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
