lab 13 biol1191

Tactile corpuscles (Meissner)

found in dermal papillae of highly sensitive areas of hairless skin; detect touch + low frequency vibration

Hair root plexus

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

Nonencapsulated sensory corpuscles (Merkle/tactile discs)

Free nerve endings that associate with Merkel/tactile cells in stratum basale in fingertips, hands + lips; detect pressure + continuous touch

Bulbous corpuscles (Ruffini)

encapsulated receptors deep in dermis, in ligaments + tendons; detect stretching + continuous pressure

Lamellar corpuscles

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

Free nerve endings

in skin that stimulated by certain chemicals; result in itch sensation; tickle too

Tactile Localization

?? go back n look nga

2 point discrimination test

?? go back nga

Olfactory tract and bulb

receives olfactory info + is involved in olfactory perception

Ethmoid bone

allows axons of olfactory sensory neurons to synapse w/ 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

Secretion of mucus luricates olfactory epithelium + dissolves odor molecules to allow olfactory perception by stimulating olfactory cilia

Olfactory sensory neuron

Detect + transmit info of smell to the primary olfactory area of the cortex by dissolving an ordorant molecules to stimulate olfactory cilia generate AP

Axon

Detect + transmit info of smell to the primary olfactory area of the cortex by dissolving an ordorant molecules to stimulate olfactory cilia generate AP

Dendrite

Detect + transmit info of smell to the primary olfactory area of the cortex by dissolving an ordorant molecules to stimulate olfactory cilia generate AP

Olfactory cilia/hair

Detect + transmit info of smell to the primary olfactory area of the cortex by dissolving an ordorant molecules to stimulate olfactory cilia generate AP

Odorant molecule

Detect + transmit info of smell to the primary olfactory area of the cortex by dissolving an ordorant molecules to stimulate olfactory cilia generate AP

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 + rings of smooth muscle; changes pupil diameter to regulate how much light enters eye

Sclera

“white” of the eye 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 + mediallyAlso helps depress the eye

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 + produces aqueous humor

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 + creates internal pressure to keep eyeball inflated

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; helps focus light on retina

Lens

avascular organ 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

innermost layer containing photoreceptors; forms + interprets clear images when light is focused on

Choroid

highly vascular membrane containing melanocytes; provides nutrients to sclera + absorbs scattered light

Macula (macula lutea)

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

eyeball cavity filled w/ 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

formed of elastic cartilage 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

on sides of skull; protects nerves + structures in ear controlling hearing + equilibrium

External acoustic meatus

tube connecting outer ear w/ inner ear; channels sound waves to tympanic membrane

Auditory ossicles

Malleus, incus, stapes

Malleus

amplifies sound vibration from outer ear → vesibular window

Incus

amplifies sound vibration from outer ear → vesibular window

Stapes

amplifies sound vibration from outer ear → vesibular window

Vestibular (oval) window

Posterior to stapes; vibrates in response to sound waves, creates pressure in cochlea from fluids to produce a nerve impulse

Cochlear (round) window

below oval window; receives bult up pressure in cochlea → middle ear

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 + hearing from inner ear → temporal lobe

Cochlear branch

CN VIII; carries impulses for equilibrium + hearing from inner ear → temporal lobe

Semicircular ducts

Contained in semicircular canals; detects accelerating/decceleration of the head during rotatory movements by stimulation of hair cells

Semicircular canals

3 bony canal filled w/ endolymph forming a loop-like shape; sends signals to brain abt rotational movement via vestibular branch to maintain balance

Ampulla

sacs of membranous labyrinth; detects + signals brain for head rotation/movement

Crista

Small region 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

snail - shaped filled w/ fluid in inner ear; contains receptors for hearing + involved in sound transduction

Cochlear duct (scala media)

hollow bony tube containing endolymph in cochlea of inner ear; converts sound vibration → electrical impulse sent to brain for sound perception

Scala vestibuli

superior part of bony labyrinth; contains perilymph above cochlear duct conducts sound vibrations to scala media + spiral organ

Scala tympani

Scala tympani inferior part of bony labyrinth; contains perilymph equalizes pressure in the cochlea

Vestibular membrane

thin membrane; seperates cochlear duct from scala vestibuli + creates pressure in cochlear duct

Basilar membrane

thin membrane; seperates cochlear duct from scala tympani + spinal organ rests on it

Spiral organ (organ of corti)

epithelium resting on basilar membrane; allows transduction of auditory stimuli + converts into AP from stimulation of hair cells

Tectorial membrane

gelatinous, sheet like structure within the cochlea of inner ear; 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 maculaFound in the utricle and saccule, these crystals provide information about head position and movement

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