Anatomy and Physiology I Ch 12

Where would you find glial cells?

In the Dorsal Root, Gray and White matter of the spinal cord

The following helps prevent lateral and inferior movement of the spinal cord:

denticulate ligaments

When is it that an impulse does not have to reach the brain?

In a reflex arc

Below L1-L2, the vertebral canal is occupied by a bundle of spinal nerve roots called the:

Cauda Equina

Autonomic (visceral) reflexes

- Reflex that is not consciously perceived. - Pupillary reflex & Ciliospinal reflex

Cranial reflex

- Integration occurs in the brainstem rather than in the spinal cord. - Tracking movements of the eye. Etc.

Somatic reflexes

- Integration takes place in the spinal cord gray matter - Patellar, flexor etc.

The spinal cord tapers at a conical tip called the:

Conus medullaris

The lateral cord gives rise to which nerves?

Musculocutaneous and median

The phrenic nerve ______________.

Reaches diaphragm and innervates it.

If you were to find glial cells in letter C, which ones will be located in this area? (Dorsal root)

Satellite cells

The posterior cord gives rise to which nerves?

Radial and axillary

If you were to find glial cells in letter B, which ones will be located in this area? (White matter)

Oligodendrocytes

Where in the spinal cord is the cerebrospinal fluid located?

Subarachnoid Space

Spinal Reflex

- Involves contraction of skeletal muscle - Any movement

Within the gray matter of the spinal cord are three horns, the (1) dorsal gray horns, (2) lateral gray horns, and (3) ventral gray horns.

1 - Axons of sensory neuron and cell bodies of interneurons 2 - Cell bodies of autonomic motor neurons 3 - Cells bodies of somatic motor neurons

Match the structures using the terms on the RIGHT.

Box 1 - Brain Box 2 - Spinal cord Box 3 - Cervical nerves (8 pairs) Box 4 - Thoracic nerves (12 pairs) Box 5 - Lumbar nerves (5 pairs) Box 6 - Sacral nerves (5 pairs) Box 7 - Coccygeal nerves (1 pair)

If you were to find glial cells in letter A, which ones will be located in this area? (Gray Matter)

Astrocytes and microglial cells

1. The blank 1 cord is formed by the merging of the superior, middle, and inferior trunks 2. A patient is experiencing pain on the posterior part of his thigh. What nerve may be implicated? blank 2 3. Musculocutaneous nerve stems from blank 3 cord, which stems from blank 4 trunks. 4. The blank 5 trunk stems from C7, which gives rise to the blank 6 cords. 5. The sciatic nerve branches into the blank 7 nerves.

Blank 1 - Posterior Blank 2 - Sciatic Blank 3 - Lateral Blank 4 - Superior and middle Blank 5 - Middle Blank 6 - Posterior and Lateral Blank 7 - Common fibular and tibial

6. Damage to the blank 8 nerve will interfere with one's diaphragm which may be deadly. This nerve originates between blank 9 (vertebral nerves). 7. The superficial fibular nerve runs on top of the blank 10 (bone) while the deep fibular nerve runs on top of the blank 11 (bone). 8. The posterior cord gives rise to the blank 12 nerves, while the medial cord gives rise to the blank 13 nerves. 9. The blank 14 cords merge to form the median nerve. 10. The cervical plexus is comprised of blank 15 nerves (total number).

Blank 8 - Phrenic Blank 9 - C3 - C5 Blank 10 - Fibula Blank 11 - Tibia Blank 12 - Radial and axillary Blank 13 - Ulnar median Blank 14 - 5

The nerve branching off of C5 can belong to both the _________ and ________ plexuses.

Cervical; brachial

The sensory systems keep the CNS informed of changes in the external and internal environments. The sensory information is integrated by interneurons in the spinal cord and brain. Responses to the integrative decisions are brought about by motor activities (muscular contractions and glandular secretions). The cerebral cortex, the outer part of the brain, plays a major role in controlling precise voluntary muscular movements. Other brain regions regulate involuntary movements. Motor output to skeletal muscles travels down the spinal cord in two types of descending pathways: direct and indirect. Choose which pathways are direct and which ones are indirect.

Direct Motor Pathway - Pyramidal pathways - Lateral corticospinal tract - Ventral (anterior) corticospinal tract - Corticobulbar tract - Convey action potentials that originate in the cerebral cortex and are destined to cause voluntary movements of skeletal muscles Indirect motor pathway - Extrapyramidal pathways - Tectospinal tract - Vestibulospinal tract - Rubrospinal tract - Lateral reticulospinal tract - Medial reticulospinal tract - Convey action potentials from the brain stem to cause involuntary movements that regulate posture, balance, and muscle tone

Match the 5 functional components of a reflex arc (reflex circuit) on LEFT with their definitions on RIGHT.

Effector - Part of body that responds to the motor neuron, usually muscle or gland. Sensory neuron - depolarization triggers one or more action potentials in the axon of sensory neuron that propagate along the axon into CNS. Motor neuron - Action potentials triggered by the integrating center propagate out of the CNS along the axon of a motor neuron to the effector. Integrating center - Gray matter within the brain stem or spinal cord that processes the incoming sensory information. Sensory receptor - It responds to a specific stimulus—a change in the external or internal environment—by producing a graded potential known as a receptor potential.

The spinal cord has two principal functions in maintaining homeostasis: action potential propagation and integration of information.

The white matter tracts in the spinal cord serve as the "highways" for action potential propagation. Sensory input travels along these tracts toward the brain, and motor output travels from the brain along these tracts toward skeletal muscles and other effector tissues. The gray matter of the spinal cord receives and integrates incoming and outgoing information.

The dorsal root ganglion has which types of neurons relaying what type of information?

Unipolar Neurons, sensory information

One way the spinal cord promotes homeostasis is by propagating action potentials along tracts. The name of a tract often indicates its position in the white matter and where it begins and ends. Using this knowledge, select the location, the beginning and end of each tract and the function.

Ventral Corticospinal Tract - location in white column anterior - Beginning cerebral cortex; ends spinal cord; - function motor Dorsal columns - location in white column Posterior - Beginning Spina cord; ends thalamus - Function sensory Spinothalamic tract - Anterior - Spinal cord; thalamus - Sensory Dorsal Spinocerebellar tract - Dorsolateral - Spinal Cord; cerebellum - Sensory Ventral Spinocerebellar tract - Ventrolateral - Spinal cord; cerebellum - Sensory Lateral Corticospinal Tract - Ventrolateral - Cerebral cortex; spinal cord - Motor