(Anatomy & physiology) Essay Question: (25 Pts) Answer the following question as
ID: 213416 • Letter: #
Question
(Anatomy & physiology)
Essay Question: (25 Pts) Answer the following question as thoroughly as possible. 25) Transduction of extracellular stimuli into intracellular changes is one of the foundations of physiology. We use the process to control everything from our heart rate to our ability to see. Answer the following questions related to our cells abilities to respond to changes in their environment. Explain ALL of the steps a rod would use to generate an action potential in a ganglion cell when it detects light. a. b. In stressful situations heart rate needs to be increased. Describe the basic architecture of the part of the nervous system that increases heart rate including... i. 1. Name of the system Para. 2. Name and length of the neurons involved 3. Neurotransmitter(s) involved 4. Receptor type present on the cardiac tissue Hypothesize how the receptor on the cardiac tissue could increase depolarization. ii. We also need to move information quickly in the nervous system. Explain saltatory conduction. c.Explanation / Answer
a) Phototransduction occurs in the rods. This process is comparable to activity at the G-protein-neurotransmitter receptor.Light energy interacts with photopigment which generates a variation in membrane potential. Steps involved in Transduction of Light by Rods
1) light initiates rhodopsin
2) The bleaching of rhodopsin causes a G-protein known as transducin to be stimulated
3) Phosphodiesterase (the effector enzyme) is activated
4) Phosphodiesterase activation decreases cGMP level
5) which in turn leads o reduced cGMP, Na+ channels close and the cell membrane hyperpolarizes
Sodium channels open and they are gated by an intracellular secondary messenger (cGMP). it is produced in the photoreceptor by an enzyme, which keeps the Na+ channels open. Light reduces cGMP, which leads to the closing of Na+ channels and membrane potential becomes more negative. Thus photoreceptors hyperpolarize in response to light.
b) 1 a.
Sympathetic nervous system
b. pre-ganglionic(short) and post-ganglionic neurons (long)
c.preganglionic sympathetic neurons release acetylcholine, that binds and activates nicotinic acetylcholine receptors on postganglionic neurons. In response to this inducement, postganglionic neurons release noradrenaline
d. beta-1 adrenergic receptor
2. Saltatory conduction is the generation of action potentials accompanying myelinated axons from one node of Ranvier to the next node, which leads to increase in the conduction velocity of action potentials.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.