Senses human biology

sensory transduction

the process by which sensory signals to nerve impulses

Extroceptors

detect external stimuli

olfactory

smell

rod and cone cells

photoreceptor

hair cells in ear

mechanoreceptors

taste and olfactory cells

chemoreceptor

olfactory epithelium

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

interoceptors

detect internal stimuli

Baroreceptors

detect changes in blood pressure

Osmoreceptors

respond to the osmolarity of the blood (water homeostasis)

Chemoreptors monitor what?

pH of blood

Nociceptors

pain receptors

Thermoreceptors

respond to changes in temperature

sensation

conscious perception of stimuli

Where does perception occur?

cerebral cortex

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

somatic senses

touch, pressure, temperature, pain

proprioceptors

reflex actions, muscle tone, equilibrium, and posture

cutaneous receptors

Sensitive to touch, pressure, pain, and temperature.

Meissner corpuscles

respond to light touch

Krause end bulbs

tactile; in mucous membranes

Merkel disk receptors

sense pressure, where epidermis meets dermis

root hair plexus

free nerve ending (touch) around follicles

Pacininan corpuscles

heavy pressure, in dermis

Ruffini endings

respond to stretch, encapsulated by connective tissue

What are prostaglandins?

A group of bioactive, hormone-like chemicals derived from fatty acids.

What role do prostaglandins play in inflammation?

They are involved in the inflammatory response.

How do prostaglandins affect platelet aggregation?

They play a role in platelet aggregation.

What effect do prostaglandins have on vascular smooth muscle?

They can cause dilation and constriction of vascular smooth muscle.

What role do prostaglandins have in cell growth?

They are involved in the regulation of cell growth.

How do prostaglandins protect the stomach?

They help protect the stomach from acid.

nociceptors

pain receptors

referred pain

pain felt in a part of the body other than its actual source

Papillae of the tongue

taste buds

5 taste receptors

sweet, sour, salty, bitter, umami

gustatory cortex

area of the brain that receives and interprets tastes from the tongue, in parietal lobe

olfactory epithelia

Lines the olfactory region of the nasal cavity.

olfactory bulb

the first brain structure to pick up smell information from the nose

3 layers of the eye

sclera, choroid, retina

sclera

white of the eye

choroid

middle, vascular layer of the eye, between the retina and the sclera

ciliary body

controls the shape of the lens

suspensory ligaments

hold the lens in place

aqueous humor

fluid in the eye, found between the cornea and the lens

glaucoma

drainage ducts are blocked and aqueous humor builds up, leads to blindness

Retina

Light sensitive layer of the eye; contains rods and cones, posterior compartment

vitreous humor

jellylike substance found behind the lens in the posterior cavity of the eye that maintains its shape

rods

Retinal receptors that detect black, white, and gray

Cones

color vision

fovea centralis

tiny pit or depression in the retina that is the region of clearest vision

optic nerve

made of sensory fibers from the retina

humors of the eye

transmit light rays and support the eye

Rhodopsin

the visual pigment found in rods

night vision: rods or cones?

rods

opsin and retinal

two components of rhodopsin

where are cones in the eye

fovea centralis

3 types of cones?

blue, green, red

blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there

optic nerve

the nerve that carries neural impulses from the eye to the brain

optic chiasma

the crossing of the optic nerves from the two eyes at the base of the brain

where do optic tracts lead to

thalamus

visual cortex is where?

occipital lobe

nearsightedness

myopia, eye is elongated and distant objects are in focus in front of the retina

Farsightedness

eye is shortened, close objects are focused behind the retina

lenses for nearsightedness

convex

lenses for nearsightedness

concave

astigmatism

irregular curvature of cornea or lens, corrected with uneven lens

stereocilia

small hairlike projections on the tops of inner and outer hair cells

outer ear consists of

pinna and auditory canal

tympanic membrane

eardrum

ossciles

malleus, incus, stapes

malleus

hammer; first of the three auditory ossicles of the middle ear

incus

anvil; middle of the three auditory ossicles of the middle ear

stapes

stirrup; last of the three auditory ossicles of the middle ear

eustachian

auditory tube

semiciruclar canals and vestibule handle ___

equilibrium

cochlea

snail, handles hearing

cochlea parts detect what pitches

tip = low

base = higher pitches

Vestibular nerve orginates in ___

semicircular canals, saccule, and utricle.