Ch. 17 HW Human Physiology

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

1 billion molecules of O2 Yes, there are 4 heme groups in each hemoglobin molecule and there are 250 million hemoglobin molecules in each red blood cell.

In order to diffuse from the blood into the alveoli, oxygen and carbon dioxide have to cross __________ cell layer(s) and a basement membrane.

2

Under normal conditions, the oxygen carrying capacity of hemoglobin is about __________.

200 mL of O2 /L of blood

The invention of the SCUBA tank by Jacques Cousteau allowed humans to dive underwater and remain there for around __________. The SCUBA tank contained normal air, which is comprised of __________ percent nitrogen and __________ percent oxygen.

30-60 minutes; 79; 21

For every __________ feet that a diver descends under water, the pressure increases by 1 atmosphere (760 mm Hg). This increased pressure can drive nitrogen into the blood. Because nitrogen is minimally soluble in blood, it forms bubbles in the bloodstream, just as carbon dioxide does when forced (pushed) into a beverage to make it carbonated.

33

From the oxygen-hemoglobin dissociation curve, hemoglobin is __________ when the partial pressure of oxygen is 40 mm Hg. Would this be in the lungs, inactive tissues, or active tissues?

75% saturated; in the inactive tissues Yes, hemoglobin saturation would be 75% when the partial pressure of oxygen is 40 mm Hg and this would be in the inactive tissues. Active tissues would have a lower saturation.

At sea level, the atmospheric pressure is __________ mm Hg. According to Dalton's law, __________ would have the highest partial pressure in Earth's atmosphere.

760; nitrogen

According to the hemoglobin dissociation curve, in systemic arteries at 100 mmHg, what is the percentage saturation of hemoglobin?

98%

Q: According to the hemoglobin dissociation curve, in systemic arteries at 100 mmHg, what is the percentage saturation of hemoglobin?

98.5

In the lungs, HCO3- (bicarbonate) combines with H+ to form carbonic acid, which carbonic anhydrase then converts to __________.

CO2 and H2O

According to __________, the partial pressure of a gas in a mixture of gases is equal to the percent of the gas present in the mixture multiplied by the total combined pressure of all the gases in the mixture of gases. PP of certain gas = (% of certain gas in mixture/100) x (total combined pressure of all the gases in the mixture)

Dalton's

What directly stimulates the central chemoreceptors, thus increasing respiration?

H+ (hydrogen ions) Yes, hydrogen ions (H+) stimulate the central chemoreceptors. CO2 is converted to H+ in the extracellular fluid of the brain.

__________ law determines how much a certain gas will dissolve in a certain liquid. The Henry's formula states that the molar concentration 'c' of a gas that will dissolve in a liquid is equal to the partial pressure of the gas above the liquid 'P' times Henry's constant.

Henry's

Which statement is correct? Carbon dioxide diffuses from the alveoli into surrounding capillaries. Oxygen diffuses from large blood vessels into the body's cells. In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. Oxygen is released from the mitochondria as a product of cellular respiration. As oxygen diffuses from the lungs into capillaries, blood becomes deoxygenated.

In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. When oxygen diffuses from the alveoli to the surrounding capillaries, it enters a red blood cell and binds to hemoglobin.

Q: Which of the following statements is FALSE regarding a leftward shift in the hemoglobin-oxygen dissociation curve?

It can be caused by an increase in PCO2.

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. Yes, exercise shifts the curve to the right, making more oxygen available to the tissues.

Hemoglobin is...

a protein that can bind four molecules of oxygen.

From which structures do oxygen molecules move from the lungs to the blood?

alveoli Alveoli are tiny sacs in the lungs surrounded by capillaries. The alveoli are where oxygen diffuses from the lungs to the blood.

Q: Which of the following will cause a shift in the hemoglobin-oxygen dissociation curve to the right?

both an increase in temperature and an increase in plasma pH

Oxygen is transported in the blood by which methods? attached to platelets bound to hemoglobin converted to bicarbonate dissolved in plasma

bound to hemoglobin, and dissolved in plasma

Carbonic anhydrase is an enzyme involved in the conversion of __________ to __________.

carbon dioxide; bicarbonate

A decrease in PCO2 causes __________ of the bronchioles and __________ of the pulmonary arterioles.

constriction; dilation

How is the majority of CO2 transported in blood?

converted to and transported as bicarbonate ions Yes, 70% of CO2 is converted to bicarbonate ions in the red blood cells. The bicarbonate then moves out of the red blood cell into the plasma.

Carbon dioxide is transported in the blood by which methods? attached to platelets bound to hemoglobin converted to bicarbonate dissolved in plasma

converted to bicarbonate, bound to hemoglobin, and dissolved in plasma

Q: Hypoventilation would lead to a(n) __________ within the systemic arteries.

decrease in PO2 and increase in PCO2

As a result of hyperventilation, what will happen to the partial pressures of CO2 (pCO2) and pH?

decreased pCO2 and increased pH Yes, pCO2 would decrease and pH would increase. As CO2 is blown off, H+ would decrease, thus increasing pH.

Nitrogen bubbles in the circulation may cause an air __________. One treatment that drives the nitrogen bubbles back into solution is to place the person in a __________.

embolism; hyperbaric chamber

Links to Helpful Flashcards

https://www.studyblue.com/#flashcard/view/10579299 http://quizlet.com/61870789/bio-2160-final-mastering-ap-ch-16-17-flash-cards/

After blood becomes oxygenated...

it returns to the heart, and is then pumped to body cells.

The Henry's law constant 'k' is experimentally derived; it depends on the particular chemical properties of a certain gas and chemical properties of a certain liquid. Thus, a low value for Henry's constant reflects that a certain gas has a __________ solubility in a certain liquid. A high value reflects that a certain gas has a __________ solubility in a certain liquid.

low; high

Q: What is the most abundant gas in the air that we breathe?

nitrogen

Though __________ is the major gas in the atmosphere, it does not dissolve easily into blood plasma because of a low Henry's constant. However, it can be forced into the blood if there is an increase in its partial pressure.

nitrogen

Dalton's law describes the __________ of gases.

partial pressure

The concentration gradient of oxygen is affected by the __________ and solubility of oxygen.

partial pressure

The diaphragm is the most important muscle of respiration. It is innervated by the __________ nerve.

phrenic

Inspiratory neurons send information to the diaphragm via what nerve?

phrenic nerve Yes, the phrenic nerve innervates the diaphragm. Stimulation causes the diaphragm to contract (increasing volume and decreasing pressure), thus causing inspiration.

Which receptors inhibit inspiration during hyperinflation of the lungs?

pulmonary stretch receptors Yes, inspiration stimulates the pulmonary stretch receptors (PSRs), which send input to the respiratory centers, inhibiting further inspiration.

Newly oxygenated blood returns from the lungs to the heart via the __________.

pulmonary veins

A homeostatic control mechanism controls respiration. What acts as the effector(s) in this system?

respiratory muscles Yes, the respiratory muscles change the volume of the thoracic cavity (and thus the pressure), resulting in inspiration and expiration.

What stimulates increased respiration at the beginning of exercise?

sensory input from receptors in joints, neural input from the motor cortex, and other factors Yes, at the beginning of exercise, blood gases have not changed; thus, other factors such as anticipation of exercise contribute to the increase in respiration.

Peripheral chemoreceptors respond to all EXCEPT which of the following? small changes in PO small changes in H+ ion concentration small changes in pH small changes in PCO2

small changes in PO

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

the Haldane effect Yes, the Haldane effect states that the amount of CO2 carried in the blood is influenced by the amount of O2 carried in the blood. Thus, O2 loading facilitates CO2 unloading.

The nitrogen bubbles will lodge in joints and cause cramps and pain known as __________. When the bubbles move into the nervous system they may cause a loss or decrease in consciousness known as nitrogen narcosis.

the bends

During inhalation,

the diaphragm and rib muscles contract. The contraction of these muscles causes air to enter the lungs.

Q: Hyperpnea describes the increase in ventilation that occurs to meet an increase in metabolic demands of the tissues.

true

What area in the brain sets the respiratory rhythm?

ventral respiratory group (VRG) Yes, the VRG is the rhythm-generating center in the medulla.