BCOR Exam Chaps 40, 45, 48, 50

Which of the following is a typical resting potential of a neuron?

-70 mV

An epithelial cell with a relatively large amount of cytoplasm probably has what function?

Absorption and secretion

Which hormone functions in both the body's stress response and in the maintenance of salt and water balance?

Aldosterone

The interplay of multiple excitatory and inhibitory inputs most affects what part of a neuron?

Axon hillock

How are neurons structurally adapted to chemically transmit impulses to neighboring neurons?

Axon terminals contain neurotransmitters within synaptic vesicles.

Vertebrate skeletal muscle contraction is regulated by ________ ions, which interact with ________ in muscle contraction.

Ca2+; the troponin complex

Which of the following lists of animal structures is ordered from smallest to largest?

Cell, tissue, organ, organ system

Which of the following is a benefit of multicellularity compared to organisms consisting of just one cell?

Cells can specialize.

Which of the following statements is an accurate description of external effects on hormones?

Certain molecules in the environment can function like hormones or block the actions of hormones.

Which of the following organ systems in mammals is mismatched with its function? Endocrine; coordination of body activities Nervous; coordination of body activities Muscular; locomotion and other movements Excretory; disposal of metabolic wastes Circulatory; coordination of body activities Digestive; food processing

Circulatory; coordination of body activities

Acetylcholinesterase is the enzyme that degrades acetylcholine. What effect on nerve transmission would occur following the administration of a chemical that inhibited acetylcholinesterase?

Continuous excitatory postsynaptic potentials would occur in the postsynaptic neuron.

Which of the following correctly traces the path of light into your eyes?

Cornea→ pupil→ lens→ retina

Which of the following systems is correctly paired with one of its parts? Circulatory system; lung Integumentary system; kidneys Excretory system; intestine Endocrine system; thyroid gland Respiratory system; heart

Endocrine system; thyroid gland

Which of the following neurotransmitters typically has inhibitory effects?

GABA

Why is having a hydrostatic skeleton, rather than an internal skeleton, advantageous to an earthworm?

Having a hydrostatic skeleton allows the earthworm to use peristaltic motion to move over the substrate.

How is the level of thyroxine in the blood regulated?

High levels of T3 and T4 inhibit the secretion of TRH and TSH.

Which of the following statements is an accurate description of the function of hormones in homeostasis?

Homeostasis in humans is maintained by many of the same hormones that have regulatory roles in other animals.

Which of the following statements is an accurate description of the regulation of the endocrine system?

Hormone pathways are regulated by both positive- and negative-feedback loops.

Which of the following statements correctly describes a difference between hormone signaling and neuron signaling?

Hormone signals travel throughout the body, but neuron signals travel to specific locations.

All else remaining constant, which of the following would constitute hyperpolarization of a neuron at rest?

Increasing Na+ outside of the cell

Which of the following statements about the resting potential is true?

Inside the cell, the concentration of potassium is much higher than the concentration of sodium.

Which of the following is a pair of hormones that have antagonistic effects? Epinephrine and norepinephrine Triiodothryronine (T3) and thyroxine (T4) Insulin and glucagon Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) Prolactin and oxytocin

Insulin and glucagon

Which of the following conditions in a silkworm moth would result in metamorphosis from pupa to adult?

Low concentration of juvenile hormone and high concentration of ecdysteroid

Which of the following is not a tropic hormone? Follicle-stimulating hormone (FSH) Thyroid-stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) Melanocyte-stimulating hormone (MSH) Luteinizing hormone (LH)

Melanocyte-stimulating hormone (MSH)

__________ feedback most directly maintains homeostasis because it __________.

Negative; tends to keep a system at a desirable "set point"

What is the relationship between neurons and nerves?

Nerves are comprised of neurons.

Which of the following is a pair of hormones that function to regulate blood calcium in mammals?

Parathyroid hormone and calcitonin

Which disorder is correctly matched with its cause? Acromegaly; hyposecretion of growth hormone Acromegaly; hypersecretion of thyroxine Diabetes mellitus; hypersecretion of insulin Diabetes mellitus; hyposecretion of glycogen Pituitary dwarfism; hyposecretion of growth hormone

Pituitary dwarfism; hyposecretion of growth hormone

Where would a ligand-gated ion channel typically be found on a neuron?

Postsynaptic membrane

What is the relationship between membrane potential and resting potential?

Resting potential is the membrane potential of a neuron that is at rest.

Which of the following statements correctly describes the differences between simple squamous cells and stratified squamous cells?

Simple squamous cells form a single layer, which is useful for gas exchange, and stratified squamous cells are multilayered and regenerate rapidly.

Which of the following statements is incorrect regarding muscle tissue? Skeletal muscle consists of cells that each have a single nucleus. Cardiac muscle is striated. Cardiac muscle contains intercalated disks. Smooth muscle is not striated. Skeletal muscle consists of cells with multiple nuclei.

Skeletal muscle consists of cells that each have a single nucleus.

Which of the following statements is an accurate description of neurotransmitters? Once released from the synaptic terminal, neurotransmitters are permanently lost from the neuron. Each type of neurotransmitter receptor binds only a single molecule. There are fewer than a dozen different neurotransmitters. Neurotransmitters all act by triggering a depolarization of membrane potential. Some neurotransmitters can bind to multiple different types of receptors.

Some neurotransmitters can bind to multiple different types of receptors.

An autocrine signal produced by a T cell has an effect on a _____________.

T cell

Which of the following pairs of connective tissue and its function is correctly matched? Ligaments; attach muscles to bones Tendons; attach muscles to bones Bone; pads and insulates the body Tendons; attach muscles to other muscles Adipose tissue; connects epithelia to underlying tissue

Tendons; attach muscles to bones

How does the hypothalamus control the secretion of growth hormone (GH) from the anterior pituitary?

The hypothalamus produces a releasing hormone that stimulates the pituitary to secrete GH.

What governs the opening of the potassium channels, which establish the resting membrane potential in the plasma membrane of a neuron?

The potassium channels are always open.

Which of the following statements is an accurate description of sex hormones? Production of the sex hormones is triggered by tropic hormones released by the gonads. In the complete absence of estrogen, a human will develop as a male. The sex hormones have effects on tissues other than those comprising the reproductive system. Androgens, such as testosterone, are present only in males, and estrogens, such as estradiol, are present only in females. The sex hormones first begin functioning during puberty to regulate development.

The sex hormones have effects on tissues other than those comprising the reproductive system.

Where in the body would you be most likely to find secretory cells shaped like dice?

Thyroid and salivary glands

Which type of transmembrane protein is directly responsible for maintaining the propagation of action potentials across an axon once it has been initiated?

Voltage-gated sodium channels

Which of the following characteristics is likely to be found in larger versus smaller animals?

a highly branched respiratory system

In regard to its role in the endocrine system, nitric oxide (NO) is best described as ______________.

a local regulator

Action potentials differ from graded potentials in that __________.

action potentials are all of the same magnitude

A sensory receptor is best described as a(n) ___________.

afferent neuron

An organ such as the heart or liver consists of __________. All of the listed responses are correct. connective tissue muscle tissue epithelial tissue nervous tissue

all of the listed responses are correct

As a young girl, Maria suffered a head injury that damaged her pituitary. An injury to the pituitary is particularly serious because of all the functions controlled by this gland. As Maria got older, she and her doctors found that all of the following except her __________ were affected.

blood sugar level

Which of the six major types of connective tissue has a rigid matrix that contains collagen and calcium salts?

bone

Ligaments connect ________ to ________.

bone to bone

Microscopic analysis of an unknown tissue sample reveals the presence of chondrocytes, indicating that the sample was probably taken from __________ tissue.

cartilage

A neuron receives nerve impulses from other neurons via its _________ and __________.

cell body; dendrites

Blocking potassium ion channels in a mammalian cell membrane would __________.

decrease the magnitude of the membrane potential

The part(s) of a neuron that receive(s) signals is/are the ____________.

dendrites

Which of the following is a natural pain reliever?

endorphins

An organism that generates body heat by means of its own metabolism is _________, and an organism that gains body heat from external sources is ________.

endothermic; ectothermic

Which of the following hormones is thought to act at the cellular level by inducing a change in gene expression?

estrogen

FSH (follicle-stimulating hormone) and LH (luteinizing hormone) are tropic hormones that are also known as __________.

gonadotropins

The neurotransmitter nitric oxide (NO) ____________.

has more than one target in the body

The brain region that most directly integrates the endocrine and nervous systems in mammals is the __________.

hypothalamus

During a fever, the __________ readjusts the set point of the body to a __________ temperature.

hypothalamus; higher

In insects, ecdysteroid is released __________.

in response to prothoracicotropic hormone

A drug that causes potassium to leak out of a neuron, increasing the positive charge on the outside, would __________.

inhibit transmission of nerve signals by the neuron

Every time you eat a cookie or candy bar, your blood sugar increases. This triggers an increase in the hormone __________.

insulin

Which of the following is specifically a part or a function of the central nervous system?

integration

Humid weather makes you feel warmer because humid air, which is saturated with water molecules, __________.

interferes with heat loss by evaporation

The body uses the vitamin A precursors from some foods to make a substance called retinal, which __________.

is a visual pigment that absorbs light

Type 1 diabetes mellitus __________.

is an autoimmune disease in which the immune system attacks beta cells in the pancreas

Any signaling molecule referred to as a neurohormone __________.

is produced by a neuron

The major tropic action of growth hormone is to signal the ________ to release _________.

liver; insulin-like growth factors (IGFs)

A goiter may form because __________.

low blood levels of T3 and T4 inhibit the negative feedback loop, and an overload of TSH causes enlargement of the gland

Schwann cells make up the __________.

myelin sheath in PNS

When a person's body temperature increases, sweating helps bring the temperature down. This is an example of __________.

negative feedback

The __________ system and the __________ system work together to coordinate and control the bodies of most animals.

nervous; endocrine

"Saltatory conduction" means that the membrane potential changes __________.

only at the nodes of Ranvier

Because of the __________, the visual fields of each human eye are transmitted to the __________ sides of the brain.

optic chiasm; opposite

A cell releases a cytokine, which binds to, and acts on, a neighboring cell. This represents an example of __________.

paracrine signaling

In blood, the matrix component is ________, and the cellular component contains _________.

plasma; red and white blood cells

Threshold is of great significance in the physiology of neurons because if threshold is not reached, __________

positive-feedback depolarization will not occur

In descriptions of synapse organization, the __________ cell is the transmitting neuron and the __________ is the neuron, muscle, or gland cell that receives the signal.

presynaptic; postsynaptic

Which of the following functions as a local regulator? Estrogen Testosterone Melatonin Epinephrine Prostaglandin

prostaglandin

Ibuprofen is known for its pain-relieving and anti-inflammatory properties because it inhibits the synthesis of __________.

prostaglandins

Myosin and actin are __________.

proteins that play a major role in muscle contraction

The brain determines the loudness of a sound from the __________.

rate of nerve impulses received

Glial cells function in which of the following roles?

regulating extracellular fluid around some neurons Transmitting signals Insulating axons of neurons Nourishing neurons

You look all over for your glasses and then find them pushed back onto your forehead. This error could be attributed to __________.

sensory adaptation

A neuron that transmits an impulse to the central nervous system after the neuron is stimulated by the environment is called a(n) __________.

sensory neuron

Which of the following mammals would you expect to have the highest basal metabolic rate (BMR)?

shrew

In a neuron, ion channels permit movement of (but don't pump) ____________.

sodium (Na+) and potassium (K+)

Sodium-potassium pumps transport ___________.

sodium ions (Na+) out of a neuron and potassium ions (K+) into a neuron

A signaling molecule is released from the adrenal gland and, after being transported through the blood, enters a cell, where it binds to a receptor and then moves into the nucleus, where it alters gene expression. What type of signaling molecule would this most likely be?

steroid

Skeletal muscle is said to be "striated" because __________.

the arrangement of the sarcomeres gives it a striped appearance

Interstitial fluid is __________.

the fluid that fills the spaces between cells of vertebrates

The equilibrium potential for a particular ion is __________.

the magnitude of the membrane voltage at equilibrium for that ion

Most cells are microscopic because at this small size, __________.

the ratio of surface area to cell volume is maximized

The period in which an axon membrane cannot act is called __________.

the refractory period

The functional relationship between the anterior pituitary and the posterior pituitary is that ___________.

they both release hormones in response to signals from the hypothalamus

Compound eyes are advantageous for small prey species to detect a potential predator because __________.

they permit sensitive motion detection

In the sliding-filament model, __________.

thin filaments move toward the center of the sarcomere

Hyperthyroidism, typically characterized by a high metabolic rate and high blood pressure, might be expected when __________.

thyroid-stimulating hormone (TSH) concentration is high

The main function(s) of connective tissues in the body is/are _________.

to hold tissues and organs in place and to join adjacent tissues together

A physiological state of decreased activity and metabolism that is an adaptation enabling animals to save energy while avoiding difficult and dangerous conditions is known as ________

torpor