MCQ Flashcards
Which of the following cell types produce testosterone in the male?
Select one:
a. Glomerulosa cells
b. Leydig cells
c. Thecal cells
d. Sertoli cells
B
Sperm develop from stem cells called
Select one:
a. spermatogonia
b. spermatozoa
c. secondary spermatocytes
d. primary spermatocytes
e. spermatids
A
The process of spermiogenesis produces
Select one:
a. spermatozoa
b. primary spermatocytes
c. spermatids
d. spermatogonia
e. secondary spematocytes
A
When in spermatogenesis and/or oogenesis does “crossing over” of the chromosomes occur?
Select one:
a. Upon fertilization
b. During meiosis I
c. During meiosis II
d. during mitosis
B
The hormones produced by the corpus luteum include:
Select one:
a. Progesterone
b. GnRH
c. LH
d. FSH
A
The hormones most responsible for the LH surge and ovulation in a normal woman are:
Select one:
a. GnRH and inhibin
b. Estradiol and GnRH
c. Activin and inhibin
d. Estradiol and progesterone
B
At what time is the second meiotic division of oogenesis completed in the human female?
Select one: a. Upon ovulation b. After menopause c. Upon fertilisation d. Prior to birth Feedback
C
On day 21 of the female reproductive cycle, how do the following hormones change?
Estradiol Progesterone FSH LH Inhibin
Select one:
a. ↑ ↑ ↓ ↓ ↑
b. ↑ ↑ ↑ ↓ ↓
c. ↑ ↓ ↓ ↓ ↑
d. ↓ ↑ ↓ ↓ ↑
A
The surge in luteinizing hormone that occurs during the middle of the ovarian cycle triggers
Select one:
a. ovulation
b. atresia
c. monopause
d. follicle maturation
e. menstruation
A
A rise in the blood levels of follicle-stimulating hormone at the beginning of the ovarian cycle is responsible for
Select one:
a. ovulation
b. follicle maturation
c. mentruation
d. menopause
e. atresia
B
The principal hormone secreted by the corpus luteum is
Select one:
a. FSH
b. estrogen
c. LH
d. progesterone
e. luteosterone
D
Which of the following is true regarding hormone binding to plasma proteins?
Select one:
a. It increases hormonal activity
b. it increases the half-life of the hormone
c. It is uncommon for steroid hormones
d. It is uncommon for thyroid hormones
e. It increases in the plasma clearance of the hormone
B
Which of the following peptide-second messengers are incorrectly paired?
Select one:
a. Glucagon:cAMP
b. Insulin:cAMP
c. TSH:AMP
d. ACTH:cAMP
e. ADH (V2 receptor):cAMP
B
Which of the following statements about peptide or protein hormones is usually true?
Select one:
a. They have receptors on the cell membrane
b. They have longer half-lives than steroid hormones
c. They are not highly stored in endocrine producing glands
d. They have a slower onset of action than both steroid and thyroid hormones
A
Which of the following hormones does not activate G protein-linked receptors when producing its predominate physiological effects?
Select one:
a. ACTH
b. ADH
c. TSH
d. Aldosterone
e. Glucagon
D
Which of the following regarding T4 is false?
Select one:
a. Secretion rate from thyroid is decreased by propylthiouracil
b. Peripheral deiodination is the major source of circulating T3
c. Plasma concentration is less than that of T3
d. A. Secretion rate from thyroid exceeds that of T3
C
A patient has uncontrolled type I diabetes. Which of the following is likely to be present?
Select one:
a. Decreased rate of lipolysis
b. Decreased plasma osmolality
c. Increased plasma volume
d. Increased release of glucose from the liver
e. Increased plasma pH
D
Which of the following are incorrectly paired?
Select one:
a. Epinephrine: increased glycogenolysis in muscle
b. Glucagon: increased glycogenolysis in liver
c. Insulin: increased gluconeogenesis in liver
d. Epinephrine: increased glycogenolysis in liver
e. Cortisol: decreased glucose uptake in muscle
C
Which of the following statements about hormone activation is true?
Select one:
a. Conversion of testosterone to estradiol is an example of hormone activation
b. Prohormones are inactive messengers that must undergo conversion to an active form at their site of production
c. Both prohormones are inactive messengers that must undergo conversion to an active form at their site of production and conversion of testosterone to estradiol is an example of hormone activation are true
d. Conversion of T3 to T4 is an example of hormone activation
e. Both prohormones are inactive messengers that must undergo conversion to an active form at their site of production and conversion of T3 to T4 is an example of hormone activation are true
C
The main difference between the modes of action of peptide hormones and steroid hormones is that
Select one:
a. Peptide hormones bind to receptors in the nucleus whereas steroid hormones bind to receptors in the cytosol
b. Peptide hormones bind to receptors on the cell surface whereas steroid hormones bind to intracellular receptors
c. Peptide hormones bind to intracellular receptors whereas steroid hormones bind to receptors on the cell surface
d. Peptide hormones bind to receptors on the cell surface whereas steroid hormones act as second messengers
e. There are no differences; both act by binding to receptors on the cell surface
B
Receptors for steroid hormones
Select one:
a. Are proteins in the nucleus and/or cytoplasm
b. Undergo allosteric modulation when they bind to the hormone
c. Regulate gene transcription
d. Both are proteins in the nucleus and/or cytoplasm and regulate gene transcription are correct
e. All of the choices are correct
E
Hormones known as “catecholamines” are
Select one:
a. derivatives of the amino acid tyrosine
b. steroids
c. peptides
d. lipids
e. derivatives of the reproductive glands
E
A kinase is an enzyme that performs
Select one:
a. active transport
b. as a membrane channel
c. protein synthesis
d. phosphorylation
e. as an antibody
D
When a catecholamine or peptide hormone binds to receptors on the surface of a cell, the
Select one:
a. hormone is transported to the nucleus where it alters the activity of DNA.
b. hormone receptor complex moves into the cytoplasm
c. cell membrane becomes depolarized.
d. second messenger appears in the cytoplasm
e. cell becomes inactive
D
After a steroid hormone binds to its receptor to form an active complex
Select one:
a. cyclic nucleotides are formed
b. adenyl cyclase if activated
c. G proteins are phsophorylated
d. protein kinases are activated
e. gene transcription is initiated
E
The pituitary hormone that controls the release of glucocorticoids from the suprarenal cortex is
Select one:
a. ACTH
b. FSH
c. LH
d. GH
e. TSH
A
The pituitary hormone that causes the kidney to reduce water loss is
Select one:
a. FSH
b. TSH
c. ADH
d. STH
e. MSH
C
Which of the following elements is necessary for the production of thyroid hormone?
Select one:
a. iodine
b. potassium
c. colloid
d. iron
e. sodium
A
The median eminence of the hypothalamus is
Select one:
a. A major link connecting the nervous system and the endocrine system
b. A site of neurohormone release into blood vessels and a major link connecting the nervous system and the endocrine system
c. A site of neurohormone release into blood vessels
d. The site of synthesis of ACTH and a site of neurohormone release into blood vessels
e. The site of synthesis of ACTH
Feedback
B
The gonadotropic hormones
Select one:
a. Stimulate hormone secretion by the gonads
b. Are secreted by the anterior pituitary gland of both males and females
c. Are LH and prolactin
d. Both stimulate hormone secretion by the gonads and are secreted by the anterior pituitary gland of both males and females are correct
e. All of the choices are correct
D
A subject consuming a diet deficient in iodine is likely to have
Select one:
a. A low plasma concentration of thyroxine and an enlarged thyroid gland and a high plasma concentration of TSH
b. A high plasma concentration of TSH
c. A low plasma concentration of thyroxine and an enlarged thyroid gland
d. A low plasma concentration of thyroxine due to reduced secretion of TSH by the pituitary gland and a low plasma concentration of thyroxine and an enlarged thyroid gland
e. A low plasma concentration of thyroxine due to reduced secretion of TSH by the pituitary gland
A
Deficiency of iodine in the diet results in a goiter (an enlarged thyroid gland). Which of the following statements offers the best explanation for this phenomenon?
Select one:
a. The thyroid enlarges so that it can secrete more thyroid hormones to compensate for the lack of iodine
b. Decreased plasma iodine levels are detected by the hypothalamus, which stimulates the anterior pituitary to secrete more thyroid stimulating hormone
c. Without iodine, the thyroid gland cannot produce thyroid hormones. Thyroid hormones normally act as a negative-feedback signal for the hypothalamus and pituitary gland. Loss of this signal results in excessive secretion of thyroid stimulating hormone
d. All of the choices are correct
e. None of the choices are correct
C
Prolonged changes in neuronal activity are achieved through the activation of:
Select one:
a. A. Voltage gated chloride channels
b. G-protein coupled channels
c. Transmitter gated sodium channels
d. Voltage gated potassium channel
B
In a neuron with a resting membrane potential of -65 mV, the distribution of which ion across the neuronal membrane represents the greatest potential electromotive force (EMF)?
Select one:
a. Calcium
b. Sodium
c. Potassium
d. Chloride
B
The opening of which of the following ion channels would have the least effect on the resting membrane potential of an average neuron?
Select one:
a. Potassium
b. Chloride
c. Sodium
d. The opening of any of the above ion channels would effect the resting membrane potential to a similar degree
B
An excitatory postsynaptic potential (EPSP):
Select one:
a. Results from the opening of potassium channels
b. Results from the opening of calcium channels
c. Results from the simultaneous opening of sodium and chloride channels
d. Results from the opening of sodium channels
D
An inhibitory postsynaptic potential (IPSP):
Select one:
a. Results from the opening of voltage-gated sodium channels
b. Results from the opening of sodium channels
c. Results from the opening of voltage-gated calcium channels
d. Results from the opening of potassium channels
D
Which of the following statements best describes the role of calcium in the release of a neurotransmitter substance from the presynaptic nerve terminal?
Select one:
a. Calcium entry into the presynaptic terminal results in the formation of cAMP which induces a conformational change in the presynaptic sodium channel that leads to the release of neurotransmitter
b. Calcium induces the opening of calcium-dependant sodium channels on the presynaptic terminal
c. Calcium entry into the presynaptic terminal prevents the release of the neurotransmitter
d. Calcium entry into the presynaptic terminal is necessary for the release of the neurotransmitter
D
Which of the following neurotransmitters is thought to be involved in the phenomenon of presynaptic inhibition?
Select one:
a. GABA
b. Acetylcholine
c. Norepinephrine
d. Serotonin
A
Which of the following statements regarding sensory systems is correct?
Select one:
a. Both all sensory information that reaches the brain can be experienced as a conscious sensation and the term, “sensory unit,” refers to a group of receptors that receive a particular stimulus and the afferent neuron associated with those receptors are correct
b. All sensory information that reaches the brain can be experienced as a conscious sensation
c. Sensory information that leads to conscious awareness of the stimulus is called a sensation
d. The term, “sensory unit,” refers to a group of receptors that receive a particular stimulus and the afferent neuron associated with those receptors
e. Both sensory information that leads to conscious awareness of the stimulus is called a sensation and the term, “sensory unit,” refers to a group of receptors that receive a particular stimulus and the afferent neuron associated with those receptors are correct
E
This part of the brain is thought to control the various states of consciousness
Select one:
a. Cerebellum
b. Cerebral cortex
c. Reticular activating system
d. Hippocampus
e. Thalamus
E
Regarding its role as a neurotransmitter in the CNS, noradrenaline
Select one:
a. Is secreted by brain stem neurons in response to sensory stimulation
b. Amplifies weak sensory signals and dampens strong ones so that more information can reach conscious levels
c. Is important for maintaining directed attention
d. Both is secreted by brain stem neurons in response to sensory stimulation and is important for maintaining directed attention are correct
e. All of the choices are correct
D
Drugs that are used to treat depression increase the levels of this neurotransmitter in the brain
Select one:
a. Acetylcholine
b. GABA
c. Dopamine
d. Glutamine
e. Serotonin
E
Regarding psychoactive drugs,
Select one:
a. They can be taken to relieve altered states of consciousness
b. They can be taken to experience altered states of consciousness
c. They may stimulate neuronal activity in the “reward” areas of the brain
d. Both they can be taken to experience altered states of consciousness and they may stimulate neuronal activity in the “reward” areas of the brain are correct
e. All of the choices are correct
E
A person with bilateral damage to the hippocampus will probably
Select one:
a. Experience all of the choices
b. Suffer from aphasia
c. Have difficulty learning new physical skills
d. Suffer impairment of consolidation of declarative memory
e. Develop symptoms of Parkinson’s disease
D
Damage to which of the following brain structures is most likely to result in difficulty in being able to remember meeting new people?
Select one:
a. Thalamus
b. Corpus callosum
c. Hypothalamus
d. Hippocampus
e. Broca’s area
D
Damage to that part of the brain known as Wernicke’s area is likely to
Select one:
a. Impair comprehension of language
b. Cause blindness
c. Cause difficulty in recognizing faces
d. Be associated with impairment of procedural memory
e. Impair one’s ability to speak
A
Damage to that part of the brain known as Broca’s area is likely to
Select one:
a. Be associated with paralysis on the left side of the body
b. Both be associated with paralysis on the left side of the body and impair speech are correct
c. Impair speech
d. Both cause difficulty in recognizing faces and be associated with paralysis on the left side of the body are correct
e. Cause difficulty in recognizing faces
C
The ________ nervous system is composed of the brain and spinal cord
Select one:
a. peripheral
b. central
c. efferent
d. afferent
e. autonomic
B
The ________ nervous system controls the skeletal muscles
Select one: a. sympathetic b. parasympathetic c. autonomic d. afferent e. somatic Feedback
E
The part of the peripheral nervous system that carries sensory information to the CNS is designated
Select one:
a. efferent
b. afferent
c. autonomic
d. motor
e. somatic
B
he efferent division of the peripheral nervous system innervates:
Select one:
a. skeletal muscle cells
b. smooth muscle cells
c. heart muscle cells
d. glandular cells
e. all of the answers are correct
E
The most abundant class of neuron in the central nervous system is
Select one:
a. anaxonic
b. bipolar
c. multipolar
d. unipolar
e. pseudopolar
C
Axons terminate in a series of fine extensions known as
Select one:
a. dendrites
b. telodendria
c. synapses
d. terminals
e. collaterals
B
The site of intercellular communication between a neuron and another cell is the
Select one:
a. telodendria
b. synaptic terminals
c. hillock
d. collateral
e. synapse
E
Neurons that have one axon and one dendrite, with the soma in between, are called
Select one: a. multipolar b. bipolar c. anaxomic d. triploar e. unipolar Feedback
B
Neurons that have several dendrites and a single axon are called
Select one:
a. anaxomic
b. mulipolar
c. unipolar
d. triploar
e. bipolar
B
Sensory neurons of the PNS are
Select one:
a. anaxomic
b. multiploar
c. unipolare
d. bipolar
e. tripolar
C
Which of the following is not a function of the neuroglia?
Select one:
a. memory
b. maintenance of blood-brain barrier
c. secretion of cerebrospinal fluid
d. support
e. phagocytosis
A
Which of the following is a type of glial cell found in the peripheral nervous system?
Select one:
a. satellite cells
b. ependymal
c. microglia
d. astrocytes
e. oligodendrocytes
A
The neuroglial cells that participate in maintaining the blood-brain barrier are the
Select one:
a. Schwann cells
b. ependymal cells
c. astrocytes
d. oligodendrocytes
e. microglia
C
The myelin sheath that covers many CNS axons is formed by
Select one:
a. satellite cells
b. ependymal
c. astrocytes
d. oligodendrocytes
e. microglia
D
________ line the brain ventricles and spinal canal.
Select one:
a. ependymal cells
b. astrocytes
c. satellite cells
d. microglia
e. oligodendrocytes
A
Small, wandering cells that engulf cell debris and pathogens in the CNS are called
Select one:
a. satellite cells
b. oligodendrocytes
c. astrocytes
d. microglia
e. ependymal cells
D
Ion channels that are always open are called ________ channels.
Select one:
a. local
b. active
c. gated
d. regulated
e. leak
E
Opening of sodium channels in the axon membrane causes
Select one:
a. increased negative charge inside the membrance
b. depolarization
c. repolarization
d. hyperpolarization
e. inhibition
B
The sodium-potassium ion exchange pump
Select one:
a. transports sodium ions into the cell during depolarization.
b. depends on a hydrogen gradient for energy.
c. must reestablish ion concentrations after each action potential
d. moves sodium and potassium opposite to the direction of their electrochemical gradients.
e. transports potassium ions out of the cell during repolarization.
D
The equilibrium potential for potassium ion occurs at approximately
Select one:
a. -70 mV
b. 0 mV
c. +30 mV
d. -90 mV
e. +60 mV
D
________ open or close in response to binding specific molecules.
Select one:
a. Activated channels
b. Voltage-gated channels
c. Chemically-gated channels
d. Voltage-gated and chemically-gated channels
e. Leak channels
C
________ channels open or close in response to physical distortion of the membrane surface.
Select one:
a. Chemically-gated
b. Leak
c. Active
d. Mechanically-gated
e. Voltage-gated
D
If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur, except
Select one:
a. the neuron will slowly depolarize.
b. the intracellular concentration of sodium ions will increase.
c. the membrane will slowly lose its capacity to generate action potentials
d. the inside of the membrane will have a resting potential that is more positive than normal.
e. the intracellular concentration of potassium ions will increase
E
If the potassium permeability of a resting neuron increases above the resting permeability, what effect will this have on the transmembrane potential?
Select one:
a. The membrane will depolarize to threshold.
b. The membrane will become depolarized.
c. There will be almost no effect on transmembrane potential
d. The inside of the membrane will become more negative.
e. The inside of the membrane will become more positive.
D
Voltage-gated sodium channels have both an activation gate and a ________ gate.
Select one:
a. replarization
b. threshold
c. inactivation
d. ion
e. swinging
C
A stimulus that changes a postsynaptic neuron’s membrane from resting potential to -85 mV is:
Select one:
a. an exciting stimulus
b. a depolarizing stimulus
c. a saltatory stimulus
d. an inhibitory stimulus
e. a temporal stimulus
D
Which of the following statements about the action potential is false?
Select one:
a. In the after-hyperpolarization phase, membrane potential approaches the potassium equilibrium potential.
b. Repolarization occurs as potassium ions leave the axon.
c. During the depolarization phase, membrane potential becomes positive.
d. The rapid depolarization phase is caused by the entry of potassium ions.
e. During the repolarization phase, sodium channels close and potassium channels open.
Feedback
D
How would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactivate?
Select one:
a. It would last indefinitely
b. It would be basically unaffected
c. It would be much briefer
A
Type ________ fibers have the largest diameter axons.
Select one:
a. A
b. C
c. B
d. F
e. S
A
Rapid impulse conduction from “node” to “node” is called
Select one:
a. synaptic transmission
b. spatial propagation
c. saltatory propagation
d. divergent propagation
e. continuous propagation
C
A neuron that receives neurotransmitter from another neuron is called
Select one:
a. an interneuron
b. the postsynaptic neuron
c. the oligodendrocyte
d. the motor neuron
e. the presynaptic neuron
B
Which type of synapse is most common in the nervous system?
Select one:
a. electrical
b. processing
c. mechanical
d. radioactive
e. chemical
E