What is the resting potential of a neuron?
threshold potential? ~CORRECT ANSWER~✓✓-65mV
-55mV
Where is the juxtaglomerular apparatus located? ~CORRECT
ANSWER~✓✓Between the afferent arteriole and the distal convoluted
tubule.
What is the cause of the absolute refractory period? ~CORRECT
ANSWER~✓✓Insufficient sodium channels available for activation
The refractory period follows membrane depolarisation during an action
potential. First is the absolute refractory period, where the are too few
sodium channels available for activation, no matter the depolarisation
stimulus. Potassium channels may be open and the membrane may be
hyperpolarised but these are not the cause of the refractory period. The
relative refractory period describes the state where an action potential
requires a larger depolarisation stimulus than normal.
What do A-beta fibers do? ~CORRECT ANSWER~✓✓Non-painful touch
& innervate muscles
,A-Beta fibers overrides painful A-Delta C-fibers, therefore overriding
the pain.
What do A-delta fibres do? ~CORRECT ANSWER~✓✓A-delta are
general sensory fibres that can transmit both innocuous and noxious
stimuli - they are small and myelinated.
What do C fibres detect? ~CORRECT ANSWER~✓✓dull pain
What proteins make up gap junctions? ~CORRECT
ANSWER~✓✓connexins
What makes up adherens junctions? ~CORRECT
ANSWER~✓✓Adherens junctions contains plaque, a dense layer of
proteins on the inside of the plasma membrane that attaches both to
membrane proteins and to microfilaments of the cytoskeleton.
What are cadherins? ~CORRECT ANSWER~✓✓glycoproteins, calcium
dependent adhesion proteins that help muscle and epithelial cells stay
bound together. They are transmembrane proteins that bind within the
cytoplasm to intermediate filaments like keratin. Extracellularly, bind
to other cadherins forming desomosomes and adherens junctions. *All
interactions are calcium dependent, thus removing calcium will cause
dissociated of cadherin mediated junctions = loss of cell adhesion*.
,What are the 3 parts of troponin? ~CORRECT ANSWER~✓✓Troponin
C, I and T. Troponin C binds to calcium; it is linked to troponin I, which
binds to actin, and troponin T that is bound to tropomyosin. The
binding of calcium to Trop C causes movement in troponin I and T,
which results in movement of tropomyosin out of the myosin binding-
sites on actin.
What protein on the sarcoplasmic reticulum mediates calcium release in
response to dihydropyridine activation? ~CORRECT
ANSWER~✓✓ryanodine
What process allows formation of cross bridges? ~CORRECT
ANSWER~✓✓movement of tropomyosin on actin
What is the consequence of phosphate group loss from myosin in
skeletal muscle contraction ~CORRECT ANSWER~✓✓movement of
myosin head
What is the difference between type I and II skeletal muscle fibres?
~CORRECT ANSWER~✓✓Type I fibres generate low contraction force,
use aerobic metabolism (utilising glycogen), are very fatigue resistant
and comprise the postural musculature.
Type II fibres are anaerobic, with high contraction force but fatigue
quickly; they have myoglobin stored to use when oxygen falls very low.
What are satellite cells? ~CORRECT ANSWER~✓✓stem cells which
give rise to myoblasts
, What is the difference between neuromuscular junction and other types
of synapse? ~CORRECT ANSWER~✓✓The neuromuscular junction
(NMJ) is like a specialised electrical synapse with a motor end-plate on
the myofibres. The end-plate generates an end-plate potential (EPP)
when acetylcholine (ACh) binds nicotinic receptors. The EPP is a large
excitatory post-synaptic potential (EPSP), which has a high chance of
stimulating an action potential. The EPP decays, like other EPSP. ACh
acts like other transmitters: released by calcium, diffuses across the
cleft and is re-uptaken.
What ligand-receptor combination mediates sympathetic neurone
vasoconstriction of peripheral arterioles? ~CORRECT
ANSWER~✓✓Noradrenaline - alpha-1-adrenoreceptor
Post-ganglionic sympathetic neurones release noradrenaline from
secretory vesicles. This acts on alpha-1-adrenoreceptors on vascular
smooth muscle to increase intracellular calcium. Acetylcholine binds
nicotinic receptors at the pre- to post-ganglionic sympathetic neurone
synapse. Adrenaline shows preference for beta-adrenoreceptors.
Adrenaline acts at beta-adrenoreceptors to cause vasodilatation in the
coronary vessels.
What is the stimulus for release of adrenaline from the adrenal
medulla? ~CORRECT ANSWER~✓✓acetylcholine at nicotynic receptors
What is the autonomic innervation of sweat glands? ~CORRECT
ANSWER~✓✓Sympathetic acetylcholine released
threshold potential? ~CORRECT ANSWER~✓✓-65mV
-55mV
Where is the juxtaglomerular apparatus located? ~CORRECT
ANSWER~✓✓Between the afferent arteriole and the distal convoluted
tubule.
What is the cause of the absolute refractory period? ~CORRECT
ANSWER~✓✓Insufficient sodium channels available for activation
The refractory period follows membrane depolarisation during an action
potential. First is the absolute refractory period, where the are too few
sodium channels available for activation, no matter the depolarisation
stimulus. Potassium channels may be open and the membrane may be
hyperpolarised but these are not the cause of the refractory period. The
relative refractory period describes the state where an action potential
requires a larger depolarisation stimulus than normal.
What do A-beta fibers do? ~CORRECT ANSWER~✓✓Non-painful touch
& innervate muscles
,A-Beta fibers overrides painful A-Delta C-fibers, therefore overriding
the pain.
What do A-delta fibres do? ~CORRECT ANSWER~✓✓A-delta are
general sensory fibres that can transmit both innocuous and noxious
stimuli - they are small and myelinated.
What do C fibres detect? ~CORRECT ANSWER~✓✓dull pain
What proteins make up gap junctions? ~CORRECT
ANSWER~✓✓connexins
What makes up adherens junctions? ~CORRECT
ANSWER~✓✓Adherens junctions contains plaque, a dense layer of
proteins on the inside of the plasma membrane that attaches both to
membrane proteins and to microfilaments of the cytoskeleton.
What are cadherins? ~CORRECT ANSWER~✓✓glycoproteins, calcium
dependent adhesion proteins that help muscle and epithelial cells stay
bound together. They are transmembrane proteins that bind within the
cytoplasm to intermediate filaments like keratin. Extracellularly, bind
to other cadherins forming desomosomes and adherens junctions. *All
interactions are calcium dependent, thus removing calcium will cause
dissociated of cadherin mediated junctions = loss of cell adhesion*.
,What are the 3 parts of troponin? ~CORRECT ANSWER~✓✓Troponin
C, I and T. Troponin C binds to calcium; it is linked to troponin I, which
binds to actin, and troponin T that is bound to tropomyosin. The
binding of calcium to Trop C causes movement in troponin I and T,
which results in movement of tropomyosin out of the myosin binding-
sites on actin.
What protein on the sarcoplasmic reticulum mediates calcium release in
response to dihydropyridine activation? ~CORRECT
ANSWER~✓✓ryanodine
What process allows formation of cross bridges? ~CORRECT
ANSWER~✓✓movement of tropomyosin on actin
What is the consequence of phosphate group loss from myosin in
skeletal muscle contraction ~CORRECT ANSWER~✓✓movement of
myosin head
What is the difference between type I and II skeletal muscle fibres?
~CORRECT ANSWER~✓✓Type I fibres generate low contraction force,
use aerobic metabolism (utilising glycogen), are very fatigue resistant
and comprise the postural musculature.
Type II fibres are anaerobic, with high contraction force but fatigue
quickly; they have myoglobin stored to use when oxygen falls very low.
What are satellite cells? ~CORRECT ANSWER~✓✓stem cells which
give rise to myoblasts
, What is the difference between neuromuscular junction and other types
of synapse? ~CORRECT ANSWER~✓✓The neuromuscular junction
(NMJ) is like a specialised electrical synapse with a motor end-plate on
the myofibres. The end-plate generates an end-plate potential (EPP)
when acetylcholine (ACh) binds nicotinic receptors. The EPP is a large
excitatory post-synaptic potential (EPSP), which has a high chance of
stimulating an action potential. The EPP decays, like other EPSP. ACh
acts like other transmitters: released by calcium, diffuses across the
cleft and is re-uptaken.
What ligand-receptor combination mediates sympathetic neurone
vasoconstriction of peripheral arterioles? ~CORRECT
ANSWER~✓✓Noradrenaline - alpha-1-adrenoreceptor
Post-ganglionic sympathetic neurones release noradrenaline from
secretory vesicles. This acts on alpha-1-adrenoreceptors on vascular
smooth muscle to increase intracellular calcium. Acetylcholine binds
nicotinic receptors at the pre- to post-ganglionic sympathetic neurone
synapse. Adrenaline shows preference for beta-adrenoreceptors.
Adrenaline acts at beta-adrenoreceptors to cause vasodilatation in the
coronary vessels.
What is the stimulus for release of adrenaline from the adrenal
medulla? ~CORRECT ANSWER~✓✓acetylcholine at nicotynic receptors
What is the autonomic innervation of sweat glands? ~CORRECT
ANSWER~✓✓Sympathetic acetylcholine released
