Human Physiology

Which blood vessel layer secretes paracrine factors, which participate in the regulation of blood pressure and blood vessel growth?

Endothelium

White blood cells are generally too large to pass through capillaries. What route must they follow to move from the arterial to the venous circulation?

Metarterioles

What type of tissue, present in the walls of blood vessels, allows for regulation of vessel diameter?

Smooth Muscle

Perfusion is

blood flow through an organ

The only blood vessels whose walls permit exchange between the blood and the surrounding interstitial fluids are the

venules and capillaries

Angiogenesis is

the growth of new blood vessels

Cerebral capillaries are surrounded by ________ and glial cells and have tight junctions that create the ________.

pericytes, BBB

Venules are similar to capillaries: they have ________ epithelium and only small amounts of ________.

a thin exchange, connective tissue

What maintains the driving pressure on blood while the heart is not contracting (ventricular diastole)?

Recoil of the elastic arteries

Which is the correct relationship between pressure, flow, and resistance?

Pressure ~ Flow x Resistance

Mean arterial pressure is equal to diastolic pressure plus one-third of the pulse pressure. An equivalent equation is MAP = 2/3 DBP + 1/3 SBP. Why is diastolic blood pressure a larger component of MAP than systolic blood pressure?

The heart spends more time in diastole than systole; therefore, the equation reflects the difference in time.

Using a sphygmomanometer, a nurse measures a patient’s blood pressure as 134/86. What is the patient’s pulse pressure and mean arterial pressure?

PP = 48 mmHG MAP = 102 mmHG

What compensatory mechanisms are available to help maintain blood pressure when a large volume of blood is lost, such as during a hemorrhage?

Vasoconstriction, increased thirst, and decreased renal fluid output in the urine

What effect would an increase in blood volume have on the resistance to blood flow?

Nothing, they are not directly linked

What effect would an increase in venous tone have on mean arterial pressure?

It would increase it by shifting blood from the veins to the arteries

Blood pressure can be measured with a sphygmomanometer. When the display indicates diastolic pressure, what is heard through the stethoscope. Why?

Nothing is heard because blood flow is smooth through the fully open artery.

What is the role of the kidney in blood pressure regulation?

The kidney can eliminate water to decrease blood volume or it can conserve water to maintain blood volume.

The mean arterial pressure (MAP) is important because

It represents the driving pressure for blood flow

Which of the following is occurring during systole?

BP increases and more stress is placed on arterial walls

The difference between the systolic and diastolic pressures is called the

Pulse pressure

All of the following would cause an increase in blood pressure

decrease in arterial diameter, increase in arterial resistance, sympathetic stimulation

What is the mechanism behind myogenic autoregulation in vascular smooth muscle?

When cells stretch, mechanically gated cation channels open, depolarizing the cell, resulting in contraction

Which paracrine acts as a vasoconstrictor?

Serotonin (Kinins, Adenosine & Histamine are vasodilators)

What causes active hyperemia?

Increased metabolism results in a local increase in CO2

Which type of vessel changes most to regulate resistance to blood flow. Why?

Arterioles b/c of the large amount of smooth muscle in their walls

Which changes in paracrines cause vasodilation? What is the result?

Decreased O2, increased CO2, increased H+, increased NO, result in increased blood flow.

Blood flow to a tissue will increase if the

level of carbon dioxide at the tissue increases.

The vessels that are the main site of variable resistance in the circulatory system, and that contribute more than 60% of the total resistance, are the

arterioles

At rest, the majority of blood flows through the

liver and digestive tract

The matching of blood flow to the changing metabolic needs of a tissue is due to

local control

The bone marrow, the liver, and the spleen do NOT have traditional capillaries. Instead, they have modified vessels called ________ that are ________ than a capillary

sinusoids, wider

Which of the following cardiovascular control factors contribute to changes in blood pressure?

force of cardiac contraction, heart rate, blood vessel diameter (cardiac factors!!)

MAP ~

CO x Total peripheral resistance

Which of the following neurotransmitters will play a role in the regulation of blood pressure by creating a change in cardiovascular function?

Ephinephrine, norepinephrine, acetylcholine

Which of the following are the effects of the parasympathetic nervous system when blood pressure is too high?

decrease heart rate

Why is the velocity of blood lowest in the capillaries as compared to all other types of vessels?

The capillaries have the largest cross sectional area

What is the mechanism by which bulk flow occurs at the capillaries?

Relatively higher hydrostatic pressure on the arterial end of the capillary and relatively higher colloid oncotic pressure on the venous end results in net flow out of the capillary.

If a person’s lymph vessels suddenly vanished (an impossible scenario), what impact would this have on the circulatory system?

Blood volume and BP would decrease

Which set of changes correctly describes the baroreceptor reflex in response to increased blood pressure?

Increased vessel diameter, decreased resistance, decreased cardiac output

The lipid material of an atherosclerotic plaque accumulates _______

deep to the tunica intima in the arterial wall

In the capillaries, hydrostatic pressure (HP) is exerted by __________.

Blood pressure

The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________.

capillary, interstitial fluid (the capillary hydrostatic pressure (HPC; caused by blood pressure) is much higher than the interstitial hydrostatic pressure (HPI). The interstitial fluid is forced out of the capillaries.)

Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary?

34 mmHG (HPc (35 mm Hg) – HPI (1 mm Hg) = 34 mm Hg, which is the net hydrostatic pressure at the arterial end. The hydrostatic pressure of the blood is much higher at the arterial end of the capillary, thus favoring filtration.)

The colloid osmotic pressure in the capillary is caused by __________.

proteins in the blood

Which net pressure draws fluid into the capillary?

net osmotic pressure

Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary?

venous

Where are the sensors for the arterial baroreceptor reflex located?

carotid sinus and aortic arch

If blood pressure is increased at the arterial baroreceptors, what would happen with the activity level of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS)?

increased PNS activity and decreased SNS activity

Which of the following would cause vasodilation of arterioles?

decrease in the activity of the sympathetic nervous system would result in decreased activity of vasomotor fibers, resulting in vasodilation.

Stimulation of the adrenal medulla would result in which of the following?

epinephrine and norepinephrine are released from the adrenal medulla and act as part of the sympathetic nervous system, increasing heart rate and contractility. Epinephrine and norepinephrine have other effects that would also increase blood pressure.

A decrease in blood pressure at the arterial baroreceptors would result in which of the following?

increase in heart contractility (sympathetic nervous system activity would be increased because of the low blood pressure. Sympathetic fibers go to the ventricles of the heart and increase their contractility. An increase in contractility would increase stroke volume which would lead to an increase in cardiac output and blood pressure.)

Which of these blood values are in the normal range?

Arterial PCO2 = 38 mmHg

What is the primary mechanism by which gases move from the alveoli into the blood and cells and back?

simple diffusion

Low alveolar PO2 can be caused by one of two mechanisms. One of them is that the inspired air has a low oxygen content. What is the other reason?

hypoventilation

If alveolar PO2 is normal but arterial PO2 is low, what is the most likely cause?

decreased barrier permeability

Emphysema causes a loss of septa between individual alveoli, resulting in fewer, but larger, alveoli. What component of gas diffusion would be most affected by emphysema?

surface area

At the same pressure, about 25 times more CO2 will dissolve in plasma as O2. Why does this occur?

CO2 has a higher solubility than O2

Because this factor normally varies, the most important variable that influences the diffusion of respiratory gases is the ________.

concentration gradient

High carbon dioxide concentration in body fluids is called

hypercapnia

The partial pressure of oxygen in arterial blood is approximately ________ mm Hg.

100 mmHG

The partial pressure of carbon dioxide in the cells of peripheral tissues is approximately ________ mm Hg.

45 mmHG

Of the factors that influence diffusion of respiratory gases, the most variable and, therefore, important factor to consider is the

concentration gradient

The process by which dissolved gases are exchanged between the blood and interstitial fluids is

diffusion

The lung pathology most likely to result from certain kinds of heart disease is

pulmonary edema

CO2 bound to hemoglobin

23 %

CO2 dissolved in the plasma

7%

CO2 transported by conversion to HCO3 + H+

70%

Increase oxygen/Hb affinity

decrease temp, increase pH, decrease pp CO2, decrease [2,3 DPG]

If a red blood cell is 100% saturated, how many molecules of O2 are bound to it?

1 billion molecules of O2

Predict which way exercise would shift the oxygen-hemoglobin dissociation curve. Would this shift in the curve increase or decrease hemoglobin saturation?

The curve would shift to the right thus decreasing the hemoglobin saturation.

How is the majority of CO2 transported in blood?

converted to and transported as bicarbonate ions

In the lungs, O2 loading facilitates CO2 unloading from hemoglobin. This is known as __________.

the Haldane effect

In a healthy respiratory system, if the alveolar PO2 is 85 mmHg, what will arterial PO2 be?

85 mmHG

What is the main difference between fetal and adult hemoglobin?

Fetal hb has a higher affinity for O2

What would a rightward shift in the oxygen-hemoglobin binding curve indicate?

a decrease in hemoglobin affinity for oxygen

Which change would cause a leftward shift in the oxygen-hemoglobin binding curve?

decreased temperature

In what form is most carbon dioxide transported in the blood?

as bicarbonate ion

Which of the following statements most accurately describes hypoxia?

a decrease in the amount of dissolved oxygen in plasma or air

Why is hyperventilation a usual response when someone is exposed to a high altitude hypoxic situation?

Because it increases alveolar ventilation, which increases the partial pressure of O2 in the alveolus.

Which change would cause the greatest stimulus for an increase in ventilation?

arterial PCO2 increasing to 46 mmHg

Approximately what percentage of the total blood oxygen is bound to hemoglobin instead of dissolved in plasma?

98%

A hemoglobin molecule binds to a maximum of how many oxygen molecules?

up to 4

About 23% of the carbon dioxide in blood is carried ________.

by Hb, bound to amino groups

Conditioning of air by the respiratory tract has three purposes: warming, filtering, and which other component?

humidifying

Which of the following is NOT a muscle that assists in the pressure changes associated with breathing?

pleural sac

Gas exchange between the lungs and the atmosphere occurs at the ________.

alveoli

Which is NOT considered to be a primary function of the respiratory system?

regulation of water balance (protection against pathogens, regulation of pH balance, gas exchance, and vocalization ARE)

The upper respiratory tract includes all of the following

nasal cavity, trachea, mouth, larynx

The lower respiratory tract includes

all of the bronchial branches and the lungs

Alveolar ventilation refers to the

movement of air into and out of the alveoli

The actual sites of gas exchange within the lungs are

alveoli

Place the following structures of the respiratory tree in the order in which air passes through them.
1. secondary bronchi
2. bronchioles
3. primary bronchi
4. alveoli
5. terminal bronchioles

3, 1, 2, 5, 4

Which factor(s) from the ideal gas equation can be ignored in the human body?

ideal gas constant, temperature, moles of the gas

Which of the following correctly describes the relationship between pressure and volume?

As V increases, P decreases proportionally

When the respiratory diaphragm contracts, it flattens. At the same time, the intercostal muscles pull the ribs up and out. The active forces of the muscle groups cause a(n) _______________ (increase/decrease) in thoracic volume. Given the relationship between pressure and volume, this would cause pressure within the lungs to __________________ (increase/decrease).

increase, decrease

If you have an alveolus with an initial volume of 3 ml of air with a total pressure of 810 mmHg and you decrease the volume of this alveolus to 1.7 ml, what would the new pressure be and how would this affect air flow? Assume you are at sea level.

1429 mmHg; air flow out of the alveolus to the environment

Which of the following statements best describes the definition of Dalton’s Law of Partial Pressures?

The total pressure of a mixture of gases is the sum of the pressures of the individual gases.

Which of the following parameters do you need to know in order to calculate the partial pressure of a gas?

the percentage of the gas, the water vapor pressure, the total pressure in the atmosphere

As one moves up in altitude, the atmospheric pressure decreases. In Vail, CO (altitude 8022 ft or 2445 m), the atmospheric pressure is approximately 570 mmHg. What would the partial pressure of oxygen be in Vail?

120 mmHG

If you were visiting Vail, CO, what would the partial pressure of oxygen be in your inspired air once it had been fully conditioned (warmed and humidified)? You may need to use the information calculated from Question 8.

110 mmHG

In its simplest form, what relationship between pressure and volume does the ideal gas law demonstrate?

they are inversely proportional

Which of the following correctly states the relationship known as Boyle’s Law?

P1V1=P2V2

Is it true that respiratory air flow obeys the same laws as blood flow?

It is mostly true; the main differences are related to the fact that gas is compressible, but liquid is not.

Dalton’s law states that

in a mixture of gases like air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.

Air moves into the lungs because

the gas pressure in the lungs is less than outside pressure.

Air moves out of the lungs because

the volume of the lungs decreases with expiration

What are the two conditions that most people with COPD have?

emphysema or chronic bronchitis

What happens to the resistance in the bronchioles of patients with chronic bronchitis and how does this affect air movement into and out of their lungs?

increases; decreases

The ability for the lung to passively recoil and push air out is attributed to what type of tissue? What is this property called?

elastic tissue, elastance

Which capacity is the sum of inspiratory reserve volume, expiratory reserve volume, and tidal volume?

vital capacity

What is the main driving force that directly causes air to flow in and out of the respiratory system? Hint: It is the same force that creates blood flow.

As the volume of the thoracic cavity changes, it creates a pressure gradient that allows air to flow.

What causes the greatest change in thoracic volume during quiet inspiration?

contraction of the diaphragm

What happens to intrapleural pressure during a pneumothorax?

it becomes equal to atmospheric pressure

Just like the cardiovascular system, what is the primary determinant of resistance to flow in the respiratory system?

tube radius

Which is the best definition of anatomical dead space?

the volume of the conducting system

Why is the regulation of extracellular fluid osmolarity so important?

It strongly influences cell volume.

Where is the location for one of the primary structures responsible for monitoring blood volume?

atria

Why is maintaining osmolarity so important to the body?

The membranes of most cell types are freely permeable to water.

The primary route for water loss from the body is the ________ system.

urinary

The primary route for ion loss from the body is the ________ system.

urinary

Cell volume (and therefore cell function) in most cells is dependent upon careful regulation of

ECF osmolarity

The two organ systems that work together to regulate most aspects of the body’s water balance are

urinary and cardiovascular.

Kidneys respond relatively ________ to changes in blood volume.

slowly

Most body water is located

inside cells

What process causes insensible water loss?

respiration

What is the primary mechanism through which the kidneys can preserve water volume?

decreasing GFR

Why is a high medullary interstitial osmolarity important to renal function?

It allows selective reabsorption of water.

What is the mechanism of action of vasopressin?

insertion of AQP-2 into the apical membrane of collecting duct epithelium

What would cause osmoreceptors in the hypothalamus to shrink and what effect would that have?

high plasma osmolarity, release of vasopressin

Where does the reabsorption of ions occur in the nephron to produce a hyposmotic solution in the tubules?

ascending limb of the loop of Henle

Which is NOT an important route of water loss from the body?

metabolic breakdown of water molecules

Osmoreceptors are located in the _____.

hypothalamus

Dehydration triggers a/an _____ in osmolarity and secretion of _____.

increase, ADH

Hyponatremia _____ the secretion of ADH/vasopressin and _____ the secretion of aldosterone.

decreases, increases

What two mechanisms cause an increase in extracellular fluid volume with salt ingestion?

vasopressin secretion and thirst

What is the site and mechanism of the early response phase of aldosterone action?

increased Na+/K+-ATPase activity in P cells of the distal tubule

When aldosterone causes sodium reabsorption, why doesn’t water automatically follow?

The distal nephron epithelium is impermeable to water.

How does angiotensin II (ANGII) directly affect the kidneys?

it increases sodium reabsorption in the proximal tubule

Which hormone increases sodium excretion?

atrial natriuretic peptide

What is the primary stimulus for natriuretic peptide release?

myocardial cell stretch

Aldosterone secretion increases in response to ________ and causes ________.

increased angiotensin II; sodium reabsorption

Juxtaglomerular cells in the nephron secrete

renin

ACE converts

angI to angII

Stimuli for the activation of the RAAS pathway include

low blood pressure in arterioles in the nephron and a decrease in fluid flow through the distal tubule.

Angiotensin II

stimulates thirst, causes widespread vasoconstriction throughout the body, and causes the synthesis and release of aldosterone from the adrenal cortex.

Drugs that treat hypertension by preventing Angiotensin I from becoming Angiotensin II are called

ACE inhibitors

The ion imbalance known as ________ initially leads to ________ in excitable cells.

hyperkalemia, depolarization

An increase in plasma potassium levels is properly called

hyperkalemia

A decrease in fluid osmolarity may result from ingesting too much water. What mechanism exists to counteract the drinking of too much water?

salt appetite

A hormone that helps to regulate the sodium ion concentration of the blood is

aldosterone

During severe dehydration, the adrenal cortex receives two competing stimuli: high plasma osmolarity and decreased volume. In response to this, aldosterone is not released. Why is this beneficial?

Aldosterone would increase sodium retention, leading to shrinkage of cells throughout the body.

Starvation would cause which of the following acid-base conditions? Also, determine what type of compensation (metabolic or respiratory) there would be.

metabolic acidosis with respiratory compensation

A patient is admitted to the hospital with the following plasma values: pH = 7.2, pCO2 = 55 mmHg, and HCO3¯ = 30 mEq/L. What is the acid base imbalance?

respiratory acidosis with metabolic compensation. Since pCO2 is above the normal range, it is the cause of the acidosis. HCO3 is increased to compensate, which is a metabolic compensation.

A patient is admitted to the hospital with the following plasma values: pH = 7.5, pCO2 = 45 mmHg, and HCO3¯ = 30 mEq/L. What is the acid-base imbalance?

metabolic alkalosis with no compensation

A patient is admitted to the hospital with the following plasma values: pH = 7.2, pCO2 = 25 mmHg, and HCO3¯ = 18 mEq/L. What is the acid base imbalance?

metabolic acidosis with respiratory compensation

Diarrhea can lead to which acid/base disturbance? Assuming compensation, would it be a metabolic or respiratory compensation?

metabolic acidosis with respiratory compensation

Emphysema can lead to which acid/base disturbance? What would be the compensation?

respiratory acidosis; kidneys will retain more HCO3 and excrete H+

Of the three buffering mechanisms in the body, which is the strongest?

Yes, although slow, the renal system is the strongest buffering system in the body. By altering the reabsorption and excretion of hydrogen ions and bicarbonate ions, the kidneys control the pH of body fluids.

The bicarbonate buffer system is one of the chemical buffer systems of the body. How would the bicarbonate buffer system work if sodium hydroxide were added to a solution?

A hydrogen on carbonic acid would dissociate and join the hydroxyl group on the base to form water and sodium bicarbonate.

The respiratory system is one of the three systems that regulate acid-base balance in the body. How does it work to decrease an acidosis?

Carbonic acid is broken down into water and CO2; the CO2 is then exhaled.

In a respiratory acidosis the kidney would do which of the following?

The kidney would reabsorb bicarbonate and secrete hydrogen ions.

Ingesting too much antacid would cause which of the following acid-base disturbances?

metabolic alkalosis

Vomiting will cause which type of acid-base disturbance?

metabolic alkalosis

Severe anxiety would cause which type of acid-base disturbance? What would be the compensation?

respiratory alkalosis; kidneys would excrete HCO3

What is the most important function of the kidneys (in the sense that loss of this function results in serious medical problems before loss of other functions become problems)?

regulation of water and ion content of the blood

The kidneys function to produce hormones, excrete wastes, regulate blood pressure, and maintain ion balance. Which of the following is another function of the kidneys?

regulate osmolarity

Functions of the kidneys include all of the following

maintenance of ion balance in body fluids homeostatic regulation of blood pH regulation of blood osmolarity regulation of extracellular fluid volume

Ions directly regulated by the kidney include all EXCEPT which of the following?

OH-

The characteristic yellow color of urine is attributed to the presence of

urobilinogen

Put the following in order from where urine is produced to where it exits the body:
Urethra
Urinary bladder
Nephron
Ureter

3421

Blood leaves the glomerulus via which vessel?

efferent arteriole

Blood flow through the kidney includes a feature seen in only a few organs. What is it?

portal system

The three filtration barriers that substances must pass through when leaving the blood and entering the tubule lumen are the glomerular capillary endothelium, the epithelium of Bowman’s capsule, and which other structure?

basal lamina

What unique epithelial cells of Bowman’s capsule allow for the final stage of filtration?

podocytes

Which of the following kidney processes is always active and always requires energy to occur?

secretion

A glomerulus is

a "knot" of capillaries that lies within the Bowman’s capsule.

Glomerular filtration rate is determined by the net filtration pressure and the filtration coefficient. What two factors determine the filtration coefficient?

glomerular surface area and the permeability of the filtration barrier

Which of these would cause the greatest increase in glomerular filtration rate?

increased resistance in the efferent arteriole

Which change would cause an increase in afferent arteriolar resistance due to paracrine signaling from the macula densa?

greater sodium concentration in the distal tubule

Of the following, which is the most likely reason that GFR would fall below normal?

hypotension

What is the primary driving force for glucose transport into proximal tubule cells?

Sodium concentration gradient allows secondary active transport of glucose.

Once glucose has entered the epithelial cells lining the proximal tubule, how does it cross the basolateral membrane?

facilitated diffusion via GLUT proteins

If all glucose is normally reabsorbed in the proximal tubule of the nephron, why do people with diabetes have glucose in their urine?

The amount of glucose filtered is greater than the renal threshold

Why is inulin administration an effective way of measuring renal clearance rates?

Inulin is neither secreted nor reabsorbed

Secretion into the nephron is a/an ________ process because the direction is ________ the concentration gradient.

active, against

Which of the following would help a clinician understand how the kidney was able to handle a substance?

clearance of the substance

Which of the following statements best describes clearance?

the rate at which a solute disappears from the body by either excretion or metabolism

Which of the following parameters must be known in order to calculate the clearance of a substance?

concentration of the solute in the plasma, excretion rate of the substance

Which equation correctly describes the relationship between excretion, filtration, reabsorption, and secretion?

excretion = filtration – reabsorption + secretion

During the micturition reflex, what does activation of parasympathetic efferent neurons cause the bladder to do?

contract

Leptin release is triggered from

adipocytes

Where is neuropeptide Y released and what is its effect on appetite?

in the brain, increases appetite

Which peptide, secreted by the stomach, increases hunger in humans?

ghrelin

Adipocytes secrete the hormone

leptin

Most obese humans are deficient in leptin.

false

The first law of thermodynamics states that

energy can be neither created nor destroyed and thus must be accounted for.

Several things, including food ingestion, amount of lean muscle mass and gender can affect metabolic rate. What other factor can affect metabolic rate?

age

Energy input equals energy output. This statement is known as the

1st law of thermodynamics

One kilocalorie (kcal) is the amount of energy needed to raise one ________ of water by 1 degree Celsius.

liter

The most practical way to estimate a person’s basal metabolic rate is to measure it when the person is

resting after a 12-hour fast

The nutrients that yield the most energy per gram when metabolized are

fats

Diet-induced thermogenesis is highest after ingestion of

proteins

Which of the following factors increases basal metabolic rate?

thyroid hormones and epinephrine

Where is the primary site of nutrient pools that are available for immediate use in the body?

plasma

Metabolism is a term that describes

all chemical reactions that take place within an organism.

anabolism describes

reactions that require a net input of energy and reactions that result in the synthesis of large biomolecules.

gluconeogenesis

creating glucose from glycerol, amino acids, or lactate.

Which path is the opposite of lipogenesis?

B-oxidation

Insulin is produced by pancreatic

B cells

During the absorptive state,

the liver forms glycogen

In the fasted state, which hormone combination would occur?

high glucagon, low insulin

The alpha cells of the pancreas produce

glucagon

The beta cells of the pancreas produce

insulin

WHen blood glucose levels fall

only glucagon is released

When blood glucose levels rise, as in the "fed" state,

only insulin is released

Homeothermic refers to

regulating body temperature within a narrow range.

Haploid cell includes

an egg cell

From which embryonic structure does ovarian tissue develop?

bipotential gonad cortex

Whether an embryo will develop into a male or female is determined by the presence or absence of what?

SRY gene

Which embryonic structure gives rise to the seminal vesicles and vas deferens during fetal differentiation into a male?

Wolffian duct

Which statement most accurately describes how the gender of a human embryo is determined?

Embryos with the SRY gene become male; those lacking the gene become female.

The fertilized egg is properly referred to as a(n) ________.

zygote

The male gamete is called a

sperm

The female gonad is called a(n)

ovary

While still undifferentiated, gametes are called ________ cells

germ

identify the false statement

Estrogens control the development of the reproductive organs in the female fetus. TRUE:Meiosis is never completed in most oocytes. Androgens control the development of reproductive organs in the male fetus. Females have one less active chromosome than males. Gametogenesis begins in the female fetus.

What is the main regulatory hormone responsible for regulation of gonad function?

GnRH

Choose the TRUE statement.

Human females are thought to be born with all the primary gametes they will ever have.

During meiosis, the chromosome number is halved

during the first meiotic division

Mitotic divisions in germ cells

the answer depends on gender

Meiosis of one cell results in production of

four gametes if male, one if female.

The structure(s) in testes that produces testosterone is/are the ________.

Leydig/interstitial cells

The mucus present in semen comes primarily from the ________.

bulbourethral glands

Sperm production occurs in the

seminiferous tubules

What is the third phase of the ovarian cycle called and what occurs during this time?

luteal phase, transformation of a ruptured follicle into a corpus luteum

Which hormone is important for male development in utero and for regulation of the ovarian cycle?

AMH

Which hormone is the most important regulator of endometrium proliferation during the follicular phase?

estrogen

What causes the LH surge that occurs during the late follicular phase

Progesterone and high estrogen output stimulate GnRH release from the hypothalamus.

The first phase of the ovarian cycle is the ________ phase.

follicular

The principal hormone secreted by the corpus luteum is

progesterone

What efferent signaling occurs to cause the erection reflex?

parasympathetic nervous stimulation

Birth control pills containing hormones estrogen and progesterone work by directly preventing ________.

ovulation

Besides sterilization, the only sure way to avoid pregnancy is

abstinence

Fertilization of the human egg normally occurs in the ________.

fallopian tube

The corpus luteum in a nonpregnant woman usually lasts about

12 days

Sperm cannot fertilize an egg until they

undergo capacitation

The hormone that is the basis for a pregnancy test is

hCG human chorionic gonadotropin

Which disease is fought by the immune system as part of its function to recognize and remove abnormal "self" cells?

cancer

Autoimmune diseases are an example of a(n) ________ response by the immune system.

incorrect

Which of the following acts as the earliest form of defense against exogenous pathogens in the list?

skin

Antibiotics are drugs that destroy or inhibit the growth of

bacteria

Viruses

must reproduce inside cells of the host and are considered to be parasitic.

A decrease in which population of lymphocytes would impair all aspects of an immune response?

helper T cells

Milly has just received a kidney transplant and is taking cyclosporin A, a drug that suppresses cytotoxic T cells. What does this medication do?

prevents rejection

What are the two primary lymphoid tissues?

thymus and bone marrow

What is the function of secondary lymphoid tissues?

to allow mature immune cells to interact with pathogens

What makes up the white pulp of the spleen and most of the interior of lymph nodes?

lymphocytes

Which cell type functions to both ingest invaders and present antigens?

macrophages

The majority of leukocytes in the blood are the ________ .

neutrophils

How do glands in the airway contribute to the defense of the body?

They secrete mucus to trap pathogens.

By which mechanism do natural killer cells destroy virally infected cells?

induction of apoptosis through secretion of interferons

Which class of molecules attracts phagocytes to the site of an infection?

chemotaxins

Which compound causes pain and acts as a vasodilator?

bradykinin

What is the ultimate outcome when the complement cascade is activated?

Pores are formed in a pathogen membrane, causing it to lyse.

Phagocytic leukocytes ingest pathogens and foreign particles into ________.

phagosomes

When the immune system creates a response that is overblown in relation to the threat it has been exposed to, the response is called an

allergic reaction

Swelling and soreness of the lymph nodes indicate that

immune cells are fighting infection

All of the following are characteristics of acquired immunity EXCEPT

nonspecific immunity INCLUDES: cell mediated, humoral, and adaptive immunity

Opsonins function by

marking or tagging pathogens so phagocytes can find and ingest them.

Which type of antibody makes up the majority of immunoglobulins secreted during a secondary immune response?

IgG

Antigens expressed by plasma cells are secreted from the cell. What is the function of these free antibodies?

They can cause clumping of pathogens, enhancing phagocytosis.

Example of passive immunity

acquisition of maternal antibodies by a fetus

Stem cells that will form B lymphocytes are found in the

bone marrow

Lymphocytes that attack foreign cells or body cells infected with viruses are

Cytotoxic T Cells

Stem cells that will form T lymphocytes are modified in the

thymus

When an antigen complex is bound to a Class I MHC molecule, it can stimulate a

Cytotoxic T cell

Class II MHCs are found

only on lymphocytes and macrophages.