Physiology EXAM 3
After dilation of an arteriole, the arterial blood pressure returns to the level that it was before the dilation.
False
An action potential in a cardiac muscle fiber is identical to an action potential in a skeletal muscle fiber.
False
As the lungs expand while breathing, the pressure in the lungs decreases.
False
If given the choice between traveling through a vessel with high resistance and one of low resistance, blood will travel through the vessel of most resistance.
False
Oxygen-rich blood is carried through pulmonary arteries from the lungs to the heart.
False
List in order the three layers of the hear wall from deep to superficial.
1. endocardium 2. myocardium 3. epicardium
List in the correct order the major phases of the cardiac cycle following ventricular filling.
1. isovolumetric contraction 2. ventricular ejection 3. isovolumetric relaxation
Which of the following statements is not true concerning blood vessels?
as vessel size decreases in cross section, volume increases.
Plasma consists of:
water, electrolytes, nutrients, organic waste, albumins, globulins, and fibrinogen
During which complete phase of the cardiac cycle do both the atria and ventricles relax?
Isovolumetric - ventricles relax
How does carbon monoxide reduce the amount of oxygen in the blood?
It combines with haemoglobin in red blood cells, preventing oxygen combining with the haemoglobin. This causes an increase in heart rate to compensate for the reduced amount of oxygen carried in the blood.
Match the levels of Po2 and Pco2 with the corresponding point in the circulatory route.
Tissue Fluid - Po2 40 mm Hg -Pco2 46 mm Hg Oxygenated Blood - Po2 95 mm Hg -Pco2 40 mm Hg Alveolar Air - Po2 104 mm Hg -Pco2 40 mm Hg
What are the two principal functions of erythrocytes?
To pick up oxygen from the lungs and deliver it to tissues elsewhere and to pick up carbon dioxide from the tissues and unload it in the lungs. A severe deficiency of RBCs can be fatal within minutes
As the volume in the alveoli increases, the pressure decreases.
True
Blood flow is affected by both blood pressure and vessel resistance.
True
Blood pressure is directly proportional to vessel resistance.
True
During an action potential, the cardiac muscle cell membrane is most permeable to sodium.
True
In the ventricles, the action potential travels along the interventricular septum to the apex of the heart, where it then spreads superiorly along the ventricle walls.
True
Oxygen-poor blood is carried through systemic veins from the body tissues back to the heart.
True
The partial pressure of oxygen usually has little effect on respiration.
True
The sum of the blood velocity of arterioles is equal to the blood velocity of the artery that feeds them.
True
Which brainstem respiratory nucleus is indispensable to respiration?
Ventral Respiratory Group (VRG) - elongated nucleus in medulla > generates rhythm of breathing
During which phase of the cardiac cycle does aortic pressure reach its maximum?
Ventricular Ejection
An individual with high blood pressure (hypertension) is expected to benefit from the administration of ________ inotropic drugs that _________ the hearts workload.
negative, decrease
The direction of gas movement is determined by
partial pressure differences.
Name the discipline that specifically deals with the study of the blood
hematology
Malaria can cause _____ anemia
hemolytic
For a healthy 15-year-old girl at rest, what would be typical readings for systolic pressure, diastolic pressure, pulse pressure, and mean arterial pressure?
sys:120 dia: 75 pp: 45=120-75 map: MAP=dp+1/3pp=75+(1/3)(45)=90
Which of the following statements is true concerning blood vessels?
the sum of the volume per minute of the blood in the capillaries is equal to the volume per minute in the artery that feeds them.
Describe how various plasma components are continuously replaced in the body.
water, nutrients and electrolytes are obtained through absorption in the digestive tract most proteins are produced by the liver gamma globulins come from plasma cells
In a cardiac muscle cell, the membrane potential begins to decrease...
when calcium gates open and calcium diffuses into the cardiac muscle fiber.
In a cardiac muscle cell, the membrane potential decreases rapidly..
when potassium gates open and potassium diffuses out of the cardiac muscle fiber.
In a cardiac muscle cell, the membrane potential increases rapidly...
when the sodium gates open and sodium diffuses into the cardiac muscle fiber.
Place a single word into each sentence to make it correct.
- Electrical currents in the heart can be detected by means of electrodes applied to the skin. - An instrument called the electrocardiograph amplifies these signals and produces a record on a moving paper chart. - The chart includes three principle deflections above and below the baseline; the P wave, QRS complex, and the T wave. - The P wave is produced when a signal from the SA node spreads through the atria and depolarizes them. -The QRS complex is produced when the signal from the AV node spreads through the ventricular myocardium and depolarizes the muscle. - The T wave is generated by ventricular repolarization immediately before diastole.
Define hypocapnia and hypercapnia. Name the pH imbalances that result from these conditions and explain the relationship between Pco2 and pH.
-HYPOCAPNIA - Pco2 less than 37mm Hg (most common cause of alkalosis: blood pH>7.45) - HYPERCAPNIA - Pco2 greater than 43mm Hg (most common cause of acidosis: blood pH<7.35)
Identify at least two each of the transport, protective, and regulatory functions of the circulatory system.
-TRANSPORT: O2, CO2, nutrients, waste, hormones, stem cells -PROTECTIVE: WBCs, inflammation, antibodies, platelets -REGULATORY: stabilize fluid distribution, balance pH of ECF, body temp
What happens to each component of an RBC and its hemoglobin when it dies and disintegrates?
-fragments are digested by macrophages in the liver and spleen -Hb > heme >iron (storage use) AND >biliverdin > bile > feces >globin > free amino acids
List in order the events of platelet plug formation.
1. Contact with collagen of a broken vessel or another rough surface. 2. Platelets grow long spiny pseudopods 3. Platelets stick to each other 4. The pseudopods then contract and draw the vessel walls together 5. This mass of platelets forms a platelet plug
List the correct order for the steps of hemostasis
1. Vascular spasm 2. blood coagulation 3. platelet plug formation
Complete each sentence with the correct word
According to Boyle's law, as volume decreases, pressure increases, and as volume increases pressure decreases. Air always moves from an area of high pressure to an area of low pressure. During inspiration, the pressure in the alveoli is less than the atmospheric pressure. During expiration, the atmospheric pressure is less than the alveolar pressure. When the diaphragm muscle contracts, the pressure in the alveoli decreases. As the intercostal muscles relax and the thoracic cavity becomes smaller, the pressure in the alveoli increases.
Place a single word into each sentence to make it correct.
Capillary beds have precapillary sphincters at the junction of capillaries and the met arteriole. Constriction of these sphincters reduces the blood flow through their respective capillaries. When this occurs, blood is diverted to tissue or organs elsewhere. When the sphincters are open, blood will fill the capillary bed.
The term ______ is defined as the production of red blood cells.
Erythropoiesis
Which of the following contains chemoreceptors?
Medulla oblongata
Carrying the action potentials, the _____ ________ spread throughout the ventricular myocardium to exit the ventricles.
Purkinje fibers
Which of the following structures are considered to be part of the cardiac conduction system?
Purkinje fibers SA node AV node
Which side of the hear pumps blood to the lungs?
Right
What is the best way to estimate the MAP?
Take the diastolic pressure and add one-third of the pulse pressure.
Complete each sentence by dragging the proper label into the appropriate position.
The highest pressure exerted on the arterial walls during the heart cycle is referred to as systolic blood pressure . When one third of pulse pressure is added to the diastolic pressure, a good estimate of mean arterial pressure is obtained. The diastolic blood pressure is measured when the heart is relaxing and represents the lowest pressure exerted in the walls of the arteries during the heart cycle. Subtracting the SBP from the DBP results in pulse pressure which is directly proportional to the overall strength of one's pulse.
Choose the accurate statement(s) about the two reaction pathways that lead to the common pathway of coagulation. Check all that apply.
The intrinsic mechanism uses only clotting factors found in the blood itself. In most cases of bleeding, both the extrinsic and intrinsic mechanisms work simultaneously to contribute to hemostasis. The extrinsic mechanism is initiated by clotting factors released by the damaged blood vessel and perivascular tissues.
Complete each sentence with the correct word.
The majority of CO₂ in the blood is carried as bicarbonate ion. The reaction between CO2 and H2O to H2CO3 is catalyzed by carbonic anhydrase. The chloride shift is an anion exchange that takes place in red blood cells as a mechanism to transport bicarbonate ion out of the cell. The combination of carbon dioxide and protein known as carbaminohemoglobin is abbreviated HbCO₂. Less than 10% of CO₂ is transported as dissolved gas. The ability of CO₂ to bind to deoxygenated hemoglobin more readily than it binds oxyhemoglobin is referred to as the Haldane effect.
Which of the following is caused by excitation of cardiac muscle?
The opening of voltage sensitive membrane calcium channels on the T tubules
Which of the following statements is not true regarding ventricular systole?
The ventricles relax.
Neutrophils
They are the most abundant leukocyte They have nuclei of various shapes
Arteries branch into narrower blood vessels called arterioles.
True
Place a single word into each sentence to make it correct.
Typically, fluid filters out the arterial end of a capillary. Fluid will then osmotically reenter at the venous end. This fluid delivers materials to the cells and removes its waste. This shift in fluid balance at the arterial end is referred to as hydrostatic pressure. This is the physical force exerted by a liquid against a surface like a capillary wall.
Initially, as arteriole outflow increases..
arterial pressure decreases
When arterial outflow becomes greater than inflow..
arterial pressure decreases
Eventually, after the arteriole outflow has remained at an increased level...
arterial pressure reaches a steady state.
In the breakdown of hemoglobin, the globin chains __________.
broken down by macrophages into amino acids
Explain how the baroreflex serves as an example of homeostasis and negative feedback.
chemoreflexes and baroreflexes, responses to fluctuation in blood chemistry, are both NEGATIVE feedback loops
The ______ system consists of the heart, blood vessels, and blood. The ______ system consists only of the heart and blood vessels.
circulatory system ; cardiovascular system
Describe a common source and effect of pulmonary embolism.
clots most often form in the leg vein of most inactive people then travel to small arteries to block the flow >> kidney, heart, brain, lung >> causing tissue death "infarction" pulmonary embolism >> lung clot
Vasoconstriction...
decreases blood flow and increases blood pressure.
Blood flow is...
directly proportional to the cross section of the blood vessel.
The result of the process of inspiration is...
increased alveolar volume causes decreased alveolar pressure.
Vasodilation...
increases blood flow and decreases blood pressure.
The blood flow to the body organs...
is inversely proportional to the resistance of the arterioles leading to them.
The alternate term for a white blood cell is
leukocyte
The transport function of plasma includes the transport of:
nutrients from the digestive system
Contrast the tunica media of a conducting artery, arteriole, and venule and explain how the histological differences are related to the functional differences between these vessels.
oLarge (conducting/elastic) artery •High pressure transport oMedium (distributing/muscular) artery •Distinct elastic lamina •Can regulate blood flow oArteriole •Little elastic tissue •Can regulate blood flow oVenule •Thinner than in artery
Identify a benefit and a disadvantage of normal (non-pathological) bronchoconstriction.
protection from damage due to heat loss in cold BUT can be bad if brought about the asthma or anaphylactic shock
Erythrocyte
red blood cell, the most abundant formed element in the blood
Systolic
refers to contraction of the heart
The depolarization of the SA node (from threshold to peak) is due to the inflow of _____ and ______ ions.
sodium, calcium
The expected effect of the drug Digoxin is to _________ ventricular contraction and _______ stroke volume.
strengthen, increase
The RBC count and hemoglobin concentration are clinical data that describe:
the amount of oxygen the blood can carry
Inspiration begins as _________.
the diaphragm contracts
Inspiration begins as..
the diaphragm contracts.
The portion of the circulatory system that involves moving blood to and from the lungs for gas exchange is known as:
the pulmonary circuit
Distinguish between the pulmonary and systemic circuits and state which part of the heart supplies each one.
-PULMONARY:supplied by RIGHT side of heart; carries blood TO the lungs for gas exchange and returns it to the heart -SYSTEMIC: supplied by LEFT side of heart; supplies blood to every organ (incl. other parts of the lungs and the heart itself)
Place a single word into each sentence to make it correct. Then rearrange the sentences into the correct order to explain the process of the cardiocyte action potential.
1. The action potential of a ventricular cardiocyte begins with opening a voltage gated sodium ion channel. 2. Na+ inflow depolarizes the membrane, triggering the opening of more channels causing a positive feedback cycle. 3. Channels will then close when the voltage reaches +30 mV. 4. Depolarizations is then prolonged via slow calcium ion channels. 5. Once these channels close, potassium ions flow out quickly and restore the resting membrane potential.
List the three mechanisms of capillary exchange and relate each one to the structure of capillary walls.
1. the endothelial cell cytoplasm 2. Intercellular clefts between the endothelial cells 3. Filtration pores (fenestrations) of the fenestrated capillaries.
Air consists of about 78.6% nitrogen, 20.9% oxygen, and 0.04% carbon dioxide. If we assume sea-level pressure of 760 mm Hg, what is the Po2?
159 mm Hg
Which of these events lead to increased airflow and which lead to decreased airflow?
Decreased airflow -Decreased levels of surfactant. - Scar tissue from tuberculosis. - An anaphylactic reaction caused by bee sting. - Breathing sub-zero air. Increased airflow - Bronchodilation caused by using an inhaler to treat asthma. - Aerobic exercise which improves pulmonary compliance.
How do materials get from the blood to the surrounding tissues?
Diffusion, filtration and absorption, and transcytosis
Describe normal erythrocytes
Discoidal cells with a biconcave shape Contain hemoglobin to transport gases like oxygen
The alveoli never attain equal pressure with the ambient (outside) air.
False
_____ is the rupture of red blood cells.
Hemolysis
Indicate which of the following are the correct values of some characteristics of blood.
Osmolarity: 280-296 mOsm/L pH: 7.35-7.45 Volume in females: 4-5L; males 5-6 L Total WBC count: 5,000-10,000/uL
Which of the following statements about partial pressures of gases is TRUE?
PO2 in blood is greater than PO2 in tissues ; PCO2 in blood is less than PCO2 in tissues
Which of the following statements about partial pressures of gases is TRUE?
PO2 in lung is greater than PO2 in blood ; PCO2 in lung is less than PCO2 in blood
What are the two principal components of the blood?
Plasma and The actual red blood cells. They are composed of oxygen and nutrients to be sent around the body. And there is also a tad bit of white blood cells. If you leave blood sit in a vial for a long time, you can see the plasma, rbc's and wbc's.
After tissue repair is completed, factor XII catalyzes the formation of a plasma enzyme called kallikrein, that in turn converts an inactive plasminogen into _________, a fibrin-dissolving enzyme that breaks up the clot.
Plasmin
During expiration...
decreased alveolar volume causes increased alveolar pressure.
The heartbeat originates in the heart muscle itself. The term that describes this characteristic is _____.
myogenic
Positive inotropes allow the heart to pump _____ blood with fewer heart beats. They do this by ___________ the end-systolic volumes (ESV).
more, decreasing