Nervous and Endocrine System Work Sheet
View the following case studies on the Anatomy and Physiology place website: Chapter 7 –Nervous System;
Chapter 8- Special Senses
Chapter 9 – Endocrine
Try to answer the questions in the case study and be sure to check the correct answers! However you will not need to submit your answers to these questions, only the questions on the worksheet ( see below). Submit your answers as a word document to the Week 4 dropbox
1. Define a reflex and list the components of a reflex arc. The reflex arc is the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between. The components are receptor, sensory neurons, motor neurons, relay neurons, and effector.
2. Describe the events of an action potential.
The events that take place are that the motor neuron will be stimulated. At the axon hillock, this will cause Na+ to rush into the axon, triggering an action potential. Once that happens then the action potential will propagate down the axon until it reaches the terminal button. Here, Ca++ will enter the cell. This stimulates exocytosis of neurotransmitter molecules (acetylcholine in this case). We have that then the acetylcholine will travel across the synaptic cleft and bind on receptors located on the motor end plate. The motor end plate is a specialized plasma membrane found in muscle cells. This will cause Na+ to rush into the muscle cell, triggering an action potential. Now after all the other thing take place then this action potential will travel through a network of T-tubules, causing a release of Ca++ from the sarcoplasmic reticulum. This Ca++ allows for muscle contraction to occur.
3. What is presbyopia?
Presbyopia is the farsightedness caused by loss of elasticity of the lens of the eye, occurring typically in middle and old age.
4. Distinguish between myopia and hyperopia.
Myopia - Nearby objects are clear but far away objects...
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