Intro to the cardio and resp systems Flashcards
what does the pharynx do
it branches to the oesophagus and larynx
what are the upper airways
nose
mouth
pharynx
larynx
what does the larynx do
it connects to the trachea
what does the trachea branch to
to alveoli which enable gas exchange
where do arteries and veins carry blood to
arteries carry blood away from the heart
veins carry blood towards the heart
is pressure in the pulmonary artery higher or lower than in the aorta
lower
what does bronchial circulation do
supplies lung cells with oxygen and nutrients
which layer contains smooth muscle in veins and arteries
tunica media
what does the tunica media do
controls vasoconstriction and dilation
what do endothelial cells do
relese relaxing or contraction substances
release bio active substances
should there always be some form of contraction
yes or else blood can’t be pumped to the rest of the body
what does the tunica adventitia contain
fibroblasts
what controls contraction and relaxation of smooth muscle in tunica media
nerve supply
endogenous substances released from endothelium
what can abnormalities in smooth muscle regulation lead to
restricted blood flow and airways
what do the bioactive substances released by endothelial cells do
- prevent inadvertent thrombus formation
- cause relaxation or contraction of smooth muscle
how do endothelial cells prevent inadvertent thrombus formation
they release mediators that inhibit platelet activation
how to calculate blood pressure
CO x PVR
CO - cardiac output
PVR - peripheral vascular resistance
what happens to PVR if blood vessels are open
it will increase and vice versa for closed
what happens to blood pressure if CO goes up
blood pressure increases and vice versa
what are baroreceptors
pressure receptors
what do baroreceptors do
sense stretch and through that can sense if heart rate is high or low
sends signals to heart to increase or decrease heart rate
what can issues with blood pressure lead to
hypertension, cardiac hypertrophy
what is cardiac hypertrophy
thickened cardiac muscle
what do therapies for blood pressure issues target
they target cardiac output and/or peripheral vascular resistance
what do ace inhibitors do
they increase urine output and so decrease the volume of blood
lowers BP
examples of drugs that reduce BP
ace inhibitors and beta blockers
example of drugs that target oedema/BP
furosemide
is there gas exchange in the conducting zone of the lungs
no
is there gas exchange in the respiratory zone
yes
why are alveoli so thin
to allow for gas exchange
why are alveoli shaped the way they are
to increase surface area for gas exchange
step 1 of respiration
air is alternately moved into and out of the lungs
step 2 of respiration
exchange of O2 and CO2 between air in lung and blood in capillaries
step 3 of respiration
transport of O2 and CO2 by blood through the pulmonary and systemic circulation
step 4 of respiration
exchange of O2 and CO2 between blood and tissues
step 5 of respiration
tissue/cell use of O2 and production of CO2
how do the properties of the lungs make breathing easy
the tissue is compliant and elastic
what does the lungs contain to make breathing easy
surfactants
pleural membranes
what do surfactants in the lungs do
lower surface tension
is normal breathing voluntary or involuntary
involuntary
what helps to control breathing rhythm
a number of sensory inputs (peripheral and central chemoreceptors) which respond to changes in the internal environment
where in the brain do sensory inputs come from
higher areas of the brain meaning breathing can be conscious
what does breathing depend upon
respiratory muscle excitation of the diaphragm and intercostal muscles by their motor neurons
where does neuronal control of breathing reside
in neurons in the medulla of the brain (medullary respiratory centre)
why is the inhalation route of drugs good
quick absorption
avoids first pass metabolism
acts locally and systemically
what can restrict breathing
inflamed lung and airway
mucus in the lungs
what drugs can be used to help the lungs
- drugs that target receptors leading to smooth muscle relaxation in airway
eg b2 agonist - anti inflammatory drugs
eg prednisolone
