Please ANSWER ALL parts 24. In a reflex arc, the sensory receptor synapses onto
ID: 210041 • Letter: P
Question
Please ANSWER ALL parts
24. In a reflex arc, the sensory receptor synapses onto the which travels through the posterior root into the spinal cord to synapse onto the (found entirely in the gray matter), which synapses onto the ,which leaves the spinal cord through the anterior root, to synapse onto the , which performs the action. 25. Define two of the following terms: dermatome map, epineurium, paresthesia, saltatory conduction 26. Describe two ways that released neurotransmitters can be inactivated in a synaptic cleft. Page 3 of 3 BIO 201 QuizExplanation / Answer
24. i) Afferent nerve fibers carry signals from the somatic receptors.
ii)Integrating center
iii)Efferent nerve fiber carry motor nerve signals to muscle.
iv)Effector muscle innervated by the Effector nerve fiber.
25) Paresthesia: It is an abnormal sensation such as tingling,tickling,numbness or burning of person's skin with no apparent physical cause.The fingers,toes,ears and nose are commonly involved in the numbness.
This may be caused due to lack of blood supply and sensitivity to cold.
Saltatory conduction
It is the propogation of action potential along myelinated axons from one node of ranvier to the next.It speed up the conduction because the action potential jumps.It not only increases the speed of conduction but it also reduces the energy expenditures over the axon membrane as a whole.
26)The released neurotransmitters can be inactivated in the synaptic cleft by:
1)It is by the reuptake of the neurotransmitter.The cell which has released the neurotransmitter has the ability to reuptake it.After being in the synaptic cleft after binding to receptor the binding is not parmanent so neurotransmitter can be taken up the cell who released it.
2)The activity of some neurotransmitter is terminated by the degradation by the enzymes present in the synaptic cleft.Eg acetylcholine is breaker by acetylcholinesterase.