Bio Ch 26.1: The Nervous System :(

what is the basic unit of structure and function of the nervous system?

neurons

what are the three regions of a neuron?

cell body, dendrites, axon

what are dendrites and what are their functions?

branchlike extensions that receive impulses and carry them toward cell body

what are axons and what are their functions?

extension of a neuron that carries impulses away from cell bodies

what is the white covering on cells and what is its purpose?

myelin sheath; to insulate the axon

what is a synapse?

tiny space between neurons

what is a neurotransmitter and what is its purpose?

chemicals that diffuse and signal receptor sites to open neuron channels

what is the central nervous system composed of?

brain and spinal cord

what are the functions of the CNS?

interpret sensory info and issue instruction based on past experiences and current conditions

what is the peripheral nervous system composed of?

cranial and spinal nerves

what is the function of the PNS

to communicate between all parts of the body

what are the three functions of the nervous system?

1. monitor changes

2. processing and interpreting sensory info

3. causing responses by activating muscles or glands

how does the nervous system control homeostasis and what is it like?

fast acting control via electrical signals (gmail)

how does the endocrine system control homeostasis and what is it like?

slow acting control via hormones being released into the blood (facebook)

what are the two divisions of the PNS?

sensory (afferent) and motor (efferent) division

what is the sensory (afferent) division’s function?

nerve fibers that carry impulses to the CNS

what is the motor (efferent) division’s function?

nerve fibers that carry impulses away from the CNS

what are the two types of the motor division?

somatic and autonomic

what is the function of the somatic nervous system?

voluntary control over skeletal muscles

what is the function of the autonomic nervous system (ANS) ?

involuntary control over cardiac and smooth muscle

what are the two divisions of ANS?

sympathetic and parasympathetic

what is the function of the sympathetic division?

speeding you up in extreme situations

what is the function of the parasympathetic division?

slowing you down when body is at rest to conserve energy

what is a cell body?

a metabolic center composed of typical cell organelles

what are axon terminals?

branches at the terminal end of axon full of neurotransmitters

what is myelin and what is its function?

fatty substance covering long neurons that speed up neural transmission

what are association neurons? (interneurons)

connections between motor and sensory neurons

what does the cerebrum control?

speech, memory, logical and emotional response, consciousness, voluntary movement, and problem-solving

what are the cerebrum hemispheres separated by?

corpus callosum

what side does the left hemisphere of the cerebrum deal with?

the right side of the body

what side does the right side of the cerebrum deal with?

left side of body

what does the cerebrum look like and why?

wrinkled b/c it increases surface area (affects intelligence)

what does the cerebellum control?

balance and muscle coordination

what is function of the brain stem?

controlling homeostasis through involuntary activities

what are the three parts of the brain stem?

1. midbrain

2. pons

3. medulla oblongata

where does the PNS relay info?

CNS and skeletal systems

what is an automatic, unconscious response called?

reflex

which part of the brain controls a reflex?

brain stem

where does the autonomic nervous system carry impulses?

CNS to internal organs

to which division of the nervous system do sense organs belong to?

PNS