31

what is the costophrenic recess

Answer 31

A potential space around the lung inside the pleural cavity. Is in the lower most part of the pleura, and from the angle between the ribs and the diaphragm.

Question 32

what is the blood supply to the lungs

Answer 32

pulmonary arteries | bronchial arteries

Question 33

why is the right hemidiaphragm higher than the left?

Answer 33

as the liver pushes it higher