ICPP random Flashcards
Intraocular administration meaning?
means into the eye
enteral administration meaning and example
rectal
system-wide effect, delivered through the gastrointestinal tract
parenteral administration
systemic action, but delivered by routes other than the GI tract
e.g. epidural, intraocular, IV or intra-articular (into joint space)
describe parasympathetic neurones
pre ganglionic= long and myelinated
(on para so want to go direct, and wear a coat like paranoid dealers)
post ganglionic = short and unmyelinated
describe sympathetic neurones
pre ganglionic= short and myelinated
post ganglionic = long and unmyelinated
what are oligodendrocytes?
found only in the CNS (i.e. brain and spinal cord).
-provide support and insulation to axons in CNS > create myelin sheath
difference between Schwann cells and oligodendrocytes
Schwann cells- form myelin sheath in PNS
oligodendrocytes- form myelin sheath in CNS
role of 1)astrocytes
2) ependymal cells
1) star shaped glial cells in CNS. regulate the extracellular ionic environment, facilitate neurotransmitter uptake and modulate synaptic transmission
2) thin lining of the ventricular system CNS. produce cerebrospinal fluid.
which receptor and transmitter is used for PNS divisions?
- somatic
- parasympathetic
- sympathetic
- ALL PRE-synaptic are Ach on nicotinic
- PARA POST synaptic= Ach at muscarinic (on para, jittery, move muscles)
- POST synaptic SYMP (stress) noradrenalin
and Ach on muscarinic AND nicotinic
what is intrinsic efficacy?
Intrinsic efficacy is the capacity of a drug to activate (or inactivate) a receptor.
a higher maximum response =it must have a higher intrinsic efficacy
What are chromaffin cells?
- reside in the adrenal medulla
- considered as postganglionic sympathetic neurones that do not project into target tissue.
- release adrenaline into the blood
what is Pheochromocytoma ?
Pheochromocytoma is a condition arising from a tumour in chromaffin cells resulting in a increase in adrenaline production
where is the ryanodine receptor expressed in skeletal muscle?
Sarcoplasmic reticulum membrane
what is the role of DHP receptor?
voltage gated Ca2+ channels.
- sense membrane depolarisation and undergo conformational change.
- this is transmitted to ryanodine receptors causing them to open allowing the release of Ca2+ into the sarcoplasm> triggering contraction of the muscle fibre.
describe an inhibitory neurotransmitter and how its receptor works
GABA.
GABA~a receptor= ligand gated ion channel. selectively conducts Cl- ions.
activation causes hyperpolarisation.
GABA~b receptors also activated which are GPCRs.
how do inhibitory synapses work
IPSP inhibitory post synaptic potential
hyperpolarization
permeable to K+ and Cl-
excitatory synapses examples
Acetylcholine and glutamate
how does insertion of cholesterol in the plasma membrane effect it?
reduces phospholipid packing> inc fluidity
reduces phospholipid chain motion> dec fluidity
difference between primary and secondary active transport
primary- driven directly by ATP
secondary- driven by the ionic gradients
What 3 places in the kidneys does sodium reuptake occur?
Thick ascending limb, distal convoluted tubule and cortical convoluted tubule
The equilibrium potential for K+ is -95mV. Why in a real cell is the membrane potential higher than this value (-70mV)?
As Na+ and Ca2+ are moving into the cell due to spontaneously opening and closing of voltage sensitive channels.
decreases size of membrane potential to around -70mV
why are proteins unable to flip flop?
their exposed hydrophilic surface is too big
interstitial water % of a 70kg man
25%
what occurs during diarrhoea?
CFTR activated by protein kinase A. inc cl- movement
resting membrane potential of cardiac muscle
-80mV
where do sympathetic nerves originate?
in the lateral horn of the lumbar and thoracic spinal cord
Growth factor receptors e.g. insulin receptors are linked directly to what enzyme?
Tyrosine kinase
which endocrine gland is responsible for calcium homeostasis
parathyroid
secondary messenger of PLC
DAG
the effect of spare receptors?
dec EC50
