|
Homeobox genes- and the homeodomain they code for |
their proteins have a homeodomain which allows them to bind to DNA; regulate eukaryotes |
|
homeotic genes- what do these code for, and what do they influence? |
a subset of home box genes that control anatomical pattern conformation in early embryonic development (multicellular eukaryotes) |
|
HOX genes |
a subset of homeotic genes that control the anterior-posterior organization of animals |
|
transcription factors |
a regulatory protein that binds to DNA and affects transcription of specific genes |
|
blastula |
a hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals |
|
blastocoel |
the fluid filled cavity that forms in the center of the blastula |
|
gastrulation |
in animal development, a series of cell and tissue movement in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula |
|
gastrula |
an embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm and endoderm |
|
endoderm |
the innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract in species that have these structures |
|
mesoderm |
the middle primary germ layer in a triploblastic animal embryo; develops into a notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system in species that have these structures |
|
ectoderm |
the outermost of the three primary germs layers in animal embryos; gives rise to the outer coverings and, in some phyla, the nervous system, inner ear, and lens of the eye |
|
blastopore |
in a gastrula, the opening of the archenteron that typically develops into the anus in dueterostomes and the mouth in protostomes |
|
radial symmetry |
symmetry in which the body is shaped like a pie or barrel (lacking a left or right side) and can be divided into mirror-imaged halves by any plane through its central axis |
|
bilateral symmetry |
body symmetry in which a central longitudinal plane divides the body into two equal but opposite halves |
|
dorsal |
pertaining to the top of the animal with radial or bilateral symmetry |
|
ventral |
pertaining to the underside or bottom of an animal with radial or bilateral symmetry |
|
posterior |
pertaining to the rear, or tail end, of a bilaterally symmetrical animal |
|
anterior |
pertaining to the front, or head, of a bilaterally symmetrical animal |
|
cephalization |
an evolutionary trend toward a clustering of sensory neurons and interneurons at the anterior (front) end of the body |
|
coelom |
a body cavity lined by tissue derived only from the mesoderm |
|
epithelial tissue |
sheets of tightly packed cells that line organs and body cavities as well as external surfaces |
|
connective tissue |
animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix |
|
nerve tissue |
tissues made up of neurons and supportive cells |
|
muscle tissue |
tissue consisting of long muscle cells that can contract, either on its own or when stimulated by nerve impulses |
|
homeostasis |
the steady-state physiological condition of the body |
|
regulator |
an animal for which mechanisms of homeostasis moderate internal changes in a particular variable in the face of external fluctuation of that variable |
|
conformer |
an animal for which an internal condition conforms to (changes in accordance with) changes in an environmental variable |
|
positive feedback systems |
a form of regulation in which an end product of a process speeds up the process |
|
negative feedback systems |
a form of regulation in which accumulation of an end product of a process slows the process |
|
hormone (distinguish between animal and plant hormones) |
in multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the organism, changing the target cells’ functioning |
|
endocrine system |
in animals, the internal system of communication involving hormones, the ductless glands that secrete hormones, and the molecular receptors on or in target cells, that respond to hormones; functions in concert with the nervous system to effect internal regulation and maintain homeostasis |
|
nervous system |
in animals, the fast-acting internal system of communication involving sensory receptors, networks of nerve cells, and connections to muscles and glands that respond to nerve signals; functions in concert with the endocrine system to effect internal regulation and maintain homeostasis |
|
local regulators |
a secreted molecule that influences cells near where it is secreted |
|
different signaling: endocrine |
hormones secreted into extracellular fluid by endocrine cells reach target cells via the bloodstream, to maintain homeostasis |
|
different signaling: paracrine |
signaling by local regulators in which target cells lie near the secreting cells |
|
different signaling: autocrine |
signaling by local regulators in which the secreting cells themselves are the target cells |
|
different signaling: synaptic |
neurons form specialized junctions called synapses with target cells, such as other neurons and muscle cells |
|
endocrine glands |
a ductless gland of endocrine cells that secretes hormones directly into the interstitial fluid, from which they diffuse into the bloodstream |
|
endocrine cells |
cells specialized to secrete substances which influence other cells, either locally or at some distance |
|
water-soluble hormones |
receptor proteins that are secreted by exocytosis and travel freely in the bloodstream, can’t diffuse through plasma membrane of target cells because they’re insoluble in lipids so bind to cell-surface receptors |
|
lipid-soluble hormones |
receptor proteins that diffuse out across the membranes of endocrine cells |
|
hypothalamus |
the ventral part of the vertebrate forebrain; functions in maintaing homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors that regulate the anterior pituitary |
|
anterior pituitary glands |
a portion of the pituitary gland that develops from non neural tissue; consists of endocrine cells that synthesize and secrete several tropic and non tropic hormones |
|
posterior pituitary glands |
an extension of the hypothalamus composed of nervous tissue that secretes oxytocin and antidiuretic hormone made in the hypothalamus; a temporary storage site for these hormones |
|
thyroid gland |
an endocrine gland, located on the ventral surface of the trachea, that secretes two iodine-containing hormones, triidothyronine (T3) and thyroxine (T4), as well as calcitonin |
|
pancreas |
a gland with exocrine and endocrine tissues. the exocrine portion functions with digestion, secreting enzymes and an alkaline solution into the small intestine via a duct; the ductless portion functions in homeostasis, secreting the hormones insulin and glucagon into the blood |
|
insulin |
a hormone secreted by pancreatic beta cells that lower blood glucose levels. it promotes the uptake of glucose by most body cells and the synthesis and storage of glycogen in the liver and also stimulates protein and fat synthesis |
|
glucagon |
a hormone secreted by pancreatic alpha cells that raises blood glucose levels. it promotes glycogen breakdown and release of glucose by the liver. |
|
glucose |
smallest molecule into which a carbohydrate is broken down |
|
glycogen |
an extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch |
|
oxytocin |
a hormone produced by the hypothalamus and released from the posterior pituitary. it induces contraction of the uterine muscles during labor and cause the mammary glands to eject milk during nursing |
|
ADH (antidiuretic hormone) |
a peptide hormone, also called vasopressin, that promotes water retention by the kidneys. produced in the hypothalamus and released from the posterior pituitary, ADH also functions in the brain |
|
gas exchange (in the context of O2 and CO2 in animals) |
the uptake of molecular oxygen from the environment and the discharge of carbon dioxide to the environment |
|
ventilation |
the flow of air or water over a respiratory surface |
|
respiratory surface |
the part of an animals body where gas exchange occurs |
|
respiratory medium |
the source of the gas needed |
|
tracheal system |
in insects, a system of branched, air-filled tubes that extends throughout the body and carries oxygen directly to cells |
|
gill system |
gills are the outfoldings of the body surface that are suspended in water, fish pump water through mouth and over gill arches, then use countercurrent exchange |
|
lung system |
lungs are localized respiratory organs, process in which O2 is absorbed down to lungs then exhaled back out |
|
countercurrent exchange (really understand how this works) |
the exchange of a substance or heat between two fluids flowing in opposite directions. for example, blood in a fish gill flows in the opposite direction of water passing over the gill, maximizing diffusion of oxygen into and carbon dioxide out of the blood. |
|
negative pressure breathing |
a breathing system in which air is pulled into the lungs |
|
positive pressure breathing |
a breathing system in which air is forced into the lungs |
|
hemoglobin |
an iron-containing protein in red blood cells that reversibly binds oxygen |
|
open circulatory systems |
a circulatory system in which fluid called hemolymph bathes the tissues and organs directly and there is no distinction between the circulating fluid and the interstitial fluid |
|
closed circulatory systems |
a circulatory system in which blood is confined to vessels and is kept separate from the interstitial fluid |
|
hemolymph |
in invertebrates with an open circulatory system, the body fluid that bathes the tissues |
|
blood |
a connective tissue with a fluid matrix called plasma in which red blood cells, white blood cells, and cell fragments called platelets are suspended |
|
arteries |
a vessel that carries blood away from the heart to organs throughout the body |
|
veins |
a vessel that carries blood toward the heart |
|
capillaries |
a microscopic blood vessel that penetrates the tissues and consists of a single layer of endothelial cells that allows exchange between the blood and interstitial fluid |
|
single circulation |
a circulatory system consisting of a single pump and circuit, in which blood passes from the sites of gas exchange to the rest of the body before returning to the heart |
|
double circulation |
a circulatory system consisting of separate pulmonary and systematic circuits, in which blood passes through the heart after completing each circuit |
|
systole |
the stage of the cardiac cycle in which a heart chamber contracts and pumps blood |
|
diastole |
the stage of the cardiac cycle in which a heart chamber is relaxed and fills with blood |
|
sinoatrial node |
a region in the right atrium of the heart that sets the rate and timing at which all cardiac muscle cells contract; the pacemaker |
|
plasma |
the liquid matrix of blood in which the blood cells are suspended |
|
low density lipoproteins (LDL) |
a particle in the blood made up of thousands of cholesterol molecules and other lipids bound to a protein. LDL transports cholesterol from the liver for incorporation into cell membranes. |
|
high density lipoproteins (HDL) |
a particle in the blood made up of thousands of cholesterol molecules and other lipids bound to a protein. HDL scavenges excess cholesterol. |
|
atherosclerosis |
a cardiovascular disease in which fatty deposits called plaques develop in the inner walls of the arteries, obstructing the arteries and causing them to harden |
|
heart attack |
the damage or death of cardiac muscle tissue resulting from prolonged blockage of one or more coronary arteries |
|
stroke |
the death of nervous tissue in the brain, usually resulting from rupture or blockage of arteries in the head |
|
sensory neurons |
a nerve cell that receives information from the internal or external environment and transmits signals to the central nervous system |
|
motor neurons |
a nerve cell that transmits signals from the brain or spinal cord to muscles or glands |
|
interneurons |
an association neuron; a nerve cell within the central nervous system that forms synapses with sensory and/or motor neurons and integrates sensory input and motor output |
|
cell body |
the part of a neuron that houses the nucleus and most other organelles |
|
dendrite |
one of usually numerous, short, highly branched extensions of a neuron that receive signals from other neurons |
|
axon |
a typically long extension, or process, of a neuron that carries nerve impulses away from the cell body toward target cells |
|
synapse |
the junction where a neuron communicates with another cell across a narrow gap via a neurotransmitter or an electrical coupling |
|
synaptic terminal |
the part of each axon branch that forms the synapse |
|
synaptic cleft |
the gap that separates the presynaptic neuron from the postsynaptic neuron |
|
hillock |
the cone shaped base of an axon where signals that traveled down the axon are generated |
|
neurotransmitter |
a molecule that is released from the synaptic terminal of a neuron at a chemical synapse, diffuses across the synaptic cleft, and binds to the postsynaptic cell, triggering a response |
|
glia (glial cells) |
cells of the nervous system that support, regulate, and augment the functions of neurons |
|
schwann cells |
a type of glial cell that forms insulating myelin sheaths around the axons of neurons in the peripheral nervous system |
|
myelin sheath |
wrapped around the axon of a neuron, an insulating coat of cell membranes from Schwann cells or oligodendrocyte. it is interpreted by nodes of Ranvier, where action potentials are generated. |
|
equilibrium potential |
the magnitude of a cell’s membrane voltage at equilibrium; calculated using the Nernst equation |
|
resting potential |
the membrane potential characteristic of a nonconducting excitable cell, with the inside of the cell more negative than the outside |
|
action potential |
an electrical signal that propagates (travels) along the membrane of a neuron or other excitable cell as a nongraded (all-or-none) depolarization |
|
hyperpolarization |
a change in a cell’s membrane potential such that the inside of the cell become more negative relative to the outside. Hyperpolarization reduces the chance that a neuron will transmit a nerve impulse |
|
depolarization |
a change in a cell membrane’s potential such that the inside of the membrane is made less negative relative to the outside. For example, a neuron membrane is depolarized if a stimulus decreases its voltage from the resting potential of -70 mV in the direction of zero voltage |
|
threshold |
the potential that an excitable cell membrane must reach for an action potential to be initiated |
|
refractory period |
the short time immediately after an action potential in which the neuron cannot respond to another stimulus, owing to the inactivation of voltage-gated sodium channels |
|
nodes of Ranvier |
gap in the myelin sheath of certain axons where an action potential may be generated. in saltatory conduction, an action potential in regenerated at each node, appearing to "jump" along the axon from node to node |
|
saltatory conduction |
rapid transmission of a nerve impulse along an axon, resulting from the axon potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane |
|
ligand-gated ion channel |
a transmembrane protein containing a pore that opens or closes as it changes shape in response to a signaling molecule (ligand), allowing or blocking the flow of specific ions; also called an ionotropic receptor |
|
excitatory postsynaptic potential (EPSP) |
an electrical change (depolarization) in the membrane of a postsynaptic cell caused by the binding of an excitatory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more likely for a postsynaptic cell to generate an action potential |
|
inhibitory postsynaptic potential (IPSP) |
an electrical charge (usually hyper polarization) in the membrane of a postsynaptic neuron caused by the binding of an inhibitory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more difficult for a postsynaptic neuron to generate an action potential |
|
peripheral nervous system (PNS) |
the sensory and notary neurons that connect to the central nervous system |
|
central nervous system (CNS) |
the portion of the nervous system where signal integration occurs; in vertebrate animals, the brain and spinal cord |
|
motor nervous system |
an efferent branch of the vertebrate peripheral nervous system composed of motor neurons that carry signals to the skeletal muscles in response to external stimuli |
|
autonomic nervous system |
an efferent branch of the vertebrate peripheral nervous system that regulates the internal environment; consists of the sympathetic, parasympathetic and enteric divisions |
|
parasympathetic divisions |
1/3 divisions of the autonomic nervous system; generally enhances body activities that gain and conserve energy, such as digestion and reduced heart rate |
|
sympathetic divisions |
1/3 divisions of the autonomic nervous system; generally increases energy expenditure and prepares the body for action |
|
enteric divisions |
1/3 divisions of the autonomic nervous system; consists of networks of neurons in the digestive tract, pancreas, and gallbladder; normally regulated by the sympathetic and parasympathetic divisions of the autonomic nervous system |
|
notochord |
derived character of chordate; a flexible rod that runs along the anterior-posterior axis, may be associated with a jointed skeleton |
|
pharyngeal clefts |
derived character of chordate; grooves that separate pouches along the side of the pharynx, may develop into parts of the ear |
|
pharyngeal slits |
derived character of chordate; openings to the outside of the body along the side of the pharynx, may develop into gill slits |
|
dorsal, hollow nerve chord |
derived character of chordate; a bundle of nervous tissue running along the length of the body, may develop into the brain and spinal cord |
|
muscular, post-anal tail |
derived character of chordate; a structure that contains muscles and extends past the anus, may be used to propel some species in water |
|
characteristics of lancelets (lancelets vs. tunicates, 2 groups of chordates) |
all chordate characters present in adults, adults bury themselves into the sediment of the seafloor, adults swim by the contraction of a series of muscles along the notochord |
|
characteristics of tunicates (lancelets vs. tunicates, 2 groups of chordates) |
most chordate characters not present in adults, larvae swim using the notochord but adults may be sessile, in adults water enters through one siphon and leaves through another |
|
characteristics of lancelets and tunicates (2 groups of chordates) |
adults feed with the aid of pharyngeal slits |
|
characteristics of neither lancelets and tunicates (2 groups of chordates) |
adults swim using the vertebral column |
|
This phylogenetic tree indicates that mammals are most closely related to _____. |
reptiles |
|
According to this phylogenetic tree, the animals most closely related to reptiles and mammals are _____. |
amphibians |
|
Which one of these chordate groups lacks a post-anal tail and a notochord as adults? |
tunicates |
|
The common ancestor of all these chordate groups EXCEPT the _____ probably had paired appendages. |
lampreys |
|
Select the vertebrate taxon or taxa whose origin(s) involved duplication of Hox genes. |
Craniates Gnathostomes |
|
What is the significance of the evolution of Hox gene clusters during vertebrate evolution? |
Duplication of Hox genes made increased morphological complexity possible. |
|
4 major categories of tissue |
muscle epithelial connective nervous |
|
Term that describes a mechanism by which the internal conditions of an organism are kept at set values without regard to the external conditions? |
Regulatory homeostasis. |
|
Which of the following actions is not a function of the epithelium? |
Allows the internal environment to alter its conditions to match those of the external environment. |
|
True or false? Organisms must maintain homeostasis because optimal enzyme activity is achieved within a very narrow range of conditions. |
true |
|
Which component of a homeostatic system sends instructions based on sensory information? |
integrator |
|
Which component of a homeostatic system perceives changes in some parameter of the environment? |
sensor |
|
Which of the following statements describes a negative feedback response? |
After a meal, blood sugar levels in the body rise; insulin is secreted to lower blood sugar levels. |
|
Which of these is an example of negative feedback? |
After you eat, insulin stimulates the lowering of blood sugar levels. |
|
Type 1 diabetes |
the immune system destroys most of the beta cells of the pancreas. Little or no insulin is produced. As a result, blood glucose levels remain elevated for a longer period than in healthy individuals. |
|
type 2 diabetes |
the pancreas produces sufficient insulin. However, the body’s target cells do not respond to insulin effectively. As a result, blood glucose levels remain elevated for a longer period than in healthy individuals. Because glucose levels remain high, the pancreas continues to release insulin — this is why insulin levels are also higher than in healthy individuals. |
|
Oxytocin secretion and milk release from the mammary glands of lactating female mammals are initiated by _____. |
the physical sensation of the baby sucking at the nipple |
|
The counter-regulatory functions of the pancreas refer to the fact that it _____. |
releases one hormone that reduces glucose levels in the blood and another that increases them |
|
characteristics of Endocrine glands in the human brain: hypothalamus |
integrates nervous and endocrine systems, synthesizes oxytocin and ADH, synthesizes some hormones that are released into blood vessels bound for another gland |
|
characteristics of Endocrine glands in the human brain: posterior pituitary |
extension of the hypothalamus, releases oxytocin |
|
characteristics of Endocrine glands in the human brain: anterior pituitary |
regulated by hormones released into portal blood vessels, synthesizes and releases PRL and TSH |
|
Suppose that a woman had to have part of her thyroid gland surgically removed. She would most likely suffer from a condition known as hypothyroidism due to too little thyroid function. |
Thyroid hormones levels decrease, TRH levels increase, and PRL levels increase. |
|
The anterior and posterior lobes of the pituitary differ in that _____. |
many anterior pituitary hormones regulate other endocrine glands whereas posterior pituitary hormones regulate nonendocrine tissues |
|
Which secretion is not a barrier that prevents pathogens from entering the body? |
antigens |
|
True or false? The leukocytes of the innate immune system are B cells, macrophages, and neutrophils. |
false, The leukocytes of the innate immune system are mast cells, macrophages, and neutrophils. |
|
How do cells involved in the innate immune response detect the presence of pathogens? |
Leukocytes recognize unique molecules on pathogens. |
|
Which of the following cells can engulf a pathogen? |
Macrophages |
|
Which of the following statements best describes the role of mast cells in the inflammatory response? |
They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream. |
|
Which of the following events of the innate immune response occurs first when a wound that breaks the skin has occurred? |
Platelets release proteins that form clots and decrease bleeding. |
|
The site of inflammation may become swollen due to the increased numbers of cells and fluids at the site and painful due to signals from pain receptors. |
true |
|
items involved in humoral response of acquired immunity |
antibodies, plasma cells, B cells |
|
items involved in cell-mediated response of acquired immunity |
cytotoxic T cells |
|
items involved in both humoral and cell-mediated response of acquired immunity |
helper T cells and cytokines, memory cells, antigen-presenting cells |
|
Name a cell that is a phagocytic leukocyte that can engulf a foreign bacterium? |
macrophage |
|
_____ interact with the antigen-class II MHC complex presented by macrophages. |
helper T cells |
|
B cells that have been stimulated by interleukin-2 develop into _____. |
plasma cells |
|
The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response. |
perforin … cell-mediated |
|
Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____. |
B cells … plasma cells and memory cells |
|
Which of these cells is responsible for the rapidity of the secondary immune response? |
memory cells |
|
Which of these cells produce and secrete antibodies? |
plasma cells |
|
Which structure is not a component of the adaptive immune system? |
tissues |
|
True or false? B cells were originally isolated from the bursa in chickens, and their function is to produce antibodies |
true; T cells were originally isolated from the thymus in mice, and their functions include killing host cells that are being infected with a virus. |
|
Which of the following statements about the clonal-selection theory of immune system function is false? |
Antigens are recognized by receptor proteins inside the lymphocyte. |
|
What is the final step in the cell-mediated response to a viral infection? |
Cytotoxic T lymphocytes punch holes in the membranes of infected host cells. |
|
How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell? |
Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies. |
|
Which protein presents viral antigens on the outer surface of cells? |
MHC protein |
|
How are cytotoxic T lymphocytes (CTLs) produced? |
CD8+ T cells divide and differentiate into cytotoxic T lymphocytes. |
|
Carbon dioxide enters the blood at the _____. |
capillaries of the head, forelimbs, abdominal organs, and hind limbs |
|
The _____ has(have) the thinnest walls. |
capillaries |
|
Blood pressure is highest in the _____. |
aorta |
|
Most gas exchange with blood vessels occurs across the walls of the structure ____. |
alveoli |
|
What is the function of a circulatory system? |
It brings a transport liquid into close contact with all cells in the body. |
|
Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body? |
The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body. |
|
True or false? The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body. |
false; The pulmonary circulation is the lower-pressure circuit to the lung, whereas the systemic circulation is the higher-pressure circuit to the rest of the body. |
|
What is the function of the left ventricle? |
It pumps oxygenated blood around the body via the systemic circulation. |
|
Which of the following statements about blood circulation in the body is true? |
Valves prevent the backflow of blood into the atria and ventricles. |
|
Which event occurs first during diastole? |
The atria and ventricles are relaxed, and blood flows into the atria. |
|
Which event of the cardiac cycle occurs when systolic blood pressure is measured? |
The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria. |
|
In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid? |
grasshoppers |
|
Voice sounds are produced by the _____. |
larynx |
|
The primary functions of the _____ are to warm, filter, and humidify air. |
nasal cavity |
|
Arteries carry blood _____. |
away from the heart only |
|
Blood returns to the heart via the _____. |
pulmonary veins |
|
From the pulmonary veins, blood flows to the _____. |
left atrium |
|
From the anterior vena cava, blood flows to the _____. |
right atrium |
|
From the capillaries of the abdominal organs and hind limbs, blood flows to the _____. |
posterior vena cava |
|
statements about oxygen during respiration |
required for cellular respiration, net diffusion from alveoli to lung capillaries |
|
statements about carbon dioxide during respiration |
sometimes transported as bicarbonate, waste product of cellular respiration, net diffusion from body tissues to blood, net diffusion from lung capillaries to alveoli |
|
statements about oxygen and carbon dioxide during respiration |
transported by hemoglobin, enters alveoli during respiration |
|
Which of the following codes for proteins in all cells, including cancer cells? |
genes |
|
You are a cancer researcher studying the use of flow cytometry on three different forms of thyroid cancer. Which of the following are you using to label the cancer cells? |
antibodies |
|
Which of the following is true regarding bone marrow transplants? |
Even if the patient and the donor are a match, the patient can still experience side effects. |
|
Select the correct statement about capillary beds. |
Capillary beds are the site of nutrient and oxygen delivery to tissues. |
|
How are gases transported in insect bodies? |
in tracheal systems |
|
Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries? |
Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles. |
|
What is the function of endocrine glands? |
They release hormones into the bloodstream for distribution around the body. |
|
True or false? The homeostatic system for blood calcium concentration is maintained by the hormones calcitonin and parathyroid hormone. |
true |
|
Which of the following statements about the pituitary gland is false? |
Neurosecretory cells produce hormones that are stored in the anterior pituitary. |
|
True or false? The pancreas is responsible for producing hormones that maintain the homeostatic levels of glucose in the blood. |
true |
|
How is the production of hormones such as thyroxine and estrogen regulated? |
The hypothalamus directs the anterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones. |
|
Which of the following statements about endocrine glands and the hormones they produce is true? (Aldosterone) |
Aldosterone produced by the adrenal glands controls the reabsorption of sodium ions by the kidneys. |
|
Gigantism, a condition characterized by exceptionally rapid growth, is sometimes caused by a tumor that induces the gland in which it develops to overproduce a certain hormone. Where would such a tumor be expected to grow? |
Pituitary gland. |
|
glands secretes releasing hormones? |
hypothalamus |
|
`Which of these hormones are responsible for the "fight or flight" response to danger? |
epinephrine and norepinephrine |
|
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress. |
glucocorticoids |
|
_____ are the main male hormones. |
Androgens |
|
What hormone promotes water retention by the kidneys? |
antidiuretic hormone (ADH) |
|
Which hormone opposes the action of parathyroid hormone? |
calcitonin |
|
Which hormone stimulates hormone production by the ovaries and testes? |
luteinizing hormone (LH) |
|
Which hormone stimulates milk production? |
prolactin |
|
A neuron’s nucleus is located in its _____. |
cell body |
|
A nerve impulse moves toward a neuron’s cell body along _____. |
dendrites |
|
A nerve impulse moves away from a neuron’s cell body along _____. |
axons |
|
An impulse relayed along a myelinated axon "jumps" from _____ to _____. |
node of Ranvier … node of Ranvier |
|
Axons insulated by a(n) _____ are able to conduct impulses faster that those not so insulated. |
myelin sheath |
|
What type of cell makes up the myelin sheath of a motor neuron? |
Schwann cells |
|
What part of a neuron relays signals from one neuron to another neuron or to an effector? |
synaptic terminal |
|
True or false? Action potentials travel in only one direction down an axon because potassium channels in the neuron are refractory and cannot be activated for a short time after they open and close. |
false, Action potentials travel in only one direction down an axon because sodium channels in the neuron are refractory. |
|
Which event triggers the creation of an action potential? |
The membrane depolarizes above a certain threshold potential. |
|
Which of the following terms describes how a neuronal membrane’s potential is altered in the presence of inhibitory signals? |
Hyperpolarization. |
|
Where in the neuron do action potentials begin? |
Axon hillock. |
|
How is an action potential propagated down an axon after voltage-gated sodium channels open in a region of the neuron’s membrane? |
Sodium ions enter the neuron and diffuse to adjacent areas, resulting in the opening of voltage-gated sodium channels farther down the axon. |
|
Which term describes the difference in electrical charge across a membrane? |
Membrane potential. |
|
Resting neurons are most permeable to which of the following ions? |
K+. |
|
True or false? The potential energy of a membrane potential comes solely from the difference in electrical charge across the membrane. |
false, The potential energy of a membrane potential comes both from the difference in electrical charge and from the concentration gradient of ions across a membrane. |
|
Which channel is mainly responsible for the resting potential of a neuron? |
Potassium leak channel. |
|
Which term describes an electrical signal generated by neurons? |
Action potential. |
|
Which channel maintains the concentration gradients of ions across a neuronal membrane? |
The sodium-potassium pump moving Na+ ions out and K+ ions in. |
|
What behavior is observed if the voltage across a neuronal membrane is set to -20 mV? |
The sodium channel opens, and Na+ ions flow in. |
|
Which of the following characteristics determines when the refractory period ends? |
how long it takes for the voltage-gated Na+ channels to reactivate at the end of an action potential |
Share This
Flashcard
