cardio respiratory system Flashcards
pathway of air
taken in through mouth/nose
down trachea (lined with cilia to trap dust)
trachea divides into two bronchi
each bronchi leads to a lung and divides into bronchioles
alveoli at end of bronchioles for gas exchange
how alveoli are adapated for gas exchange
thin walls (1 cell thick)
moist
rich blood supply
large surface area
steep conc gradient
site of gaseous exchange
oxygen diffuses to blood down conc gradient
CO2 diffuses out of blood down conc grad
haemoglobin carries CO2 to lungs
-binds w O2 to form oxyhaemoglobin
-carried oxygen through blood
arteries
vasoconstrict and vasodilate to distribute
thick walls + smaller walls to cope w high pressure
elasticated walls to prevent bursting
veins
carry blood toward heart (mainly deoxygenated)
large lumen + thin walls (lower pressure)
valves to prevent backflow
capillaries
make diffusion easier
one cell thick (only allow one blood cell at a time)
link around arteries and veins
vena cava
returns deoxygenated blood to right atrium
pulmonary artery
deoxygenated blood from right ventricle goes to lungs
pulmonary vein
oxygenated blood from lungs to left atrium
aorta
carries deoxygenated blood from left ventricle to body
atria
right receives deoxygenated blood from body via vena cava
-pumps through to right ventricle
left atrium receives oxygenated blood via PV
- pumps through to left ventricle
ventricle
right V has thinner,less muscular walls
- less pressure needed to pump deoxy blood to lungs
left V has thick strong walls
- pumps oxy blood at high pressure
cardiac cycle deoxy blood
from body to RA via VC
contracts, pushed through valve to RV
RV contracts and pumps blood through PA
PA carries deoxy blood to lungs where gaseous exchange takes place
oxy blod cardiac cycle
from lungs enters heart through PV
oxy blood enters left atrium
contracts and pushes through valve to left ventricle
contracts and pumps blood through aorta to rest of body at high pressure
systole and diastole
1) atria contract + pump blood into ventricles (atria systole)
ventricles relax and fill with blood (ventricular diastole)
2) ventricles contract to pump blood out of heart ( ventricular systole)
atria relax and fill with blood (atria diastole)
cardiac output
(q)
vol of blood heart pumps out
p/m
= SV x HR
stroke volume
(sv)
vol of blood left ventricle pumps out with each beat
heart rate
HR
number of times heart beats
usually bpm
anticipatory rise
HR increases just before starting exercise due to increase of adrenaline
effects of exercise on heart
HR increase
anticipatory rise
SV increased as more oxy blood is ejected from LV
Cardiac output increases, as HR and SV increases
inhale mechanics
intercostals contract
-ribs move upwards and outward
diaphragm contracts and flattens
exhale mechanics
intercostals relax, ribs fall, vol of chest cavity decreases
diaphragm relaxes
breathing during exercise
inspiration- pectorals and sternocleidomastoid contract and lungs expand
expiration- abdominals contract to force air out of chest cavity to speed up exhalation
flow of air exhalation
vol of chest cavity decreases, high pressure
causes air to rush out of lungs
flow of air inhalation
vol of chest cavity increases , low pressure
causes air to rush in and fill lungs
air flow
from low to high pressure to create an equilibrium
tidal volume
volume of air breathed in/ out at rest
air that enters = air that leaves
500ml
expiratory reserve volume
additional air that can be forced out of lungs after normal breath
about 1000ml
always some air left in lungs to prevent them from collapsing
residual vol
volume of air left in lungs after one normal exhalation
(about 1500ml)
inspiratory reserve vol
air that can be forced into lungs after one normal inhalation (around 3000ml)
spirometer traces
at rest- consistently equal peaks (roughly 500ml)
during exercise- peak will increase due to IRV, will also dip into ERV
