Nervous/Special Senses Flashcards
define AGEUSIA
absence of gustatory sense (taste)
define ANOSMIA
absence of olfactory sense (smell)
aka: anosmia
anosphrasia
define DYSGEUSIA
taste impaired leading to either an unpleasant taste when previously pleasant or a taste w/o stimulus
define HYPEROSMIA
abnormally heightened sense of smell
define HYPOSMIA
abnormally weak sense of smell
define FISSURE
normal folds in contours of brain
PNS is composed of what
12 pairs of cranial nerves & 31 pairs of peripheral spinal nerves
define NERVE
at least 1 bundle of neurons
define TRACT
bundle/group of nerve fibers in brain/spinal cord
define GANGLION
nerve center made of cluster of nerve cell bodies outside CNS
define INNERVATION
supply of nerves to specific body part
define PLEXUS
network of intersecting spinal nerves
define RECEPTORS
sites in sensory organs getting stimulation
define STIMULUS
anything that excites nerve to cause impulse
define REFLEX
automatic, involuntary response to any change
define AFFERENT NEURONS
sensory
define EFFERENT NEURONS
motor
define CONNECT/ASSOCIATE NEURONS
link afferent & efferent neurons
define DENDRITES
root-like processes that receive impulses & conduct to cell body
define AXON
process that conducts impulse away from cell
define TERMINAL END FIBERS
branching fibers @ end of axon that lead nerve impulse from axon to synapse
describe SYNAPSE
space between 2 neurons/neuron & receptor; 1 neuron can have few/hundreds
describe NEUROTRANSMITTERS
chemical substances that allow for messages to cross synapse to receptors; 200-300 known
define ACETYLCHOLINE
neurotransmitter for muscle action
define DOPAMINE
neurotransmitter for motivation, pleasure, & movement
define ENDORPHINS
neurotransmitter that relieves pain
define NOREPINEPHRINE
neurotransmitter for alertness & arousal
define SEROTONIN
neurontransmitter for sleep, hunger, & pleasure
define GLIAL CELLS
suppport & protect neurons by surrounding & holding neurons in place, supply nutrients & O2 to neurons, insulate, & destroy & remove neurons
aka: glial cells
neuroglial cells
describe MYELIN SHEATH
protective covering made of glial cells that covers some of spinal cord & most peripheral nerves; white sheath signifies white matter
define MENINGES
system of membranes enclosing brain & cord w/3 layers of connective tissue (dura mater, arachnoid membrane, & pia mater)
define DURA MATER
outermost layer of meninges that is thick & tough, lining inner surface of cranium
define ARACHNOID MEMBRANE
2nd layer of meninges that is loosely attached to other layers to allow fluid to flow inbetween
define PIA MATER
3rd layer of meninges nearest brain & cord, delicate w/blood vessels
describe CEREBROSPINAL FLUID
clear, colorless, & water fluid that cool & cushions organs & transports nutrients/chemicals; made by special capillaries in ventricles in middle of cerebrum
define CEREBRUM
largest & uppermost part of brain responsible for thought, judgment, memory, emotion, & motor & sensory functions
define CEREBRAL
pertaining to cerebrum/brain
define CEREBRAL CORTEX
outer layer of cerebrum made of gray matter, gyri, & sulci
define CEREBRAL LOBES
subdivided parts of hemispheres (frontal, parietal, occiptal, & temporal)
describe THALAMUS
below cerebrum that produce sensations & relay impulses to & from cerebrum & sense organs
describe HYPOTHALAMUS
below thalamus regulating ANS, sleep-wakefulness cycles, thirst, hunger, temperature, emotional response, & endocrine system; secretes hormones (GHRH, GHIH, CRH, GnRH, TRH)
define GROWTH HORMONE RELEASING HORMONE (GHRH)
stimulates release of GH from pituitary
define GROWTH HORMONE INHIBITING HORMONE (GHIH)
inhibits release of GH from pituitary
define CORTICOTROPIN RELEASING HORMONE (CRH)
regulate release of adrenocorticotropic from pituitary
define GONADOTROPIN-RELEASING HORMONE (GnRH)
regulate release of LH & FSH from pituitary
define THROTROPIN-RELEASING HORMONE (TRH)
regulate release of TSH from pituitary
define CEREBELLUM
2nd largest part of brain that receive incoming messages about movement to make smooth & coordinate movement & maintain equilibrium & normal posture
describe BRAINSTEM
connects hemispheres; consists of midbrain, pons, & medulla oblongata
midbrain & pons
conduction pathways to & from high & low brain centers on brain stem that respond to visual & auditory stimuli & reflexes of eyes & head
define MEDULLA OBLONGATA
lowest part of brain stem, connected to stem that controls basic survival
define SPINAL CORD
long, fragile & tube like structure surrounded & protected by CSF & meninges
define AUTONOMIC NERVOUS SYSTEM
controls involves involuntary actions & consists of sympathetic & parasympathetic
describe SYMPATHETIC NERVOUS SYSTEM
prepares for emergencies & stress; reaction to real or imaginary danger
define PARASYMPATHETIC NERVOUS SYSTEM
returns body to normal after stress & maintains normal function
define COGNITION
mental activities w/memory, thinking, & learning
define ADNEXA OF EYES
structures outside eyeball including orbit, eye muscles, eyelids, eyelashes, conjunctiva, & lacrimal apparatus
aka: adnexa of the eyes
adenxa oculi
define ORBIT
bony cavity containing & protecting eyeball
aka: orbit
eye socket
define EYE MUSCLES
3 pairs to create wide range of movement (superior & inferior oblique & rectus + lateral & medial rectus)
define BINOCULAR VISION
both eyes work together to create 3D depth perception
define CANTHUS
angle upper & lower eyelids meet
define CILIA
small hairs of brows & lashes
define TARSUS
framework within upper & lower eyelid to create its stiffness & shape
aka: tarsus
tarsal plate
define CONJUNCTIVA
transparent mucous membrane lining underside of eyelids acting as protective covering over exposed eye surface
describe LACRIMAL APPARATUS
produce, store, & remove tears; consists of glands, fluid, canal, sac & duct
aka: lacrimal apparatus
tear apparatus
define LACRIMAL GLANDS
secretes tears
describe LACRIMAL FLUID
tears; maintain eye moisture
define LACRIMAL CANAL
duct @ inner corner of eye that collects tears & empty into lacrimal sacs
define LACRIMAL SAC
enlargement of upper part of lacrimal duct
aka: lacrimal sac
tear sac
define LACRIMAL DUCT
drains excess tears into nose
aka: lacrimal duct
nasolacrimal duct
define EYEBALL
1 in sphere w/ only 1/6 visible
aka: eyeball
globe
define SCLERA
maintains shape & protects inner layers of eye
aka: sclera
white of the eye
define CHOROID
opaque middle layer w/lots of blood vessels
aka: choroid
choroid coat