Body Senses

Which of the following is not found in the bony labyrinth of the ear? Cochlea Vestibule Auditory ossicles Semicircular canals

Auditory ossicles The ear can be broken up into three sections: The outer ear: It is also called the auricle or pinna and consists of cartilage and skin. The middle ear: It is an air-filled cavity that sits between the eardrum (tympanic membrane) and the inner ear and includes three tiny bones called ossicles. These bones are the incus, malleus, and stapes. The inner ear: It is made up of the bony labyrinth (the semicircular canals, vestibule, and cochlea), membranous labyrinth, and eustachian tube.

Which structure in the eye is responsible for color vision? Lens Rods Iris Cones

Cones The cones are photoreceptors found in the retina. They function in high light intensity and, as such, are for daytime and color vision. The rods are another type of photoreceptor found in the retina. They function in low light intensity and are for night vision and black and white color. The lens is a structure held in place by ligaments attached to the ciliary body (an extension of the iris). They focus and refract light rays from objects, which enter the eyes through the pupils. The iris is a pigmented structure that regulates the size of the pupils. It is also responsible for the color of the eyes.

Which of the following sequences correctly describes how light rays from an object get to the retina? Cornea - lens - aqueous humor - pupil - vitreous humor - retina Cornea - vitreous humor - pupil - lens - aqueous humor - retina Cornea - aqueous humor - pupil - lens - vitreous humor - retina Cornea - aqueous humor - lens - pupil - vitreous humor - retina

Cornea - aqueous humor - pupil - lens - vitreous humor - retina Light rays from an object enter the eye through the transparent cornea. They travel across the aqueous humor and pass through the pupil to get to the lens. The lens refracts the rays which travel across the vitreous humor to reach the retina.

Which structure is responsible for equalizing ear pressure? Membranous labyrinth Eustachian tube Cochlear duct Tympanic membrane

Eustachian tube The Eustachian tube links the middle ear to the nasopharynx. It helps to equalize ear pressure. It also clears the debris and secretions in the middle ear. The tympanic membrane, also called the eardrum, separates the outer ear from the middle ear. It transmits sound waves from the outer to the inner ear. The cochlear duct contains the organ of Corti, which detects sound waves and generates neural impulses that are sent to the brain for interpretation. The membranous labyrinth is found in the inner ear and consists of three parts: The three semicircular ducts, each with a sense organ for rotational movement The cochlear duct, with the sense organ for sound vibrations The vestibule, containing the utricle and saccule, with their two sense organs for linear movement

Of the following, which structure has the highest visual acuity? Retina Aqueous humor Macula Fovea

Fovea The central depressed portion of the macula is called the fovea centralis, and it contains only cones. As such, the fovea centralis is the point with the highest visual acuity. The retina is the inner nervous layer of the eye. It contains photoreceptors and nerves. Light rays trigger the photoreceptors so that the retina generates impulses that travel through the nerves to the brain, where the impulses are interpreted. The aqueous humor is the clear fluid filling the space in the front of the eyeball between the lens and the cornea. It supplies nutrients and oxygen to the structures in the anterior segment of the eye, i.e., the cornea and the lens. The macula is the central portion of the retina. It is rich in cones, and so, it has high visual acuity. However, the fovea centralis has the highest visual acuity.

The central part of the retina with high visual acuity (sharpness) is called the __________. Cones Rods Macula Aqueous humor

Macula The macula is the central part of the retina. It contains a lot of cones, which are the photoreceptors that perceive color. Thus, the macula has high visual acuity. The rods are photosensitive cells that perceive black and white. The aqueous humor is the clear fluid filling the space in the front of the eyeball between the lens and the cornea. It supplies nutrients.

Which structure generates auditory nerve impulses recognized by the brain? Vestibule Auditory ossicles Semicircular canals Organ of Corti

Organ of Corti The organ of Corti detects sound waves and generates neural impulses, which are sent to the brain. The organ of Corti is found in the cochlear duct. Sound waves which arrive at the oval window disturb the perilymph (an internal ear fluid) found in the cochlea. These waves are transmitted to the cochlear duct. The organ of Corti senses these vibrations and generates nerve impulses transmitted to the brain, where they are interpreted. The semicircular canals sense rotatory motion and function in balancing. The vestibule contains the saccule and utricle. They sense movements in the vertical and horizontal planes, respectively. The auditory ossicles are three small bones (malleus, incus, and stapes) in the middle ear which amplify sound waves and transmit them to the inner ear.

Which of the following structures in the retina is responsible for night vision? Fovea Macula Rods Cones

Rods The rods are photosensitive receptors found in the retina. They function in low light intensity, so they are for night vision and black and white vision. The cones are also photoreceptors found in the retina. They function in high light intensity, so they function in daytime and color vision. The macula is the central part of the retina. As it is rich in cones, it has high visual acuity (sharpness). The central portion of the macula is the fovea. It contains only cones so it has the highest visual acuity (sharpness).

The cristae ampullaris is found in the _________ . Semicircular canal Cochlea Eustachian tube Vestibule

Semicircular canal The semicircular canals have three membranous ducts, which have dilated ends called the ampulla. Sensory receptors on the ampulla are called cristae ampullaris. The cristae ampullaris are sensitive to rotatory and angular movement. The semicircular canals empty into the vestibule. The vestibule comprises the utricle and the saccule. The saccule connects the vestibule to the cochlea. When there is a change in the position of the head, the perilymph and endolymph (inner ear fluids) move. The semicircular canals, utricle, and saccule pick up vibrations following motion and generate impulses. These impulses are carried by the vestibular nerve, which joins the cochlear component to form the vestibulocochlear nerve. Impulses from the vestibular branch are sent to the cerebellum. The eustachian tube is found in the middle ear, where it equalizes ear pressure. The eustachian tube also clears debris from the middle ear.

Which of the following structures is correctly paired with its function? Semicircular canal - transmit auditory nerve impulses to the brain Tympanic membrane - for vertical balance Auditory ossicles - amplifying sound waves Cochlear - for horizontal balance

Auditory ossicles - amplifying sound waves The auditory ossicles include three bones: incus, malleus, and stapes. Their function is to amplify sound waves. The semicircular canals are for rotatory balance. The cochlea is for hearing and not for horizontal balance. The tympanic membrane separates the outer ear from the middle ear. It conducts sound waves from the outer ear to the middle ear.

Which of the following sequences correctly describes the passage of sound waves? Auricle - external auditory meatus - tympanic membrane - malleus - incus - stapes - round window - organ of Corti - brain Auricle - external auditory meatus - tympanic membrane - stapes - incus - malleus - round window - organ of Corti - brain Auricle - external auditory meatus - tympanic membrane - stapes - incus - malleus - oval window - organ of Corti - brain Auricle - external auditory canal - tympanic membrane - malleus - incus - stapes - oval window - organ of Corti - brain

Auricle - external auditory canal - tympanic membrane - malleus - incus - stapes - oval window - organ of Corti - brain The auricle picks up sound waves and funnels them down the external auditory canal, where they hit the tympanic membrane. The tympanic membrane conducts the sound waves to the malleus. The malleus, incus, and stapes amplify the sound waves as these move across them to reach the oval window. The sound waves then cause a vibration in the cochlea picked up by the organ of Corti. After that, the organ of Corti generates nerve impulses which it sends, via the cochlear nerve, to the brain for interpretation.

Which of the following is incorrectly paired with its function? Auricle - funnels sound waves to the external auditory canal Oval window - transmits sound from ossicles to cochlea Tympanic membrane - conducts sound to the malleus Cochlea - equalizes ear pressure

Cochlea - equalizes ear pressure The cochlea does not equalize ear pressure. It detects sound waves and generates nerve impulses that are transmitted to the brain. It is the eustachian tube that maintains ear pressure. The auricle funnels sound waves down the external auditory canal, where they hit the tympanic membrane (eardrum). The tympanic membrane (eardrum) conducts the sound waves to the malleus, which is attached to it. The malleus, incus, and stapes (called the auditory ossicles) amplify the sound waves as these move across to reach the oval window. The oval window transmits sound waves to the cochlea, where the vibration is picked up by the organ of Corti.

Light enters the eye through which of the following structures? Cornea Iris Sclera Lens

Cornea Light passes through the transparent cornea and the pupils to get to the lens. The lens refracts the light rays, and subsequently, the rays travel across the vitreous humor to hit the retina. The iris is a pigmented structure that contains smooth muscles that regulate the pupil's size, controlling how much light enters the eye. Light does not pass through the iris; instead, it passes through the pupil, which is an opening in the middle of the iris. The lens is a biconvex structure that refracts and focuses light rays that have entered the eye. The ciliary body controls the shape of the lens. The sclera is the white part of the eye. Light rays do not pass through it. Instead, it protects the eye, maintains the shape of the eyes, and serves as a point of attachment to the muscles.

Which of the following structures gives the eye its color? Cornea Retina Iris Pupil

Iris The iris is a pigmented structure with smooth muscles. It controls how much light is let into the eye by regulating the size of the pupils and gives individuals their characteristic eye color. The retina is the inner nervous layer of the eye. It contains photoreceptors and nerves. Light rays trigger the photoreceptors so that the retina generates impulses that travel through the nerves to the brain, where the impulses are interpreted. The cornea is the transparent portion of the outer layer of the eye and lies anteriorly to the pupil. The cornea protects the pupil and helps refract light entering the eye. The pupil is an opening in the center of the iris. Furthermore, the size of the pupils is controlled by the iris. Light passes through the pupils to reach the lens.

Which of the following sequences shows how visual impulses move from the retina to the brain where they are interpreted? Retina - optic radiations - optic nerve - thalamus - optic chiasm - optic tract - cerebral cortex Retina - thalamus - optic tract - optic nerve - optic radiations - optic chiasm - cerebral Cortex Retina - optic nerve - optic chiasm - optic tract - thalamus - optic radiations - cerebral cortex Retina - optic radiations - optic chiasm - optic nerve - optic tract - thalamus - cerebral cortex

Retina - optic nerve - optic chiasm - optic tract - thalamus - optic radiations - cerebral cortex All sensory information must reach the cerebral cortex in the brain to be perceived. Here is the pathway that information follows: Retina: The retina is made up of two types of photoreceptors, rods and cones, which are neurons that detect light. Rods process low levels of light and motion while cones distinguish color and detail. Optic nerve: The visual information received by the rods and cones in the retina is then sent through the optic nerve and out the back of the eye towards your brain. Optic chiasm: The nerves then cross over in an area called the optic chiasm. This crossover allows your primary cortex to get information from both eyes. The optic chiasm is where visual information is sorted and broken up for more processing. The left field of vision is processed by the right side (or cerebral hemisphere), and the right field of vision is processed by the left cerebral hemisphere. Optic Tract: The optic nerve then continues from the optic chiasm to the thalamus. This part of the optic nerve is called the optic tract. Thalamus: All sensory information enters the thalamus. In particular, it enters a part of the thalamus called the LGN (lateral geniculate nucleus). From here, visual information is organized and sent off to the primary cortex. Optic Radiations: The organized information is then sent through axons (nerve fibers) to the cerebral cortex. This series of nerve fibers is called optic radiations. Cerebral Cortex: This is where images received from your retina begin to get processed and is the very beginning of your brain's process of interpreting and recognizing what you see. Here, depth perception is processed and shapes, color, and motion are perceived.

Which of the following amplifies sound waves? Semicircular canal Stapes Organ of Corti Bony labyrinth

Stapes The stapes is an auditory ossicle. The auditory ossicles are three small bones (malleus, incus, and stapes) in the middle ear which amplify sound waves and transmit them to the inner ear. The semicircular canals sense rotatory motion and function in balancing. The organ of Corti detects sound waves and sends neural impulses to the brain. The bony labyrinth has three parts: the semicircular canals, the vestibule, and the cochlea. They contain sensory cells which generate impulses and send them to the brain for interpretation. The semicircular canal and vestibule are for balance. The cochlea is for hearing. The auricle funnels sound waves to the external auditory canal. These waves are conducted from the outer ear to the middle ear by the tympanic membrane (eardrum). These sound waves are then amplified by the auditory ossicles as they transmit the waves to the inner ear, where they are picked up by the cochlea. The cochlea generates nerve impulses which it sends to the brain for interpretation.

Which of the following does not correctly pair the structure with its function? Choroid: prevents light that enters the eye from reflecting Ciliary body: secretes aqueous humor Aqueous humor: supplies nutrients to the retina Iris: regulates the size of the pupil

The aqueous humor does not supply nutrients to the retina. It supplies nutrients and oxygen to the structures in the anterior segment of the eye, i.e., the cornea and the lens. The ciliary body has epithelial cells which secrete aqueous humor into the anterior segment of the eye. Additionally, the ciliary body is attached to the lens, and it regulates the size and thickness of the lens. The iris is a pigmented structure that regulates the size of the pupil and gives the eye its color. The choroid is the vascular layer of the eye and supplies it with oxygen and nutrients. It also prevents light entering into the eye from reflecting.

Which of the following correctly describes the retina? The inner layer of the eye which generates nerve impulses The middle layer of the eye which supplies nutrients to the eye The middle layer of the eye which focuses light rays The outer layer of the eye which protects the eye

The inner, nervous layer of the eye is called the retina. The eye comprises an outer layer, a middle layer, and an inner layer. The outer fibrous layer has two parts: The sclera - the white portion of the outer eye. It protects and supports the eyes. The cornea - the transparent portion that lies anteriorly to the pupil. It protects the pupil and helps refract light entering the eye. The middle vascular layer has three parts: The choroid - supplies the eye with oxygen and nutrients and prevents light that enters the eye from being reflected. The ciliary body - has epithelial cells that secrete aqueous humor into the anterior segment of the eye. Additionally, the ciliary body is attached to the lens, and it regulates the size and thickness of the lens. The iris - a pigmented structure with smooth muscles. It regulates the size of the pupils and gives individuals their characteristic eye color. The inner nervous layer is the retina, which includes two types of photosensitive receptors: Rods to see black and white Cones to see color

Which of the following describes the function of the saccule? Detects vertical movement of the head Amplifies sound waves Detects sound waves Detects horizontal movement of the head

The saccules are sensitive to the vertical movement of the head. They help in balance and posture. The organ of Corti detects sound waves. The auditory ossicles (malleus, incus, and stapes) amplify sound waves. The utricle detects horizontal movement of the head. Auricle/PinnaFunnels:sound waves to the external auditory canal External auditory canal: Funnels sound waves to the tympanic membrane Tympanic membrane: Conducts sound waves to the middle ear Auditory ossicles (malleus, incus, and stapes): Amplify sound waves picked from the tympanic membrane and send to the oval window Cochlea: Picks sound waves from the oval window and sends vibrations to the organ of Corti Organ of Corti: Generates auditory nerve impulses and transmits them to the brain Semicircular canals: Rotatory balance Utricle: Balance following motion in the horizontal plane Saccule: Balance following motion in the vertical plane Eustachian tube: Equalizes ear pressure

Which structure in the ear is most sensitive to horizontal movement? Eustachian tube Tympanic membrane Auditory ossicles Utricle

Utricle The utricle is a membranous structure found in the vestibule. It is sensitive to horizontal motion. In contrast, the saccule, which is also a part of the vestibule, is sensitive to vertical motion. The tympanic membrane, also called the eardrum, separates the outer ear from the middle ear. It transmits sound waves from the outer ear to the inner ear. The eustachian tube links the middle ear to the nasopharynx. It helps to equalize ear pressure. The auditory ossicles are three small bones that extend from the tympanic membrane to the oval window. They amplify sound waves and send them to the inner ear. The three bones are the: Malleus, which is hammer-shaped. Its handle is in contact with the tympanic membrane and the head is in contact with the incus. Incus, which links the malleus and stapes. It is anvil-shaped with its body touching the malleus and the long process of touching the stapes. Stapes, which is stirrup-shaped and links the incus and the oval window.