2402 Lecture Test 1

specialized neuron (neural cell) designed to detect stimuli

any detectable change in environment (anything that alters the Resting Membrane Potential (RPM) of a sensory receptor)

any stimulus processed in CNS (brain/spinal cord)...(alters RMP of 2nd order neuron)

• conscious awareness of a stimulus
• (3rd order neuron releases Neurotransmitter (N.T.))

type of stimulus to which a receptor can detect

the area of body monitored by a single receptor cell

any change in resting membrane potential in a receptor cell

any stimulus that results in 1st order neuron

or

any stimulus that results in an action potential in a 1st order neuron

is the conversion of a stimulus into a signal action potential

• 1. touch & vibration (tactile receptors-touch)
• 2. temperature (thermoreceptors)
• 3. pain (nociceptors)
• 4. proprioception (proprioceptors-body positions)
• 5. pressure (baroreceptors)
• 6. some internal chemoreception (internal chemorecptor's

• 1. olfaction - external chemoreception (smell)
• 2. gustation (taste)
• 3. vision (sight)
• 4. audition (hearing)
• 5. equilibrium (balance)

is the pathway from the receptor cell to the brain

the brain interprets only the location and type of stimulus based upon the labeled line that carries that information

receptors is always "on" (releasing neurotransmitter), & will increase or decrease neurotransmitter release upon a stimulus.

"always off" unless stimulated to turn "on"

(off no action potential)

(on fire action potential)

decrease in sensitivity to a stimulus at the receptor cell (in peripherg)

decrease in sensitivity to a stimulus at a nucleus along the sensory pathway

is the detection of pain and algesia.

are free nerve-endings and are abundant in skin, joint capsules, and vessel walls.

• 1. extremes of temperature
• 2. mechanical damage
• 3. dissolved chemicals

are myelinated fibers that carry sensations of fast pain or prickling pain or sharp pain (large axon diameter)

are unmyelinated fibers that carry sensations of slow pain or burning and dull aching pain (small axon diameter)

is pain from an organ or area of the body that is detected as coming from a different area

is pain felt in a limb that has been amputated

is the detection of rapid changes in temperature

are free nerve-endings and are located very high in the dermis, just below the epidermis, as well as in skeletal muscles and the hypothalamus.

they are also phasic and adapt quickly.

respond to stimuli that physically distort their cell membrane

function: thermo receptors or pain fibers(sensation)

location: between epidermal cells (don't have any connective tissue coverings

function: wrap around the root of a hair

location: wherever hairs are located 9tell you about the direction of movement along the surface of the body)

function: extremely sensitive tonic receptors fine touch

location: found on hairy skin

function: perceive sensations of fine touch and pressure and low-frequency vibration

location: on hairless skin (eyelids, lips, fingertips, nipples, and external genitalia)

function: deep pressure

location: throughout the dermis

function: deep pressure

location: in the reticular (deep) dermis

provide information about body position, joint position, and movement

function: amount of tension or stretch in a muscle

location: muscles

function: amount of tension or stretch in a tendon

location: tendons

detect changes in pressure in walls of some blood vessels, the digestive organs (stomach, intestines, colon) the urinary bladder, and the respiratory tract

detect blood pressure

(near the origin of the internal carotid arteries on each side of the neck)

detect blood pressure

(between the major branches of the aortic arch)

detect changes in concentration of certain chemicals (glucose, O₂, CO₂) and substances (minerals like Na⁺, K⁺, Ca²⁺, Cl^-, H⁺) in our blood and body fluids

is the sense of smell

• 1. odorant binds to an OBP (odorant binding protein) & activates it
• 2. activated OBP activates AdC
• 3.activated AdC converts ATP into cAMP
• 4. cAMP binds to and opens a gated channel (starts an action potential)

it passes through the limbic system

(limbic=emotion & memory)

as we age our ability to detect aromas decrease

is the sense of taste and involves receptor organs called taste buds

contains gustatory receptor cells that detect chemicals from the external environment

taste buds are located within the bumps on the surface of the tongue

Facial Nerve (VII)

Glossopharyngeal Nerve (IX)

is a small sebaceous gland that secretes a lipid-rich product that helps keep the eyelids from sticking together

is a small lump or cyst, generally results from the infection of a tarsal gland

an infection in a sebaceous gland of one of the eyelashes, a tarsal gland, or one of many glands that open to the surface between the follicles produces a painful localized swelling

enzyme in tears that has antimicrobial properties

clean layer of squamous epithelium that covers the outer surface of the eyelid

clean layer of squamous epithelium that covers the outer surface of the eye

pink eye / it can be contagious

• 1. lacrimal gland
• 2. lacrimal duct
• 3. surface of the eye
• 4. lacrimal caruncle
• 5. lacrimal punctum
• 6. lacrimal canal
• 7. lacrimal sac
• 8. nasolacramal duct

• 1. fibrous tunic
• 2. vascular tunic
• 3. neural tunic

white, provides shape & structure, a point of attachment for extraoccular muscle

translucent (opaque) portion of the sclera that allows light into the front of the eye

vasculature (vessels) that provide blood flow to internal eye

95% cilivary muscle controls the shape of the lens for accommodation (focusing)

5% secretory portion=blood is filtered to secrete aqueous humor

pigmented portion of the eye that has muscles that control pupil size.

it increases the size of the pupil, (radial muscle) to allow more light in (dark room, sympathetic stimulation)

it decreases the size of the pupil in a bright room (parasympathetic) (anular muscle)

• 1. ciliary body
• 2. posterior chamber
• 3. pupil
• 4. anterior chamber
• 5. absorbed at the canal of Schlem

the constant secretion and reabsorption of aqueous humor

increase of intraocular pressure

the formation of functional microvascular networks with red blood cell perfusion

layer of cells that absorb photons of light that photoreceptors cannot absorb (that we don't see)

(prevents vision echoes)

has 3 sub layers of cells

• 1. photoreceptors=absorb photons in visible spectrum (the ones we see)
• 2. bipolar cells=1st order neurons
• 3. ganglion cells=axons exit the eye at the optic disc / nerve

is damage to the eyes retina caused by complications of diabetes mellitus, which can eventually lead to blindness

spot on the retina that contains the highest density (concentration) of photoreceptors

spot on the retina where all ganglion cell axons exit the eye to the optic nerve it contains 0 (zero) photoreceptors

fibers that make up the lens of the eye, very elastic

are proteins that are clear, refracts light, magnify things

a change in the direction of a ray of light as it passes from one medium to another (bending of light)

• 1. cornea
• 2. aqueous humor
• 3. lens
• 4. vitreous humor

the lens loses its transparency of the cornea or lens

a change in the shape of the lens to focus light on the retina

abnormal curvature of the lens or cornea

normal vision 20/20

near sighted

far sighted

being far sighted due to a loss of elasticity of the lens

normal vision

eagle eye

near sighted

legally blind

Rod

1. are an elongated outer segments that contain membranous discs with visual pigment (rhodopsin)

2. do black/white vision (night vision)

Cones

1. are a tapered outer segments (conical) with membraneous folds that contain visual pigments (Iodopsins)

2. color vision and detail (sharp vision)

(need lens to be "more round")

• 1. ciliary muscle contracts
• 2. suspensory ligaments go slack
• 3. lens becomes more round

(need the lens to be "less round")

• 1. ciliary muscle relaxes
• 2. suspensory ligament light
• 3. lens is more flat

any substance that can hold on to a photon of light and holds on to it or catches it

absorbs photons that are not absorbed by visual pigments

• 1. Rhodopsin
• 2. Iodopsin I
• 3. Iodopsin II
• 4. Iodopsin III

photoreceptor cells that are found in the retina of the eye

• 1. 11-cis-retinal is struck by photons of light and converted 11-trans-retinal. The change in shape of retinal activates an enzyme called Opsin.
• 2. Activated Opsin then interacts with and activates many Transducin molecules.
• 3. Activated Transducin molecules then interact with and activate many PDE (Phosphodiesterase) molecules.
• 4. Activated PDE molecules then breakdown many cyclic guanosine monophosphate(cGMP) molecules.
• 5. Breakdown of cGMP results in closing of Na⁺ channels and hyperpolarization of the rod cell. This decreases neurotransmitter release on the bipolar cell which then sends a signal to a ganglion cell that communicates to the brain that we have seen something.

the maze of bone in the inner ear

the fluid between the bony and membranous labyrinth

by hair cells found in the vestibule (vestibular complex)

rotational

vertical rotation (anterior/posterior rotation)

horizontal rotation (saying no)

lateral rotation (side to side) (cartwheel)

angular and linear

increase of speed or velocity

decrease of velocity