Physiology finals semester 2

Peptide hormones A) are composed of amino acids. B) are produced by cells in the suprarenal glands. C) are derived from the amino acid tyrosine. D) are lipids. E) are chemically related to cholesterol.

A

The ________ contains vesicles filled with acetylcholine. A) synaptic knob B) motor end plate C) neuromuscular junction D) synaptic cleft E) transverse tubule

A

The amount of oxygen needed to support the conversion of lactic acid to glycogen is called the A) oxygen debt. B) refractory amount. C) anaerobic threshold. D) aerobic threshold. E) aerobic conversion.

A

Hormone concentration levels are most commonly controlled by a. positive feedback b. the quantity of circulating hormone c. negative feedback d. cellular demands e. body temperature

c

The hypothalamis controls the secretion of the posterior pituitary by way of a. direct neural stimulation b. direct mechanical control c. releasing and inhibiting hormones d. altering ion concentration in the anterior pituitary e. gap junctions

A

The muscle that adducts and rotates the scapula laterally is the A) rhomboideus. B) levator scapulae. C) serratus anterior. D) pectoralis minor. E) subclavius.

A

When a calcium ion binds to troponin, A) tropomyosin moves out of the groove between the actin molecules. B) active sites on the myosin are exposed. C) actin heads will bind to myosin. D) muscle relaxation occurs. E) all of the above

A

Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have A) a rich nerve supply. B) a rich vascular supply. C) very few mitochondria. D) little need for oxygen. E) all of the above

B

Creatine phosphate serves to A) cause the decomposition of ATP. B) supply energy to synthesize ATP. C) decompose ADP. D) synthesize ADP. E) synthesize glucose.

B

In a recording of a muscle twitch, the delay between the stimulus and the muscle response is called the A) refractory period. B) latent period. C) contraction period. D) relaxation period. E) both B and D

B

Myasthenia gravis is an autoimmune disorder in which antibodies attack acetylcholine receptors. The resulting muscle weakness is likely due to A) increasing the amount of acetylcholinesterase in the synapse. B) making the cells less permeable to sodium ions. C) increasing the amount of potassium ion in the intercellular fluid. D) making the plasma membranes more permeable to calcium ion. E) antibodies competing with acetylcholinesterase for acetylcholine.

B

Neurotransmitters that cause skeletal muscle contraction are normally stored in A) myofibrils. B) motor neuron endings. C) motor units. D) motor end plates. E) actin.

B

Rigor mortis that occurs in skeletal muscles a few hours after death is due to A) excessive ATP and decreased permeability to calcium. B) decreased ATP and increased permeability to calcium. C) excessive ATP. D) lack of oxygen. E) lactic acid buildup.

B

Skeletal muscle fibers differ from "typical cells" in that these muscle fibers A) lack a plasma membrane. B) have many nuclei. C) are very small. D) lack mitochondria. E) all of the above

B

The all-or-none response means that A) all of the muscles in a region contract together. B) when a muscle fiber contracts, it contracts completely. C) all of the muscle fibers within a muscle contract together. D) when a muscle fiber contracts, all of its ATP is converted to ADP. E) none of the above

B

The center of the sarcomere is the a. Z line b. M line c. H band d. A band e. I band

B

The specialized sarcolemma that contains acetylcholine receptors is the A) synaptic knob. B) motor end plate. C) motor unit. D) synaptic cleft. E) I band.

B

The terminal cisternae are parts of the A) myofilaments. B) sarcoplasmic reticula. C) myofibrils. D) I bands. E) sarcolemma.

B

What is the function of the transverse tubule? A) the storage of calcium ions B) to transmit muscle impulses to the cell's interior C) to store sodium ions D) to allow cross-bridge attachment E) all of the above

B

A resting muscle generates most of its ATP by A) conversion of creatine phosphate. B) anaerobic respiration. C) aerobic respiration. D) the tricarboxylic acid cycle. E) both C and D

C

An example of partial but sustained contraction is A) treppe. B) tetany. C) muscle tone. D) fatigue. E) a twitch.

C

At rest, myosin molecules are A) bound to other myosin molecules. B) bound to troponin molecules. C) blocked from binding tropomyosin molecules. D) bound to ATP molecules. E) blocked from binding to calcium ions.

C

Hypothalamic hormones that activate the release of other hormones are called a. permissive hormones b. synergistic hormones c. tropic hormones d. stimulating hormones e. releasing hormones

C

Muscle fascicles are separated by A) endomysium. B) perimysium. C) epimysium. D) sarcolemma. E) periosteum.

C

Nonstriated, involuntary muscle is A) cardiac. B) red skeletal. C) smooth. D) white skeletal. E) intermediate skeletal.

C

The area of the sarcomere that contains only thick filaments and no zone of overlap is the A) Z line. B) M line. C) H band. D) A band. E) I band.

C

The tropomyosin molecules are attached to A) actin molecules. B) myosin molecules. C) troponin molecules. D) ATP molecules. E) calcium ions

C

When a protein or peptide hormone binds to receptors on the surface of a cell, A) the hormone receptor complex moves into the cytoplasm. B) the plasma membrane becomes depolarized. C) a second messenger appears in the cytoplasm. D) the cell becomes inactive. E) the hormone is transported to the nucleus, where it alters the activity of the DNA.

C

When myosin cycling generates less tension than the load, A) an oxygen debt is repaid. B) fatigue occurs. C) relaxation occurs. D) tetany occurs. E) atrophy occurs.

C

Which of the following muscles is named for its shape? A) pectoralis major B) biceps brachii C) deltoid D) erector spinae E) tibialis anterior

C

Steroid hormones A) bind to receptors on the surface of the cell. B) function by way of a second messenger system. C) cannot diffuse through the plasma membrane. D) bind to intracellular receptors. E) function by activating cAMP.

D

The advantage of having many nuclei in a skeletal muscle fiber is A) the ability to contract. B) the ability to produce more ATP with little oxygen. C) the ability to repair the fiber after an injury. D) the ability to produce large amounts of the enzymes and structural proteins needed for contraction. E) none of the above

D

The brief moment following stimulation when a muscle is unresponsive to another stimulus is called the ________ period. A) latent B) contraction C) relaxation D) refractory E) both C and D

D

The nervous system A) produces rapid and specific responses to environmental stimuli. B) communicates by the release of neurotransmitters. C) continues to produce a response long after neural output ceases. D) A and B only E) all of the above

D

The skeletal muscles store calcium ions in the A) sarcolemma. B) sarcomere. C) sarcosome. D) sarcoplasmic reticulum. E) sarcoplasm.

D

The striated appearance of skeletal muscle results from A) transverse tubule pattern. B) the sarcoplasmic reticulum. C) cisternae placement. D) sarcomere arrangement. E) all of the above

D

Which of the following inserts into fascia, rather than a bone? A) extensor carpi ulnaris B) flexor carpi radialis C) extensor digitorum D) palmaris longus E) flexor digitorum

D

Which of the following is an muscular adaptation as a result of exercise? A) Muscle fibers become smaller in diameter. B) Muscles become less elastic. C) Muscles fatigue more rapidly. D) Muscle fibers increase their reserves of glycogen. E) Muscle fibers become less efficient.

D

Increased oxygen consumption would accompany A) increased heat production. B) increased conversion of lactic acid to glucose. C) increased aerobic respiration by muscle cells. D) increased muscle activity. E) all of the above

E

Multi-unit smooth muscle A) is composed of sheets of muscle cells. B) is found in the wall of the stomach. C) tends to contract rhythmically. D) is connected by gap junctions. E) none of the above

E

Steroid hormones A) are lipids. B) diffuse through plasma membranes. C) bind to protein receptors within the cell. D) cause mRNA synthesis. E) all of the above

E

The endocrine system A) releases chemicals into the bloodstream for distribution throughout the body. B) releases hormones that alter the metabolic activities of many different tissues and organs simultaneously. C) produces effects that can last for hours, days, and even longer. D) A and C only E) all of the above

E

The muscle that inserts on the superior angle of the scapula is the A) serratus anterior. B) trapezius. C) sternocleidomastoid. D) pectoralis minor. E) levator scapulae.

E

The skeletal muscle organelles that actually contracts is (are) the A) sarcolemma. B) sarcomere. C) transverse tubules. D) myotubules. E) myofibrils.

E

Which of the following can be a stimulus for contraction in all three muscle tissue types? A) epinephrine B) thyroid hormone C) testosterone D) parathyroid hormone E) acetylcholine

E

Which of the following is (are) a function of skeletal muscle? a. produce movement b. maintain posture c. maintain body temperature d. A and B only e. all of the above

E

The area between Z lines is the A) sarcolemma. B) sarcomere. C) sarcoplasmic reticulum. D) myofibril. E) myofilament.

B

Myofibrils are made primarily of A) actin and myosin. B) epimysium. C) ATP and ADP. D) troponin. E) tropomyosin.

A

Myoglobin stores A) oxygen. B) glycogen. C) ATP. D) calcium ions. E) glucose

A

A muscle cramp is most likely due to lack of A) ATP. B) ADP. C) actin. D) myosin. E) acetylcholine.

A

An important second messenger in hormonal action is a. cAMP b. ATP c. adenylate cyclase d. calcium e. ADP

A

At the neuromuscular junction, the muscle fiber membrane is folded to form a A) motor end plate. B) motor unit. C) neuroreceptor. D) neurotransmitter. E) motor neuron.

A

Calcium ions are released from the sarcoplasmic reticulum during the ________ phase of contraction. A) latent B) contraction C) twitch D) relaxation E) recovery

A

Contraction during muscle lengthening is called A) eccentric contraction. B) concentric contraction. C) isometric contraction. D) isotonic contraction. E) all of the above

A

Which of the following is characteristic of cardiac muscle? A) Cardiac muscles are striated. B) Cardiac muscles achieve tetany with every contraction. C) Cardiac muscle fibers are multinucleated. D) Cardiac muscles are faster than skeletal muscles. E) Neurons that innervate cardiac muscles are under voluntary control.

A

Which of the following is the smaller amount? A) the concentration of calcium ions in the sarcoplasm of a resting muscle B) the concentration of calcium ions in the sarcoplasmic reticulum of a resting muscle

A

In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases A) acetylcholine. B) sodium ions. C) potassium ions. D) calcium ions. E) all of the above

D

Rigor mortis occurs at death due to a lack of A) cAMP. B) DNA. C) RNA. D) ATP. E) tRNA

D

Steroid hormones A) are lipids. B) are structurally similar to cholesterol. C) bind to cell surface receptors. D) have characteristics of both A and B. E) have characteristics of all of the above.

D

Compared to skeletal muscle, smooth muscle A) contracts faster. B) relaxes faster. C) contracts and relaxes faster. D) contracts faster and relaxes more slowly. E) contracts and relaxes more slowly.

E

Connective tissue that surrounds an entire muscle is called A) endomysium. B) perimysium. C) sarcolemma. D) sarcomere. E) epimysium

E

Cyclic AMP often causes activation of a. calcium ion channels b. myosin kinase c. phosphodiesterase d. protein kinases e. steroids

E

Endocrine organs can be controlled by a. hormones from other endocrine glands b. releasing hormones from the hypothalamus c. direct neural stimulation d. A and C only e. all of the above

E

Generally, the actions of hormones A) tend to be more widespread than actions of the nervous system. B) are longer lasting than actions of the nervous system. C) are slower to react than the nervous system. D) cause changes in the machinery of the cells. E) all of the above

E

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Which of the following statements describes how muscles help maintain homeostasis? A) The contractions of skeletal muscles pull on tendons and move elements of the skeleton. B) Skeletal muscles are responsible for guarding the openings of the digestive and urinary tracts. C) Skeletal muscles are responsible for the pumping action of the heart. D) Skeletal muscles support the weight of some internal organs. E) Skeletal muscle contractions help maintain body temperature.

e

Increasing the frequency of stimulation so that a muscle contracts without relaxation is called A) tetany. B) a twitch. C) relaxation. D) recovery. E) recruitment

A

The enzyme acetylcholinesterase causes acetylcholine to A) decompose. B) synthesize. C) bond to actin. D) be secreted. E) form cross-bridges.

A

Decreasing tension in a muscle due to lowering levels of ATP is called A) muscle fatigue. B) the conduction of neural information to the muscle fiber. C) muscle contraction. D) muscle relaxation. E) the striped appearance of skeletal muscle.

A

Glycolysis A) refers to the process of anaerobic respiration. B) can replace ATP in binding to myosin molecules during contraction. C) acts as the only source of ATP in muscle tissue. D) is only active during strenuous exercise. E) can usually make enough ATP for skeletal muscle function

A