1.taste

2.smell

3.vision

4.hearing

5.equilibrium

1.fungiform papillae-most numerous type. Found mostly on the tongue, but also on other parts of the mouth. Contain taste buds

2.circumvallate papillae-large papillae and form a V shape on the posterior 2/3 portion of the tongue. Contain papillae

3.filiform-small papillae that project from the tonge to provide the surface of the tongue with friction. DO NOT contain papillae

1.basal cells- these do mitosis and give rise to new supporting cells

2.supporting cells-provide physical support to the taste cells and can differentiate into new taste cells when the taste cells are dead or damaged

3.taste cells(gustatory cells)-contain taste receptors for tastants and when stimulated will activate neurons for taste

What are the chemicals that the taste receptors bind called?

What molecule is required for this chemical to be able to bind to the receptor?

How does the mouth supply this molecule?

tastants

water

produces saliva, which is mostly water

Are the receptors for taste on a neuron? explain

What crainal nerve contains the axons that will carry the signals for taste?

Which lobe of the brain will interpret this information?

NO! the receptors are on gustatory cells,which are EPITHELIA cells. The binding of the tastant to the receptor causes an increase of calcium influx into the tastant cell. The Ca++ binds to synaptic vesicles that will dock with the membrane and release of neurotransmitter to a nerve ending at the bottom of the taste cell.

CN VII, IX, or X

Insula

a. sweet,bitter,umami-G-protein pathways that lead to Ca++ influx

b.salty-Na+ ions open channels, causing positive influx that depolarizes the membrane and leads to Ca++ influx

c.sour-hydrogen ions cause ion channels to open and depolarize the membrane, leading to Ca++ influx

a.sweet-need for carbs as fuel to make ATP

b.salty-need for ions

c.sour-need for vitamin C

d.bitter-expel spoiled foods

e.umami-need for protein intake

a.adaptation is when there is a diminished sensitivity to the sensation over time. Partial adaptaion will occur in 3-5 secs and complete adaptation is achieved within a few mins.

b.taste association is when you refer to a taste and something the brain has stored before

olfactiory epithelium

located on the superior nasal concha of the ethmoid bone

a.bipolar neurons-contain the receptors for odorants(chemical stimuli)

b.supporting cells-columnar EPITHELIA cells that physically support the bipolar neurons and can differentiate into bipolar neurons to replace dead or damaged ones

c.basal cells-epithelial cells that undergo mitosis to give rise to supporting cells

for smell, the receptors are on a neuron and for taste they are on an EPITHELIA cell that conveys the message to a neuron below it

odorants

water

olfactory glands produce mucus and coat the olfactory epithelia with it

What is the pathway of neurons from the olfactory epithelium to the brain?

a. What types of cells do the bipolar neurons synapse with?

b.in what special structure does this synapse occur?

c.What is the synapse ratio?

The bipolar cells are filaments of CN I. They pass the info to mitral cells, whose axons form the olfactory TRACT in the CNS.

a.mitral cells(multipolar)

b.glomerulus located in the olfactory bulb of the brain

c.many bipolar receptor cells: one mitral cell

a.anosmias- loss of sense of smell

b.uncinate fits- interpretation of pleasant smells as unpleasant

Describe olfactory adaptation.

Do nociceptors adapt? WHY or WHY NOT?

decreased sensitivity to stimulus over time. This can occur in smell by the release of GABA from inhibitory neurons or by downregulation

NO. The brain must always be aware of stimuli that is harmful to body tissue

List and describe the 3 layers of the eye

Which of these layers contain the receptors for light?

What are the receptors called?

What 2 forms of receptors are they?

a.fibrous layer-includes the sclera,& the cornea(clear anterior portion that allows light to pass into the eye)

b.vascular layer-includes the choroid(pigmented layer that is vascular;absorbs excess light energy),iris(colored portion of the eye that controls the size of the pupil) & ciliary body(ciliary processes that make aqueous humor

c.neural layer-includes pigmented layer(different than the choroid)&retina(sensory part).

a.retina

b.photoreceptors

c.rods and cones

Into what two chambers is the eye divided?

What fluids fill these chambers?

anterior and posterior segments

aqueous humor fills the anterior and vitreous humor fills the posterior

What is accommodation?

List the clinical terms for normal, nearsighted and farsighted vision.

Determine if the focus point is prior to or after the retina for nearsighted and farsighted.

the act of focusing light

emmetropic=normal,myopic=nearsighted, hyperopic=farsighted

nearsightedness-focus point is in front of the retina

farsightedness-focus point is behind the retina

Explain the visible light spectrum.

Of what broader classification of radiant energy is the visible spectrum?

It is a range of light energy that can stimulate photoreceptors in the retina that is interpreted by the brain as images

the electromagnetic spectrum

violet

red

photoreceptors-contain the receptors for light energy. Come in rods(dim light,grayscale) and cones(brightlight,color). These are bipolar classification nuerons.

bipolar cells- bipolar classification

ganglion cells-bipolar neurons that receive info form the bipolar cells and their axons carry info to the brain as CN II

What is the structure of the eye called where the axons carry action potential? Are there photoreceptors here?

a.What is this structure commonly referred to as?

b.What cranial nerve do these axons form when they leave the eye?

this area is the optic disc,allowing the axons from the ganglion cells to pass through the eye wall. NO photoreceptors

a.blindspot

b.CN II(optic nerve)

Describe/or draw and label the structure of a photoreceptor.

Which part of the photoreceptor contains the receptors for light?

the outer segment is the rod/cone shaped part and is modified dendritic ending. The outer segment is connected to the inner segment by the connecting stalk. The inner segment attaches to the soma(cell body),which gives rise to the axon.

out segment

Define opsin, retinal, and rhodopsin. How are they related?

Where do opsin and retinal come from?

opsin is a visual protein

retinal is a vitamin A derivative

rhodopsin is opsin bound to retinal

In their bound(rhodopsin) form, they play a role in photoransduction that keeps rodsin their "on" position. When detached, the rods turn "off"

opsin is a pigment made by protein synthesis and retinal is made from vitamin A from the food we eat

What is the external auditory canal? What is its function?

What special glands are found in this canal? What product do they secrete? What is the function of this product?

The structure leading from the outer opening of the ear to the tympanic membrane. This canal leads sound waves to the tympanic membrane.

sebaceous and sudoriferous glands. They secrete oil and sweat,respectively. The modified sweat glands secrete cerumen(ear wax) to trap debris in the air entering the canal

What are the names and order of the ossicles in the middle ear? What is their function?

Describe the characteristics of sound.

Explain frequency and amplitude and the units used to measure them.

sound is a disturbance in the air molecules that travels in waves through space.

frequency is the nember of waves/second of sound. The smaller the wave, the higher the frequency. Measured in hertz(Hz)

amplitude is the loudness of the soundwave and is indicated by the height of the wave(amplitude). The unit of measurement is in decibels(dB).

a. vestibule-egg shaped,fluid filled cavity that contains the receptors for static equilibrium and leads to the semicircular canals and the cochlea

b. semicircular canals-three 2/3 circular, fluid filled canals that contain the receptors for dynamic equilibrium

c. cochlea- snail shaped fluid filled canal that contains the receptors for hearing

a.deafness-can be sensorineoural,which inhibits transmission of sound from the CN to temporal lobe,or conduction, which inhibits transmission from the external auditory canal to the the organ of Corti.

b.tinnitus-characterized by a ringing or clicking sound. Thought to be caused by CN VIII degeneration,inflammation or as a side effect of some medication

c.meniere's syndrome-believed to be a disorder of the labyrinth(semicircular canals,vestibule). Characterized by a howling tinnitus and causes vertigo,nausea and vomiting. May be caused by mixing of lymph fluids or by and accumulation of endolymph

Describe the difference between dynamic and static equilibrium.

What structures of the inner ear is responsible for these forms of equilibrium?

Describe the structure of the macula inside the saccule and utricle

list the 3 types of cells in the macula

describe otoliths and the otolithic membrane and their functions

a pad of cells within the utricle or saccule that contain receptors for static equilibrium

macula contain hair cells(receptor cellsfor static equilibrium). The receptors are mechanoreceptors

supporting cells and basal cells

The macula is covered in a jelly like membrane called the otolithic membrane. The membrane contains otolith crystals(Ca++ corbonate) that give the membrane mass.  This membrane moves with the movements of the head and are the mechanical stimulus for the receptors on the hair cells in the macula.

Describe the crista ampularis.

Describe the three types of cells found in the crista ampularis and their functions.

It is a pad of epithila cells covered in a jelly-like mass called the cupula.

types include hair cells,supporting cells and basal cells,like in the macula. The receptors on the hair cells are mechanoreceptors. As the head moves in 3 dimensions of space,the capula moves and acts as the mechanical stimulus for the receptors.  This opens up ion gated channels and ions enter the cell, depolarizing it. This leads to release of NT to the nerve endings of the vestibular nerve(CN VIII) below the receptor cells and info goes to the brain as an action potential.