Response long questions Flashcards
1
Q
transmission of nerve impulses across synapse
A
- When nerve impulse reaches presynaptic membrane
synaptic vesicles triggered to release neurotransmitters into the synaptic cleft
- neurotransmitter diffuse across synapse to bind to the receptor proteins
- generation of new electrical signals in postsynaptic membrane
2
Q
Reflex action (knee-jerk reflex)
A
- hit tendon that connects the quadriceps muscle in the thigh to a bone in lower leg
2.force stretches quadriceps muscles
stimulates stretch receptors in muscles
trigger nerve impulse
- afferent neurone transmit information to efferent neurones in spinal cord
- efferent neurone transmit information to quadriceps muscle
muscle contract
lower leg jerk forward
3
Q
effects of alcohol consumption
A
- transmission of nerve impulses becomes slower
(alcohol affects transmission of neurotransmitters across synapse) - coordination is affected
4
Q
patient suffering from diabetes mellitus
A
- High intake of glucose
cause excess glucose in blood
cannot be fully reabsorbed from proximal convoluted tubule into blood capillaries - excess glucose is excreted in urine
5
Q
diet rich in proteins cause increase in urea content
A
1, proteins are digested to amino acids
- excess amino acids cannot be stored in body
must be deaminated in liver - the amino group from amino acids is converted to urea
- urea is transported by blood to kidneys
excreted in urine
6
Q
how reabsorption of sodium ions is controlled
A
- when blood osmotic pressure decreases
stimulate adrenal cortex to secrete aldosterone - cause distal convoluted tubule and collecting duct becomes more permeable to sodium ions
3, more sodium ions is reabsorbed into blood
7
Q
how athlete regulates blood osmotic pressure on hotday
A
- athlete secrete sweat to lose heat
increase blood osmotic pressure
2.hypothalamus stimulate pituitary glands to release more ADH into blood
- high level of ADH increase the permeability of distal convoluted tubule and collecting duct
more water is reabsorbed - blood osmotic pressure returns to normal