Physio exam 3

Utricle and saccule

Utricle and saccule

Otolithic Membrane

The dissociation of rhodopsin in the rods in response to light causes

the bipolar cells to become either stimulated or inhibited

Tonic receptors

produce action potentials at a greater frequency as the generator potential is increased.

Semicircular canals

Capula

cochlea

Basilar membrane

Cutaneous receptive fields are smallest in

the fingertips

The process of lateral inhibition

increases sensory acuity.

The receptors for taste are

specialized epithelial cell

Which of these statements about the utricle and saccule are true?

Both a and c are true. -a. They are otolith organs c. They provide a sense of linear acceleration.

Because fibers of the optic nerve that originate in the nasal halves of each retina cross over at the optic

the contralateral visual field of both eyes

When a person with normal vision views an object from a distance of at least 20 feet

all of these apply the ciliary muscles are relaxed. the suspensory ligament is tight. the lens is in its most flat, least convex shape.

Glasses with concave lenses help correct

myopia

Parasympathetic nerves that stimulate constriction of the iris (in the pupillary reflex) are activated by

the superior colliculus

The ability of the lens to increase its curvature and maintain a focus at close distances is called

accommodation.

Which of these sensory modalities is transmitted directly to the cerebral cortex without being relayed through the thalamus?

Smell

Stimulation of membrane protein receptors by binding to specific molecules is not responsible for

sour taste sensations

Epithelial cells release transmitter chemicals that excite sensory neurons in all of these senses except

smell

Which of these statements about hypothalamic-releasing hormones is true?

All of these are true They are secreted into capillaries in the median eminence. They are transported by portal veins to the anterior pituitary. They stimulate the secretion of specific hormones from the anterior pituitary.

The hormone primarily responsible for setting the basal metabolic rate and for promoting the maturation of the brain is

Thyroxine

Which of these statements about the adrenal cortex is true?

d. all of these are true It is not innervated by nerve fibers. It secretes some androgens. The zona glomerulosa secretes aldosterone. The zona fasciculata is stimulated by ACTH.

Which of these statements about the hormone insulin is true?

e. Both b and c are true It is secreted in response to a rise in blood glucose. It stimulates the production of glycogen and fat

Epinephrine

Sympathetic Nerves

Thyroxine

TSH

Corticosteroid

ACTH

ACTH

CRH

Steroid hormones are secreted by

both a and b the adrenal cortex. the gonads

The secretion of which of these hormones would be increased in a person with endemic goiter?

TSH

Which of these hormones uses cAMP as a second messenger?

Epinephrine

Which of these terms best describes the interactions of insulin and glucagon?

Antagonistic

Which of these correctly describes the role of inositol triphosphate in hormone action?

It stimulates the release of Ca from the endoplasmic reticulum

Human chorionic gonadotropin (hCG) is secreted by

The placenta

A graded whole muscle contraction is produced in vivo primarily by variations in

the number of fibers that are contracting

The series-elastic component of muscle contraction is responsible for

All of these increased muscle shortening to successive twitches. a time delay between contraction and shortening. the lengthening of muscle after contraction has ceased.

Which of these muscles have motor units with the highest innervation ratio?

Muscles that move the fingers

The stimulation of gamma motor neurons produces

isometric contraction of intrafusal fibers

In a single reflex arc involved in the knee-jerk reflex, how many synapses are activated within the spinal cord?

One

When a skeletal muscle shortens during contraction, which of these statements is false?

The A bands shorten

Electrical excitation of a muscle fiber most directly cause

Release of Ca from the endoplasmic reticulum

The energy for muscle contraction is most directly obtained from

ATP.

Which of these statements about cross bridges is false?

They bind to ATP after they detach from actin.

When a muscle is stimulated to contract, Ca binds to

Troponin

Which of these statements about muscle fatigue is false?

It may result when ATP is no longer available for the cross-bridge cycle.

Which of these types of muscle cells are not capable of spontaneous depolarization?

b. Multiunit smooth muscle d. skeletal muscle e. Both b and d

Which of these muscle types is striated and contains gap junctions?

Cardiac muscle

In an isotonic muscle contraction,

The muscle tension remains constant

Which of the following is an example of an eccentric muscle contraction?

Flexing the arms when bench-pressing to allow the weight to return to the chest

Which of the following statements about the Ca2+ release channels in the sarcoplasmic reticulum is false?

They are one-tenth the size of the voltage-gated Ca channels

Which of these statements is false?

Exchanges between blood and tissue fluid occur across the walls of venules.

All arteries in the body contain oxygen-rich blood with the exception of

the pulmonary artery.

The "lub," or first heart sound, is produced by closing of

both AV valves

The first heart sound is produced at

the beginning of systole.

Changes in the cardiac rate primarily reflect changes in the duration of

Diastole

The QRS wave of an ECG is produced by

depolarization of the ventricles.

The second heart sound immediately follows the occurrence of

The T wave

The cells that normally have the fastest rate of spontaneous diastolic depolarization are located in

The SA node

Which of these statements is true?

All of the myocardial cells in the ventricles are normally in a refractory period at the same time.

An ischemic injury to the heart that destroys myocardial cells is

a myocardial infarction.

The activation of factor X occurs in

both the intrinsic and extrinsic pathways.

Platelets

d. serve all of these function

• form a plug by sticking to each other.

• release chemicals that stimulate vasoconstriction.

• provide phospholipids needed for the intrinsic pathway.

Antibodies against both type A and type B antigens are found in the plasma of a person who is

Type O

Production of which of the following blood cells is stimulated by a hormone secreted by the kidneys

Erythrocytes

Which of these statements about plasmin is true?

It functions in fibrinolysis.

During the phase of isovolumetric relaxation of the ventricles, the pressure in the ventricles is

Falling

Peristaltic waves of contraction move fluid within which of these vessels?

Lymphatic vessels

The basic purpose of all sense organs is to convert stimulus energy into action potentials. Anything that converts one energy form into another like this is called a(an)

Transducer

Rods and cones are sensory cells that respond to light and are known functionally as _________________.

Photoreceptors

Receptors in the muscles, tendons, and joints that inform the brain of the position and movements of the body parts are functionally known as ______________.

Proprioreceptors

The cutaneous senses include all of the following except __________________.

Sight

The brain interprets signals from the eye as light even if the eye is actually being stimulated by something else, such as pressure. This best describes

The law of specific nerve energies

An environmental stimulus acting on the body initially produces an electrical response, called a(an) __________ in the receptor neuron.

generator potential

Receptors provide information about the intensity of a stimulus through ____________.

The frequency of their actions potentials

The adequate stimulus is _______________.

the amount of energy needed to produce an action potential

The area of the skin where stimulation generates action potentials in a particular sensory neuron is called that neuron's __________________.

Receptive fields

The most important effect of lateral inhibition is to ________________.

sharpen perception of the precise location of a stimulus

The sense of smell and taste have all of the following in common except that they ____________

both transmit to the brain via the glossopharyngeal nerve (IX)

Hydrogen ions are associated with which of the basic taste modalities?

Sour

Olfaction differs from other sensory modalities because it ____________

does not transmit to the cerebral cortex via the thalamus

The middle ear _________________.

is responsible for transmitting sound waves from the outer ear to the inner ear

The bone attached to the proximal side of the oval window is the __________.

Stapes

Sound waves travel from the air to the tympanic membrane by way of the ___________.

External auditory meatus

The death of hair cells by continued exposure of high amplitude sound of a single frequency such as a jet engine is _____________.

sensorineural deafness

Glaucoma is caused by _____________

inadequate drainage of aqueous humor

The area of greatest visual acuity is located at the ______________

Fovea centralis

When an object is more than 20 feet from the eye and is clearly focused on the retina the _______________.

Ciliary muscle is relaxed

A sound of zero decibels cannot be heard and is considered infrasonic

False

Sound waves are channeled by the pinna into and along the auditory or Eustachian tube to the tympanic membrane.

False

The human retina is not sensitive to ultraviolet light

True

Brown and black eye colors are due to the pigment melanin in the iris and blue eye color is due to the pigment anthocyanin in the iris

False

The right half of the visual field projects onto the retina of the left eye and the left half of the visual field projects onto the retina of the right eye

False

From the time a tactile stimulus is detected by a receptor in the foot, to the time the resulting nerve impulses arrive in the postcentral gyrus of the brain, the impulses will have traveled over _________ neuron

Three

Somatesthetic sensations reach the postcentral gyrus by way of a 3rd order neuron which begins in the ___

Thalamus

The two-point touch threshold test serves as a demonstration of _______________.

Receptive fields

The reason Braille can be read by blind people is that the raised dots are ___________.

sufficiently far apart to exceed the two-point threshold

The sense of taste depends on ______________.

microvilli of receptor cells

Within a taste bud ________________.

Ion channels are involved in detecting sour substances

Perilymph is found in the _______________.

scala vestibuli

Horizontal acceleration of the body is detected primarily by the ______________.

utricle

The bending of stereocilia toward the direction of the kinocilium of a hair cell causes ________________.

depolarization

The importance of the three bones (ossicles) between the tympanic membrane and inner ear is that __________________.

when necessary, these bones can reduce sound intensity to the inner ear

Louder sounds are discriminated from quieter sounds on the basis of _________.

how much the stereocilia of the hair cells are bent