Quiz #5 - Sensory Physiology

Sensation

The process by which information about the environmental stimuli is received by a sensory receptor and then converted to action potentials that are sent to the brain.

Perception

Involves the brain receiving and interpreting the action potentials such that we are consciously aware of the sensation.

Exteroceptor

Sensory receptors found in the skin, membranes, and sense organs

Interoceptor

Sensory receptors found in internal organs, blood vessels, and muscles

Mechanoreceptors

A sensory receptor that responds to mechanical stimuli such as touch, pressure, and vibration.

Proprioceptors

A sensory receptor found in muscle, joint, and tendon tissue that detects changes in body position or movement.

Thermoreceptors

A sensory receptor that responds to changes in temperature.

Photoreceptors

A sensory receptor that detects light or changes in light, found only in the eyes.

Chemoreceptors

A sensory receptor that responds to chemicals in solution.

Nociceptors

A sensory receptor that responds to stimuli that is harmful to the body.

Reflex Arc

The body can respond to some stimuli in a rapid, predictable pattern.

Receptor

Integration Center

Effector Organ

What are the 3 components of a reflex arc?

Motor Response

The response sent out by the integration center and carried out by the effector organ.

Intrinsic

Reflex arcs that require no experience or "learning" to be carried out by the body.

Spinal Reflex Arc

Intrinsic reflex associated with very rapid movement of skeletal muscle tissue. (Integration center is the spinal cord)

Pupil

The open space at the center of the iris, the colored portion of the eye, that allows light to enter the eye and strike the retina.

2

How many types of muscle does the iris have that will control the diameter of the pupil?

True

T/F The iris controls how much light enters the eye

When applying stimulus, the diameter of the eye became more narrow.

Pupillary Reflex + Response

Dilator Pupillae Muscle

Muscle in the iris that when contracts, causes the pupil to become wider.

Sphincter Pupillae Muscle

Muscle in the iris that when contracts, causes the pupil to become narrower.

Consensual Reflex

The stimulus is applied to only one side of the body, but the response is observed on both sides of the body.

When looking at the closer object vs the farther object, the pupils became narrower and converged inward.

Accommodation Reflex + Response

Lens

A structure inside the eye that helps to focus light directly on the retina by bending light as it enters the eye, allowing for clear vision.

Pupil accommodation

The size of the pupil changes according to distance of object requiring focus to adjust the amount of light entering the eye.

Lens accommodation

The lens can change shape to change the ability to refract (or bend) light to focus it on the retina.

Stronger

The more rounded the lens (or the more it bulges) the ________________ the refractory power.

Weaker

The flatter the lens, the ______________ the refractory power.

Highly; Higher; Less

If a person is looking at an object that is close, light from the object will be __________ scattered as it enters the eye. The lens accommodates this with a ________________ refractory power to bend light, so it is ______________ scattered when it hits the retina.

Less; Does Not; Flatter

When looking at an object farther away, light from the object is _____________ scattered as it enters the eye. The lens ________________ have to refract light as much and is therefore _______________.

Convergence

The process of both eyes moving (or pointing) inward to focus on an object. Requires use of medial and lateral rectus muscles of the eyes.

Tendon (Stretch) Reflex

Any reflex that occurs when a tendon is tapped.

The quadriceps contacts and the leg extends upward

Patellar Reflex + Response

Knee-Jerk Reflex

AKA Patellar Reflex. This reflex occurs when the patellar tendon just below to patella is stretched when it is tapped by a reflex hammer. (L2-L4)

Jendrassik's Maneuver

This maneuver alters the patellar reflex by forcing the individual to focus their attention somewhere else in the body, rather than thinking about the patellar reflex being performed on them.

When the Achilles tendon was tapped, the foot moved in plantar flexion due to contraction of the gastrocnemius

Achilles Reflex + Response

Ankle-Jerk Reflex

AKA Achilles reflex. This reflex occurs when the Achilles tendon on the back of the ankle is tapped. (S1)

Antagonistic Muscle

The relaxation of a muscle. Pairs usually have opposing action on a part of the body.

When the muscle contracts, the antagonist lengthens (and vice versa)

What is the general rule with a muscle and its antagonist?

Examining a body part by touch

Palpate

Ciliospinal Reflex

A response mediated by the sympathetic nervous system (fight/flight) in response to pain.

The pupil on the same side of the body dilated when pinched, while the opposite side had no change

Ciliospinal Reflex + Response

The toes flex plantar flexion, but dorsiflexion in Babinski test

Plantar Reflex/Babinski's Reflex + Response

Plantar Reflex

A reflex that protects the sole of the foot when a painful stimulus is applied at the sole.

Babinski's Reflex

In an adult, this is considered an abnormal response by the foot to the same stimulus for a plantar reflex. (Indicates damage to pyramidal tract fibers)

In a child under 1 year of age.

When is Babinski's reflex a normal response?

Plantar Flexion

Toes bending/curling in a downward movement.

Dorsiflexion

The big toe pointing in an upward motion

The fast-phase nystagmus was opposite the spin (left) and slow-phase nystagmus was same direction of spin (right)

Labyrinthine Reflex + Response

Semicircular Canals

Three fluid-filled tubes in the inner ear.

Contribute to balance and equilibrium while moving by aiding in visual fixation on moving objects.

What is the purpose of semicircular canals?

Nystagmus

Reflexive movement of the eyes caused by stimulated semicircular canals.

Anterior Semicircular Canal

Semicircular canal stimulated by forward and backward head movements.

Posterior Semicircular Canal

Semicircular canal stimulated by movement causing the head to tilt to the side.

Lateral Semicircular Canal

Semicircular canal stimulated by movement where the head spins or moves side-to-side.

By that of the fast phase.

How is the direction of nystagmus designated?

Slow Phase Nystagmus; Fast Phase Nystagmus

If a person is angularly accelerated in one direction, their eyes will move slowly in one direction (____________) as to maintain fixation on a moving target, then very rapidly move or twitch in the opposite direction (_______________).

Rotary Nystagmus

Can be observed during movement when the fluid in the semicircular canal moves, stimulating receptors in the inner ear.

Post-rotary Nystagmus

When the eyes continue to move reflexively after movement has stopped.

The fast phase and slow phase of post-rotary nystagmus is opposite that of rotary nystagmus.

How are rotary and post-rotary nystagmus different?

Spatial Orientation

The ability to maintain the body's position and posture in relation to our surroundings. (allows us to move around objects rather than bump into them)

Inner Ear (spatial orientation)

Receptors here respond to changes in head position during linear acceleration and rotational movement.

Proprioceptors (spatial orientation)

This sensory receptor monitors information such as joint position and stretch, joint angles, tendon tension, and muscle stretch.

Photoreceptors (spatial orientation)

Receptors in the eyes provide visual information to the brain. Allows brain to understand positioning and be aware of external environment.

The 5 senses

Taste, Vision, Hearing, Smell, and Touch

Touch

The mechanoreceptor is responsible for this sensation. Tactile sensibility (two point sensibility)

In the skin; Stimulated by physical deformation of the receptor.

Where is mechanoreceptor located and how is it stimulated?

Smaller; More

The _____________ the receptive area the _____________ sensitive the skin will be to touch.

Two-point Threshold

The smallest distance at which two points of contact can be felt on the skin.

Sensory Adaptation

If a stimulus is applied for a prolonged period without change, the rate of receptor discharge will slow, and conscious awareness of the stimulus will decline or is lost.

Conduction Deafness

Loss of hearing resulting from damage to structure from the tympanic membrane to the auditory ossicles.

The transmission of sound to the inner ear.

What does Conduction Deafness prevent?

Nerve Deafness

A form of deafness that occurs when the auditory nerve or brain is damaged.

Action potentials relating to sound are either not produced by the auditory nerve or cannot be interpreted by the brain.

What does Nerve Deafness prevent?

Weber Test: No lateralization

Rinne Test: Sound perceived longer by air conduction

Condition: No Hearing Loss

Weber Test: Lateralization to the poorer ear

Rinne Test: Sound perceived as long or longer by bone conduction

Condition: Conduction Deafness

Weber Test: Lateralization to the better ear

Rinne Test: Sound perceived longer by air conduction

Condition: Nerve Deafness

Near Point

The closest point at which an object can be placed from the face and still form a focused image within the eye's accommodation range.

The elasticity of the lens and its ability to accommodate when viewing an object up close.

What is the near point test point demonstrate?

Less; Less

As we age, the lens becomes __________ flexible and the accommodation becomes __________ effective.

Presbyopia

The loss of near focusing ability (why old people hold items farther away when trying to read)

Optic Disc

An area at the back of the eye on the retina where there are no photoreceptors for visual reception.

Visual Acuity

The sharpness of vision, involving the ability to discern letters or numbers at a given distance according to a fixed standard.

Snellen Test

Measures visual acuity (Chart with letters of different sizes in a pyramid shape)

v = d/D

Formula for a person's visual acuity

Distance at which the patient can read the letters in a particular row

What is the "d" in the visual acuity equation?

Distance at which a normal eye can read the letters in the same row

What is the "D" in the visual acuity equation?

Myopia

Nearsightedness; Individuals can see objects up close, while objects farther away are blurry or unclear.

Hyperopia

Farsightedness; Individuals can see objects far away clearly while nearby objects are blurry or unfocused.

Young-Helmholtz theory of Color vision

One type of photoreceptor in the eye (cone) allows for color vision. Different cones respond to different wavelengths of light.

Red, Blue, Green

What are the 3 colors of cones?

A lack of a particular gene on the X chromosome.

What is color blindness a result of?

Being a recessive trait, an individual with XY chromosomes has a higher likelihood of being color blind if the recessive trait is present on the X chromosome.

What type of individual has a higher liklihood of being color blind?

Red-Green Color Blindess

Most common type of color blindness; a person lacks either the red or green cones in the retina

Ishihara Test

Testing for colorblindness (collections of numbers via different colored dots)