Worksheet+11+-+Chapter+14A

.docx

School

Orange Coast College *

*We aren’t endorsed by this school

Course

A125

Subject

Biology

Date

Dec 6, 2023

Type

docx

Pages

Uploaded by UltraAlbatross3677

BIOL 125 – Human Biology Allissa M. Blystone, PhD Orange Coast College Chapter 7: The Neuron Worksheet #11 Activity 1: Characteristics of Nervous Tissue 1. Compare and contrast the two main cell types found in nervous tissue. Compare and contrast the two main cell types found in nervous tissue: The two main cell types in nervous tissue are neurons and glial cells. Neurons are specialized cells that transmit electrical and chemical signals throughout the body. Glial cells, also known as neuroglia, are support cells for the neurons and help maintain their function. 2. Describe the three main types of neurons and the functions associated with each. 1. Sensory neurons: These neurons are responsible for transmitting sensory information from the body's receptors (e.g., touch, smell, taste, sight, and hearing) to the central nervous system (CNS). 2. Interneurons: These neurons are found only in the CNS and are responsible for processing and integrating the information received from sensory neurons and issuing commands to motor neurons. 3. Motor neurons: These neurons transmit signals from the CNS to muscles, glands, and other organs in the body, controlling their activity. 3. What would happen if the brain stopped receiving sensory input? The brain would not be able to process and respond to sensory information, which could lead to an inability to react to stimuli and impaired cognitive function. 4. What would happen if the brain ceased issuing commands to the skeletal muscles? The muscles would not receive the necessary signals to contract or relax, resulting in paralysis or muscle weakness. Activity 2: The Neuron 1. Draw the neuron. Label the following, and include the function of each: axon, dendrite, cell body, direction of impulse.

2. What is the difference between a “nerve” and a “neuron”? - A neuron is a single nerve cell, while a nerve is a bundle of many neurons. 3. What is the purpose of the myelin sheath? - The myelin sheath is a fatty layer that covers the axons of some neurons and helps to speed up the transmission of nerve impulses. 4. What would happen if the myelin sheath were degraded and not present? - If the myelin sheath were degraded or not present, nerve impulses would not be able to travel as quickly and efficiently, leading to problems with motor coordination, sensation, and other neurological functions. This can be seen in diseases like multiple sclerosis, where the immune system attacks and damages the myelin sheath. Activity 3: The Action Potential 1. What is an action potential? An action potential is a brief electrical signal that travels along the membrane of a neuron, allowing it to communicate with other neurons or target cells. 2. When a neuron is at resting potential, where is the highest concentration of sodium ion? Potassium ions? When a neuron is at resting potential, the highest concentration of sodium ions is outside the cell, while the highest concentration of potassium ions is inside the cell. 3. What happens if a stimulus is not big enough to shift the resting potential past threshold? If a stimulus is not big enough to shift the resting potential past threshold, then no action potential will be initiated. 4. Describe the steps in an action potential. The steps in an action potential are: 1) depolarization, in which the membrane potential rapidly becomes more positive due to the influx of sodium ions; 2) repolarization, in which the membrane potential rapidly becomes more negative again due to the efflux of potassium ions; and 3) hyperpolarization, in which the membrane potential briefly becomes more negative than the resting potential before returning to its normal level. 5. Label the diagram below, using the following terms: resting potential, threshold, resting neuron, action potential, sodium ions entering the cell, potassium ions leave the cell 6. Why is an action potential described as “all-or-nothing”? An action potential is described as "all-or-nothing" because once the threshold is reached, an action potential is triggered and the neuron fires at its maximum intensity. If the stimulus does not reach the threshold, the neuron will not fire an action potential. In other words, the neuron either fires an action potential or it does not, there is no partial

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version