Lecture Exam 2 quiz 4-6 questions

ch.7 Which of the following statements is FALSE? Atrophy may result when muscles are not regularly stimulated. A motor unit is a single motor neuron and all the muscle fibers it innervates. Muscle tone exists when muscles contract with no movement. The more muscle fibers a motor unit contains, the finer the movement.

The more muscle fibers a motor unit contains, the finer the movement.

ch.10 The posterior pituitary gland stores follicle-stimulating hormone (FSH). thyroid-stimulating hormone (TSH) .oxytocin (OT). adrenocorticotropic hormone (ACTH). melanocyte-stimulating hormone (MSH).

.oxytocin (OT).

ch.7 Which of the following statements is true concerning motor units? Lesser tension is required in lifting a dumbbell than in lifting a cup of coffee. A small number of muscle fibers with increased tension is needed in large, gross movements Movement of the eyeball requires fewer muscle fibers with less tension being produced. A motor unit consists of all the muscle fibers it controls as well as the area of the spinal cord where it originates. An increased number of motor neurons is needed in precise movements such as lifting a cup of coffee than in lifting a dumbbell.

Movement of the eyeball requires fewer muscle fibers with less tension being produced.

ch.8 Oligodendrocytes are to CNS as ________ are to PNS. Schwann cells astrocytes microglia satellite cells

Schwann cells

ch.7 Which of the following statements describes how muscles help maintain homeostasis? Skeletal muscle contractions help maintain body temperature. Skeletal muscles are responsible for the pumping action of the heart. The contractions of skeletal muscles pull on tendons and move elements of the skeleton. Skeletal muscles support the weight of some internal organs. Skeletal muscles are responsible for guarding the openings of the digestive and urinary tracts.

Skeletal muscle contractions help maintain body temperature.

Ch.7 Which of the following pairs are mismatched? sarcolemma; plasma membrane T tubules; centrioles sarcoplasmic reticulum; smooth endoplasmic reticulum sarcoplasm; cytoplasm

T tubules; centrioles

ch.10 Which statement is true about the adrenal glands? The main hormone of the adrenal medulla is norepinephrine. The adrenal cortex is most important in the control of sodium, potassium, and glucose blood levels. The adrenal cortex regulates the adrenal medulla. The adrenal androgen hormones are found only in males. The hormones of the adrenal cortex rely on control by the autonomic nervous system.

The adrenal cortex is most important in the control of sodium, potassium, and glucose blood levels.

Ch.7 Myasthenia gravis is a disease resulting from an autoimmune attack on the ACh receptors of the motor end plate. Binding of antibodies to the ACh receptors results in generalized muscle weakness that progresses as more ACh receptors are destroyed. Which of the following medications would help alleviate the muscle weakness? a drug that binds to and inactivates acetylcholinesterase (neostigmine) a drug that blocks the release of acetylcholine (botulinum toxin) a drug that binds to the acetylcholine receptor and prevents it from opening (curare) a drug that prevents acetylcholine from being loaded into synaptic vesicles (vesamicol)

a drug that binds to and inactivates acetylcholinesterase (neostigmine)

ch.8 Recall that a single axon of a motor neuron may branch to control more than one skeletal muscle fiber (as you saw in Chapter 7: The Muscular System). Each branch ends in an axon terminal that is part of a neuromuscular junction. Each skeletal muscle fiber has only one neuromuscular junction. A motor unit is a single motor neuron and all the muscle fibers it innervates. What is the name of the neurotransmitter released by a neuron to communicate with skeletal muscle cells at the neuromuscular junction? tropomyosin actin myosin acetylcholine

acetylcholine

ch.8 Which of the following neurotransmitters usually depolarizes postsynaptic neurons? serotonin dopamine acetylcholine monoamine oxidase GABA

acetylcholine

ch. 10 What can be seen surrounding the outside of the stomach in the human model of the internal organs? the pancreas. adipose tissue the adrenal gland. the parathyroid gland. the thyroid gland.

adipose tissue

ch.8 The ________ division of the nervous system brings sensory information to the central nervous system. motor afferent efferent descending spinal

afferent

ch.8 The part of the peripheral nervous system that brings information to the central nervous system is the efferent division .motor division. afferent division. autonomic division. somatic division.

afferent division.

ch.8 Interneurons are found between neurons and their effectors. carry only sensory impulses. only connect motor neurons to other motor neurons. are found only in the central nervous system. carry only motor impulses.

are found only in the central nervous system.

ch.8 The glial cells responsible for maintaining the blood-brain barrier are the astrocytes. Schwann cells. satellite cells. microglia .ependymal cells.

astrocytes.

ch.8 A few spiders produce a venom that is a calcium-channel blocker. Where would this venom have on nerve impulse transmission? at the axon hillock at the postsynaptic membrane at the axon terminal along the dendrite along the cell body membrane

at the axon terminal

ch.7 The ________ contains vesicles filled with acetylcholine. neuromuscular junction transverse tubule motor end plate axon terminal synaptic cleft

axon terminal

ch.10 The release of parathyroid hormone is controlled by the hypothalamus .thyroid hormone. blood calcium ion levels. cellular oxygen consumption. TSH.

blood calcium ion levels.

ch.10 Parathyroid hormone stimulates the kidneys to form renin. calcitriol. calcitonin. ADH. triiodothyronine.

calcitriol.

Ch. 7 Upon death, circulation ceases, depriving skeletal muscles of nutrients and oxygen. Within a few hours, skeletal muscle fibers run out of ATP. Without ATP, the cross-bridges cannot detach from the active sites, and all of the body's muscles lock in a contracted position called rigor mortis. What crucial ion must bind to troponin in order for actin and myosin to form a cross bridge? sodium ions calcium ions potassium ions tropomyosin

calcium ions

ch.8 Unlike neurons, neuroglia are ________. capable of cell division only found in the CNS very large cells not very numerous

capable of cell division

ch.10 Cells of the adrenal cortex produce parathyroid hormone. corticosteroids. ADH. insulin. epinephrine.

corticosteroids.

ch.8 Opening of voltage-gated sodium channels in the membrane of a neuron results in repolarization. depolarization. myelination. increased negative charge inside the membrane .hyperpolarization.

depolarization

ch.8 Changes in the membrane potential that cannot spread far from the site of stimulation are called ________. graded potentials action potentials threshold hyperpolarization refractories

graded potentials

ch.10 What are chemical messengers that affect target cells? hormones neurotransmitters enzymes endocrine

hormones

ch.7 Which of the following occurs when tension production rises to a peak and very brief periods of relaxation occur? latency complete tetanus incomplete tetanus resting period tension plateau

incomplete tetanus

Ch.7 Glycolysis is the breakdown of pyruvate to glucose .occurs in the nucleus. acts as the only source of ATP in muscle tissue .is an anaerobic process. is only active during rest.

is an anaerobic process.

ch.8 Saltatory conduction occurs at the synapse. produces a stronger action potential. is faster than conduction on an unmyelinated axon. occurs only if the myelin sheath is continuous. occurs only if nodes of Ranvier are lacking.

is faster than conduction on an unmyelinated axon.

ch.10 The hormone oxytocin governs the ovarian cycle regulates blood pressure. reduces uterine contractions. stimulates melanocytes in the skin is involved in the milk "letdown" reflex.

is involved in the milk "letdown" reflex.

ch.10 The hormone responsible for daily changes in physiological processes that follow a day-night pattern is corticosteroid .aldosterone .melatonin. thyroxine. melanin.

melatonin

ch.10 Which hormone is NOT matched with its function? insulin: lowering blood glucose levels prolactin: producing milk melatonin: producing skin color ADH: water reabsorption by the kidneys

melatonin: producing skin color

Ch.7 Exhaustion of energy reserves or decline in pH due to production and dissociation of lactic acid causes muscle fatigue. muscle relaxation. the striated appearance of skeletal muscle. the conduction of neural information to the muscle fiber. muscle contraction.

muscle fatigue

ch.7 On a skeletal muscle fiber, what is the cylindrical shaped structure that is made out of thick and thin filaments? T tubule. sarcomere. myosin head. myofibril. myofilament.

myofibril.

ch.7 Recall that neurons communicate through electrical events that affect their plasma membranes (as we saw in Chapter 4: The Tissue Level of Organization). These events also occur in the sarcolemma of skeletal muscle fibers. What kind of nervous cells provide support to neurons? fibroblasts dendrites neuroglia axon

neuroglia

ch.8 Adrenergic synapses release the neurotransmitter serotonin. norepinephrine. GABA. acetylcholine. dopamine.

norepinephrine.

ch.10 The effect of prolactin closely interacts with the hormone... calcitonin melatonin. oxytocin. renin. ADH.

oxytocin.

ch.10 The hormone that inhibits osteoblasts is glucagon. thyroid hormone. parathyroid hormone. insulin. growth hormone.

parathyroid hormone.

ch.7 What phase of tension development occurs on the downward slope? latent period resting phase relaxation phase contraction phase

relaxation phase

Ch.7 The terminal cisternae are structural features of the sarcolemma. sarcoplasmic reticula. myofibrils. I bands. myofilaments.

sarcoplasmic reticula.

ch.8 Which of the following provides control over skeletal muscles? parasympathetic nervous system somatic nervous system afferent division autonomic nervous system

somatic nervous system

ch.7 Recall that the most important high-energy compound in the body is adenosine triphosphate (ATP) (as you saw in Chapter 2: The Chemical Level of Organization). ATP is made up of the nucleotide adenosine monophosphate (AMP) and two phosphate groups. What is the function of ATP? catalyst for metabolic reactions, structural components, movement, transport, buffers, defense, and control/coordination of activities as a solvent, transport medium for dissolved materials, heat for cooling through evaporation, as medium for chemical reactions, and reactant in hydrolysis storage or transfer of energy storage and processing of genetic information

storage or transfer of energy

ch.10 what endocrine gland is in between the thyroid/parathyroid glands and the heart? the thymus. the pancreas. the parathyroid gland. adipose tissue. the adrenal gland.

the thymus.

ch.10 Hypothalamic signals reach the anterior pituitary through the hypophysis. hypophyseal portal system. thymus hypothalamic axons infundibulum.

thymus

ch.10 Disorders associated with thyroid hormone excess have symptoms related to weight loss. slow heartbeat .excess pigmentation of the skin .diabetes. weight gain.

weight loss.

ch.8 Which statement is true regarding action potential propagation? In salutatory conduction, the myelin is composed of fat, which insulates the axon membrane against sodium ion flow across the membrane. Continuous propagation results in one graded potential producing multiple action potentials. The active transport of sodium and potassium through sodium-potassium ion pumps causes depolarization of the axon membrane. All voltage-gated channels along the axon open at the same time, allowing sodium to flow in simultaneously. The action potential will die out along the axon if another graded potential does not occur.

In salutatory conduction, the myelin is composed of fat, which insulates the axon membrane against sodium ion flow across the membrane.