8 Science: Chapter 18 Review

central nervous system

composed of the brain and the spinal cord

peripheral nervous system

all "non-CNS" nerves
12 cranial nerves
31 spinal nerves

somatic nervous system

division of the nervous system that communicates with voluntary muscles

autonomic nervous system

division that communicates with involuntary muscles, internal organs, and glands

sympathetic nervous system

division that mobilizes body systems during increased activity or stress

parasympathetic nervous system

division that conserves energy and promotes "housekeeping" during restful periods

brain

part of the CNS; contains 100 billion neurons; protected by the skull, 3 layers of tissue, and a fluid layer

spinal cord

part of the CNS; protected by vertebrae and cartilaginous discs; flexible yet firm

cerebrum

The function of this part of the brain is to:
- interprets sensory input
- stores memory
- controls voluntary movement

brainstem

the part of the brain connects to the spinal cord

midbrain

the part of the brainstem that connects to the cerebrum

pons

the middle part of the brainstem

medulla

leads to the spinal cord; controls breathing, heart rate, and blood pressure

cerebellum

The function of this part of the brain is to:
- store learned movements
- interpret stimuli from eyes, ears, muscles, and tendons
- coordinate learned movements, maintains muscle tone, and maintains balance

neuroforamen

spaces or holes in the backbone where nerves connect to the spinal cord

perineurium

the sheath of connective tissue surrounding a single bundle of nerve fibers within a nerve

epineurium

the outermost layer of connective tissue surrounding a multiple bundles of nerves

afferent neurons

neurons that receive info and send impulses to CNS

efferent neurons

conduct impulses from CNS to muscles, glands, etc.

interneurons

neurons that receive information from sensory neurons and integrate a response with motor neurons

cell body

aka the soma
contains organelles

dendrite

the part of the neuron that receives neurotransmitters from other neurons via endocytosis and generates an electrical impulse

axon

extension of the neuron that is wrapped in the myelin sheath; electrical impulses travel down it

axon terminal

the part of the neuron that releases neurotransmitters via exocytosis

cornea

the clear, convex, disc-shaped tissue that covers the iris and pupil; light first passes through it

lens

the second clear, convex disc-shaped tissue that light passes through

retina

the nerve tissue located at the back of the eye that is sensitive to light; very sensitive macula/ fovea

photoreceptors

neurons that detect light; includes rods and cones

rod

a type of photoreceptor that detects dim light; contains rhodopsin; you have about 100 million

cone

a type of photoreceptor that detects bright light/color; contains photopsin; you have about 6 million

macula

region of the retina where light is focused on; contains more cones than other parts of the retina

optic nerve

bundle of nerve fibers that bring information from retina to brain; causes your blind spot

outer ear

consists of the pinna and ear canal; funnels sound waves into your ear

middle ear

consists of the eardrum, three ossicles, and the eustachian tube; converts sound waves into mechanical energy

inner ear

consists of semicircular canals, cochlea, and cochlear nerve; converts mechanical energy into fluid waves and then fluid waves into electrical impulses

cochlear nerve

aka auditory nerve; brings electrical impulses from the cochlea to the brain

hair cell

sensory receptor neurons located in the cochlea

stereocilia

small projections on hair cells that bend when hit by a fluid wave in the cochlea

cochlea

a part inner ear that is filled with fluid and contains hair cells

malleus

the ossicle commonly known as the hammer; the first ossicle in the inner ear

incus

the ossicle commonly known as the anvil; the second ossicle in the inner ear

stapes

the ossicle commonly known as the stirrup; the third ossicle in the inner ear

olfactory neurons

specialized neurons in your nasal cavity that aid in smell and taste

taste bud

a structure in your mouth that consists of the taste pore, taste receptor cells, and basal cells

basal taste cells

immature taste receptor cells that can grow into mature taste receptor cells in a taste bud