Week 5 Respiratory System

Question 1

Respiration

Answer 1

Respiration is the process by which oxygen is supplied to tissues and carbon dioxide is removed
• Pulmonary ventilation or breathing
• External (pulmonary) respiration
• Internal (tissue) respiration

Question 2

Pulmonary ventilation

Answer 2

• Inhalation and exhalation of air
• Exchange of air between the atmosphere and the pulmonary alveoli of the lungs
• Permits O2 to enter the lungs and CO2 to leave

Pulmonary artery = deoxygenated
Pulmonary Vein = oxygenated

Question 3

External respiration

Answer 3

• Exchange of gases between pulmonary alveoli and blood in pulmonary capillaries
• Meet respiratory demands

Question 4

Internal respiration

Answer 4

Exchange of gases between blood in systemic capillaries and cells of tissues
• Cells absorb O2
• Cells produce CO2

Question 5

Components of the respiratory system

Answer 5

• Upper respiratory system
• Nose
• Nasal cavity
• Pharynx

• Lower respiratory system
• Larynx
• Trachea
• Bronchi
• Lungs

Question 6

Function of the respiratory system

Answer 6

Gas exchange
• Intake of O2 for cells
• Removal of CO2 produced by cells

• Regulate blood pH

• Additional features
• Receptors for smell
• Filters inspired air
• Vocal sounds
• Excrete small amounts of water and heat

Question 7

Conducting zone

Answer 7

The structures that provide passageway for air to travel into and out of the lungs in the most efficient way

• Nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

Increase SA to maximise gaseous exchange
Lots of sub divisions to get into respiratory zone
Where gaseous exchange takes place

Question 8

Repiratory zone

Answer 8

The site of O2 and CO2 exchange with the blood

• Respiratory bronchioles, alveolar ducts, alveolar saccules, pulmonary alveoli

Question 9

Upper respiratory system
External nose

Answer 9

External nose
• Protect the inner nose= filter stuff out
• Allows entry of air
• Function of interior structures
• Warm, moisten & filter incoming air= warm helps with absorption
• Olfactory receptors useful for smell
• Modify speech vibrations

Question 10

Upper respiratory system Internal nose

Answer 10

Internal nose
• Nasal cavity

• Large inferior respiratory
region
• Smaller superior olfactory region

• Respiratory epithelium
• Ciliated columnar epithelium = move mucus along

• Goblet cells= secrete mucus to grab and trap toxins and other stuff

Question 11

Upper respiratory system pharynx

Answer 11

• Skeletal muscle lined with
mucous membrane Immune function and stop things getting further into are system
• Passageway for air and food
• Resonating chamber for speech
• Tonsils

Respiratory and digestion

Question 12

Lower respiratory system larynx

Answer 12

• Connects laryngopharynx with
the trachea

Question 13

Lower respiratory system trachea

Answer 13

Trachea (windpipe)
• Tubular passageway
• Semi-rigid structure to maintain patency(hold it open)

Trachea
• Anterior to the oesophagus
• Extends from the inferior border of the larynx to the superior borders of the 5th thoracic vertebra
• 4 layers
• Respiratory mucosa – ciliated epithelial cells = filter things out

• Submucosa – areolar connective tissue (seromucous glands and ducts) secretes mucus

• Hyaline cartilage: 16-20 C-shaped horizontal rings for flexibility as oesophagus runs down the back

• Aventitia – areolar connective tissue holds it in place

Question 14

Lower respiratory system structure

Answer 14

Trachea divides into right main and left main (primary) bronchus
• Incomplete rings of cartilage
• Lined by ciliated epithelium

Right bronchus is bigger
• Main bronchi divide into lobar (secondary) bronchi
• 3 right • 2 left

• Segmental (tertiary) bronchi
• 13 right. • 8 left

Question 15

Lower respiratory system – structure Bronchioles

Answer 15

Bronchioles
• Clara cells
• Non ciliated secretory cells
• Protect against harmful effects of
inhaled toxins and carcinogens
• Develop into epithelial cells
• Produce surfactant
• Lipid and protein complex to enhance pathogen clearance
• Regulate innate and adaptive immune function

Question 16

Lungs

Answer 16

Paired cone-shaped organs in the thoracic cavity

• Separated by the heart and other structures of the mediastinum
• Pleural membrane
• Encloses and protects each lung
• Double-layered serous membrane
• Parietal pleura – superficial layer – lines thoracic
cavity
• Visceral pleura – deep layer – covers lungs
• Layers are separated by the pleural cavity (lubricating fluid)

Each lung is divided into lobes
• Each lobe has many lobules
• Wrapped in elastic connective tissues
• Contains: lymphatic vessel, arteriole, venule and branch from terminal bronchiole

Question 17

Alveolar sacs and alveoli

Answer 17

Microscopic airways
Respiratory bronchioles > alveolar ducts >alveolar saccules > pulmonary alveoli

Alveolar saccule has outpouchings – pulmonary alveoli (grapes)
Increase SA for faster diffusion and is highly vasculated
• Alveoli contain two types of epithelial cells
• Type1
• Simple squamous epithelial cells = flatterned but big
• Most abundant
• Main site of gas exchange

• Type2
• Septal cells
• Rounded epithelial cells
• Found in between Type 1 cells
• Microvilli
• Secrete pulmonary alveolar fluid = surface tension to maintain structure

Question 18

Alveolar sacs & alveoli macrophages and fibroblasts

Answer 18

Macrophages
• Phagocytes
• Remove fine dust and debris

• Fibroblasts
• Reticular and elastic fibres to allow alveoli to move/ flexibility

Question 19

Respiratory membrane

Answer 19

Formed by pulmonary alveolar and capillary walls

• Four layers
• Alveolar wall (Type I and II
pneumocytes and macrophages) • Epithelial basement membrane • Capillary basement membrane
• Capillary endothelium

• 0.5 μm thick – rapid diffusion like beffy 🐐