Anatomy 6.1

Spinal nerves that transmit info to and from the spinal cord and cranial nerves that transmits info to and from the brain.

Describe the structure and function of the peripheral nervous system (PNS).

Neuroglia and Neurilemma

Name two types of nervous tissues found in the nervous system.

3: Sensory, Motor and Interneurons. Sensory - Carry impulses, Motor - Transmit impulses, Interneurons - Form bridges to transmit impulses.

Neurons are classified according to function. How many types are there, and what are their functions?

Sensory Neurons - Carry impulses from the skin and organs to the spinal cord and brain, providing info about the internal and external environments. Motor Neurons - Transmit impulses from the brain and spinal cord to the muscles and glands, directing body actions. Interneurons - Neurons that form bridges to transmit impulses between other neurons.

There are three different neuron structures. Describe the structure and function of each.

Astrocytes: the most numerous cell type within the central nervous system (CNS) and perform a variety of tasks, from axon guidance and synaptic support, to the control of the blood brain barrier and blood flow. Ependymal: line the CSF-filled ventricles in the brain and the central canal of the spinal cord. Microglia: these cells mediate immune responses in the central nervous system by acting as macrophages, clearing cellular debris and dead neurons from nervous tissue through the process of phagocytosis (cell eating). Oligodendrocytes: provide support and insulation to axons in the central nervous system of some vertebrates, equivalent to the function performed by Schwann cells in the peripheral nervous system.

What are four types of neuroglia found in the CNS? Describe the function of each.

Axon terminals filled with tiny sacs, or vesicles, that contain chemical messengers.

What are neurotransmitters?

Central Nervous System & Peripheral Nervous System

What are the two major divisions of the nervous system?

Schwann cells and Satellite cells. Schwann - form fatty myelin sheaths. Satellite - crushing support cells.

What are the two types of neuroglia found in the PNS? Describe the function of each.

Somatic and autonomic nervous systems. Somatic stimulates skeletal muscles. Autonomic controls the cardiac muscle of the heart and smooth muscles in internal organs.

What are two subdivisions of the efferent nerves? Name the function of each.

Afferent transmits impulses and efferent carry impulses.

What is the difference between afferent and efferent nerves?

White Matter - Tracts myelinated fibers. Gray Matter - Tracts unmyelinated fibers.

What is the difference between white matter and gray matter?

Form bridges to transmit impulses.

What is the main function of neurons?

Intersection, including the Synaptic cleft.

What is the synapse between an axon terminal and muscle fiber called?

Brain and Spinal Cord. The CNS directs the entire nervous system's activity.

Which body structures and function of the peripheral nervous system (CNS)? What is the function of the CNS?

To insulate the axon fibers, which increases the rate of neural impulse transmission.

Why is it important for an axon to be covered with a myelin sheath?