BPK 105 Study Guide - Midterm Guide: Axon Hillock, Neuroglia, Ependyma
27 Apr 2018
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Module 4 - Objectives - Part 2
● Describe the structure of neurons and the function of their components.
neurons = receive stimuli, conduct action potentials, and transmit signals to other neurons or
effector organs
3 parts - a cell body + 2 types of processes [dendrites + axons]
a cell body= contains a single nucleus, which is the source of information for gene expression
- Extensive rough endoplasmic reticulum (rough ER), a Golgi apparatus, and mitochondria
surround the nucleus
- neurofilaments (intermediate filaments) and microtubules organize the cytoplasm into
distinct areas
dendrites = branch out, usually receive information from other neurons or from sensory
receptors and transmits the information towards the neuron cell body
-short, often highly branching cytoplasmic extensions that are tapered from their bases at
the neuron cell body to their tips
- Most dendrites are extensions of the neuron cell body, but dendrite-like structures also
project from the peripheral ends of some sensory axons.
axon= conducts action potential towards the CNS, brain and spinal cord
- a single long cell process extending from the neuron cell body.
- Main process of a neuron
- Usually conducts action potentials away from the neuron cell body
- area where the axon leaves the neuron cell body is called the axon hillock.
- Axons of sensory neurons conduct action potentials towards the CNS, and axons of
motor neurons conduct action potentials away from the CNS.
- Axons also conduct action potentials from one part of the brain or spinal cord to another
part.
- An axon may remain unbranched or may branch to form collateral axons.
- Axons can be surrounded by a highly specialized insulating layer of cells - myelin
sheath
● Describe the general function and location of each of the types of neuroglial cells
(excluding Ependymal cells).
astrocytes- major supporting cells in the CNS, can stimulate or inhibit the signaling of nearby
neurons
- serve as major supporting cell in the CNS, stimulate or inhibit the signalling activity of
nearby neurons, forms blood-brain barrier, help limit damage to neural tissue
microglia- act as immune cells of CNS, protect brain by removing bacteria and cell debris
- act as immune cells of the CNS. they help protect the brain by removing bacteria and
cell debris
Document Summary
Describe the structure of neurons and the function of their components. neurons = receive stimuli, conduct action potentials, and transmit signals to other neurons or effector organs. 3 parts - a cell body + 2 types of processes [dendrites + axons] a cell body= contains a single nucleus, which is the source of information for gene expression. Usually conducts action potentials away from the neuron cell body. Axons of sensory neurons conduct action potentials towards the cns, and axons of area where the axon leaves the neuron cell body is called the axon hillock. motor neurons conduct action potentials away from the cns. Axons also conduct action potentials from one part of the brain or spinal cord to another. An axon may remain unbranched or may branch to form collateral axons. Axons can be surrounded by a highly specialized insulating layer of cells - myelin part. sheath. K movement out of cell increases, cell goes back to neg.
