Bio 102: Chapter 42 & 43
A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. To travel from the artery to the thumb and then back to the left ventricle, this red blood cell must pass through _____.
2 capillary beds
To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a(n) ___
4 chambered heart
A patient with a heart rate of 70 beats per minute and a stroke volume of 70 mL/beat will have a cardiac output of ______
4,900 mL/minute
Stroke occurs when _____
A blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue
You are a cardiologist interested in helping people with long QT syndrome be able to safely engage in exercise. What do you need to manage?
Abnormal electrical activity in the heart
By picking up hydrogen ions, hemoglobin prevents the blood from becoming too ____
Acidic
What is the direct cause of demineralization of the enamel on teeth?
Acids produced by bacteria
A normal event in the process of blood clotting is the ___
Activation of prothrombin to thrombin
Chambers A and B are separated by a membrane permeable to substance X. The concentration of X is 5% in A and 15% in B. The volume of A is three times that of B. What will occur?
Although diffusion is random, the result will be the net movement of X from B to A
Which lung structure is a tiny sac that functions as an interface between air and blood?
Alveoli
Consider the following reaction. If the pH of the blood was decreased, then the ________. CO2 + H2O ↔ H2CO3 ↔ HCO3- + H+
Amount of carbon dioxide would increase
_____ in carbon dioxide in your red blood cells, which causes _____ in pH, causes your breathing to speed up
An increase ... a drop
Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to ___
Be unaffected
An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it ___
Blocks the openings into the tracheal system
The diagnosis of hypertension in adults is based on the ____
Blood pressure being greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolic
In order for blood to always flow unidirectionally through a closed circulatory system, the ______
Blood vessels farthest from the heart must have valves
The systemic circulation is the higher-pressure circuit to the
Body
Your diaphragm spasms. What bodily function will be most affected?
Breathing
The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the ____
Bronchiole
High blood pressure in a mammal would most likely result in what?
Bursting of blood vessels in capillary beds
Compared to mammals that are not adapted for diving, diving mammals ______
Can store more oxygen in their muscles
Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries?
Capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.
During most daily activities, the human respiration rate is most closely linked to the blood levels of _____
Carbon dioxide
Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have a _______
Closed circulatory system
In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues ____
Combined with hemoglobin
In order for the diaphragm to form properly, a layer of which tissue develops first?
Connective tissue
During aerobic exercise, the partial pressure of oxygen in muscle cells will ________, thus the rate of diffusion of oxygen into the muscle tissue from the blood will ________
Decrease; increase
Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the _____
Development of an osmotic pressure difference across capillary walls
Countercurrent exchange in the fish gill helps to maximize _____
Diffusion
Damage to the sinoatrial node in humans would _____
Disrupt the rate and timing of cardiac muscle contractions
What organism has no specialized respiratory structures?
Earthworms
A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to ______
Give up more of its oxygen molecules
Under identical atmospheric conditions, freshwater ______
Has more dissolved oxygen than seawater
Your cousin is quite ill and needs Novalung. What organ will it be connected to?
Heart
You are a transplant doctor. When doing a transplant, you would use ECLS to do the work of what organs?
Heart and lungs
Your aunt is a cardiac surgeon performing surgery on a former marathon runner. Which of the following will she most likely find?
Her patient's heart has larger than average left and right ventricles
Blood and interstitial fluid are considered to be the same body fluid in what group of animals?
Insects
What is the function of a circulatory system?
It brings a transport liquid into close contact with all cells in the body
If a molecule of CO2 released into the blood in your left toe is exhaled from your nose, it does NOT pass through what structure?
Pulmonary Vein
The greatest difference in the concentration of respiratory gases is found in what pair of mammalian blood vessels?
Pulmonary vein and Superior vena cava
From the superior vena cava, blood flows to the ____
Right atrium
The driving force for the diffusion of oxygen from hemoglobin into tissues is
The difference in PO2 levels between the blood (100 mm Hg when oxygenated) and body tissues (40 mm Hg at rest).
The lungs of humans form from
The embryonic foregut
Which of the following respiratory systems is not closely associated with a blood supply?
The tracheal system of an insect
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
Humans infected with some types of parasitic worms develop a condition called elephantiasis, which is characterized by swelling of the limbs. What would most likely cause of elephantiasis?
The worms are blocking the lymph vessels
Countercurrent exchange is evident in the flow of _____
Water across the gills of a fish and the blood within those gills
Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a
higher P(O2)
flow of air into the lung of a mammal
larnyx → trachea → bronchi → bronchioles → alveoli
Blood returns to the heart via the _____.
pulmonary veins
Sequence of blood flow (beginning at the vena cava) through birds and mammals
vena cava → right atrium → right ventricle → pulmonary artery
When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO2 is ______
40 mm Hg
A person with a tidal volume of 450 mL (milliliters), a vital capacity of 4000 mL, and a residual volume of 1000 mL would have a potential total lung capacity of ____
5000 mL
Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO2) on Mount Everest is approximately _______
53 mm Hg
Most carbon dioxide is carried from the body tissues to the lungs ___
As bicarbonate ions (HCO3 -)
An anthropologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was well-formed, and had four chambers, with no connection between the right and left sides. A reasonable conclusion supported by these observations is that the animal was ____
Endothermic and had a high metabolic rate
Your aunt is a biochemical engineer assigned to improve the ECMO machine. This would help with
Gas exchange of oxygen and carbon dioxide
Your cousin finishes an Ironman triathlon. Which of the following is most likely?
His heart will have increased leakiness following the race
What mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates?
I) Changing the force of heart contraction II) Constricting and relaxing smooth muscle in the walls of arterioles III) Opening or closing precapillary sphincters
How are gases transported in insect bodies?
In tracheal systems
From the pulmonary veins, blood flows to the ____
Left atrium
The pulmonary circulation is the lower-pressure circuit to the
Lung
In an open circulatory system, blood is _____
Not always confined to blood vessels and is under lower pressure than in closed circulatory systems
One feature that amphibians and humans have in common is
Number of circuits for circulation
Capillary beds are the site of
Nutrient and oxygen delivery to tissues
Atrial systole _______
Occurs at the same time as ventricular diastole
What event occurs first during atrial and ventricular diastole?
The atria and ventricles are relaxed, and blood flows into the atria
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
Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as _____
The medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing
The sun shining on a tidal pool during a hot day heats the water, causing some water to evaporate. Because the water has become warmer and saltier, _______
The oxygen content will decrease
An electrocardiogram (ECG) provides information about _______
The rhythm of heart contractions
Circulatory systems compensate for ___
The slow rate at which diffusion occurs over large distances
An advantage of gas exchange in fresh water, compared with gas exchange in air, is that ____
Water loss through evaporation across the respiratory surface can be minimized
Dentists sometimes give a patient antibiotics after a teeth-cleaning procedure, especially if the patient is older or has heart disease. What is the best explanation for this?
Antibiotics help kill the bacteria that move from the mouth to the bloodstream, and prevent the bacteria from contributing to atherosclerosis
________ is a hormone that is released from the ________ to stimulate the production of red blood cells
Erythropoietin; kidney
Which barrier(s) must O2 and CO2 cross to pass between air and blood inside lungs?
Extracellular fluid, epithelial cells, capillary wall
True or false? The pressure inside the human chest cavity is always positive, so the lungs stay relatively inflated even upon exhalation
False
The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the _____.
Fishes
To become bound to hemoglobin for transport in mammals, atmospheric molecules of oxygen must cross _______
Five membranesin and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cellto bind with hemoglobin
If the osmotic pressure on the venous side of capillary beds is lower than the hydrostatic pressure, then _______
Fluid will tend to accumulate in tissues
In what organism does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body?
Frogs
How has the avian lung adapted to the metabolic demands of flight?
Gas exchange occurs during both inhalation and exhalation
Small swollen areas in the neck, groin, and axillary region are associated with _____
Increased activity in the immune system
The amount of oxygen bound to hemoglobin ___
Increases in the presence of high concentrations of oxygen
From the capillaries of the abdominal organs and hind limbs, blood flows to the ____
Inferior vena cava
What is the function of the left ventricle?
It pumps systemic blood to the lungs via the pulmonary circulation
Blood returning to the mammalian heart in a pulmonary vein drains first into the
Left atrium
Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?
Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle
What is the direct cause of gum disease?
Plaque formed by bacteria
The circulatory systems of bony fishes, rays, and sharks are most similar to the _______
Portal system of mammals
What is the function of valves?
Prevent backflow of blood
Hyperventilation (rapid inhalation and exhalation) can result in respiratory alkalosis (increased blood pH). Why?
Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases.
What would be the consequence if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would _______
Reduce efficiency of gas exchange
When you hold your breath, which of the following blood gas changes first leads to the urge to breathe?
Rising CO2
People who produce very little saliva often have more cavities. What is the best explanation for this?
Since saliva normally helps neutralize acid and replace minerals on teeth, a lack of saliva leads to more cavities
What develops the greatest pressure on the blood in the mammalian aorta?
Systole of the left ventricle
What would you expect of a species that has a high resting cardiac output?
The animal likely has a very long distance between its heart and its brain
A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why?
The partial pressure of oxygen in the air at high elevations is lower than at sea level
Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin. What selective pressure most likely led to the convergent evolution of these respiratory structures?
When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse
While jogging, a person has a stroke volume of 130 ml/beat and a heart rate of 120 beats per minute. If their resting stroke volume was 70 ml/beat and resting heart rate was 60 beats per minute, how did this person's cardiac output change?q
increased from 4,200 ml/minute to 15,600 ml/minute after jogging