Tutorial physiology

Dr.Mohammed shariqueAssistant 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– _______________________– ________________________– _________________________

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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 ______________