lab 13 biol1191

Meissner

found in dermal papillae of thick skin; detects fine and light touch

Hair root plexus

Consists of nerve endings wrapped arnd hair follicles; detects movements that disturb the hair

Merkle discs

in stratum basale of thick skin; detect pressure and fine touch

Bulbous corpuscles (Ruffini)

in ligaments + tendons; detect stretching + continuous pressure

Lamellar corpuscles

in dermis + subcutaneous; detect high frequency vibrations + continuous pressure

Free nerve endings

sensory receptors that detect pain, temperature, itch, and tickle

Tactile Localization

ability to determine which portion of the skin has been touched

2 point discrimination test

?? go back nga

Olfactory tract and bulb

receives olfactory info + is involved in smell perception

Ethmoid bone

bone containing the cribriform plate, which olfactory nerve fibers pass through to reach the olfactory bulbs

Cribriform plate

allows axons of olfactory sensory neurons to synapse w/ olfactory bulbs

Nasal cavity

filters, warms, + humidifies inhaled air

Olfactory gland + mucus

Secretes mucus to dissolve odor molecules, allowing them to stimulate olfactory cilia

Olfactory sensory neuron

Detects odor molecules via olfactory cilia and transmits smell signals to the primary olfactory cortex

Axon

Detects odor molecules via olfactory cilia and transmits smell signals to the primary olfactory cortex

Dendrite

Detects odor molecules via olfactory cilia and transmits smell signals to the primary olfactory cortex

Olfactory cilia/hair

Detects odor molecules via olfactory cilia and transmits smell signals to the primary olfactory cortex

Odorant molecule

Detects odor molecules via olfactory cilia and transmits smell signals to the primary olfactory cortex

Olfactory adaptation

?? go back nga

When does olfactory adaptation occur irl

When applying perfume

Gustation

The sense of taste, involving the detection of chemical substances by taste buds on the tongue.

Lacrimal gland

Secretes fluid (tears) to lubricate + moisten eye for protection

Lacrimal sac

Acts as a reservoir for tears to prevent overfilling

Eyelid

Protective covering of the eye from light + foreign objects entering

Pupil

hole in center of iris; allows light to enter eye

Iris

coloured portion of eye formed of melanocytes + changes pupil diameter to regulate how much light enters eye

Sclera

formed of dense irregular CT; gives shape to eyeball

Rotate medially

All them except lateral rectus

Rotates laterally

Superior oblique + Inferior oblique + Lateral rectus

Superior rectus

Cranial nerve: III (Oculomotor)
Func: move eye superior + medially

Inferior rectus

Cranial nerve: III (Oculomotor)
Func: Moves inferiorly + medially

Lateral rectus

Cranial nerve: V (Abducens)
Func: Moves eye laterally

Medial rectus

Cranial nerve: III (Oculomotor)
Func: moves eye medially

Superior oblique

Cranial nerve: IV (trochlear)
Func: moves inferiorly + laterally, rotates eyes medially

Inferior oblique

Cranial nerve: III (Oculomotor)
Func: moves eyes superioly + laterally, rotates eyes laterally

Func in name

Superior rectus, inferior rectus, lateral rectus, medial rectus

Func opp of name

Superior oblique + Inferior oblique

Ciliary body

Ciliary muscle + ciliary process

Ciliary muscle

Alters curve of lens for near/far vision

Ciliary process

Alters curve of lens for near/far vision + produces aqueous humor

Anterior segment:

aqueous humor, anterior chamber, posterior chamber

Aqueous humor

clear fluid produced by ciliary process from blood filtration

nourishes + Maintains pressure in the eye to keep its shape

Anterior chamber

nourishes + creates internal pressure to keep eyeball inflated

Posterior chamber

nourishes + creates internal pressure to keep eyeball inflated

Cornea

transparent organ covering the iris; refracts light onto retina

Lens

filled w/ layers of thin transparent cells; focuses/bends light to create a sharp image

Zonular fibers of lens (suspensory ligaments)

attaches to ciliary process; holds lens in place + contracts/relax to adjust lens for near or far vision

Bulbar conjunctiva

covers the sclera; protects eyes from bacteria + infection

Retina

contains photoreceptors (rods and cones) that absorb light and convert it into nerve signals, so the brain can interpret them as an image

Choroid

contains melanocytes; provides nutrients to retina + absorbs scattered light

Macula (macula lutea)

region of the retina with the highest visual activity and colour vision due to its high concentration of cones

Fovea centralis (central fovea)

tiny point in centre of depression

part of the retina that offers visual acuity (clear resolution of images at any distance) + colour visual b/c they contain cones

Optic disc (blind spot)

where optic nerve (CN II) exits the eyeball; does not interpret images form lightrays b/c no photoreceptors

Optic nerve

CN II: sends visual signals → brain (occipital lobe)

Posterior segment (vitreous chamber)

gel-like substances; holds retina against choroid + maintains shape of eye

Vitreous humor/body

eyeball cavity filled w/ gel-like substances; holds retina against choroid + maintains shape of eye

Auricle Helix

covered w/ skin; collects sound waves + channels into ear canal

Auricle lobule

formed of elastic cartilage covered w/ skin; collects sound waves + channels into ear canal

Temporal bone

protects nerves + structures in ear controlling hearing + equilibrium

External acoustic meatus

tube connecting and channels sound waves from outer ear to tympanic membrane

Auditory ossicles

Malleus, incus, stapes

tympanic membrane

thin membrane; vibrates in response to sound waves + passes vibration → middle ear

Malleus

amplifies sound vibration from tympanic membrane → vestibular window

Incus

amplifies sound vibration from outer ear → vesibular window

Stapes

amplifies sound vibration from outer ear → vesibular window

Vestibular (oval) window

where stapes transmits vibrations into the cochlea, creating fluid pressure waves that generate a nerve impulse

Cochlear (round) window

releases fluid pressure from the cochlea by bulging outward

Auditory tube (eustachian tube)

connects middle ear + nasopharynx; equalizes pressure b/w outer + middle ear

Vestibulocholear nerve

Vestibular branch + Cochlear branch

Vestibular branch

CN VIII; carries impulses for equilibrium → temporal lobe

Cochlear branch

CN VIII; hearing from inner ear → temporal lobe

Semicircular ducts

contains endolymph and crista ampullaris to detect rotational head movement

Semicircular canals

housing/protects the semicircular ducts

Ampulla

made of membranous labyrinth; detects rotational movement using hair cells

Crista

within walls of ampullae; contains hair cells detecting angular accelerations + decelerations of the head

Hair cells in Crista

responds to endolymph movement

Internal auditoary canal

canal passing thru temporal bone; gives passage facial + vestibulocochlear nerves

Cochlea

contains hair cells for hearing; convert sound vibrations into nerve impulses

Cochlear duct (scala media)

membranous tube containing endolymph and hair cells that convert sound vibrations to nerve impulses

Scala vestibuli

upper chamber; contain perilymph; starts at the oval window, carries pressure waves into the cochlea

Scala tympani

lower chamber; contains perilymph; carries pressure waves out of the cochlea to the round window

Vestibular membrane

thin membrane; separates scala media from scala vestibuli + transfers pressure waves into the cochlear duct

Basilar membrane

thin membrane; seperates cochlear duct from scala tympani

Spiral organ (organ of corti)

the spiral organ’s hair cells convert sound vibrations into nerve impulses

Tectorial membrane

gelatinous, sheet like structure; provides point of contact for hair cells for stimulation from sound vibration when pushed

Vestibule

contains receptors that detect movement and body position for balance

Utricle

Superior sac of vestibule; senses horizontal movement of head (side to side = tilting)

Saccule

sac of estibule; sense vertical movement of head (up down)

Macula

small region within wall of utricle + saccule; contains receptors for horizontal + vertical movement

Otoliths

calcium carbonate crystals; sends signals of crazy head movement to brain (temp lobe) by stimulating the hair cells in the macula

Describe the func of sensory receptors

detect change in environment + converts stimuli → electrical signal

List 3 somatic sensations that are detected by free nerve endings

pain tickle itch

List 3 somatic sensations that are detected by encapsulated nerve endings

pressure, vibration, deep touch

Is there a relationship between the receptor density of an area and the size of the cerebral cortex receiving information from those receptors?

areas w/ higher density of sensory receptors have a larger corresponding area in cerebral cortex

Imagine yourself without any cutaneous receptors. Why might this be dangerous?

Cutaneous receptors protect us from harm by sending impulses early, having no cutaneous receptors would elad to serious injuries

Several minutes after applying perfume or cologne, you notice you cannot smell the fragrance. Explain this response by your olfactory receptors. Should you apply more?

the olfactory receptors are undergoing olfactory adaptation; the perfume/cologne is a repeated stimulus so the olfactory receptors decreases sensitivity to the smell → don’t apply more

look pg 27 lab maneul add it nga

fdas