1 - Intro to CV and R systems Flashcards
Where does the superior vena cava receive deoxygenated blood from?
upper region (head, arms etc.)
Where does the inferior vena cava receive deoxygenated blood from?
lower region of body
What’s another name for the larynx?
voice box
What do problems with right atrium cause?
lung problems as it’s important in pulmonary circulation
structure of artery (from lumen out)
lumen, tunica intima (endothelium), tunica media (smooth muscle) and tunica adventitia (externa)
Differences between veins and arteries
veins have a smaller tunica media (less smooth muscle) and a wider lumen, also has valves preventing backflow
what are smooth muscle cells responsible for?
contract/relax to modify lumen diameter and therefore blood flow through vessel
what is smooth muscle contraction in blood vessels controlled by
nerve supply and endogenous substances secreted from endothelium
Systemic circulation
blood travels from LV via arteries to capillaries in tissues of body and back to heart via veins
Vascular structure of artery (from lumen out)
lumen, endothelium layer (tunica intima), tunica media (smooth muscle), tunica externa/adventitia
How are smooth muscle cells found in blood vessels controlled?
nerve supply, endogenous substances released from endothelium
What do endothelial cells secrete and why?
mediators that inhibit platelet activation preventing inadvertent thrombus formation
how is blood pressure calculated?
BP= CO x SV
Why does the baroreceptor reflex happen?
to maintain stable BP and homeostasis in body
What do baroreceptors respond to?
changes in pressure, they are stretch receptors (increased BP stretches artery walls which causes BRs to fire higher rate of action potentials towards NTS of brainstem
Where are baroreceptors located?
aortic arch, carotid sinus. Others located in systemic veins, pulmonary vessels and walls of the heart.
How long does baroreceptor control of BP last?
short term, if BP is continuously high/low BPs will eventually except these as the new norm
Cardiac Hypertrophy
an irreversible increase in size of muscle of heart (myocytes) not because of new cells, but cells are bigger as they contain more structural proteins and organelles
Causes of Cardiac Hypertrophy
hypertension (see written notes for reason why), aortic stenosis, CVD
What do ACE Inhibitors/Beta blockers do and what are 2 examples?
reduce BP by targeting receptors or mechanisms that modulate BP. Captopril (ACE inhib) and Propranolol (Beta blocker)
What is captopril?
Ace inhibitor
What is propranolol ?
Beta blocker
What is oedema
problem with fluid retention, symptom of advanced heart disease. Can be caused by high BP as increased pressure forces fluid out of blood vessels into surrounding tissue.
Drug given for oedema?
furosemide
Angiotensin II
most important vasoconstrictor
Where does gas exchange happen/not happen in lungs?
respiratory (gas exchange), conducting zone (no gas exchange)
4 stages of respiration
air inspired and expired from lungs, exchange of O2 and CO2 between air in lungs and blood in capillaries, transport of O2 and CO2 by blood via Pulmonary and systemic circulation, tissue/cellular use of O2 and CO2 production.
What makes breathing easy?
compliance/elasticity of lung tissue, surfactants, pleural membranes
What parts of the brain control involuntary breathing? (pretty vague)
lower levels
What do chemoreceptors do and how do they effect breathing?
they detect changes in arterial O2 levels and send out sensory inputs to help control breathing rhythm
Neuronal control of breathing
respiratory muscle is excited (diaphragm and intercostal muscles) by motor neurons. This is controlled by neurons in the medulla (Medulla Respiratory Centre)
Administration routes for respiratory system
oral (simple linctus), inhalation, aerosols, IV/Intramuscular, nasal spray
3 main respiratory disorders
asthma, bronchitis, COPD
