A&P 1: Ch 27 Nervous Tissue and Nerves

Sensory (afferent) Neuron

Conducts impulses from receptors in peripheral body parts into the brain or spinal cord

Motor (efferent) Neuron

Conducts impulses from the brain or spinal cord out to muscles and glands

What is the shape of ependymal cell?

Cuboidal cells lining cavities of the brain and spinal cord.

Neuron process with many branches that conducts an action potential (impulse toward the cell body)

Dendrite

Bipolar Neuron

One axon and one dendrite

What is the function of microglia?

- Structural support - Phagocytosis of microorganisms and damaged tissues

The PNS contains a. 12 pairs of cranial nerves only b. 31 pairs of spinal nerves only c. 12 pairs of cranial nerves and 31 pairs of spinal nerves d. 43 pairs of spinal nerves

12 pairs of cranial nerves and 31 pairs of spinal nerves

Unipolar Neuron

A single process that divides into two branches and functions as an axon

Star-shaped neuroglia between neurons and blood vessels

Astrocyte

What type of cells are found in the CNS?

Astrocytes, microglia, oligodendrocytes, ependyma

Nerve-fiber arising from a slight elevation of the cell body that conducts an action potential (impulse) away from the cell body

Axon

Myelinated Axon

Axon with myelin sheath around it

Unmyelinated Axon

Axon without myelin sheath around it

Branch of an axon

Collateral

What does the axon (nerve fiber) do?

Conduct impulses away from the cell body

What do dendrites do?

Conduct impulses toward the cell body

Structure capable of responding to motor impulse

Effector

Cells that line cavities of the brain and secrete cerebrospinal fluid

Ependymal cell

True or false: Sensory neurons conduct impulses from the spinal cord to a muscle or a gland

False

What is the function of an oligodendrocyte?

Form myelin sheaths in the brain and spinal cord

Specialized mass of neuron cell bodies outside the brain or spinal cord

Ganglion

Schwann cells a. Are only in the brain b. Are only in the spinal cord c. Are throughout the CNS d. Have a myelin sheath and neurilemma

Have a myelin sheath and neurilemma

Substance of Schwann cell composed of lipoprotein that insulates axons and increases impulse speed

Myelin

Transmits impulse from sensory to motor neuron within central nervous system

Interneuron

A multipolar neuron contains a. One dendrite and many axons b. Many dendrites and one axon c. One dendrite and one axon d. A single process with the dendrite and axon

Many dendrites and one axon

Phagocytic neuroglia

Microglia

What is the function of an astrocyte? (5)

Most abundant type- - Provide structural support - Communicate with other neurons - Remove excess ions and neurotransmitters - Transport of substances between blood vessels and neurons -Form scar tissue to replace damaged neurons

Multipolar, Bipolar, or Unipolar? Sensory neuron

Most unipolar; some bipolar

Transmits impulse out of the brain or spinal cord to effectors (muscles and glands)

Motor (efferent) neuron

A _____________ neuron is the most common structural neuron in the brain and spinal cord a. Multipolar b. Tripolar c. Bipolar d. Unipolar

Multipolar

Multipolar, Bipolar, or Unipolar? Interneuron

Multipolar

Multipolar, Bipolar, or Unipolar? Motor neuron

Multipolar

Sheath of Schwann cell containing cytoplasm and nucleus that encloses myelin

Neurilemma

Network of threadlike structures within cell body and extending into axon

Neurofibrils

Corresponds to rough endoplasmic reticulum

Nissl bodies

The cell body of a neuron contains the a. Nucleus b. Dendrites c. Axon d. Neuroglia

Nucleus

Myelin-forming neuroglia in brain and spinal cord

Oligodendrocyte

Neuroglia that produce myelin insulation in the CNS are a. Microglia b. Astrocytes c. Ependymal cells d. Oligodendrocytes

Oligodendrocytes

Multipolar neuron

One axon and multiple dendrites

What is the axon hillock?

Origin region of axon

What types of cells are found in the PNS (Peripheral nerves)?

Schwann cells & satellite cells

What is the function of ependymal cell?

Secrete and assist in circulation of cerebrospinal fluid

Transmits impulse into brain or spinal cord from receptors

Sensory (afferent) neuron

What is the shape of an oligodendrocyte?

Shaped like astrocytes, but with fewer cellular processes

What is the shape of microglia?

Small cells with slender cellular processes

What is the shape of an astrocyte?

Star-shapes cells contacting neurons and blood vessles

Where does nervous tissue occur?

The brain, spinal cord, and peripheral nerves

Possesses a single process from the cell body

Unipolar Neuron

What do Schwann cells do?

They are cells that wrap tightly around the axons of peripheral neurons; speed up neurotransmission

What do Satellite cells do?

They are flattened cells that surround cell bodies of neurons in ganglia; they support ganglia

Interneuron

Transmits impulses between neurons in the brain and spinal cord

True or False: Astrocytes have contacts between blood vessels and neurons in the CNS

True