Senses

The human ear can detect what frequency of vibrations?

20 to 20,000 Hz Below 20 Hz: infrasonic, not detected by ear Above 20 Hz: ultrasonic, inaudible. Humans are most sensitive to 1,500 - 5,000 Hz.

Human vision is limited to wavelengths ranging from __________ nm.

400 to 700

What is a sensation?

A subjective awareness of a stimulus

Which of the following is not considered an optic component of the eye?

A. Aqueous humor = serous fluid secreted by ciliary body B. Vitreous body = transparent jelly that fills space called the vitreous chamber behind lens C. Lens = flattened, tightly compressed, transparent cells. Suspended behind pupil by suspensory ligament. D. RETINA E. Cornea The retina is a neural component (along with the optic nerve). It is part of the brain, and is a thin transparent membrane attached to the rest of the eye at two points: optic disc and optic serrata.

Which of the following is not considered an accessory structure of the eye?

A. Conjunctiva = transparent mucous membrane that covers the inner surface of the eyelid and anterior surface of eyeball, except for the cornea B. Palpebra = eyelid C. Lacrimal apparatus = apparatus consisting of tear glands and ducts D. Superior oblique = travels along medial wall of orbit, its tendon passes through the trochlea and inserts on the superolateral aspect of the eyeball E. CORNEA The cornea is the interior transparent region that admits light into the eye, and is part of the outermost of the three tunics.

When you view objects close to the eye, the eye makes an adjustment called __________.

Accommodation Accommodation is a change in the curvature of the lens that enables you to focus on a nearby object. Emmetropia is the state in which the eye is relaxed and focused on an object more than 6 meters away. Diplopia is double vision.

Which structure allows upper respiratory infections to spread from the throat to the tympanic cavity?

Auditory (Eustachian) tube The auditory tube is usually flattened and closed, but swallowing or yawning opens it and allows air to enter or leave the tympanic cavity. This equalizes air pressure on both sides of the tympanic membrane, allowing it to vibrate freely. However, it also allows throat infections to spread to the middle ear.

Stimuli produced by sound waves reach the brain following which pathway?

Auditory canal tympanic membrane ossicles oval window cochlear duct spiral organ fibers of cochlear nerve

Which organ does not have nociceptors?

BRAIN According to text- not in brain or liver? In some brain surgery, the patient must remain conscious and able to talk to the surgeon.

What are the first-order neurons in the visual pathway?

Bipolar cells Bipolar cells: first-order neurons Ganglion cells: second-order neurons

Which of the following is not an analgesic (pain reliever) found naturally in the central nervous system?

Bradykinin Bradykinin is the most potent pain stimulus known. It is released by injured tissues, and hurts intensely when injected under the skin. It makes us aware of injuries and activates reactions that promote healing. The others are all analgesics that occur naturally in the body and bind to receptors. They are secreted by the CNS, pituitary gland, digestive tract, and other organs in states of stress or exercise.

Changes in cerebrospinal fluid pH are detected by __________.

Chemoreceptors Respond to chemicals, including odors, tastes, and BODY FLUID COMPOSITION. Nocioreceptors occur in the meninges, play an important role in headaches. Mechanoreceptors sense pressure and touch.

Which of the following structures houses the spiral organ?

Cochlea Within the cochlear duct, supported on the basilar membrane, is the spiral organ... It converts vibrations into nerve impulses.

The spiral organ is housed within which of the following structures?

Cochlear duct

Which of these is most vulnerable to irreversible damage caused by a very loud noise?

Cochlear hair cells

Which cells are responsible for photopic (day) vision as well as trichromatic (color) vision?

Cones Cones function in brighter light; they are responsible for day (photopic) vision as well as color (trichromatic) vision.

What is the crista ampullaris associated with?

Dynamic equilibrium in angular acceleration

What do pheromones stimulate?

Olfactory cells

Half of the fibers of each optic nerve decussate at the __________.

Optic chiasm "The optic nerves leave each orbit through the optic canal and then converge to form an X, the optic chasm... Within the chasm, half of the fibers from each optic nerve cross over to the opposite side of the brain."

Nerve fibers from all regions of the retina converge on the __________ and exit the eye by way of the optic nerve.

Optic disc

What is the correct order of cells in the retina from back to front?

Photoreceptor - bipolar - ganglion Photoreceptor cells: absorb light, generate a chemical or electrical signal. Include rods, cones, certain ganglion. Only rods and codes produce visual images. Bipolar cells: rods and cones synapse with the dendrites of bipolar cells, the first order neurons of the visual pathway. Ganglion cells: largest neurons of the retina. Second-order neurons of visual pathway.

The initial effect of a stimulus on a sensory receptor is a local electrical change specifically called a(an) __________.

Receptor Potential

Which of the following structures belong to the inner ear?

Semicircular duct Tympanic membrane: the "eardrum," closes the inner end of the auditory canal and separates it from the middle ear Incus: bone of the middle ear Tensor tympani muscle: muscle of middle ear Helix: part of the outer ear, outermost / superiormost fold? SEMICIRCULAR DUCT: ?

When you spin while sitting in a swivel chair with your eyes closed, you can sense this movement by means of your __________.

Semicircular ducts Receptors for equilibrium consist of a vestibular apparatus, which consists of three semicircular ducts and two chambers.

What is the only sense in which signals can reach the cerebral cortex without passing first through the thalamus?

Smell Olfactory signals can reach the cerebral cortex directly, without first passing through the thalamus.

Most somesthetic signals in the right side of the body reach the cerebral cortex in the contralateral primary somesthetic area.

TRUE

Olfaction results from the stimulation of chemoreceptors.

TRUE

The cornea belongs to the tunica fibrosa (fibrous layer) of the eyeball.

TRUE

Vitamin A is necessary for the synthesis of rhodopsin.

TRUE

Taste signals travel from the tongue through the facial and glossopharyngeal nerves.

TRUE The facial nerve collects sensory info from taste buds from the anterior two thirds of the tongue, the glossopharyngeal nerve from the posterior third, the vagus from the palate, pharynx, and epiglottis.

The ossicles belong to the middle ear.

TRUE: 3 irregular bones of the middle ear

Where is the primary olfactory cortex located?

Temporal lobe

Where do most second-order somesthetic neurons synapse with third-order neurons?

Thalamus The thalamus receives signals from second order neurons, and relays them through third-order neurons to the POSTcentral gyrus of the cerebrum.

The three types of cones in the retina are differentiated from one another by what feature?

The absorption peak of their photopsin Photopsin: light-sensitive receptor protein. Dominant protein in cone cells. Short-wavelength (S) cones Medium-wavelength (M) cones Long-wavelength (L) cones

A 100 dB sound (loud) of 150 Hz (low pitch) would cause which of the following to occur?

The basilar membrane to vibrate vigorously near its distal end. HIGH frequency sounds cause the basilar membrane to vibrate nearer to the oval window (which separates the middle ear from the cochlea- stapes pushes it in and out). LOW frequency sounds cause the basilar membrane to vibrate near its DISTAL end, further from the oval window. Loud sounds produce more vigorous vibrations that quiet sounds.

When you travel in an elevator, what senses when the elevator is moving?

The hair cells of the otolithic membrane of the macula sacculi Macular utriculi detects tilt of head. The macula sacculi is nearly vertical and its hair cells therefore respond to vertical acceleration and deceleration.

Which taste sensation is produced by amino acids such as aspartic acid and glutamic acid?

Umami

Which of the following does not contribute to the sense of equilibrium?

Vallate papillae Vallate papillae are small bumps on the surface of the tongue that contain taste buds (one of the four types of lingual papillae).

Which of the following correctly describes the vestibular projection pathway to the brain?

Vestibular nerve - vestibulocochlear nerve - vestibular nuclei - thalamus - cerebral cortex

Sensory receptors sense only stimuli external to the body, such as light, sound waves, smell, and touch.

FALSE INTEROreceptors detect stimuli in the internal organs such as the stomach, intestines, and bladder, and produce feelings of stretch, pressure, visceral pain, and nausea. CHEMOreceptors respond to body fluid composition (in addition to chemicals in the external environment). MECHANOreceptors respond to physical deformation of a cell or tissue caused by vibration, touch, pressure or tension (in addition to hearing and balance). Propioreceptors sense the position and movement of the body and its parts.

Light falling on the retina is absorbed by rhodopsin and photopsin in the pigment epithelium.

FALSE Rhodopsin: light-sensitive receptor protein. Dominant protein in rod photoreceptors. Photopsin: light-sensitive receptor protein. Dominant protein in cone cells. Retinal pigment epithelium: just outside the retina, plays a role in light absorption. The rods and cones are NOT in the pigment epithelium- THEY ARE INSIDE THE RETINA.

Rods secrete glutamate from the base of the cell when exposed to light.

FALSE Rods secrete glutamate in the DARK, when they are not being stimulated.

The middle ear consists of a fluid-filled chamber.

FALSE There is fluid inside the cochlea of the inner ear, and inside the semicircular canals of the inner ear (equilibrium).

The vestibule contains organs of hearing and equilibrium.

FALSE Portion of the inner ear. Contains only organs of equilibrium Semicircular canals

Pain, heat, and cold are detected by __________.

Free nerve endings Tactile (Meissner) corpuscles: light touch, texture Tactile discs: Light touch, pressure Lamellar (Pacinian) corpuscles: deep pressure, stretch, tickle vibration End (Krause) bulbs: similar to tactile corpuscles, in mucous membranes

What are the only retinal cells that produce action potentials?

Ganglion cells All other retinal cells produce only graded local potentials.

In a taste bud, which cell produces a receptor potential?

Gustatory cells Taste hairs are the apical microvilli of gustatory cells. Basal cells are stem cells that multiply and replace taste cells that have died. Supporting cells resemble taste cells but have no sensory role.

Each upward movement of the basilar causes the stereocilia of the inner hair cells to bend, opening __________ gates.

K+ A soft sound causes the basilar membrane to vibrate slightly, a louder sound causes it to vibrate more vigorously. The hair cells generate a higher firing frequency as a sound gets louder. Each stereo cilia has a K+ channel at its tip. Vibrations of the cochlea cause each stereocilum to bend, pulling open the K+ channel of the ADJACENT sterocilium. The inflow of K+ depolarizes the hair cell.

Adjustment to close-range vision involves all of the following except __________.

Light adaptation Light adaptation occurs when you go from a darker environment to a brighter one.

Which of the following structures is visible to the naked eye?

Lingual papilla Visible bumps on the tongue. There are four types (filiform, foliate, fungiform, and vallate) and all but filiform contain taste buds.

The incus articulates with which bone(s)?

Malleus and stapes

Changes in blood pressure are detected by __________ in certain arteries.

Mechanoreceptors