Tutorial physiology
Dr.Mohammed sharique
Assistant prof Physiology
Neuromuscular Junction
 Neuromuscular junction is an example of ______
 Action potentials arriving at the presynaptic
terminal (terminal button) cause ______channels
to open.
 Neurotransmitter released from presynaptic
terminal at neuromuscular junction is _________
• ___________________ causes release of the
neurotransmitter acetylcholine into synaptic cleft,
which has been synthesized and stored into
synaptic vesicles
• Motor end plate contains nicotinic ____________
which are ____________________channels
• when Ach triggers opening of ion channels at
motor end plate more Na+ moves inwards
than K+ out wards, depolarizing the end plate.
This potential change is called _____________
• To ensure purposeful movement ,muscle cell
electrical response is turned off by _________
which degrade Ach to choline & acetate
Factors influencing NMJ
• Venum of black widow spider ?
• Clostridium botulinum toxin ?
• Myasthenia Gravis ?
Myasthenia Gravis
• Gap junction is an example of _________________.
• A lipophilic chemical messenger uses a second
messenger system to alter the activity of a target cell.
True/false
• Most endocrine glands secrete paracrine substances
that function as neurohormones. True/false
• _____________________-soluble hormones
must use _____________________ systems to
exert their effects on target cells.
• _____________________ are local chemical
messengers that exert an effect only on
neighboring cells in the immediate environment.
• ______ are released into the blood by
neurosecretory neurons.
• _____________________ is a second messenger
formed when a membrane enzyme called adenyl
cyclase becomes activated by a G protein
• Extracellular chemical messengers bring about
cell responses primarily by _______________
which is Process by which incoming signals are
conveyed to target cell’s interior
• Binding of extracellular messenger (first
messenger) to matching receptor brings about
desired intracellular response by either
– _______________________
– ________________________
– _________________________
1
2
3
4
5
6
7
A particular hormone is known to elicit, completely
by way of the cyclic AMP system, six different
responses in its target cell. A drug is found that
eliminates one of these responses but not the other
five. Which of the following, if any, could the drug
be blocking?
 The hormone’s receptors,
 Gs protein,
 Adenylyl cyclase,
 Cyclic AMP
CNS
• Nerves of the autonomic nervous system
control skeletal muscle responses.
ANSWER:TRUE/ False
• Efferent neurons are motor neurons.
ANSWER:TRUE/ False
TRUE /FALSE
• Interneurons lie entirely within the central
nervous system.
• Afferent neurons have a long peripheral axon and
a short central axon.
• The cell bodies of afferent and efferent neurons
both originate in the CNS.
• Efferent neurons are the most abundant type of
neuron.
True/False
• Astrocytes contributes in formation of blood brain
barrier.
•
Oligodendrocytes form myelin around the axons
of the CNS.
• Hydrocephalus is caused by insufficient
cerebrospinal fluid.
• Microglia are phagocytic cells that help move
CSF within the ventricles of the brain.
• The most abundant type of neuron in the
body is (are) the__________________
• Afferent neurons transmits information
from________________ to _____________
• Efferent neurons transmits information
from________________ to _____________
• The sympathetic and parasympathetic divisions
are part of the_________________
• type of glial cell which lines the ventricles of the
brain are ____________________
• The outer most meningeal layer is
the_____________
• Cerebrospinal fluid is formed by ______________