Organisation - L1 Flashcards
What is the general function of respiration?
To get oxygen for use by the body’s cells and to eliminate the carbon dioxide that the body’s cells produce
What does respiration encompass?
2 separate but related processes: internal and external respiration
Broadly speaking - What is internal respiration?
Oxidative phosphorylation
What is external respiration and how many processes?
There are 4 processes
It is the exchange of oxygen and carbon dioxide between the atmosphere and body tissues
What does internal respiration refer to?
It is cellular respiration and it refers to metabolic processes that are carried out within the mitochondria. This uses oxygen and makes carbon dioxide while deriving energy from nutrient molecules
4 broad steps of external respiration:
- Ventilation or gas exchange between the atmosphere and air sacs (alveoli) in the lungs.
- Exchange of oxygen and carbon dioxide between air in the alveoli and the blood in the pulmonary capillaries.
- Transport of oxygen and carbon dioxide by the blood between the lungs and the tissues.
- Exchange of oxygen and carbon dioxide between the blood in the systemic capillaries and the tissue cells.
Secondary functions? HINT 7
- Short term regulation of pH (acid-base balance)
- Enabling speech, singing, and other vocalizations
- Help in defense against pathogens in the airways
- Removes, modifies, activates (i.e. angiotensin II), or inactivates (i.e. prostaglandins) various materials passing through the pulmonary circulation
- Eliminates heat and water
- Assist venous return
- Nose serves as the organ of smell
What is the anatomy of the respiratory system?
Lungs, respiration airways leading into the lungs and structures of the thoracic cavity
Upper airways consists of:
Nasal cavity - nose, oral cavity, epiglottis, pharynx and larynx
Respiratory zone?
Alveolar sac and alveoli
Structure of the Conducting zone?
Primary, secondary and tertiary bronchi, bronchioles and trachea
What is trachea?
C shaped bands of cartilage for structural rigidity
Diameter and length of trachea?
2.5cm diameter and 10cm long
Primary bronchi?
Just the rings of cartilage - right and left
Secondary bronchi?
right side has 3 lobes of right lung and left side has 2 lobes of the left lung
Tertiary bronchi?
20-23 orders of branches with up to 8 million tubules
Bronchioles? Is there cartilage why/why not… what is there instead
Less than 1mm in diameter
No cartilage as there is risk of collapse
To prevent this, there is walls of elastic fibres and smooth muscle
Functions of the conducting zone?
Air passageway that is 150mL volume of dead space volume
Humidify air
Increase air temperature to body temperature
Structures of respiratory zone?
Alveoli, alveolar sacs, alveolar ducts, and respiratory bronchioles
Epithelium of conducting zone is made up of which 2 specialised cells? what are their functions?
Goblet cells that secret mucus and trap foreign particles
Ciliated cells that move the mucus up the glottis to be swallowed or released - this process is called mucus escalator
What is the function of the respiratory zone?
To exchange gases between air and blood via diffusion
What is the epithelium of the respiratory zone made up of?
Respiratory membrane that has epithelial cells of alveoli and endothelial cells of capillary
What is the alveoli the site for?
Alveoli is the site of gas exchange
Size of alveoli?
300-500 million
3 cell types of alveoli and functions?
Type I alveolar cells:
- Make up wall of alveoli, single layer epithelial cells
Type II alveolar cells:
- Secrete surfactant
- Reduces surface tension in alveolar walls
- Helps prevent alveolar collapse
Alveolar macrophages:
- Removes foreign particles
What forms a sheet over alveoli and acts as a rich blood supply?
Capillaries
What do the pores of Kohn in alveoli allow?
Pores of Kohn permit airflow between adjacent alveoli (collateral ventilation)
What is the respiratory membrane a barrier for?
Barrier for diffusion
Alveoli: Type 1 cells and basement membrane
Capillaries: endothelial cells and basement membrane
How thick is the respiratory membrane?
0.2 microns thick
