learn smarts exam 4

which of the following statements about myosin are correct? -at rest, each globular myosin head is attached to actin -at rest, each globular myosin head is not attached to actin -each globular myosin head has a binding site for actin and one for ATP -each globular myosin head has a binding site for calcium and one for actin -each myosin head acts as a myosin ATPase enzyme

-at rest, each globular myosin head is not attached to actin -each globular myosin head has a binding site for actin and one for ATP -each myosin head acts as a myosin ATPase enzyme

the transverse tubules, or T-tubules of skeletal muscle ________. -release calcium -conduct action potentials -release acetylcholine -are continuous with the plasma membrane

-conduct action potentials -are continuous with the plasma membrane

satellite cells in muscle tissue -differentiate into myoblasts -are stem cells -proliferate in response to muscle damage -are neuroglia cells that aide in muscle signaling -are a type of myostatin

-differentiate into myoblasts -are stem cells -proliferate in response to muscle damage

which of the following statements about myosin are correct -each globular myosin head has a binding site for actin and one for ATP -each myosin had acts as a myosin ATPase enzyme -each global myosin head has a binding site for calcium and one for actin -at rest, each globular myosin head is attached to actin -at rest, each globular myosin head is not attached to actin

-each globular myosin head has a binding site for actin and one for ATP -each myosin head acts as a myosin ATPase enzyme -at rest, each globular myosin head is not attached to actin

myosin _______. -makes up the thick filament of the sarcomere -is an enzyme that regulates acetylcholine -is released from the sarcoplasmic reticulum -is a protein involved in muscle contraction

-makes up the thick filament of the sarcomere -is a protein involved in muscle contraction

put the following structures in order as signals travel from the cochlea -auditory cortex -brainstem -organ of corti -thalamus -vestibulocochlear nerve

-organ of corti -vestibulocochlear nerve -brainstem -thalamus -auditory cortex

which of the following applies to cross-bridge heads? -part of the myosin protein -bind to calcium and move tropomyosin -part of the actin protein -bind to and pull on actin

-part of the myosin protein -bind to and pull on actin

below is a sequence of events occurring when rotation of the head is sensed by the semicircular canals. Put them in the proper order from top to bottom -action potentials are initiated in the vestibulocochlear nerve -neurotransmitter is released from the hair cells -rotation of the head rotates the bony canal -stationary endolymph within the canal pushes against that gelatinous cupola within the ampulla -stereocilia are bent to one side -the opening of ion channels depolarizes the hair cells

-rotation of the head rotates the bony canal -stationary endolymph within the canal pushes against that gelatinous cupola within the ampulla -stereocilia are bent to one side -the opening of ion channels depolarizes the hair cells -neurotransmitter is released from the hair cells -action potentials are initiated in the vestibulocochlear nerve

which of the following are characteristics of skeletal muscle -intercalated disks -branched fibers -straited -uninucleate -multinucleate

-striated -multinucleate

which factors help humans locate sound sources -the different timing of when the sound reaches each ear -the hair cells can only bend in one ear at a time -the difference in loudness perceived by the ear facing toward a sound and the ear facing away from the sound -the hair cells in both ears bend away from the course of a sound, like grass blades blowing in a breeze

-the different timing of when the sound reaches each ear -the difference in loudness perceived by the ear facing toward a sound and the ear facing away from the sound

which three are present in the I bands of skeletal muscle -tropomyosin -actin -cross-bridges -myosin -titin

-tropomyosin -actin -Titin

within the skeletal muscle sarcomere, the wide dark stripes called the __________ are defined by the presence of mainly myosin proteins

A bands

the area within the A band of the sarcomere where thin filaments do not overlap the thick filaments is called the

H zone

when a hair cell is activated, mainly __________ ions enter the channel marked A, and mainly ____________ ions enter the channel marked B.

K+, Ca2+

the _____________ is a feature found at the center of a sarcomere, and is composed of proteins filaments that interconnect neighboring thick filaments

M line

what structures in the sarcomere connects adjacent thick filaments in the middle of the A-band, keeping them aligned during contraction

M lines

the ___________________ define the millets of a sarcomere

Z lines

the dark lines that can be seen in the middle of each I band and which mark and which marks the end of the sarcomere are known as

Z lines

which best defines the term "muscle fiber"

a skeletal muscle cell

________ is a globular protein composed of a single polypeptide that polymerizes with other monomers to make up the major structure of thin filaments

actin

the thin filaments are primarily composed of the protein

actin

what primarily makes up thin filaments

actin

Each globular myosin head has binding sites for

actin and ATP

irregularity of the curvature of the lens or cones of the eye causes a visual defect known as _____________

astigmatism

which taste categories involve transduction pathways that use G-Protein-coupled receptors

bitter, sweet, umami

objects that absorb all wavelengths of light are perceived as the color _________, while those that reflect a mixture of light are perceived as the color ___________.

black, white

olfactory nerves synapse onto the

bulbs

the three basic types of muscle are

cardiac, smooth and skeletal

the spiral shaped structure of the vertebrate inner ear that contains the sensory receptors for hearing is called the _________-

cochlea

there are 3 fluid-filled chambers within the cochlea. The middle cochlear chamber contains the organ of corti and is called the _________ duct. The basilar membrane separates that chamber from one below it (connected to the round window) called the Scala __________, and the chamber above it (connected to the oval window) is called the Scala ______________.

cochlear, tympani, vestibuli

astigmatism results from an irregularity in the curvature of either the ___________ or ___________ of the eye

cornea, lens

during active muscular contraction, when _______________ that are part of myosin attach to actin, they pull the actin toward the M line of the sarcomere

cross-bridges

the second messenger involved in the olfactory cell sensory transduction pathway is

cyclic AMP

photoreceptors maintain a _______________ resting membrane potential when in the dark

depolarized

a single skeletal muscle cell is also called a muscle ___________

fiber

when light strikes the retina and initiates action potentials that travel to the visual cortex, the first cell type that undergoes an action potential is a ___________ cell

ganglion

light waves must pass several cell types before they reach the pigmented epithelium at the back of the retina. The first cell type that they encounter is ____________

ganglion cells

the sense of taste is known as

gustation

which portion of the myosin molecule forms the long tail that joins with other myosin molecules to form the backbone of the thick filament

heavy chains

which portion of a myosin molecule forms the long tail that joins with other myosin molecules to form the backbone of the think filament

heavy-chains

hair cells near the base of the cochlea by the oval window are activated mainly by ___________--pitched sounds, while hair cells at the distal end are activated mainly by __________-pitched sounds

high; low

sour taste is created when __________ ions block K+ channels in the receptors plasma membrane

hydrogen

inability to focus light rays from nearby objects on the retina is a characteristic of the condition

hyperopia (occurs when the eyeball is too short (farsightedness) causing light rays to each the retina before they are in focus.)

an increase in size of a muscle fiber is referred to as

hypertrophy

an increase in size of a muscle fiber is referred to as __________

hypertrophy

which term means that a skeletal muscle fiber has increased in size

hypertrophy

what is the function of the pigment epithelium of the retina

it absorbs light rays and thus prevents reflection and scattering of light rays that would cause the visual image to blur

which best defines the A bands in striated muscle -it is the region that contains protein kinase A -it is the region that contains thick filaments -it is the region that contains both thick and thin filaments -it is the region that contains only thin filaments

it is the region that contains thick filaments

when a ray of light enters the cornea perpendicular to the corneas surface____________________

it passes straight into the cornea without changing its direction of travel

the basilar membrane can distinguish sounds of different pitch because

it varies in stiffness along its length, and high pitches vibrate regions near the oval window and low pitches vibrate it farther along

astigmatism results from an irregularity in the curvature of either the _____________ or ___________ of the eye

lens, cornea

All of these sites contain taste buds. what's the site where taste buds are most abundantly located cheeks soft palate epiglottis lingual papillae pharynx

lingual papillae

differences in arrival time and intensity of the input from the two ears help humans ______________

locate sound sources

the tympanic membrane vibrates when sound waves hit it. This moves a small bone called the ___________, which moves another bone called the _____________, which then moves a third bone called the ___________, which then presses on the oval window of the inner ear

malleus, incus, stapes

a special class of ganglion cells contains an opsinlike pigment called _____________, and when activated they send signals to the _________ nucleus, an area of the hypothalamus that acts as a "biological clock"

melanopsin, suprachiasmatic

which of the following increase the surface area of taste receptor cells and contain integral membrane proteins that transduce the binding of a given chemical into a receptor potential

microvilli

which of the following are components of taste buds microvilli (taste hairs) gustatory cells ciliary body otoliths basal cells nociceptor

microvilli (taste hairs) gustatory cells basal cells

which of the following are components of taste buds? microvilli (taste hairs) gustatory cells basal cells nociceptor ciliary body otoliths

microvilli (taste hairs) gustatory cells basal cells

which of the following are characteristics of skeletal muscle uninucleate intercalated disks multinucleate striated branched fibers

multinucleate striated

during embryonic development, skeletal muscle fibers are formed by the fusion of a number undifferentiated, mononucleated cells known as pacemaker cells smooth muscle cells monocytes satellite cells myoblasts

myoblasts

muscle fibers are formed during development by the fusion of a number of undifferentiated, mononucleated cells known as ______________ into a single, cylindrical, multinucleated cell

myoblasts

within each skeletal muscle fiber densely pack, started subunits known as __________ extend in parallel rows from one end of the cell to the other leaving little room between for other organelles. The striation in these elongated structures are caused by the regular arrangement of thick and thin filaments into sarcomeres.

myofibrils

individuals with ________ have difficulty focusing on objects that are further away

myopia

what makes up the majority of the think filament

myosin

when light rays activate a photoreceptor, the cell's membrane potential becomes more ____________

negative

where are the olfactory bulbs located

on the undersurface of the frontal lobes

list the structures in the order the would be encountered by action potentials traveling from the eyes to the visual cortex lateral geniculate nucleus occipital lobe optic chiasm optic nerve optic tract

optic nerve optic chiasm optic tract lateral geniculate nucleus occipital lobe

which part of the photoreceptor cell contains the photopigment molecules that absorb light

outer segment

whereas the photopigment discs are found in the ____________ segment of photoreceptors, most of the organelles are found in the _____________ segment

outer, inner

during activation of visual neural pathways, ___________ cells and _________ cells only undergo gadded potentials, action potentials are first initiated in ___________ cells.

photoreceptor, bipolar, ganglion

two layers at the back of the eye absorb stray light rays and prevent blurring of the visual image, the choroid layer and the _______________ epithelium

pigment

objects that absorb shorter wavelengths of light are perceived as _________, those that absorb longer wavelengths are perceived as _______, those that reflect all wavelengths are perceived as _____________, and those that absorb all wavelengths are perceived as _____________.

red, blue, white, black

arrange the following from top to bottom in the order that they undergo altered electrical activity when light strikes the retina rods and cones ganglion cells bipolar cells

rods and cones bipolar cells ganglion cells

the increase in perilymph pressure caused by inward movements of the stapes and the oval window is lived by outward movements of the membrane covering the _____________--

round window

which of the following taste sensors does NOT involve G-protein-coupled signaling pathways bitter salty sweet umami

salty

the plasma membrane of a skeletal muscle cell is also called the

sarcolemma

the arrangement of thick and thin filaments between Z lines forms a repeating subunit called a ______________ which is the basic functional unit of striated muscle

sarcomere

in skeletal muscle, stem cells, also known as ____________ cells are located between the plasma membrane and the surrounding basement membrane along the length of the muscle fibers. they are activated after injury and fuse with the damaged muscle cell

satellite

put the cochlear chamber sin the order they are affected by pressure waves entering the cochlea, from upper to lower -cochlear duct -scala tympani -scala vestibuli

scala vestibuli cochlear duct scala tympani

the scapula is a gelatinous mass found in the __________.

semicircular canals

gustation is defined as

sense of taste

what type of muscle tissue lacks a striated appearance

smooth

the thee basic types of muscle are

smooth, skeletal, and cardiac

foods that contain large numbers of hydrogen ions will stimulate taste cells that are sensitive to which major taste category

sour

visual signals from one class of ganglion cells travels to the _________________ nucleus- a region of the hypothalamus that acts as a biological clock.

suprachiasmatic

sensory receptors for taste, found mainly on the lingual papillae, are

taste buds

the sense organs for taste are called

taste buds

bundles of collagen fibers that attach muscle to bone are referred to as

tendons

what term describes bundles of collagen fibers that attach bone to muscle

tendons

most of the calcium in skeletal muscle cells is stored in the _____________________ of the sarcoplasmic reticulum

terminal cisternae

where is most of the calcium stored in a relaxed skeletal muscle fiber

terminal cisternae of SR

within skeletal muscle fibers, what structure stores and releases calcium

terminal cisternae of the S

which of the following statements describes what is directly responsible for the mechanical gating of ion channels during activation of inner hair cells in the cochlea? -the fluid rushes into the cochlear duct, stretching the walls and opening the ion channels in the walls -the bending of the stereo cilia open channels by stretching the tectorial membrane -stretching of the basilar membrane pulls embedded channels open -the bending of the stereocilia pulls channels open via tip links - the outer hair cells pull the tectorial membrane away from the inner hair cells, exposing ion channels

the bending of the stereocilia pulls channels open via tip links

myopia is a condition caused by

the eyeball being too long relative to the focusing power of the lens

in the visual signaling pathway, the lateral geniculate nucleus send action potentials to ______________.

the primary visual cortex

what is a sarcomere

the smallest contractile unit of the cell, the ends of which are defined by the Z lines

what is the name of the elastic protein that extends from the Z line to the M line of a sarcomere

titin

next to the terminal cisternae of the sarcoplasmic reticulum are tubular invaginations of the sarcolemma called

transverse tubules