Anatomy Practical 2 Chapter 16

chapters 13,14,15,11,16,19,17,18

central nervous system consists of…

consists of brain and spinal cord

peripheral nervous system consists of…

consists of spinal nerves, dorsal root ganglia, the somatic nerves, and the cranial nerves

what does the sensory division of pns do?

conducts impulses from the regions of the body to the cns

what does the motor division of pns do?

conducts impulses from the cns to the various regions of the body

what are the motor division of pns subunits?

somatic motor nervous system and the autonomic nervous system

what does the somatic motor nervous system do?

takes impulses from the cns and innervates skeletal musles

what does the autonomic nervous system do?

innervates glands, smooth muscle, cardiac muscle, and organs

where does the autonomic nervous system have centers in?

central nervous system (midbrain, pons, medulla oblongata, and spinal cord)

what are the three main parts of a neuron?

axon (nerve fiber), dendrites, and cell body (soma)

neuron cell bodies consist of…

neuroplasm (cytoplasm of the neuron), Nissl bodies (rough endoplasmic reticulum of the neuron), and nucleus

what is an axon hillock and what does it lead to?

triangular region of the neuron cell body that is devoid of Nissl bodies

leads to the axon that exits the neuron cell body

what do sensory neurons (afferent neurons) do?

conduct impulses to the cns

convey information from the external or internal body environment to the spinal cord and/or the brain

what do motor neurons (afferent neurons) do?

conduct impulses away from the cns

where are association neurons (interneurons) located and what do they do?

located between sensory and motor neurons and are part of the integration center

they transmit information to the brain for processing

multipolar neuron consists of…

several dendritic processes, a single neuron cell body, and a single axon

in most neurons, dendrites take information __ the neuron cell body, and axons take information __ the neuron cell body.

to; away from

where are bipolar neurons located?

located in nerves conducting the senses of smell and vision

pseudo-unipolar neurons have…

have a neuron cell body with a single process attached to it

most of the common nerves in the body are…

pseudo-unipolar neurons

where are anaxonic neurons found? what do they consist of?

found in the brain and retina

consist of only dendrites and neuron cell bodies

neurons transmit information electrochemically along the length of the exon to the…

presynaptic terminal

what is the space between neurons called?

synapse

what are the molecules (such as acetylcholine) that move across the synapse called?

neurotransmitters

about half the weight of the brain is composed of…

glia

what is the common clia of the pns?

Schwann cells, or neurolemmocytes

what are nodes of Ranvier?

thin regions between successive cells, left after Schwann cells wrap around the axon

the neurolemmocyte consists of a significant amount of lipoprotein material called…

myelin

the series of neurolemmocytes produces a…

myelin sheath

why is this type of nervous tissue called white matter?

because myelinated nerve fibers appear white

what is saltatory conduction?

type of jumping transmission

nodes of Ranvier allows for the nerve transmission to jump from node to node, increasing the transmission speed of the neuron

gray matter in the nervous system consists of mostly…

unmyelinated fibers

what are oligodendrocytes?

cells that produce myelin in the cns

what do oligodendrocytes do?

wrap around several neurons, creates the white matter of the spinal cord and brain

what are astrocytes and what do they do?

branched glia that nourish neurons and provide a barrier between the nervous tissue and the blood

what makes up the blood-brain barrier and what does it do?

astrocytes along with capillary endothelial cells

protects the nervo