bio deck 2 Flashcards
what happens at the sodium-potassium exchange pump?
the sodium-potassium exchange pump maintains the cell’s resting potential by ejecting three sodium ions for every two potassium ions it brings in from the ISF
(3 Na+ out; 2 K+ in)
what effect would a chemical that blocks the voltage-gated sodium channels in the plasma membrane of a neutron have on its ability to depolarise?
if the voltage-gated sodium channels couldn’t open, sodium ions could not flood into the neutron and it would not be able to depolarise
describe four features of a polarised neuron
resting membrane potential
-70 volts
more K+ inside
more Na+ outside
which branch of the ANS has short pre-ganglionic fibres and long post-ganglionic fibres?
sympathetic
in which branch of the ANS do pre-ganglionic fibres release acetylcholine?
both
in which branch of the ANS do the post-ganglionic fibres release noradrenaline?
sympathetic
in which branch of the ANS do the post-ganglionic fibres release acetylcholine?
parasympathetic
may increase or decrease activity of effect (slows heart rate; increases motility)
what is special about cranial nerve x?
it’s the only non local cranial nerve
what is atmospheric pressure at sea level?
760mm Hg
where is the atrioventricular node located?
in the floor of the right atrium, near the septum
what is the significance of protein in the urine?
consistent presence suggests glomerular of tubular damage
transient proteinuria quite common
can indicate a UTI
what is the chemical symbol for carbonic acid?
H2CO3
what is the left AV valve also know as?
bicuspid valve or mitral valve
which layer of the blood vessel contracts to cause vasoconstriction?
smooth muscle of the tunica media
what is isovolumetric contraction?
all valves are closed, ventricles contractin
what is thrombin’s action in the clotting cascade?
converts fibrinogen into fibrin
what is CO2?
carbon dioxide is a byproduct of aerobic metabolism (cellular metabolism)
what is pulse pressure?
the difference between systolic BP and diastolic BP
what are the cells of the blood and where are they formed?
RBCs, WBCs and platelets
all formed in the bone marrow
what is the most common circulating WBC? what is its purpose?
neutrophils
phagocytosis
what are ketones, and what is indicated by their presence in the urine?
breakdown products of fat metabolism
they indicate the body has run out of glucose
ketones can be very high in diabetes; indicating an insulin deficiency
what NT causes vasoconstriction? what is the receptor for this NT?
noradrenaline
adrenergic receptors
what is MAP going to be in a person with 120/80 BP?
MAP = diastolic BP + 1/3 pulse pressure
80 is diastole
PP is 120 - 80 = 40
one third of 40 is 13.3
therefore MAP = 93.3 (80 + 13.3)
what breaks down the fibrin in a clot?
plasmin
what is fibrinolysis?
the slow process of dissolving a clot once healing is complete
where is angiotensinogen produced?
the liver
what does RAAS stand for?
renin-angiotensin-aldosterone system
what are the two types of cardiac muscle cell and what do they do?
conducting system cells: control and coordinate the heartbeat
contractile cells: produce contraction that propel blood
what two things does oxytocin stimulate during childbirth?
uterine contractions
production of prostaglandins in endometrium which stimulate further uterine contractions
what hormones are secreted by the testes?
androgens, including testosterone
inhibin
what do width and height equal on an ECG?
height equals voltage
width equals time
what effect would an increase in venous return have on stroke volume?
increased venous return = more stretch in heart muscle = greater force of contraction = higher stroke volume
what does isovolumetric mean?
all valves are closed.
same volume.
like squeezing a bottle with the lid on - pressure increases, but volume remains the same
what part of the lungs is regulated by the autonomic nervous system?
the bronchioles
what effect would an increase in sympathetic stimulation of the heart have on end-systolic volume?
increased heart rate and increased force of contraction leads to higher stroke volume = lower end-systolic volume
which cells produce antibodies?
plasma cells
define end-diastolic volume (EDV) and end-systolic volume (EDV)
EDV - amount of blood in left in the ventricle at the end of relaxation
ESV - amount of blood left in the ventricle at the end of contraction
list the phases of the cardiac cycle
atrial systole
atrial diastole
ventricular systole
ventricular diastole
describe the blood supply to the brain
two internal carotid arteries
two vertebral arteries - join to form basilar artery
all join to form the arterial circle of Willis
what is stroke volume?
the amount of blood that leaves the heart with each beat
ml/beat
which blood vessels supply the heart with oxygenated blood?
coronary arteries
cardiac veins
what are the three functions of platelets?
release important clotting chemicals
temporarily patch damaged vessel walls
reduce size of a break in vessel wall
which hormone regulates the secretion of potassium in the nephron?
aldosterone
ADH
- where?
- what?
anti-diuretic hormone
made in the hypothalamus, secreted by the posterior pituitary gland
causes kidney to retain water; less urination leads to increased blood volume, therefore increased BP
describe the pericardium
pericardial sac - visceral and parietal layers with pericardial cavity containing pericardial fluid in between
serous membrane!
dopamine - physiology?
-pathophysiology?
neurotransmitter
dopaminergic receptors
can be excitatory or inhibitory
physiology: motor control emotion and reward decreased prolactin vomiting
pathology:
schizophrenia
parkinsons
addiction
acetylcholine
physiology?
pathophysiology?
neurotransmitter
physiology: cognition learning and memory consciousness motor control
pathophysiology:
alzheimers
glutamate
physiology?
pathophysiology?
amines
main NT in brain
NMDA receptor
physiology:
learning and memory
pathophysiology
epilepsy
chronic pain
drug dependence
noradrenaline-
physiology?
pathophysiology?
neurotransmitter
physiology
arousal and mood
blood pressure
pathophysiology
bipolar disorder
depression
5HT:
physiology?
pathophysiology?
there are lots of 5HT receptors
physiology - digestion sleep/wake mood appetite vomiting
pathophysiology
depression
mania
eating disorders
what are the steps of carcinogenesis?
initiation
proliferation
progression
pharmacodynamics of NSAIDs
competitive inhibition of cox-1 and cox-2 inhibitors
inhibits prostoglandin synthesis
what are the monoamine NTs?
noradrenaline adrenaline dopamine 5HT histamine (excitatory)
describe the nerve supply of the kidneys
sympathetic fibres regulate renal blood flow according to the body’s requirements
what is RV?
residual volume = amount of air left in passageways and lungs after maximal exhalation
about 1200ml men//1100ml women
what hormones do the ovaries secrete?
oestrogen
progesterone
inhibin
what is normal tidal volume at rest?
200-500ml