GASEOUS EXHANGE Flashcards
gaseous exchange
the exchange of O2 and CO2 in the alveoli(external) and at cellular level(internal)
requirements of efficient gas exchange
- have lots of alveoli for increase in SA for max gas exchange
- alveoli have thin epithelium cells for rapid and sufficient diffusion
- mucous is produced so O2 and CO2 dissolves in the moisture
- well ventilated to allow proper flow of air in and out of the respiration system
- is protected by pleura, ribs and sternum
function of nasal cavity
- mucous from goblet cells and cilia trap dirt and sweep it out of the nose
- keeps cavity moist and removes and destroys pathogens
- blood capillaries warm incoming air
function of larynx
contains vocal chords where air passes over them and makes them vibrate in order to produce sound
function of ribs
protect the lungs from injury
function of right bronchus
takes air to the right lung
function of pharynx
connects the nasal cavity with the larynx and is lined with mucous membranes
function of epiglottis
closes trachea when swallowing to prevent choking
function of trachea
C-shaped cartilage rings that keep trachea open and is lined with ciliate epithelial cells to remove mucous
function of left bronchus
takes air to left lung
function of pleura
each lung is lined with a double pleura membrane which provides protection
function of diaphragm
seperates abdominal and thoracic cavity and aids in breathing
function of bronchioles
tubes that branch off from bronchus and then take air to the alveoli
function of alveoli
- are one cell layer thick which increases SA and then allows for gas exchange
- is humid because of mucous
gas exchange in the lungs
- capillaries surrounding the alveolus have a high concentration of CO2 and low concentration of O2
- the air in alveolus have a high concentration of O2 and a low concentration of CO2
- this concentration gradient allows for diffusion to occur
- O2 dissolves in the moisture lining the alveolus and diffuses into the bloodstream
- the CO2 then diffuses out of the bloodstream into the alveolus
- O2 forms a loose combination of haemoglobin to form oxyhaemoglobin
gas exchange in the tissues
- blood in the capillaries reaching the tissues has a high concentration of O2 and a low concentration of CO2
- tissues fluid has a higher concentration of CO2 and a lower concentration of O2
- this concentration gradient allows for diffusion to occur
- O2 diffuses into the tissue fluid, then into the cells
- CO2 diffuses out of the cells into the tissue fluid then into the blood
- cell resp causes the consumption of O2 and production of CO2
exhalation
when air is pushed out of the lungs
inhalation
when air moves into the lungs
what occurs during exhalation
- diaphragm relaxes and moves upwards
- intercoastal muscles relax
- ribcage moves down and inward
- volume of thoracic cavity decreases
- air pressure in lungs increases relative to the outside air pressure
what occurs during inhalation
- diaphragm muscle contracts and moves downwards
- intercoastal muscles between ribs contract
- ribcage lifts up and pushes outwards
- the volume of the thoracic cavity increases
- air pressure in the lungs decreases as the chest volume increases
homeostasis
the process of maintaining a constant, internal environment within narrow boundaries, despite changes taking place internally and externally
strenuos physical activity increases the bodies need for energy, what does it result in?
- CO2 levels in the blood increases above normal levels
- receptor cells in carotid artery in the neck are stimulated
- cells send impulses to the medulla oblongata in the brain
- medulla oblongata stimulates breathing muscles and heart
- breathing muscles contract more actively- increasing the rate and depth of breathing and the heart beats faster
- more CO2 is taken to and exhaled from the lungs
- the CO2 levels in the blood returns to normal
