AnaPhy (OCHEA) - SPECIAL SENSES

The process initiated by stimulating sensory receptors.

Sensation

The conscious awareness of stimuli.

Perception

2 basic groups of senses

general and special senses

receptors distributed over a large part of the body

general senses

specialized in structure and are localized to the specific parts of the body

special senses

Provide sensory information about the body and the environment.

Somatic Senses

Provide information about various internal organs, primarily involving pain and pressure.

Visceral Senses

Nerve endings or specialized cells capable of responding to stimuli by developing action potentials.

Sensory Receptors

Respond to mechanical stimuli.

Mechanoreceptors

Respond to chemicals.

Chemoreceptors

Respond to light.

Photoreceptors

Respond to temperature changes.

Thermoreceptors

Respond to stimuli that result in the sensation of pain.

Nociceptors

general senses include

Proprioception

Pressure

Pain

Temperature

Touch

Itch

Vibrations

special senses are

smell

balance

sight

taste

hearing

The simplest and most common type of sensory receptors.

Receptors (Free Nerve Endings)

Structurally more complex than free nerve endings

Touch Receptors

types of touch receptors

Merkel Disks

Hair Follicle Receptors

Light Touch Receptors

Meissner Corpuscles.

Characterized by unpleasant perceptual and emotional experiences

Pain

2 types of pain sensation

sharp & pricking (rapid action)

burning & aching (slow)

2 types thermoreceptors

cold receptor and warm receptor

Highly localized in the skin due to the simultaneous stimulation of pain receptors and tactile receptors.

Superficial Pain Sensations

Not highly localized due to the absence of tactile receptors in deeper structures.

Deep or Visceral Pain Sensations

The use of medication to block the sensation of pain.

Anesthesia

A type of anesthesia that induces loss of consciousness.

General anesthesia

Natural mechanisms in the body that can influence the perception of pain.

Inherent control systems

Pain that is felt in a different area of the body than where the pain stimulus originates.

Referred pain

Central Nervous System includes the

brain and spinal cord.

The area of the body that includes internal organs.

Visceral area

Neurons that transmit sensory information from the body to the brain.

Ascending neurons

Pain that is felt in the skin.

Cutaneous pain

The sense of smell.

Olfaction

Airborne molecules that are detected by the sense of smell.

Odorants

Neurons in the nasal cavity that detect odorants.

Olfactory neurons

The tissue lining the nasal cavity where olfactory neurons are located.

Olfactory epithelium

Hair-like structures on the ends of olfactory neurons that detect odorants.

Cilia

A thin film that covers the olfactory epithelium and helps dissolve and remove odorants.

Mucus

Molecules on the membranes of olfactory neurons that bind to odorants.

Olfactory receptors

Neuronal pathways for olfaction

The pathways in the brain that process and interpret smell.

Sensory structures on the tongue and other areas of the mouth that detect taste stimuli.

Taste buds

Enlargements on the surface of the tongue where taste buds are located.

Papillae

Cells that form the exterior supporting capsule of each taste bud.

Specialized epithelial cells

Cells within taste buds that contain taste hairs and detect taste stimuli.

Taste cells

each taste buds consist of 2 types of cell

Specialized Epithelial Cells

Taste Cells

Hair-like processes on taste cells that extend through taste pores.

Taste hairs

The five primary tastes

sour, salty, bitter, sweet, and umami.

The taste sensation associated with savory flavors.

Umami

Heat damage

Injury caused by exposure to high temperatures.

Epithelial cells

Cells that line the surfaces of the body, including the tongue and eyes.

how long does it take for epithelial cells to be replaced if the cells die

2 wacks

Cranial nerves

Nerves that emerge directly from the brain and control various functions, including taste sensation.

Neuronal Pathways for Taste

Facial Nerves/Glossopharyngeal Nerves/Vagus Nerves > Gustatory portion of the brainstem > Thalamus > Insula of the cerebrum

Cavities in the skull that house the eyes.

Orbits

Structures that protect, lubricate, and move the eyes.

Accessory structures

Accessory Structures Incude

eyebrows

eyelids

conjunctiva

lacrimal apparatus

extrinsic eye muscle

attach to the four quadrants of the eyeball

Rectus

Two muscles located at an angle to the long axis of the eyeball that control its rotational movement.

Oblique muscles

The outer layer of the eyeball, consisting of the sclera and cornea.

Fibrous tunic

The firm, white, outer connective tissue layer of the eyeball.

Sclera

The transparent anterior part of the eye that allows light to enter.

Cornea

The layer of the eye that contains the most blood vessels.

Vascular Tunic

The posterior portion of the vascular tunic, associated with the sclera, that appears black due to its melanin-containing pigment cells.

Choroid

The part of the eye that contains smooth muscle called ciliary muscles, which attach to the lens.

Ciliary body

A flexible, biconvex, transparent disc in the eye.

Lens

The colored part of the eye that regulates the diameter of the pupil.

Iris

The opening in the iris that controls the amount of light entering the eye.

Pupil

The layer of the eye that contains the retina.

Nervous tunic

A small spot near the center of the posterior retina, with a small pit called fovea centralis.

Macula

A white spot just medial to the macula, through which blood vessels enter the eye.

Optic Disc

One of the three chambers of the eye, located at the cornea and the lens.

Anterior chamber

One of the three chambers of the eye, located at the cornea and the lens.

Posterior chamber

The largest chamber of the eye, located posterior to the lens, filled with vitreous humor.

Vitreous chamber

The fluid that helps maintain pressure within the eye and refracts light.

Aqueous Humor

The jelly-like substance that helps maintain pressure within the eye and holds the lens and retina in place.

Vitreous Humor

The bending of light as it passes through different mediums.

Light Refraction

The point at which light rays converge.

Focal Point

Cells in the retina that respond to light.

Photoreceptors

A photosensitive pigment found in rod photoreceptors.

Rhodopsin

A protein found in photoreceptor cells that combines with retinal to form rhodopsin.

Opsin

A pigment in the photoreceptor cells of the retina that is responsible for vision in low light conditions.

Rhodopsin

The nerve that carries visual information from the retina to the brain.

Optic Nerve

The point where the optic nerves from each eye cross over, allowing for information from both eyes to be processed by both sides of the brain.

Optic Chiasm

The pathways that carry visual information from the optic chiasm to the thalamus.

Optic Tracts

A structure in the brain that relays sensory information, including visual information, to the cerebral cortex.

Thalamus

The area of the cerebral cortex in the occipital lobe where visual information is processed and perceived.

Visual Cortex

The ability to perceive depth and three-dimensional objects by combining the slightly different views from each eye.

Binocular Vision

The ability to perceive the relative distance and position of objects in three-dimensional space.

Depth Perception

Relating to or involving only one eye.

Monocular

Double vision, often caused by misalignment of the two eyes.

Diplopia

The outer part of the ear that collects sound waves and directs them towards the middle ear.

External Ear

The fleshy part of the external ear on the outside of the head.

Auricle (Pina)

The passageway that leads to the eardrum.

Auditory Canal

A thin membrane that separates the external ear from the middle ear.

Tympanic Membrane (Eardrum)

The air-filled cavity medial to the tympanic membrane that is involved in hearing.

Middle Ear

The three small bones in the middle ear (malleus, incus, and stapes) that transmit sound vibrations from the eardrum to the inner ear.

Auditory Ossicles

Tubes that connect the middle ear to the pharynx and help equalize air pressure.

Auditory Tubes (Eustachian)

The part of the ear that is involved in both hearing and balance, consisting of the bony labyrinth and the membranous labyrinth.

Inner Ear

Tunnels and chambers inside the temporal bone that make up the structure of the inner ear.

Bony Labyrinth

A smaller set of tunnels and chambers inside the bony labyrinth that is filled with endolymph, a clear fluid.

Membranous Labyrinth

A small, snail-shaped structure involved in hearing.

Cochlea