Anatomy_Concepts_Ch18-20 Flashcards

Question 1

Q

erythrocytes structural characteristics contribe to respiratory function:

Answer

A

their bioconcave shape provides 30% more surface area than that of spherical cells of the same volume, allowing rapid diffusion of exygen into and out of erythrocytes. discounting the water that is present in all cells, erythrocytes are over 97% hemoplobin. without a nucleus or organellse, they are little more than bags of oxygen-carrying molecules. erythrocytes lack mitochordria and generate the energy they need by anaerobic mechanisms; therefore, they do not consume any of the oxygen they pick up and are very efficient oxygen transporters

Question 2

Q

relative abundance of leukocytes

Answer

A

neutrophils (50-70%) lymphocytes (25-45%) monocytes (3-8%) eosinophils (2-4%) basophils (.5-1%)

Question 3

Q

stages of differentiation of blood cells in the bone marrow: effector T cell

Answer

A

hematopoietic stem cell lymphoid stem cell T lymphocyte effector T cell

Question 4

Q

stages of differentiation of blood cells in the bone marrow: plasma cell

Answer

A

hemotopoietic stem cell lymphoind stem cell B lymphocyte plasma cell

Question 5

Q

stages of differentiation of blood cells in the bone marrow: platelets

Answer

A

hemotopoietic stem cell myloid stem cell megakaryoblast early megakaryocyte late megakaryocyte platelets

Question 6

Q

stages of differentiation of blood cells in the bone marrow: wandering macrophage

Answer

A

hematopoietic stem cell myeloid stem cell monoblast promonocyte monocyte wandering macrophage

Question 7

Q

stages of differentiation of blood cells in the bone marrow: neutrophil (granular leukocytes)

Answer

A

hematopoietic stem cell myeloid stem cell myeloblasts promylocites neutrophilic myelocyte neutrophilic metamyelocyte neutrophilic band cell neutrophil (granular leukocytes)

Question 8

Q

stages of differentiation of blood cells in the bone marrow: basophil (granular leukocytes)

Answer

A

hematopoietic stem cell myeloid stem cell myeloblasts promyelocytes basophilic myelocyte basophilic metamyelocyte basophil (granular leukocytes)

Question 9

Q

stages of differentiation of blood cells in the bone marrow: eosinophil (granular leukocytes)

Answer

A

hematopoetic stem cell myeloid stem cell myeloblasts promyelocytes acidophilic myelocyte acidophilic metamyelocyte eosinophil (granular leukocytes)

Question 10

Q

stages of differentiation of blood cells in the bone marrow: erythrocyte

Answer

A

hemotopoietic stem cell myeloid stem cell proerythroblast basophilic erythroblast polychromatic erythroblast orthochromatic erythroblast reticulocyte erythrocyte

Question 11

Q

“leukocytes, Wright’s stain”

Answer

A

neutrophil: multilobed nucleus, pale red and blue cytoplastmic granules eosinophil: bilobed nucleus, red cytoplasmic granules basophil: bilobed nucleus, purplish black cytoplasmic granules lymphocyte (small): large spherical nucleus, thin rim of pale blue cytoplasm monocyte: kidney-shaped nucleus, abundant pale blue cytoplasm

Question 12

Q

age-related changes that affect the heart include the following:

Answer

A

hardening and thickening of the cusps of the heart valves. decline in cardiac reserve. fibrosis of cardiac muscle.

Question 13

Q

heart development

Answer

A

(days are approximate) a) day 20: endothelial tubes begin to fuse b) day 22: heart starts pumping c) day 24: heart continues to elongate and starts to bend d) day 28: bending continues as ventricle moves caudally and atrium moves cranially e) day 35: bending is complete

Question 14

Q

the intrinsic conducting system of the heart

Answer

A

1) the sinoatrial (SA) node (pacemaker) generates impulses 2) the impulses pause (0.1 sec) at the atroventricular (AV) node 3) the atrioventricular (AV) bundle connects the atria to the ventricles 4) the bundle branches conduct the impulses through the interventricular septum 5) the subendocardial conducting network stimulates the contractile cells of both ventricles

Question 15

Q

AV valves open; atrial pressure greater than ventricular pressure

Answer

A

1) blood returning to the heart fills atria, pressing tagainst the AV valves. the increased pressure forces AV valves open. 2) as ventricles fill, AV valva flaps hang limply into ventricles. 3) atria contract, forcing additional blood into ventricles.

Question 16

Q

AV valves closed; atrial pressure less than ventricular pressure

Answer

A

1) ventricles contract, forcing blood against AV valve cusps 2) AV valves close 3) papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria

Question 17

Q

semilunar valves open

Answer

A

as ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them open

Question 18

Q

semilunar valves closed

Answer

A

as ventricles relax and intraventricular pressure falls, blood flows back from arteries, filling the cusps of semilunar valves and forcing them to close

Question 19

Q

blood flow through the heart

Answer

A

systemic capillaries to heart (oxygen-poor blood returns from the body tissues back to the heart) superior vena cava (SVC)/inferior vena cava (IVC)/coronary sinus right atrium (tricuspid valve) right ventricle (pulmonary semilunar valve) pulmonary trunk to lungs (oxygen-poor blood is carried in two pulmonary arteries to the lungs (pulmonary circuit) to be oxygenated) pulmonary capillaries to heart (oxygen-rich blood returns tot he heart via the four pulmonary veins) four pulmonary veins left atrium (mitral valve) left ventricle (aortic semilunar valve) aorta to body (oxygen-rich blood is delivered to the body tissues (systemic circuit) systemic capillaries

Question 20

Q

four corners of the heart

Answer

A

“the superior right point lies on the right where the costal cortilage of the third rib joins the sternum. the superior left point lies at the costal cartilage of the second rib on the left, a finger’s breadth lateral to the sternum. the inferior right point lies at the costal cartilage of the sixth rib on the right, a finger’s breadth lateral to the sternum. the inferior leftpoint (the apex point) lies on the left in the fifth intercostal stpace at the midclavicular line–that is, at a line extending inferiorly from the midpoint of the left clavicle.”

Question 21

Q

four functions of the cardiac skeleton

Answer

A

it anchors the valve cusps 2. it prevents overdilation of the valve openings as blood pulses through them 3. it is the point of attachment for the bundles of cardiac muscle in theatria and ventricles 4. it blocks the direct spread of electrical impulses from the atria to the ventricles. this function is critical for the proper coordination of atrial and ventricular contractions

Question 22

Q

order of heart valves closing

Answer

A

mitral valve, tricuspid vave, aortic valve, pulmonary valve

Question 23

Q

the following features distinguish muscular arteries:

Answer

A

the tunica media of muscular arteries is thicker relative to the size of the lumen than that of any other type of vessel. by actively changing the diameter of the artery, this muscular layer regulates the amount of blood flowing to an organ according to the specific needs of that organ. the soomth muscle of the tunica media of muscular arteries is sandwiched between two thick sheets of elastin: a wavy iternal elastic membrane forms the outer layer of the tunica intima, and an external elastic membrane forms the outer layer of the tunica media. these elastic membranes, in addition to the thin sheets of elastin found within the tunica media, help to dampen the pulsatile pressure produced by the heartbeat.

Question 24

Q

the diameter of each arteriole is rugulated in two ways:

Answer

A

1) local factors in the tissues signal the smooth muscle cells to contract or relax, thus regulating the amount of blood sentdownstream to each capillary bed 2) sympathetic nervous system adjusts the diameter of arterioles throughout the body to regulate systemic blood pressure

Question 25

Q

capillary functions

Answer

A

deliveroxygen and nutrients cells need remove carbon dioxide and nitrogenous wastes that cells deposit into the fluid oxygen enters the blood in the lungs receive digested nutrients in the small intestine pick up hormones in the endocrine glands remove nitrogenous wastes from the body in the kidneys

Question 26

Q

molecules pass into and out of capillaries through four routes

Answer

A

direct diffusion through the endothelial cell membranes. intercellular clefts. fenestrations. pinocytotic vesicles.

Question 27

Q

veins differ structurally from arteries in the following ways

Answer

A

“the lumen of a vein is larger than that of an artery of comparable size. at any given time, veins hold fully 65% of the body’s blood. in a wein, the tunica externa is thicker than the tunica media. in an artery, the tunica media is the thicker layer. in the body’s largest veins–the venae cavae, which return systemic blood to the heart–longitudinal bands of smooth muscle further thicken the tunica externa. veins have less elastin in their walls that do arteries because veins do not need to dampen any pulsations (all of which are smoothed out by arteries before the blood reaches the veins). the wall of a vein is thinner than that of a comparable artery. blood pressure declines substantially while blood passes through the high-resistance arterioles and capillary beds; thus, blood pressure in the veins is much lower than in the arteries.”

Question 28

Q

differences in the distributions of arteries and veins:

Answer

A

whereas just one systemic artery leaves the heart (the aorta exiting the left ventricle), three major veins enter the right atrium of the heart: the superior and inferior veae cavae and the coronary sinus. all large and medium-sized arteries have deep locations and are accompanie by deep veins, commonly of similarname. in addition, veins are also found just beneath the skin unaccompanied by any arteries. these superficial veins are important clinically because they provide sites for drawing blood or placing an intravenous line. their superficial location also makes them susceptible to cuts or injuries. commonly, two or more papllel veins drain a body region rather than a single larger vein. in some regions, multiple veins anastomose to form a venous plexus. the brain and digestive tract have unual patterns of venous drainage. veins from the brain drain into dural venous sinuses, which are not typical veins but undothelium-lined channels supported by walls of dura mater. venous blood draining from the digestive organs enters a special subcirculation, the hepatic portal system, and passes through capillaries in the liver before the blood reenters the general systemic circulation.

Question 29

Q

blood is diverted from the fetal pulmanary circuit through shunts:

Answer

A

forament ovale ductus arteriosus

Question 30

Q

newborn circulation

Answer

A

blood is oxygenated in the lungsn. the heart becomes functionally divided with thefirst breaths. the right side of the heart receives and pumps poorly exygenated blood; thel eft side of the heart receives and pumps highly oxygenated blood. 1) lungs inflate with first breaths. the resistance in the pulmonary vessels is reduced; blood pressure in the pulmonary circuit falls. blood from the pulmonary trunk follows the path of least resistance into the pulmonary arteries and travels to the lungs to be oxygenated. 2) foramen ovale and ductus arteriosus close. the increased volume of blood entering the left atrium from the lungs effectively raises the pressure in the atrium, causing the closure of the flaplike valve of the foramen ovale. this structure is now called the fossa ovalis. the ductus arteriosus constricts, closing the shunt to the aorta. the remaining structure is called the ligamentum arteriosum. 3) the heart is now functionally divided. the left side receives highly oxygenated blood from the lungs and pumps blood through the systemic circuit. the right side receives poorly oxygenated blood from the body and pumps it through the pulmonary circuit.

Question 31

Q

fetal circulation

Answer

A

blood is oxygenated at the placenta; the fetal lungs are not functioning. fetal circulation has two routes to bypass the pulmonary circuit: the foramen ovale, and opening in the interatrial septum, and the ductus ateriosus, a shunt between the pulmonary trunk and the aorta. 1) the placenta oxygenates fetal blood. the umbilical vein returns highly exygenated blood to the fetus. 2) the ductus venosus shunts blood trhough the liver. most of the blood in the umbilical vein bypasses the liver capillaries and is delivered to the inferior vena cava (IVC). 3) the foramen ovale shunts blood from the right atrium to the left atrium. much of the blood delivered to the right atrium (RA) by the IVC is shunted to the left atrium (LA) via a hole in the interatrial septum, the foramen avale. this blood is pumped out of the left ventricle into the aorta for discribution to the fetal tissues. 4) the ductus arteriosus diverts blood in the pulmonary trunk to the aorta. blood entering the right atrium from the superior vena cava (SVC) passes into the right ventricle and is pumped into the pulmonary trunk. since fetal lungs are not inflated, resistance is high in the pulmonary arteries. consequently, blood is shunted from the pulmonary trunk to the ductus arteriosus, which connects to the arch of the aorta. 5) the paired umbilical arterios deliver blood to the placenta. branching off the internal iliac arteries, the umbilical arteries carry blood low in oxygen to the placenta.

Question 32

Q

tributaries of the heaptic portal vein

Answer

A

superior mesenteric vein splenic vein inferior mesenteric vein

Question 33

Q

three arteries branch from the aortic arch and run superiorly

Answer

A

brachiocephalic trunk. this largest branch ascends to the right toward the base of the neck where it divides into the right common carotid artery and the right subclavian artery left common carotid artery left subclavian artery

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Anatomy_Concepts_Ch18-20 Flashcards

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