Gaseous Exchange Flashcards
What is breathing?
Mechanical process where air moves in and out of the lungs.
What is gaseous exchange?
The exchange of 02 and CO2 across a gaseous exchange surface.
What is cellular respiration?
Chemical process which takes place inside cells in order to release energy.
Why is cellular respiration necessary?
Making oxygen from the atmosphere available to cells for respiration.
Removing CO2 which can dangerously lower body fluid pH levels.
What are the requirements for an effective gaseous exchange surface?
Large, thin, moist, transport system, well protected.
Name the three parts of the human respiratory system.
Air passages, lungs and respiratory muscles.
Which air passages carry air to and from the lungs?
Nasal passages, pharynx, trachea, bronchi and bronchioli.
What separates the two nasal cavities?
Septum.
What is the function of the small hairs in the nasal cavities?
Filter larger particles.
What divides each nasal cavity into three passages?
Three curved curved turbinate bones.
What does the mucous membrane in the nasal cavities consist of?
Ciliated columnar epithelial cells.
What is supplied to the columnar epithelial cells to warm to the air?
Superficial blood capillaries.
What in the columnar epithelium secretes musus?
Goblet cells.
What is the function of mucus from the giblet cells?
Traps germs/dust, is an antiseptic and moistens the incoming air to keep the gaseous exchange surface moist.
What is the function of the cilia?
Continuously perform sweeping movements away from the lungs, expelling dust-carrying mucus.
What does the nasal cavity open into?
The pharynx.
Which two openings does the pharynx lead to?
The glottis, which is the opening to the trachea, and the opening leading to the oesophagus.
Describe the trachea’s structure.
Long, tubular structure (12cm) located in front of the oesophagus.
What houses the vocal cords at the top of the trachea?
The larynx.
What is the shape and material of the larynx?
Triangular box made of cartilage.
What is the thin, leaf shaped cartilage structure at the top of the larynx?
the epiglottis.
What is the function of the epiglottis?
Closes the glottis during the swallowing process to prevent food entering the trachea.
What reinforces the trachea and keeps it open?
C-shaped cartilage rings.
Why are the openings of the C-shaped rings faced toward the back?
To allow the oesophagus to expand as food goes past it.
What lines the trachea?
Mucus membrane of ciliated columnar epithelial cells that secrete mucus.
What does the trachea divide into?
Left and right bronchus leading to the left and right lung.
What holds open the bronchi?
O-shaped cartilage rings.
Are the bronchi lined with a mucous membrane?
Yes.
What is the difference between bronchi and bronchioles?
Bronchioles are smaller and have no cartilage rings.
What do bronchioli end in?
An infundibulum (lung sacs) which consists of groups of alveoli.
How many pairs of ribs protect the lungs?
12.
Where are the intercostal muscles?
Between the ribs.
How many lobes do our lungs have?
Right lung - 3. Left lung - 2.
Describe the consistency of the lungs.
Spongy and elastic.
What is the pleura?
The double membrane surrounding each lung.
What prevents friction when the lungs shrink and contract?
Intrapleural fluid between the two pleural membranes.
What do the lungs rest on?
A dome shaped muscle - the diaphragm.
Describe the walls of the alveoli.
Very thin and consisting of a single layer of squamous epithelium.
What surrounds the alveoli?
A network of capillaries.
What do the capillaries consist of?
A single layer of squamous epithelium.
What is the muscle plate that separates the chest and abdomen to form an airtight thoracic cavity?
The diaphragm.
Name the two sets of intercostal muscles.
External and internal intercostal muscles.
How is oxygen transported in the blood?
It combines with haemoglobin in red blood cells to form oxthaemoglobin or it dissolves in the blood plasma.
How is carbon dioxide transported in the blood?
It combines with water to farm carbonic acid and then dissociates to form bicarbonate atoms or combines with haemoglobin to form carbaminohaemoglibin or it dissolves in the blood plasma.
What is the inhaled vs exhaled composition of Nitrogen?
Inhaled 78%.
Exhaled 78%.
What is the inhaled vs exhaled composition of Oxygen?
Inhaled 21%.
Exhaled 15%.
What is the inhaled vs exhaled composition of CO2?
Inhaled 0,04%.
Exhaled 4%.
What is the inhaled vs exhaled composition of water vapour?
Inhaled varies and exhaled is sturated.
Where are the cardiovascular centrea and the respiratory centre in the brain?
In the medulla oblangata.
What is lung capacity?
The total air that the lungs can accommodate.
What is tidal volume?
The amount of air breathed in and out during normal breathing.
What is the additional air that can be inhaled after normal normal inhilation?
Inspiratory reserve volume.
What is expiratory reserve volume?
The additional air that can be exhaled after normal exhalation.
What is the vital lung capacity?
The two reserve volumes as well as the tidal volume.
What is the air in the lungs that is never exhaled called?
Risidual volume.
What in the wall of the aorta and the base of the jugular arteries senses changes in CO2 concentration in the blood?
Chemoreceptors.
Where do the chemoreceptors send nerve impulses?
The respiratory and cardiovascular centres.
