BI 232 Lab 2: ANS, general senses, gustation, olfaction

sympathetic nervous system

"fight or flight"

controls many organs all over the body

has sole control over arrector pili muscles, adrenal glands

parasympathetic nervous system

"rest and digest"

controls many organs all over the body

has sole control of lacrimal glands

sympathetic trunk/chain ganglia

Runs along vertebrae, part of the sympathetic nervous system, keeps whole body in sync

White rami communicans

contain myelinated preganglionic fibers traveling to sympathetic trunk ganglia

gray rami communicans

contain unmyelinated postganglionic fibers traveling from ganglia to peripheral structures

general senses

somatic and visceral senses - temperature, pain, touch, pressure, vibration, proprioception

special senses

sight, hearing, smell, taste, balance

nociceptor

pain receptor (free dendritic ending) - tonic

thermoreceptor

detects heat, changes in temperature, rates of conduction (free dendritic endings)

mechanoreceptors

detect mechanical deformation of cell membranes - pressure, vibration, deep touch

tactile receptors

mechanoreceptors, associated with touch

baroreceptor

a sensory receptor that responds to changes in pressure, monitors blood pressure

proprioceptor

stretch receptor - are joints bent or straight

tactile (merkel) discs

located at the border of dermis/epidermis - detect light touch, free dendritic endings, phasic/fast adapting, concentrated in hands and face

free nerve endings

bare dendrites - pain, temp, tickle, light touch

hair root plexus

track/sense hair movement

Free dendritic endings, phasic/fast-adapting, only absent in palms and soles, exteroreceptor

Tactile (Meissner's) corpuscles

in the dermal papillae, detect fine touch, fast adapting/phasic, concentrated in face, fingers, and genitals, exteroreceptor

lamellated (pacinian) corpuscles

in dermis, detect deep touch

Ruffini's (Bulbous) corpuscles

detect position of joints, heavy/continuous touch, pressure, tonic. Located in deep dermis, all over body.

Muscle spindles

Proprioceptors that detect the rate and degree of muscle stretch

Golgi tendon organ

monitors tension in tendons, found at junction of tendon and muscle, prevents over-stretching/ripping by forcing action of antagonist/forcibly relaxing muscles

End Bulbs of Krause

encapsulated mechanoreceptor, tonic, found all over the body but highly concentrated in upper lip, responsible for mammalian dive reflex

lamellated/pacinian corpuscle

tactile/meissner's corpuscle

Olfactory (Bowman's) gland

produce the mucous that dissolves odorants to help you smell

Olfactory neuron (receptor cell)

bipolar, ciliated neurons, contain binding sites for odor molecules, axons pass through cribriform plate, get replaced every 60 days

supporting cells (olfaction)

protect olfactory neurons

Olfactory nerves

olfactory axons in PNS

olfactory tract

olfactory axons in the CNS

olfactory bulb

the end of the olfactory tract

circumvallate papillae

large papillae at the rear of tongue, associated with taste buds

fungiform papillae

scattered over tongue, concentrated at tips and lateral sides, look like a mushroom

filiform papillae

no taste buds, detect texture

foliate papillae

all over tongue, concentrated on the lateral sides

what are the five primary tastants?

salty, sweet, bitter, sour, umami, water

taste pore

opening in taste bud

gustatory receptor cells

sensory cells in the taste bud that transduce the chemical stimuli of gustation

gustatory hairs

increase surface area of taste pore

bitter

concentrated at the rear of tongue, alkaloids, hydroxyls

sour

concentrated on lateral sides of tongues, respond to acids

salty

monovalent metallic cations - lateral sides of tongue

sweet

organic molecules, concentrated at tip

umami

glutamate, savory

olfactory epithelium

a thin layer of tissue, within the nasal cavity, that contains the receptors for smell