RAT #5b Flashcards

Question

Define starling's law

Answer 1

Stroke volume increases in response to as increase in the volume of blood filling the heart

Answer 2

MAP = Mean Arterial Pressure -Average pressure in the arteries, generated by the heart -Adequate MAP is necessary to deliver blood to within a cells length of every cell in the body MAP = CO * TPR CO = (HR+SV)

Answer 3

Pressure moves from highest to lowest as follows: | -Aorta -> arteries ->arterioles and metorterioles -> capillaries -> venules -> veins -> vena cava

Answer 4

- Capillaries - thinnest walled of all the blood vessels being composed of endothelial cells and lacking the smooth muscle, elastic and fibrous tissues of blood vessels. - Arterioles - smooth muscle in their walls determines how much blood will enter a capillary bed - Venules - site of exchange between blood and ISF - Veins - have thinner walls with less elastic tissue than arteries, so they can expand easily when filled with blood. they also hold more than half of the blood in the circulatory system

Answer 5

Mainly influenced by a state of contraction of vascular smooth muscle

Answer 6

- More calcium in the cytosol = greater force of contraction | - Less calcium in the cytosol = more relaxation

Answer 7

1. increased concentration of bad stuff (co2, k+, and other organic acids) 2. Decreased good stuff (oxygen, glucose) 3. Sympathetic activation of beta-adrenergic receptors on blood vessels that supply skeletal muscle, liver, heart (bigger blood blast) 4. Increased Atrial natriuretic peptide (ANP -makes u pee) 5. Increased nitric oxide 6. Increased histamine (too much can cause anaphylactic shock and constriction)

Answer 8

1. Sympathetic activation at alpha-adrenergic receptors 2. Antidiuretic hormone 3. Anglotensin II

Answer 9

Decreased MAP causes baroreceptors in the kidney, aortic arch and carotid artery to send error signals to the integrating center or CNS, the CNS causes effector tissues, vascular circular smooth muscle, SA node (autorhythmic cells), myocardial cells and the kidney to cause an increase in MAP

Answer 10

Percentage of total blood volume that is occupied by packed red blood cells (ratio of red blood cells to plasma)

Answer 11

Erythropoietin (EPO) is secreted by the kidney in response to low oxygen levels in the blood. EPO travels to receptors in the bone marrow and causes the synthesis of more red blood cells. When people spend more time at high altitudes their hematocrit increases because they are constantly exposed to hypoxic (low oxygen) conditions

Answer 12

Hemoglobin is converted to a metabolite called bilirubin which is yellow in color and is excreted in the urine and feces. The spleen and liver are the main organs that produce bilirubin. Adults with liver disease very often appear yellow or jaundiced because they are not processing hemoglobin metabolites efficiently. This is also seen in newborns because their livers are still immature and they are switching from the fetal to adult form of hemoglobin and are producing large quantities of bilirubin.

Answer 13

Plug formation begins with platelet adhesion, when platelets adhere or stick to exposed collagen in the damaged area. The adhered platelets become activated, releasing cytokines into the area around the injury. These platelet factors reinforce local vasoconstriction and activate more platelets, which aggregate or stick to one another to form a loose platelet plug. Simultaneously, exposed collagen and tissue factor, initiate the third step, the formation of a fibrin protein mesh that stabilizes the platelet plug to form a clot. Fibrin is the end product of a series of enzymatic reactions known as the coagulation cascade. Eventually as the damaged vessel repairs itself, the clot retracts when fibrin is slowly dissolved by the enzyme plasmin.

Answer 14

1. LDL - cholesterol accumulates between the endothelium and connective tissue and is oxidized 2. Macrophages ingest cholesterol and become foam cells 3. Smooth muscle cells, attracted by macrophage cytokines, begin to divide and take up cholesterol 4. A lipid core accumulates beneath the endothelium 5. Fibrous scar tissue forms to wall off the lipid core 6. Smooth muscle cells divide and contribute to thickining o the intima 7. Calcifications are deposited within the plaque 8. Macrophages may release enzymes that dissolve collagen and convert stable plaques to unstable plaques 9. Platelets that are exposed to collagen become activated and initiate a blood clot

Answer 15

Diuretics - diuretics make you have to pee and if blood volume increases, blood pressure increases, therefore if you take a diuretic you will be decreasing your blood volume thus decreasing blood pressure

Answer 16

Decreased renal blood pressure causes increased secretion of renin from the kidney. Renin converts angiotensinogen (inactive) into angiotensin I (active). Then ACE (angiotensin converting enzyme) converts angiotensin I to Angiotensin II. Angiotensin II causes peripheral vasoconstriction, increased ADH secretion, and increased aldosterone secretion from the adrenal cortex, which combined result in increased MAP and water conservation

Answer 17

Low MAP, high plasma osmolarity, and decreased atrial stretch cause an increase number of AP in baroreceptor neurons. This causes an increased secretion of ADH from the posterior pituitary gland, where it binds to receptors in the kidney and vascular circular smooth muscle. This causes peripheral vasoconstriction and water conservation by the kidneys resulting in increased MAP

Answer 18

Excess fluid ingested causes an increase in blood volume. This increases causes an increase in atrial stretch resulting in an increase in the release of ANP from the heart. This causes more urine to be formed in the kidneys, and relaxation of VSM. Reducing blood volume and lower MAP. "ANP makes you have to pee"