Overview of Senses and Sensory Receptors

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Questions and Answers

What is the ability to perceive stimuli?

Sense

What is conscious awareness of stimuli received by sensory neurons?

Sensation

What are sensory nerve endings that respond to stimuli by developing action potentials?

Sensory receptors

What are sense receptors that provide information about the body and environment?

Somatic Senses Signup and view all the answers

What are sense receptors that provide information about internal organs, pain, and pressure?

Visceral Senses Signup and view all the answers

What are the two types of general senses?

Somatic and visceral (D) Signup and view all the answers

What are the special senses?

Taste, smell, sight, hearing, and balance (B) Signup and view all the answers

What type of receptors detect movement or mechanical stimuli, such as touch, pressure, and vibration?

Mechanoreceptors Signup and view all the answers

What type of receptors detect chemicals, such as odor molecules?

Chemoreceptors Signup and view all the answers

What type of receptors detect light, such as rods and cones in the eye?

Photoreceptors Signup and view all the answers

What type of receptors detect temperature changes?

Thermoreceptors Signup and view all the answers

What type of receptors detect pain?

Nociceptors Signup and view all the answers

What type of touch receptor detects light touch and pressure, located on the underside of the epidermis and along the sides of hair shafts?

Merkel's disks Signup and view all the answers

What type of touch receptor is located on hair follicles and detects light touch?

Hair follicle receptors Signup and view all the answers

What type of touch receptor is located deep in the epidermis and is involved in fine, discriminative (specific) sensations?

Meissner's corpuscles Signup and view all the answers

What type of touch receptor is located deep in the dermis and detects continuous pressure on the skin?

Ruffini corpuscles Signup and view all the answers

What is the deepest type of touch receptor, located deep in the dermis and associated with tendons and joints, detecting deep pressure, vibration, and position?

Pacinian corpuscles Signup and view all the answers

What is an unpleasant perceptual and emotional experience?

Pain Signup and view all the answers

What type of pain is sharp, pricking, or cutting pain with rapid action potentials?

Localized pain Signup and view all the answers

What type of pain is burning or aching pain with slower action potentials?

Diffused pain Signup and view all the answers

What type of pain control involves suppressing action potentials from pain receptors in local areas by chemicals injected near sensory nerves?

Local anesthesia Signup and view all the answers

What type of pain control involves loss of consciousness by chemicals affecting the reticular formation?

General anesthesia Signup and view all the answers

What is pain that is felt in a region that is not the source of the pain stimulus, often felt when internal organs are damaged or inflamed?

Referred pain Signup and view all the answers

How does referred pain occur?

Sensory neurons from a superficial area and neurons of the source of pain converge onto the same ascending neurons of the spinal cord. Signup and view all the answers

What is the sense of smell?

Olfaction Signup and view all the answers

What are chemicals that trigger the sense of smell?

Odorants Signup and view all the answers

Where are olfactory receptors located?

Nasal cavity and hard palate Signup and view all the answers

How many different smells can we detect?

10,000 Signup and view all the answers

How does olfaction work?

1.) Nasal cavity contains a thin film of mucous where odors (chemicals) become dissolved. 2.) Olfactory neurons are located in mucous. Dendrites of olfactory neurons are enlarged and contain cilia. 3). Dendrites pick up odor, depolarize, and carry odor to axons in olfactory bulb. 4.) Frontal & temporal lobes process odor. Signup and view all the answers

Where is odor processed?

Frontal and temporal lobes Signup and view all the answers

What is the pathway of odor (sense of smell processing)?

Nasal cavity mucous, olfactory neurons in mucous, dendrites, axons in olfactory bulb, frontal and temporal lobes (A) Signup and view all the answers

What are sensory structures that detect taste, located on tongue papillae, hard palate, and throat?

Taste buds Signup and view all the answers

Where are taste buds located?

Tongue papillae, hard palate, throat Signup and view all the answers

How many taste cells are there per taste bud?

40 taste cells Signup and view all the answers

What is the structure of a taste cell?

Each taste cell has taste hairs that extend into taste pores Signup and view all the answers

How does taste work?

<ol> <li>Taste buds pick up taste and send it to cells. 2. Taste cells send taste to taste hairs. 3. Taste hairs contain receptors that initiate an action potential 4. Parietal lobe processes taste.</li> </ol> Signup and view all the answers

What are the stages of taste?

Taste buds, taste cells, taste hairs, receptors in taste hairs, parietal lobe Signup and view all the answers

What are the five types of taste?

Sweet, sour, salty, bitter, umami (B) Signup and view all the answers

What does umami taste like?

Savory Signup and view all the answers

Taste is linked to _______.

smell Signup and view all the answers

What are the accessory structures of the eye?

Eyebrows, eyelids, conjunctiva, lacrimal apparatus, extrinsic eye muscles (D) Signup and view all the answers

What accessory structure of the eye protects the eye from sweat and provides eye shade from the sun?

Eyebrow Signup and view all the answers

What is the purpose of the eyelid/eyelashes?

Protects and lubricates eye Signup and view all the answers

What is the accessory gland of the eye, a thin membrane that covers the inner surface of the eyelid?

Conjunctiva Signup and view all the answers

What accessory gland of the eye produces tears, located on the superior and lateral portion to the eye?

Lacrimal gland Signup and view all the answers

What accessory structure of the eye helps move the eyeball?

Extrinsic eye muscles Signup and view all the answers

What is the inferior eye muscle that goes longways?

Inferior rectus Signup and view all the answers

What is the inferior eye muscle that runs up/down?

Inferior oblique Signup and view all the answers

What is the middle eye muscle that runs longways?

Lateral rectus Signup and view all the answers

What is the anatomy of the eye?

Hollow, fluid-filled sphere, composed of 3 layers (tunics), divided into chambers. Signup and view all the answers

Layers of the eye are called...

Tunics Signup and view all the answers

What is the outermost layer of the eye, consisting of the sclera and cornea?

Fibrous Tunic Signup and view all the answers

What part of the fibrous tunic is the firm, outer white part of the eye that helps maintain the eye shape, provides attachment sites, and protects internal structures?

Sclera Signup and view all the answers

What part of the fibrous tunic is the transparent, clear structure that covers the iris and pupil, allowing light to enter and focusing light?

Cornea Signup and view all the answers

What is the middle layer of the eye, containing the blood supply, choroid, ciliary body, suspensory ligaments, lens, iris, and pupil?

Vascular Tunic Signup and view all the answers

What part of the vascular tunic contains melanin (pigment that gives eye color), delivers oxygen and nutrients to the retina?

Choroid Signup and view all the answers

What part of the vascular tunic helps hold the lens in place?

Ciliary Body Signup and view all the answers

What are ligaments that help hold the lens of place (part of the vascular tunic)?

Suspensory ligaments Signup and view all the answers

What part of the vascular tunic is a flexible oval-shaped disc that focuses light onto the retina?

Lens Signup and view all the answers

What is the colored part of the eye?

Iris Signup and view all the answers

What is the black circle in the center of the eye that regulates the amount of light entering the eye?

Pupil Signup and view all the answers

When there is lots of light, the pupil...

Constricts (gets smaller) Signup and view all the answers

In lack of light, the pupil...

Dilates (gets bigger) Signup and view all the answers

What is the innermost layer of the eye that contains the retina, rods and cones, macula, fovea, and optic disk?

Nervous Tunic Signup and view all the answers

What part of the nervous tunic covers the posterior 5/6th of the inner eye surface (back lining of the eye) and consists of two layers and the rods and cones?

Retina Signup and view all the answers

What is the outer layer of the retina that absorbs light and keeps light from reflecting back in the eye?

Pigmented layer Signup and view all the answers

What is the inner layer of the retina containing the rods, cones, and interneurons?

Sensory retina Signup and view all the answers

What are rods and cones?

Photoreceptors Signup and view all the answers

What is the photoreceptor sensitive to light; functions in dim light; 20 times more of these?

Rods Signup and view all the answers

What is the photoreceptor that functions in well-lit conditions, providing color vision; there are three types: blue, green, and red?

Cones Signup and view all the answers

What is the photosensitive pigment in rod cells that causes light sensitivity?

Rhodopsin Signup and view all the answers

What is the colorless protein in the rhodopsin pigment that joins with retinal to form a photopigment?

Opsin Signup and view all the answers

What is the yellow pigment in the rhodopsin pigment that joins with opsin to form a photopigment?

Retinal Signup and view all the answers

What is a small spot near the center of the retina?

Macula Signup and view all the answers

What is the center of the macula, where light is focused when looking directly at an object; made up only of cones and able to discriminate fine images?

Fovea Signup and view all the answers

What is called the "blind spot" (no photoreceptors), a white spot/hole in the retina where optic nerve axons exit the eye; blood vessels enter the eye here and spread over the retina?

Optic disk Signup and view all the answers

What is the chamber of the eye located between the cornea and the lens, filled with aqueous humor (watery)?

Anterior chamber Signup and view all the answers

What fluid is found in the anterior chamber of the eye, helps maintain pressure, refracts light, and provides nutrients to the inner surface of the eye?

Aqueous humor Signup and view all the answers

What is the chamber of the eye located behind the anterior chamber containing vitreous humor?

Posterior chamber Signup and view all the answers

What is the jelly-like substance that fills the posterior chamber and vitreous chamber; helps maintain pressure; holds lens and retina in place; and refracts light?

Vitreous humor Signup and view all the answers

What is the chamber of the eye located in the retina region and filled with vitreous humor?

Vitreous chamber Signup and view all the answers

What is a function of the eye, bending of light?

Light refraction Signup and view all the answers

What is the point where light rays converge onto the retina and the object is inverted (flipped)?

Focal point Signup and view all the answers

What type of vision in which lens is flat, muscles are relaxed, and suspensory ligaments are tight?

Distant vision Signup and view all the answers

What type of vision in which lens is more spherical (greater refraction); muscles are contracted; and ligaments are relaxed?

Close vision Signup and view all the answers

What is the nerve that leaves the eye and exits the orbit through the optic foramen to enter the cranial cavity?

Optic nerve Signup and view all the answers

Where do the two optic nerves meet?

Optic chiasm Signup and view all the answers

What is the route of ganglion axons posterior to the optic chiasm?

Optic tracts Signup and view all the answers

What is nearsightedness (difficulty seeing distance), in which the image is in front of the retina?

Myopia Signup and view all the answers

What is farsightedness (difficulty reading up close), in which the image is behind the retina?

Hyperopia Signup and view all the answers

What is the condition when the lens becomes less elastic and reading glasses are required, happening to most at age 50?

Presbyopia Signup and view all the answers

What is the condition with irregular curvature of the lens?

Astigmatism Signup and view all the answers

What is the absence or deficiency of cones, primarily in males (X-chromosome linked trait)?

Colorblindness Signup and view all the answers

What is decreased pressure in the eye that causes the image to appear dark on the outsides; can eventually lead to blindness?

Glaucoma Signup and view all the answers

What is clouding of the lens?

Cataract Signup and view all the answers

What condition can diabetes cause, a separation of the sensory retina from the pigmented retina (vision loss), which is also known as?

Retinal detachment Signup and view all the answers

Study Notes

Senses Overview

Sense: The ability to perceive stimuli.
Sensation: Conscious awareness of stimuli from sensory neurons.
Sensory Receptors: Nerve endings that trigger action potentials in response to stimuli.
Somatic Senses: Receptors providing info about the body and the environment.
Visceral Senses: Receptors giving info about internal organs, pain, and pressure.
General Senses: Somatic and visceral senses.
Special Senses: Taste, smell, sight, hearing, and balance.

Sensory Receptors

Mechanoreceptors: Detect movement or mechanical stimuli (touch, pressure, vibration).
Chemoreceptors: Detect chemicals (odor molecules).
Photoreceptors: Detect light (rods and cones).
Thermoreceptors: Detect temperature changes.
Nociceptors: Detect pain.

Touch Receptors

Merkel's Disk: Detects light touch and pressure, located in the epidermis.
Hair Follicle Receptors: Detect light touch, located on hair follicles.
Meissner's Corpuscles: Located in the epidermis, detect fine, discriminative touch.
Ruffini Corpuscles: Located in the dermis, detect continuous pressure.
Pacinian Corpuscles: The deepest touch receptor, detects deep pressure, vibration, and joint position, located in the dermis.

Pain

Pain: An unpleasant perceptual and emotional experience.
Localized Pain: Sharp, pricking, or cutting pain with rapid action potentials.
Diffused Pain: Burning, aching pain with slower action potentials.
Pain Control: Local anesthesia suppresses pain signals locally, while general anesthesia causes loss of consciousness.
Referred Pain: Pain felt in a different location than the actual source of the stimulus (often from internal organs). This occurs because sensory neurons from the superficial area and the source of the pain converge onto the same ascending neurons in the spinal cord.

Olfaction (Smell)

Odorants: Chemicals that trigger the sense of smell.
Olfactory Receptors: Located in the nasal cavity and on the hard palate.
Olfactory Processing: Odorants dissolve in nasal cavity mucous, activating olfactory neurons. Dendrites pick up odor signals, causing depolarization, and axons transmit to the olfactory bulb. The frontal and temporal lobes process the odor.
Smell Detection: Humans can detect approximately 10,000 different smells.

Gustation (Taste)

Taste Buds: Sensory structures on the tongue papillae, hard palate, and throat that detect taste.
Taste Cells: About 40 per taste bud, each with taste hairs extending into taste pores.
Taste Mechanism: Taste cells detect taste and send signals to taste hairs. Receptors in taste hairs trigger action potentials, which are processed in the parietal lobe.
Taste Types: Sweet, sour, salty, bitter, and umami (savory).
Taste Processing: Taste is linked to smell.

Eye Anatomy

Accessory Structures: Eyebrows, eyelids, conjunctiva, lacrimal apparatus, and extrinsic eye muscles.
Eyebrows: Protect the eye from sweat and sun.
Eyelids/Eyelashes: Protect and lubricate the eye.
Conjunctiva: A thin membrane lining the inner surface of the eyelids.
Lacrimal Gland: Produces tears, located superior and lateral to the eye.
Extrinsic Eye Muscles: Muscles that move the eyeball.
Eye Anatomy: Hollow, fluid filled sphere of three layers (tunics), divided into chambers.

Fibrous Tunic

Sclera: Provides eye shape, attachment sites, and protection.
Cornea: Transparent structure for light entry and focusing.

Vascular Tunic

Choroid: Contains melanin, delivers oxygen, and nutrients to the retina.
Ciliary Body: Holds the lens in place.
Suspensory Ligaments: Hold the lens in place.
Lens: A flexible structure that focuses light onto the retina.
Iris: The colored part of the eye.
Pupil: Controls light entering the eye.

Nervous Tunic (Retina)

Retina: Covers the posterior 5/6 of the inner eye surface.
Pigmented Layer: Absorbs light, prevents reflection.
Sensory Retina: Contains rods, cones, and interneurons.
Rods: Photoreceptors for dim light.
Cones: Photoreceptors for bright light and color vision (3 types: blue, green, red).
Rhodopsin: Light-sensitive pigment in rod cells.
Opsin, Retinal: Components of rhodopsin.
Macula: Small spot in the retina.
Fovea: Center of the macula, with only cones, for fine visual detail.
Optic Disk: "Blind spot," where axons leave the eye and blood vessels enter.

Chambers of Eye

Anterior Chamber: Between cornea and lens, filled with aqueous humor.
Aqueous Humor: Maintains pressure, refracts light, and provides nutrients.
Posterior Chamber: Behind anterior chamber, contains vitreous humor.
Vitreous Humor: Maintains pressure, holds lens and retina in place, refracts light.
Vitreous Chamber: Contains vitreous humor.

Eye Function & Vision Problems

Refraction: Bending of light.
Focal Point: Point where light rays converge.
Distant Vision: Lens is flat, muscles relaxed, ligaments tight.
Close Vision: Lens is more spherical, muscles contracted, ligaments relaxed.
Optic Nerve: Carries visual information from the eye to the brain.
Optic Chiasm: Where optic nerves meet.
Optic Tracts: Pathway of ganglion axons.
Myopia: Nearsightedness (image in front of retina).
Hyperopia: Farsightedness (image behind retina).
Presbyopia: Lens loses elasticity (typically after age 50).
Astigmatism: Irregular curvature of the cornea or lens.
Color Blindness: Absent or deficient cones.
Glaucoma: Decreased eye pressure.
Cataract: Clouding of the lens.
Retinal Detachment: Separation of layers in the retina.

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Description

This quiz explores the fundamentals of senses and sensory receptors, including the distinctions between somatic, visceral, and special senses. Understand how different receptors like mechanoreceptors and chemoreceptors contribute to our perception of the environment and internal stimuli.