B3.1 gas exchange Flashcards
what are 4 properties of surfaces that allow efficient gas exchange
large surface area
thin
moist
highly covered by capillaries
larynx
hollow muscular tube forming an air passage to the lungs and holding the vocal cords
trachea
a tube reinforced by rings of cartilage, extending from the larynx to the bronchial tubes and converting air to and from the lungs. The cartilage helps support the trachea while still allowing it to move and flex during breathing
ribs
bones involved in the protection of the thorax cavity
intercoastal muscle
muscles behind the rib that control the ventilation process
alveoli
many tiny air sacs of the lungs which allow for rapid gaseous exchnage (singular, alveolus)
pluramembrane
covers the surfaces of the lungs and prevent friction by secreting a lubricant called pleural fluid
bronchi
airway that conducts air into the lungs
branches into smaller tubes, known as bronchioles, lined with smooth muscles that can dialate or constrict
lung
spongy tissue made of alveoli and capillaries
diaphragm
dome shaped muscle that seperates the thorax from the abdomen and is invlved in the ventilation process
what is the alveolar epithelium
an example of a tissue where more than one cell type if present because different adaptations are recquired for the overall functio of the tissue
2 types of cells=
type 1P
type 2P
describe the type 1 pneumocytes
Structure: flattened, extreme thin cells that line the alveolus their shape maximizes surface area and minimizes distance for diffusion of gas into and out of blood
function: the cell responsible for the exchange that takes place in the alveoli
describe type 2 pneumocytes
strucutre:
rounded cells that are sporadicaly placed in the alveolus. contain many secretory vesicles (lamellar bodies) in the cytoplasm
function:
cell responsible for the production and secretion of surfactant, discharged by secretory vesciles to the alveolar lumen
the surfactant is a fluid that; coats the inner surface of the alveoli, allowing oxygen to dissolve and then diffuse into the blood of the capillaries
prevents that sides o the alveoli from sticking to each other when the air is exhaled
capillaries in terms of the alveolus
they fully surround the alveoli, cells that line the capillary= capillary epithelium, they are thin epithelial cells to maximise surface area for diffusion
whats the basement membrnae
a thin fibrous extracellular matrix of proteins that seperates the alveolus and capillary, provides structural support to the alveolus (helps maintain its shape)
what are the 4 muscles that change the movement of the ribcage
external intercostal muscles
internal intercotal muscles
diphragm
abdominal muscles
what does the movement of the ribcage affect
changes the volume of the thoraxic cavity which changes its pressure
what are the antagonistic muscles
external intercostal muscle
internal intercostal muscle
diaphragm
abdominal muscles
what happens during inspiration
abdominal muscles- relax
diaphragm- contract (flattens move downwards)
internal intercostal muscles- relax
external intercostal muscles- contract
ribcage movements- up and out
volume change- increases
pressure change- decreases, draws air in
what happens during expiration
abdominal muscles- contract ( pushes diaphragm up)
diaphragm- relax (doms up)
internal intercostal muscles- contract
external intercostal muscles- relax
ribcage movements- down and in
volume change- decreases
pressure change- increases draw air out
how can ventilaton be monitored in humans
via simple obeservation (coutning number of breathes per min)
chest belt and pressure meter (recording rise and fall of the chest)
spirometer (recording the volume of gas expelled per breath)
describe/ explain spirometry
involves measuring the amiunt (volume) and/ or seed (flow) at which air can be inhaled or exhaled
the spirometer detects the chnages in ventilation and presents the data (spirogram) on a digital display
describe how the actual spirometry process is performed
patient places clip on nose which keeps both nostrils closed
patient takes deep breath in, holds the breath for a few seconds and then exhales as hard as possible into breathing tube
patient repeats test at least 3 times
tidal volume
volume of air lungs can accomodate at rest
