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chapter 13 (13.1 blood vessels (capillaries (capillary arrangement (higher…

- - - - higher cellular needs (brain, muscle) = more elaborate network
      - lower cellular needs = less branching
    - - smooth muscle control blood entry into capillary beds
      - metabolic need controls precapillary sphincter
    - - gases, nutrients, and wastes are exchanged between blood in capillaries and tissues in three ways
        
        diffusion
        
        most common
        
        substances include oxygen, CO2, glucose, and hormones
        
        lipid- soluble substances pass directly through endothelial cell membrane
        
        water - soluble substances may pass through gaps between endothelial cells
        
        vesicular transport ( endo/exocytosis )
        
        bulk flow ( filtration and absorption)
        
        filtration
        
        hydrostatic (blood) pressure pushes small solutes and fluid out of capillary
        
        colloid osmotic pressure (osmosis) draws fluid back into capillary
        
        net affect is a fluid loss at the beginning of capillary bed but most is regained by the end of the capillary bed
        
        fluid not regained enters lymphatic vessels
  - - - contain valves; in medium sized veins and the limbs
      - carry blood that is high in carbon dioxide and low in oxygen except the pulmonary veins
    - - composed of a tunica externa, tunica intima pressure
      - extend capillaries and merge together to form veins
  - - - is the thickest layer composed of smooth muscle cells, and elastic fibers
    - - the outermost layer composed of elastic fibers, and collagen fibers
    - - surrounds lumen and is composed of a layer of endothelium, a basement membrane, and an internal elastic lamina
  - - - vasoconstriction (contraction) = decrease vessel volume = decreased blood flow= increased blood pressure
      - vasodialation =increased vessel volume =increased blood flow = decreased blood pressure
  - - - the muscular layer of blood vessels is the tunica media
      - compared to veins, arteries are more elastic
      - the blood vessels that carry blood at the highest pressure are the arteries
      - the blood vessels that have only a tunica intima are the capillaries
      - veins hold the greatest volume of blood
      - arteries blood flow has the highest velocity
      - the brachial artery would be classified as a muscular artery
      - the outermost layer of the arterial wall is the tunica externa
      - the normal blood volume of the arterial system is the lesser amount rather than the venous system
      - the vessels that permit exchange of materials between the cells and the blood are termed capillaries
    - - plasma proteins that remain in the blood capillaries help maintain the osmotic pressure of the blood
      - blood flow through the cardiovascular system is affected by pressure differences, the viscosity of the blood, and the amount of friction in the blood vessels
      - the blood hydrostatic pressure and the blood osmotic pressure are equal in magnitude but opposite in direction would completely stop all NET filtration
      - as blood travels from the aorta toward the capillaries the resistance increases
      - 20-30 mm Hg is the normal pressure within the capillaries
      - transport mechanisms used by capillaries include diffusion, filtration, and osmosis
      - swelling of a tissue due to increased permeability of capillaries
      - blood moves through veins because the pressure in the veins is lower than in the arteries, with the aid of contractions of skeletal muscles, and with the aid of changes in cavity pressure
      - the third and fourth heart sounds are caused by turbulence
      - edema would be likely to form when the heart is an unsufficient pump
    - - increased levels of atrial natriuretic peptide will cause a decrease in blood pressure
      - relaxation of precapillary sphincters will result in increased nutrient delivery to a specific tissue
      - baroreceptors that function in the regulation of blood pressure are located in the left ventricle, brain stem, and carotid sinuses
      - blood pressure in the systemic arteries is greatest during ventricular systole
      - angiotensin increases blood pressure by increasing peripheral resistance
      - decreased blood flow to the kidneys will result in an increase in blood pressure
      - ADH causes a direct increase in blood volume
      - blood pressure when sympathetic stimulation to the heart increases is greater than blood pressure when parasympathetic stimulation increases
      - when a capillary bed decreases in blood flow due to locally high oxygen levels, it is caused by autoregulations
      - blood pressure is lowest in the vein
      - the baroreceptor reflex causes changes in blood pressure, stroke volume, and heart rate
      - a decrease in vessel diameter is called vasoconstriction
    - - the celiac artery provides blood to the liver and spleen
      - the superior mesenteric artery supplies blood to parts of the intestinal tract
      - an important artery that supplies blood to the brain is the internal carotid
      - blood from the face returns to the heart by way of the external jugular vein
      - the pulse point on the wrist is actually the radial artery
      - after passing the axilla, the axillary artery becomes the brachial artery
      - in the forearm, the brachial artery becomes the radial and ulnar artery
      - the internal carotids and the basilar artery are interconnected by an anastomosis called the circle of willis
      - the diaphragm divides the aorta into a superior thoracic aorta and an inferior abdominal aorta
      - near the level of vertebra L4, the aorta branches to form the common iliac arteries
      - the vessel that receives blood from below the diaphragm is the inferior vena cava
      - small veins of the brain empty into the dural sinuses
      - after receiving the internal jugular vein, the subclavian vein becomes the brachiocephalic vein
      - the fusion of the brachiocephalic vein forms the superior vena cava
      - ligamentum arteriosum is a remnant of a fetal blood vessel
      - the common iliac veins form the inferior vena cava
      - elderly individuals are more prone to suffer from hypertension, venous thrombosis, arteriosclerosis, and problems with the conducting system of the heart than younger individuals
      - factors that increase the risk of atherosclerosis include obesity
      - if you have a disabled posterior pituary you should expect decreased blood volume
      - in response to hemorrhage, there is mobilization of the venous reserve
      - symptoms of shock include hypotension, rapid, weak pulse, decreased urine formation, and acidosis
      - heart rate during cardiovascular shock is greater than your heart rate normally
- - - - monitor the degree of stretch in the walls of expandable organs
      - they're located in the aortic sinuses ( pockets in the walls of the aorta adjacent to the heart), and in the walls of the carotid sinuses (expanded chambers near the bases of the internal carotid arteries of the neck)
    - - respond to changes in carbon dioxide, oxygen, or pH in blood or cerebrospinal fluid
      - they're located in the carotid bodies ( located in the neck near the carotid sinuses), and in the aortic bodies ( near the arch of the aorta)
  - - - is released at the posterior pituitary gland in response to a decrease in blood volume, an increase in the osmotic concentration of the plasma, or the presence of angiotensin ll
    - - formed in the blood following the release of the enzyme renin by specialized kidney cells in response to a fall in blood pressure
      - stimulates the cardiac input and triggers the arteriole constriction, which elevates systemic blood pressure almost immediately
    - - released by the kidneys when blood pressure falls or the oxygen content of the blood becomes abnormally low
      - it stimulates red blood cell production, elevating blood volume and improving the oxygen carrying capacity of the blood
    - - is stimulated by increased blood pressure
      - is produced by cardiac muscle cells in the wall of the right atrium when they're stretched by excessive venous return
      - reduces blood volume and blood pressure by increasing the loss of sodium ions and water at the kidneys, promoting water losses by increasing the volume of urine produced, reducing thirst, blocking the release of ADH, aldosterone, E, and NE, amd stimulating peripheral vasodialation
- - - - aneurysm, stroke, myocardial infarction, or massive blood loss
- - - - any force that opposes movement
    - - liquids can't be compressed (hydrostatic pressure)
        
        liquid will flow from high to low
      - circulatory pressure 100 mm Hg base of aorta (pressure gradient)
        
        needed to force blood through arterioles and into capillaries
        
        arterial pressure (blood pressure) measured on arm
        
        systolic pressure is the peak blood pressure measured during ventricular systole
        
        diastolic pressure is the minimum blood pressure at the end of ventricular diastole
        
        capillary pressure
        
        pushes against capillary walls, just as it does in arteries
        
        venous pressure
        
        pressure at the start of the venous system is only one-tenth that at the start of the arterial system
        
        venous pressures are low, and the veins offer little resistance
    - - the resistance of the blood vessels to blood flow
        
        most vascular resistance occurs in arterioles, which are extremely muscular.
    - - resistance to flow resulting from interactions among molecules and suspended materials in a liquid
    - - slows flow and increases resistance
    - - adjustments in the peripheral resistance of vessels supplying specific organs allow the rate of blood flow to be precisely controlled
  - - - as blood travels through the venous system toward the heart, the veins become larger, resistance drops further, and the flow rate increases
    - - the pressure exerted by blood on the wall of blood vessel
- - - - short-term appear almost as soon as blood pressure starts to decline, when the carotid and aortic reflexes increase cardiac output and cause peripheral vasoconstriction
    - - after serious hemorrhage, several days may pass before blood volume returns to normal. when short-term are unable to to maintain normal cardiac output and blood pressure, the decline in capillary blood pressure triggers a recall of fluids from the interstitial places
      - over this period, ADH and aldosterone promote fluid retention and reabsorption at the kidneys, preventing further reductions in blood volume. thirst increases and additional water is absorbed across the digestive tract
- - - - ascending aorta
        
        branches of the ascending aorta
        
        right coronary artery
        
        left coronary artery
      - aortic arch
        
        branches of the aortic arch
        
        brachiocephalic
        
        right common carotid
        
        external carotid artery
        
        internal carotid artery
        
        vertebral
        
        basilar artery
        
        circle of willis
        
        right subclavian artery
        
        axillary
        
        brachial
        
        radial
        
        ulnar
        
        palmar arches
        
        left common carotid artery
        
        left subclavian artery
      - thoracic aorta
        
        intercostals
        
        superior phrenics
        
        bronchial arteies
        
        esophogal arteries
      - abdominal aorta
        
        inferior phrenics
        
        celiac trunk
        
        common hepatic arteries
        
        left gastric artery
        
        splenic artery
        
        superior mesenteric
        
        ascending/transverse colon
        
        suprarenals
        
        renal arteries
        
        gonadal arteries
        
        inferior mesenteric
      - median cubital vein
      - superior vena cava
      - coronary sinus
        
        cardiac veins
      - hepatic veins
        
        gastric veins
        
        mesenteric veins
        
        splenic veins
      - great saphenous veins
      - inferior vena cava
      - azygous system- azygous veins
- - - - rise from internal iliac arteries
    - - exchange of nutrients
    - - liver
      - ductus venosus
        
        inferior vena cava
    - - foramen ovale
      - ductus arteriosus
    - - foramen ovale closes
      - ductus arteriosus becomes ligamentum arteriosum