Nervous System

Efferent info is

Exiting the CNS to the PNS

Anaxonic neurons

Found in retina of the eye

Which part of the brain contains cell bodies of neurons?

Gray matter

Microglia

"garbage cans"; clean up unwanted substances

There are ___ coccygeal nerve(s)

1

Structural classification of neurons

1. Anaxonic 2. Bipolar 3. Unipolar 4. Multipolar

3 spinal meningeal layers

1. Dura mater 2. Arachnoid mater 3. Pia mater

Neuroglia in PNS

1. Satellite cells 2. Schwann cells

Functional classification of neurons: 3 types

1. Sensory 2. Motor 3. Interneurons (only in CNS)

There are _____ thoracic nerves

12

The entire spinal cord is divided into __ segments.

31

What are the strands projecting from the spinal cord inferior to L2?

Cauda equina, "horse's tail"

At what vertebra does the spinal cord tissue end?

L1-L2

Visceral motor nuclei are found in this part of gray matter

Lateral horn

These neuroglial cells cover CNS axons with myelin.

Oligodendrocytes

What is the name of the area where the spinal cord attaches to the coccyx?

Phyla terminal

Cell bodies of neurons in gray matter are organized into groups called _____

nuclei

Bipolar neurons

one axon and one dendrite in olfactory system, some in retina

Structural organization of gray matter

posterior (dorsal) horn lateral (intermediate) horn anterior (ventral) horn

There are ____ lumbar nerves

5

There are ____ sacral nerves

5

There are ____ cervical nerves

8

What is an axon?

A long, slender process of a neuron that is capable of conducting nerve impulses

What is myelin?

A membrane wrapping on an axon that increases the speed of action potential propogation

Multipolar neuron

A nerve cell that has many dendrites and a single axon Most common in CNS

What type of neuroglia in the CNS are satellite cells most similar to?

Astrocytes; maintain a healthy balance of nutrients

Central NS structures

Brain & spinal cord

Functions of the autonomic nervous system

Controls workings of inner organs such as smooth muscle, cardiac muscle, digestive tract, glands, adipose tissue

What is the point called at which spinal cord tissue ends?

Cornus medullaris

This is the outermost layer of the spinal meninges and acts to support and cushion the spinal cord.

Dura mater

Which white column contains tracts of axons which relay info in the same direction as other axons in the same tract?

Lateral white column

Ependymal cells

Line ventricles (brain) and central canal (spinal cord); produce and circulate cerebrospinal fluid

Pseudounipolar neurons

Neuron that has a short, single projection from the cell body; found in sensory nerves in dorsal nerve ganglia of PNS

2 types of cells

Neurons, neuroglia

Which part of gray matter contains somatic and visceral sensory nuclei?

Posterior horn

White matter divisions

Posterior white columns Anterior white columns Lateral white columns

Neuron function

Process and transfer info

Oligodendrocytes

Produce myelin in CNS

These neuroglial cells cover peripheral axons with myelin.

Schwann cells

Afferent info is the

Sensory info coming into the body

What is the function of Schwann cells?

Similar to Oligodendrocytes in CNS; create myelin sheath around peripheral axon; help repair damage to PNS nerves

Somatic vs visceral neurons

Somatic neurons transmit info from skin or skeletal muscles to CNS Visceral neurons transmit info from internal organs to CNS

Neuroglia function

Supporting cells to neurons

2 divisions of autonomic nervous system

Sympathetic and parasympathetic

Which division of the nervous system carries sensory information directly from muscles and visceral organs?

The afferent division of the PNS

Which division of the nervous system carries motor commands to muscles and glands?

The efferent division of the PNS

Functions of the somatic nervous system

Transmits sensory info from the body to the brain and motor movements from the brain to the body Controls skeletal muscle

Which part of the brain is myelinated and contains axons?

White matter

Somatic motor nuclei are found in ____

anterior/ventral horn

Neuroglia in CNS

ependymal cells, astrocytes, oligodendrocytes, microglia

Astrocytes

form blood-brain barrier created around brain to prevent certain substances from getting in

NS functions

sensory input, integration, motor output

Efferent info, as it exits the CNS, sends messages to ____ and _____

somatic & autonomic nervous systems

The ventral horn of the spinal cord is where ______________ would be found.

somatic motor neurons