Download Chapter 9.13 Spinal Cord powerpoint

9.13 Spinal Cord
By: Noor Hassouneh
Ranya Fawaz
Anatomy/physiology
3rd hour
Objectives
Content Objectives: Students will demonstrate the understanding of the structures
and functions of the spinal cord
Language Objectives: Students will be able to comprehend the types of nerve
tracts to the best of their abilities by answering questions and following along
Structure of the Spinal Cord
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The spinal cord consists of thirty-one segments, which gives pairs of spinal
nerves.
Nerve branches to body parts and connect them with the CNS.
There are two different spinal cord thickening:
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Cervical enlargement: located in the neck region and supplies nerves to the upper limbs.
Lumbar enlargement:located in the lower back and supplies nerves to the lower limbs.
The spinal cord is divided into right and left halves by two grooves, a deep
anterior median fissure and a shallow posterior median sulcus.
Gray matter resembles a butterfly with wings open
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The posterior horns and anterior horns are the upper lower wings of gray matter.
The lateral horns (gray matter) located between them on either side in the thoracic and upper
lumbar segment.
Cont. Structure Spinal Cord
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Most of the neurons in the gray matter of the spinal cord are interneurons.
However, neurons with large cell bodies that are located in the anterior horns
give rise to motor fibers that pass out through spinal nerves to skeletal
muscles.
The three reasons that gray matter divides white matter of the spinal cord are
the anterior, lateral, and posterior.
Every funiculus has longitudinal bundles of myelinated nerve fibers that
comprise major nerve pathways called nerve tracks.
The gray commissure ( horizontal bar of gray matter in the middle of the
spinal cord), connects the wings of gray matter on the right and left side.
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This surrounds the centeral canals, which contains cerebrospinal fluid.
Question
1.
What part of the body does the cervical enlargement supply nerve too?
A.) Upper limbs
B.) Lower limbs
C.) The brain
D.) The neck
Functions of the Spinal Cord
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The brain and the spinal cord make up the Central Nervous System
The Spinal Cord consists of two functions:
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b.
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Conducting nerve impulses
Serving as a center for spinal reflexes
Communication of the Dorsal and Ventral roots of the spinal cord allows the
brain to perform functions for the rest of the body
The spinal cord connects the brain to the other parts of the body and permits
walking and reflexes
Question
1.
2.
The spinal cord two major functions are conducting nerve impulses and
serving as a center for spinal reflex. True or False
What makes up the Central Nervous System (CNS)?
A
scending
Tracts
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Communication to and from the brain involves
tracts
To ascend is to rise or go up.
Ascending tracts transmit sensory information
to the cerebrum (Brain).
Ascending tracts can be divided into the type of
information they transmit
De
scending Tracts
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To descend is to move or go downward.
Descending tracts conducts motor impulses that originates in the cerebrum to
muscles and glands
It descends through tracts in the spinal cord in the lateral and ventral horns of
gray matter
This type of tract delivers information to the periphery
Corticospinal tracts also called pyramidal tracts, pass through the medulla
oblongata of the brain which looks structurally like a pyramid
The medulla oblongata is the center for balance and posture and is part of
the extrapyramidal tracts.
Cont
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Axons emerge from neuron cell bodies found in the nervous system and
terminate together in other parts
Several names that are used to recognize nerve tracts depend on the origins
and the outcomes.
For instance. a spinothalamic tract starts in the spinal cord and has the ability
to carry the sensory impulses that are related with the senses of pain, touch,
and temperature to the thalamus (directs hormonal secretions) of brain.
A corticospinal tract begins in the outer layer of the brain and transfers motor
impulses which descends through the spinal cord and nerves.
Motor impulses manages skeletal movements.
Question
1.
What does descend mean?
A.) To go up
B.) To go down
C.)To move or go down
D.) None of the above
Question
1.
Give an example of a descending tract.
Spinal Reflexes
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Spinal cord provides a pathway for nerve tracts
The spinal cord has a role in many reflexes such as withdrawal and patellar
reflexes.
The reasons why these are called spinal reflexes is because the arcs pass
through the spinal cord
For example, if you were to hold a hot pan, your senses tell you to drop the
pan within a millisecond
Sensory neurons fire and initiate an instant spinal reflex
Exit Ticket!!!
3- Write three things you learned
2- Write two things you were confused about
1- Write one question you have
Word Cited
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Hole’s essentials of Human Anatomy and Physiology (pgs 232-234)