Chap 3 Exam

Which of the following events would disrupt the activities of the lag phase of a muscle twitch?

Both "a competitor molecule blocks the binding sites for ACh on the sarcolemma" and "calcium ions are not released from the sarcoplasmic reticulum" are correct.

Which of the following statements would support the assertion that the arrector pili muscles associated with hair are smooth muscle?

Both "arrector pili muscles are under involuntary control therefore they are not skeletal muscle" and "cardiac muscle is only located in the walls of the heart" are correct.

Anaerobic respiration

Both "produces lactate within the muscle" and "occurs during limited O2 availability" are correct.

Muscles of mastication include

Both "the masseter" and "the temporalis" are correct.

___________ detect light touch and superficial pressure and are found in the epidermis.

Merkel disks

Which of the following is not one of the main characteristics of muscle tissue?

Rigidity

Which of the following is the correct sequence of structures in a reflex arc?

Sensory receptor, sensory neuron, interneuron, motor neuron, effector organ

Why is the resting membrane potential negative?

The membrane is more permeable to potassium ions than to sodium ions at rest.

Which statements are correct concerning the parasympathetic division of the ANS?a) Preganglionic neuron cell bodies are located in brainstem nuclei.b) Preganglionic neuron cell bodies are located in the lateral horns of the T1-L2 regions.c) It participates in the "fight-or-flight" response.d) It maintains homeostasis.e) Preganglionic neuron cell bodies are located in the sacral region of the spinal cord.

a, d, e

During contraction, the sarcomeres shorten because

actin is pulled past myosin towards the M line of the sarcomere.

Rod cells

are more sensitive to light than cone cells.

Taste buds

can only perceive taste if the molecules are in solution.

Inferior to the lumbosacral enlargement of the spinal cord there is a collection of spinal nerves that fill the vertebral canal and is collectively called the __________.

cauda equina

Cerebrospinal fluid is secreted by the __________ in the ventricles, and passes back into the blood through the __________.

choroid plexus; arachnoid granulations

The lacrimal canaliculi

collect excess tears from the medial corner of the eye.

A thin, transparent mucous membrane that covers the inner surface of the eyelids, and the anterior surface of the eye is the

conjunctiva.

The peripheral nervous system includes the _____.

cranial nerves

The phrenic nerves innervate the __________.

diaphragm

The enteric nervous system is located in the __________.

digestive tract

Chemoreceptors require that the chemical they sense is

dissolved in a liquid.

A single, brief contraction of a muscle fiber in response to a stimulus is called a(n) __________.

muscle twitch

A bundle of axons and their connective tissue sheaths is called a(n) __________.

nerve

Transmitting a nerve impulse from one neuron to another involves a __________.

nerve impulse stimulating a presynaptic axon to release a neurotransmitter into a synaptic cleft

Motion sickness

occurs when conflicting information reaches the brain from the inner ears and the eyes.

Each olfactory tract terminates in an area of the brain called the ______.

olfactory cortex

The brain interprets input from sensory receptors as

perception

As a result of extreme muscular fatigue, muscles can become incapable of relaxing or contracting, which is called _____________. Similarly, several hours after death, ATP levels decline, causing muscle rigidity, known as ____________.

physiological contracture; rigor mortis

Special senses arise from receptors located

primarily in the head.

All of the following are functions of muscle EXCEPT

production of red blood cells

The characteristic that allows muscles to have a slow, smooth, sustained contraction is

recruitment of motor units.

When _________ causes more motor units to contract in a whole muscle as the stimulus strength increases, the relationship between increased stimulus strength and increased number of motor units contracting is called ___________.

recruitment; summation

Pain felt in the left shoulder and arm as the result of a heart attack is an example of

referred pain.

The photoreceptors that are involved in noncolor vision are __________ and the __________ are photoreceptors that are involved in color vision and visual acuity.

rod cells; cone cells

The cell membrane of a muscle fiber is called the __________.

sarcolemma

The parasympathetic division of the autonomic nervous system __________.

stimulates digestion, defecation and urination

Most sensory input that ascends through the spinal cord and brainstem projects to the __________.

thalamus

The structure that opens into the pharynx and enables air pressure to be equalized between the middle ear and the outside is

the auditory tube.

The autonomic nervous system is composed of __________.

visceral motor neurons

Check all that are true statements regarding the sensory and motor nervous systems.

- The sensory nervous system contains both PNS and CNS components. - The somatic nervous system component of the motor nervous system conducts impulses from the CNS to skeletal muscles. - The motor nervous system contains both CNS and PNS components.

Check all of the items below that pertain to functions of the nervous system.

- receives sensory input - integration of information - controlling muscles and glands - maintaining homeostasis - establish and maintaining mental activity

Unlike skeletal muscle, smooth muscle is striated in appearance. In smooth muscle, the actin and myosin myofilaments are in loose bundles. No T tubule system exists in smooth muscles. Smooth muscle contracts faster than skeletal muscle. In smooth muscle, actin myofilaments are attached to dense bodies. Skeletal muscle contains more actin and myosin myofilaments than smooth muscle. Smooth muscle cells are larger than skeletal muscle cells.

1. Unlike skeletal muscle, smooth muscle is striated in appearance.: False 2. In smooth muscle, the actin and myosin myofilaments are in loose bundles.: True 3. No T tubule system exists in smooth muscles.: True 4. Smooth muscle contracts faster than skeletal muscle.: False 5. In smooth muscle, actin myofilaments are attached to dense bodies.: True 6. Skeletal muscle contains more actin and myosin myofilaments than smooth muscle.: True 7. Smooth muscle cells are larger than skeletal muscle cells.: False

Put the following events in chronological order. (Some of the steps may be missing.) 1) Ca2+ floods into the presynaptic terminal. 2) ACh (Acetylcholine) binds to ACh receptors in the sarcolemma. 3) Na+ floods into the muscle fiber. 4) The action potential arrives at the presynaptic terminal of the axon, causing Ca2+ channels to open. 5) ACh from the synaptic vesicles spills into the synaptic cleft. 6) An action potential results in the muscle fiber (depolarization).

4, 1, 5, 2, 3, 6

Arrange the events of synaptic transmission in correct sequence. 1) Sodium ions diffuse into the cell and cause a local potential2) Neurotransmitter binds with receptor on postsynaptic cell3) Neurotransmitter diffuses across the synaptic cleft4) Membrane permeability to sodium ions on postsynaptic cell increases5) Action potential in a presynaptic cell causes release of neurotransmitter

5, 3, 2, 4, 1

Which of the following statements best describes the epimysium?

A layer of connective tissue that surrounds a muscle.

Muscle myofibrils

All of the choices are correct.

The nervous system _____.

All of these choices are correct.

Which of the following muscles is/are involved in "puckering up" to kiss someone?

Both orbicularis oris and buccinator are required to "pucker up."

Botulinus toxin causes paralysis by preventing the exocytotic release of acetylcholine from the synaptic vesicles. Which of the following events would still occur in a tissue treated with this toxin?

Calcium ion channels in the presynaptic membrane open allowing Ca++ to enter the neuron.

Which of the following correctly lists the parts through which light passes as it enters the eye?

Cornea, aqueous humor, lens, vitreous humor

Which of the following is true about spinal cord structure?

Gray matter inside, white matter outside and a dorsal sensory root

When Oliver tries to blow out the candles on his birthday cake, he is unsuccessful. He has suffered damage to some of the muscles of his thorax. Which ones are most likely affected?

Internal intercostals

An Anatomy & Physiology student's grandfather seems really confused one day and could not follow a normal conversation. The student really worried when he seemed to have a hard time speaking. She followed the F-A-S-T guidelines for assessment of a stroke: Face drooping (yes), Arm weakness (yes - right side), Speech Difficulty (yes), and Time to call 911. A MRI confirmed her suspicions: her grandfather had a stroke in which part of his brain?

Left frontal cortex

Identify the molecule within muscle fibers that stores oxygen temporarily.

Myoglobin

Which of the following statements regarding neuroglia is false?

Neuroglia produce action potentials for skeletal muscles.

___________ detect deep pressure, vibration, and proprioception in tendons and joints.

Pacinian corpuscles

Which of the following is mismatched?

Somatic nervous system — Sensory division of PNS

Which of the following statements about taste is false?

Taste sensations are carried by three spinal nerves that synapse in the olfactory bulb.

Which of the following visual cues could be used to determine if a sarcomere is contracting completely?

The H zone is not longer visible.

An unknown substance has been discovered that blocks the binding sites on troponin. What effect would this have on overall muscle contraction?

The H zones of the sarcomeres are no longer visible.

Which of the following best explains the characteristics of a motor neuron that is said to be inhibited?

The cell has experienced a hyperpolarization, moving the membrane potential farther from threshold.

After a car accident, the ER doctor uses a hammer to test your patellar reflex response. You have no initial knee jerk response but after 2 weeks your response is exaggerated. What does it indicate?

The neurons within the brain or spinal cord that modify this reflex have been damaged.

TTX is a toxin that blocks Na+ channels from opening. What effect would this have on the function of neurons (specifically the action potential)?

The neurons would be unable to depolarize.

Myasthenia gravis is an autoimmune disorder in which the number of acetylcholine receptors is dramatically decreased. To treat some of the symptoms of Myasthenia gravis, physicians sometimes prescribe the anticholinesterase drug neostigmine. Why does this drug help with the symptoms of muscle weakness and fatigue?

The reduced activity of acetylcholinesterase prevents the breakdown of ACh. Consequently, ACh levels in the synapse remain elevated, thereby increasing the stimulation of the reduced number of functional ACh receptors.w

Which of the following statements about the inner ear is false?

The semicircular canals are involved in static equilibrium.

Which of the following statements about olfaction is false?

The threshold for detection of odors is extremely high so it takes quite a lot of odorants bound to an olfactory neuron to initiate an action potential.

Which two nerves form the sciatic nerve?

Tibial and common fibular

Which of the following is false regarding the eye and vision?

When viewing distant objects, your lens becomes thicker.

The connective tissue wrap the surrounds many fascicles to form a nerve is the ___________.

epineurium

Which cranial nerve allows one to make facial expressions and secrete tears?

facial

The anterior forearm muscles

flex the wrist and fingers.

Cones are

found in greatest quantity in the fovea centralis.

Slow-twitch muscle fibers

have a richer blood supply and contain more myoglobin than fast-twitch fibers (type IIb).

Olfactory neurons

have long cilia on the dendrites, which airborne molecules bind to.

In ___________, muscle fibers partially relax between contractions, and in ___________, no relaxation occurs between contractions.

incomplete tetanus; complete tetanus

Curare blocks acetylcholine receptors at the motor end plate. This will _____ muscle contraction.

inhibit

The cerebellum __________.

is involved in balance, maintenance of muscle tone, and coordination of fine motor movement

The deep groove that separates the right and left cerebral hemispheres from each other is the __________.

longitudinal fissure

The type of sensory receptors that respond to physical forces such as bending or stretching the receptor are called

mechanoreceptors.