Anatomy and Physiology bullshit

sensory receptors

special cells in your body that detect internal and external changes

human senses are grouped into two broad categories including_____

general and special senses

general senses

• simple neural pathways

• touch, temperature, pain, chemical, and pressure detection

• body position

proprioception

body position

presbyopia

a condition brought about by the lens slowly losing elasticity, causing farsightedness——caused by aging

special senses

• complex pathways

• receptors are housed in specialized organs

• include taste, smell, vision, hearing, and equilibrium

receptive field

the specific area monitored by a sensory receptor cell where stimuli can influence the activity of that cell

labeled line

where the neuron of a given receptive field is connected to a specific area of the sensory cortex

• CNS interprets sensory information entirely on the basis of the this are over which the information arrives

sensory coding

the pattern of action potentials——provides the CNS with information like intensity, duration, variation, and movement of stimulus

the cerebral cortex cannot_____

tell the difference between true and false sensations

referred pain

when the body projects a sensation, like pain, to another part of the body

sensory receptors are either_____

tonic or phasic

tonic receptors

always active——pain receptors are an example

phasic receptors

usually inactive——-are “turned on” by stimulation

EX) root hair plexuses, tactile corpuscles, and lamellated corpuscles

thermoreceptors

sensors for changes in temperature and have wide distribution in the body being found in the dermis, skeletal muscles, and hypothalamus

the hypothalamus stores _____

the body’s internal thermostat

chemoreceptors

found in the medulla, arteries near the heart, and in the heart

****monitor changes in concentrations of chemicals in the body’s fluids

nociceptors

pain receptors in the epidermis

mechanoreceptors

touch receptors that bend when stimulated

include: baroreceptors, proprioceptors, and tactile receptors

baroreceptors

monitor pressure changes in gases and liquids

***type of mechanoreceptor

proprioceptors

stimulated by changes in body position and information is conveyed to the cerebellum so the CNS knows where we are located in our 3-dimensional surroundings

****type of mechnoreceptor

muscle spindles

****a type of proprioceptor

informs the brain about muscle tension

golgi tendon organs

***type of proprioceptor

in tendons (near joints)————inform the brain about joint position

tactile receptors

located in the skin—-respond to touch and provide us with information regarding texture, shape, size, and location of the tactile stimulation

****may either be unencapsulated or encapsulated with connective tissue

free nerve endings

****unencapsulated tactile receptors

simple receptors that are the exposed tips of dendrites in tissue

merkel cells

******unencapsulated tactile receptors

are in direct contact with the epidermis and respond to tactile dics

tactile discs

sensory neurons at swollen synapses

pain receptors (aka nociceptors) are ____

free nerve endings with large receptive fields

root-hair plexuses

unencapsulated tactile receptors composed of sensory neuron dendrites wrapped around hair roots

***stimulated when something like an insect lands on your bare arm and moves your arm hairs

encapsulated tactile receptors have_____

branched dendrites that are covered by specialized cells

Tactile/ meissner’s corpuslces

nerve endings located in the dermal pappillae of the skin

meissner corpuscles have dendrites that are_____

wrapped in special schwann cells and are highly sensitive to pressure, touch, and a change in shape

lamellated/ pacinian corpuscles

***encapsulated receptors deep in the dermis

encases in concentric layers of connective tissue and respond to deep pressure and vibrations

ruffini corpuscles

surrounded by collagen fibers embedded in the dermis

****changes in tension or shape of the skin tug on the collagen fibers and that tugging stimulates this ~thing~

the brain can detect where a stimulus is coming from _____

by which receptive field is sending the sensory information

sensory receptors are ____

NOT evenly distributed in the skin

two-point discrimination test

used to map the distribution of touch receptors on the skin——a bent paperclip or a drawing of a compass with two points is used to determine the distance between cutaneous receptors

***by gradually increasing the distance between the points until two distinct sensations are felt, the density of the receptor population int hat region can be measured

receptors display_____

adaption so they experience reduced sensitivity to repeated stimuli

peripheral adaption

the decline in response to stimuli at receptors——reduces the amount of sensory information the CNS must process

central adaptation occurs in _____

the CNS

generator potential

olfactory reception begins with the binding of an odorant to a G-protein coupled receptor in the plasma membrane of an olfactory dendrite, creating a depolarization

generator potential leads to the _____

generation of action potentials which are then carried to the CNS by sensory afferent fibers

olfactory receptor cells are located in the____

olfactory epithelium lining the roof of the nasal cavity

olfactory receptor cells are_____

bipolar neurons with many cilia that are sensitive to airborne molecules

most of the air we inhale passes____

through the nasal cavity and into the pharynx

basal cells

stem cells that divide and replace olfactory receptor cells

sustentacular cells

***supporting cells***

provide physical support and nourishment to the olfactory receptors

the olfactory epithelium is attached to an ____

underlying layer of connective tissue called the lamina propria—-underlies a mucuous epithelium and forms part of a mucous membrane

bowmans gland

located in the lamina propria

secretions absorb water and form a thick, pigmented mucus

retinal

a visual pigment derived from vitamin A

fovea centralis

the portion of the retina within the macula that provides the sharpest vision because it has the highest concentration of cones———depression in retina

rhodopsin

the visual pigment in the membrane discs of the distal segments of rods

retina

the innermost layer of the eye, lining the vitreous chamber———also called the inner layer——light-sensitive layer at the back of the eye that converts light into nerve impulses

pupil

the opening in the center of the iris through which light enters the eye

choroid

the middle, vascular layer in the wall of the eye——-in between the sclera and retina

vallate papillae

one of the large, dome-shaped papillae on the superior surface of the tongue——forms a V———-separating the body of the tongue from the root

*****contains taste buds for bitter substances

labyrinth

a maze of passageways—-the structures of the internal ear

stapes

the auditory ossicle attached to the oval window

iris

a contractile structure made up of smooth muscle that forms the colored portion of the eye———regulates the amount of light entering through the pupil

sclera

the whites of eyes——-fibrous outer layer of the eye

perilymph

a fluid similar in composition to cerebrospinal fluid———-located in the spaces between the bony labyrinth and the membranous labyrinth of the internal ear

lens

the transparent refractive structure of the eye that is between the iris and the vitreous humor

vestibular duct (scala vestibular)

the perilymph-filled chamber of the internal ear adjacent to the vestibular membrane

—pressure waves are induced by movement of the stapes at the oval window

ciliary body

a thickened region of the choroid that encircles the lens of the eye

****includes the ciliary muscle and the ciliary processes that support the suspensory ligament of the lens

palpebrae

aka eyelids

accommodation

an alteration int he curvature of the lens of the eye to focus an image on the retina

cones

a photoreceptor responsible for sharp vision and color vision

lacrimal gland

a tear gland on the dorsolateral surface of the eye

conjunctiva

a layer of stratified squamous epithelium that covers the inner surfaces of the eyelids and the anterior surface of the eye to the edges of the cornea

cornea

the transparent portion of the fibrous layer of the anterior surface of the eye

nasal cavity

a chamber in the skull that is bounded by the internal and external nares

fibrous tunic/layer

the outermost layer of the eye composed of the sclera and cornea

hair cells

sensory cells of the internal ear

vitreous humor

the gelatinous mass int he posterior cavity of the eye

nystagmus

an unconscious, continuous movement of the eyes as if to adjust to constant motion

aqueous humor

fills the anterior chamber——-circulation the anterior cavity, passes through the posterior chamber and anterior chamber through the pupil——reabsorbed by the scleral venous sirius

filiform papillae

slender conical projections from the dorsal surface of the anterior two-thirds of the tongue

****helps manipulate food on tongue surface

rods

a photoreceptor responsible for vision in dim lighting

olfactory discrimination

the ability to distinguish different smells based on the activation of specific olfactory receptors

refraction bends light to____

focus them on the retina

color perception achieved through the _____

activation of different types of photoreceptor cells in the retina

sounds waves are transmitted through the ear and____

converted into nerve impulses sent to the brain

photoreceptor cells

cells in the retina that respond to the light and enable vision

during sympathetic activation, people experience_____

heightened awareness of sensory information

the cerebral cortex ____

interprets sensory informatin

emmetropic

someone with 20/20, or “normal”, vision

astigmatism

an irregular shape of the cornea or lens, causing a reduction in visual acuity

hyperopic

when the eye can only focus on the image behind the retina, causing the individuals to only see far objects clearly——-farsightedness

myopic

the condition in which the eye can only focus an image in front of the retina, causing the inability to see distant objects——nearsightedness

refraction

bending light

accommodation

the action in which the eye alters its shape to focus light on the retina

when your eyes look at a far object_____

the ciliary body relaxes and the ciliary zonule pulls the lens to a flatter angle for proper refraction

when your eyes look at a closer object______

the ciliary body shifts forward and the muscle contracts as the ciliary zonule releases tension and the lens bulges to a rounder shape

snellen eye chart

measures monocular and binocular visual acuity through a geometric scale of printed block letters that star off large and slowly decrease in size

Mariotte’s blind spot

Test reveals your blind spot

includes the image featuring a bold plus sign on the left side of the page and a bold dot on the right side. As you view this image, you lose your left eye and stare at the left plus sign with your right eye. Keeping the plus sign in your field of vision, you hold the image a few inches away from you and slowly move away

auricle

also called pinna

the flap of the outer ear that funnels sound waves into the external acoustic meatus

external acoustic meatus

a tubular chamber that delivers sound waves to the eardrum

****provide some protection for tympanic membrane

tympanic membrane

where the acoustic meatus ends—— also called your eardrum

****separates the external ear from the middle ear

ceruminous glands

integumentary glands that secrete cerumen

cerumen

a waxy material that helps keep out foreign objects or small insects