Term
|
Definition
| Medium-sized arteries divide into still smaller arteries called arterioles |
|
|
Term
|
Definition
- Arterioles -> Cappillaries
- Thin walls exchange of substances b/t blood and body tissues. |
|
|
Term
|
Definition
| - Capillaries w/in a tissue reunite to form small veins called venules |
|
|
Term
|
Definition
| - Blood vessels that convey blood from the tissues back to the heart. |
|
|
Term
| Basic Structure of a Blood Vessel |
|
Definition
Consists of three layers:
- Tunica interna (intima)
- Tunica media
- Tunica externa (adventia) |
|
|
Term
|
Definition
- Forms inner lining of blood vessel
- In direct contact with blood as it flows through the lumen |
|
|
Term
|
Definition
| Interior opening, of the vessel |
|
|
Term
|
Definition
- A muscular and connective tissue layer that displays greatest variation among the different vessel types
- Extend circularly around lumen like a ring encircles your finger, is to regulate the diameter of the lumen. |
|
|
Term
|
Definition
| A decrease in the diameter of the lumen of a blood vessel |
|
|
Term
|
Definition
| Increase in lumen diameter |
|
|
Term
|
Definition
- The outer covering of a blood vessel
- Contains numerous nerves and, tiny blood vessels that supply the tissue of the vessel wall
- Anchor vessels to surrounding tissues |
|
|
Term
|
Definition
- Largest arteries in the body
- Help propel blood onward while the ventricles are relaxing |
|
|
Term
|
Definition
- The union of the branches of two or more arteries supplying the same body region
- Provide alternative routes for blood to reach a tissue or organ |
|
|
Term
|
Definition
| Alternative route of blood flow to a body part through an anastomosis |
|
|
Term
|
Definition
| - Abundant microscopic vessels that regulate the flow of blood into capillary networks of body’s tissues |
|
|
Term
|
Definition
- Terminal end of the arteriole
- Tapers toward the capillary junction
- Regulating blood flow from arteries into capillaries by regulating resistance
- Vasoconstriction of arterioles increases blood pressure, and vasodilation of arterioles decreases blood pressure. |
|
|
Term
|
Definition
| The opposition to blood flow |
|
|
Term
|
Definition
- Smallest of blood vessels
- Interconnecting vessels course among individual cells of the body
- FN: exchange of substances between the blood and interstitial fluid |
|
|
Term
|
Definition
- Composed of only single layer of endothelial cells and a basement membrane
- Exchange of materials occurs only through the walls of capillaries and the beginning of venules |
|
|
Term
|
Definition
| - Network of 10–100 capillaries that arises from a single metarteriole |
|
|
Term
|
Definition
- Distal end of the vessel
- Has no smooth muscle; it resembles a capillary
- Provides a direct route for blood from an arteriole to a venule, thus by- passing capillaries. |
|
|
Term
|
Definition
- Plasma membranes of endothelial cells form a continuous tube
- Found in the central nervous system, lungs, skin, muscle tissue, and the skin |
|
|
Term
|
Definition
| - Found in kidneys, villi of small intestine, choroid plexuses of ventricles in brain, ciliary processes of eyes, and most endocrine glands. |
|
|
Term
|
Definition
- wider and more winding than other capillaries
- Large intercellular clefts, allow proteins and in some cases even blood cells to pass from a tissue into the bloodstream. |
|
|
Term
|
Definition
- Very thin walls
- Avg b/p is considerably lower than in arteries
- Pumping of heart major factor in moving venous blood back to heart
- Contraction of skeletal muscles in the lower limbs helps boost venous return to heart |
|
|
Term
|
Definition
- Vein with thin endothelial wall
- Has no smooth muscle to alter its diameter |
|
|
Term
|
Definition
| The largest portion of your blood volume at rest—about 64%—is in systemic veins and venules |
|
|
Term
|
Definition
| Blood can be diverted quickly if the need arises |
|
|
Term
|
Definition
- Movement of substances between blood and interstitial fluid
- Blood in systemic capillaries continually exchanging materials with interstitial fluid |
|
|
Term
| Mechanisms of Capillary Exchange |
|
Definition
Three basic mechanisms:
1. diffusion
2. transcytosis
3. bulk flow |
|
|
Term
|
Definition
- Most NP is simple diffusion
- O2 and nutrients higher concentrations in blood
- Diffuse down concentration gradients into interstitial fluid and then into body cells.
- CO2 and other wastes released by body cells are present in higher concentrations in interstitial fluid, so they diffuse into blood. |
|
|
Term
|
Definition
- Sml amount transfer
- Pincytosis
- NP for transporting large, lipid-insoluble molecules that cannot cross capillary walls in any other way. |
|
|
Term
| Bulk Flow: Filtration and Reabsorption |
|
Definition
- A passive process
- Large # of ions, molecules, or particles in a fluid move together in the same direction.
- Occurs from an area of higher pressure to an area of lower pressure
- NP for regulation of the relative volumes of blood and interstitial fluid. |
|
|
Term
|
Definition
| Pressure-driven movement of fluid and solutes from blood capillaries into interstitial fluid |
|
|
Term
|
Definition
| Pressure-driven movement from interstitial fluid into blood capillaries |
|
|
Term
| Net Filtration Pressure (NFP) |
|
Definition
- Determines whether the volumes of blood and interstitial fluid remain steady or change
- Balance between blood hydrostatic pressure and intersitial fluid osmotic pressure |
|
|
Term
| Blood Hydrostatic Pressure (BHP) |
|
Definition
- The pressure that water in blood plasma exerts against blood vessel walls
- “pushes” fluid out of capillaries into interstitial fluid |
|
|
Term
| Blood Colloid Osmotic Pressure (BCOP) |
|
Definition
- A force caused by the colloidal suspension of these large proteins in plasma
- “pulls” fluid from interstitial spaces into capillaries |
|
|
Term
| Interstitial Fluid Osmotic Pressure (IFOP) |
|
Definition
- Opposes BCOP
- “pulls” fluid out of capillaries into interstitial fluid
- IFOP is very small |
|
|
Term
|
Definition
| If the pressures that push fluid out of capillaries exceed the pressures that pull fluid into capillaries, fluid will move from capillaries into interstitial spaces |
|
|
Term
|
Definition
| The pressures that push fluid out of interstitial spaces into capillaries exceed the pressures that pull fluid out of capillaries, then fluid will move from interstitial spaces into capillaries |
|
|
Term
|
Definition
| If filtration greatly exceeds reabsorption, the result is an abnormal increase in interstitial fluid volume |
|
|
Term
|
Definition
| The volume of blood that flows through any tissue in a given time period (in mL/min) |
|
|
Term
|
Definition
Cardiac output (CO), volume of blood that circulates through systemic (or pulmonary) blood vessels each minute.
- Cardiac output (CO) = heart rate (HR) X stroke volume (SV) |
|
|
Term
|
Definition
- Hydrostatic pressure exerted by blood on walls of blood vessel.
- Determined by cardiac output, blood volume, and vascular resistance |
|
|
Term
|
Definition
| The highest pressure attained in arteries during systole |
|
|
Term
|
Definition
| The lowest arterial pressure during diastole |
|
|
Term
| Mean Arterial Pressure (MAP) |
|
Definition
- Average BP in arteries
- Roughly one-third of the way between the diastolic and systolic pressures. |
|
|
Term
|
Definition
| - Opposition to blood flow due to friction between blood and walls of blood vessels. |
|
|
Term
|
Definition
- Smaller lumen of blood vessel = greater resistance to blood flow
- arterioles dilate, resistance decreases, and blood pressure falls.
- arterioles constrict, resistance increases, and BP rises. |
|
|
Term
|
Definition
| - Higher blood viscosity = higher the resistance |
|
|
Term
| Total Blood Vessel Length |
|
Definition
| - Resistance to blood flow through a vessel is directly proportional to the length of blood vessel. |
|
|
Term
| Systemic Vascular Resistance (SVR) |
|
Definition
- Refers to all the vascular resistances offered by systemic blood vessels.
- A major function of arterioles is to control SVR—and therefore blood pressure and blood flow to particular tissues—by changing their diameters. |
|
|
Term
|
Definition
- Volume of blood flowing back to the heart through the systemic veins
- Occurs due to pressure generated by contractions of the heart’s left ventricle |
|
|
Term
|
Definition
| At rest -> venous valve closer to the heart (proximal valve) and the one farther from the heart (distal valve) in this part of the leg are open, and blood flows upward toward the heart. |
|
|
Term
|
Definition
- Contraction of leg muscles, compresses vein.
- Pushes blood through proximal valve, an action called milking.
- At same time, distal valve in uncompressed segment of vein closes as some blood is pushed against it |
|
|
Term
|
Definition
- Just after muscle relaxation
- Pressure falls in the previously compressed section of vein
- Causes the proximal valve to close.
- Distal valve now opens b/c blood pressure in foot is higher than in the leg, and the vein fills with blood from the foot.
- The proximal valve then reopens. |
|
|
Term
|
Definition
| - Inhalation, the diaphragm moves downward, causes a decrease in pressure in the thoracic cavity and an increase in pressure in the abdominal cavity. |
|
|
Term
|
Definition
| The speed or velocity of blood flow (in cm/sec) is inversely related to the crosssectional area. |
|
|
Term
|
Definition
| - Time required for a drop of blood to pass from the right atrium, through the pulmonary circulation, back to the left atrium, through the systemic circulation down to the foot, and back again to the right atrium. |
|
|
Term
| Role of the Cardiovascular Center |
|
Definition
- Medulla oblongata regulates heart rate and stroke volume
- Also controls neural, hormonal, and local negative feedback systems that regulate blood pressure and blood flow to specific tissues. |
|
|
Term
| Cardiac Accelerator Nerves |
|
Definition
| Path for sympathetic impulses to reach the heart |
|
|
Term
|
Definition
- Parasympathetic stimulation
- Decreases heart rate |
|
|
Term
|
Definition
- Sympathetic neurons
- Sends impulses over these routes to arterioles throughout the body, but especially to those in the skin and abdominal viscera.
- Moderate state of tonic contraction or vasoconstriction, called vasomotor tone |
|
|
Term
|
Definition
| - Sets the resting level of systemic vascular resistance |
|
|
Term
| Neural Regulation of Blood Pressure |
|
Definition
Two types of reflexes:
1. Baroreceptor Reflexes
2. Hemoreceptor Reflexes |
|
|
Term
|
Definition
- Pressure-sensitive sensory receptors, are located in the aorta, internal carotid arteries
- Send impulses to the cardiovascular center to help regulate blood pressure. |
|
|
Term
|
Definition
- Baroreceptors in the wall of the carotid sinuses initiate the carotid sinus reflex
- Helps regulate blood pressure in the brain. |
|
|
Term
|
Definition
- Initiated by baroreceptors in the wall of the ascending aorta and arch of the aorta
- Regulates systemic blood pressure |
|
|
Term
|
Definition
| - Located close to baroreceptors of carotid sinus and arch of the aorta in small structures called carotid bodies and aortic bodies |
|
|
Term
| Hormonal Regulation of Blood Pressure (X4) |
|
Definition
1. Renin–angiotensin–aldosterone (RAA) system.
2. Epinephrine and norepinephrine
3. Antidiuretichormone(ADH)
4. Atrialnatriureticpeptide(ANP) |
|
|
Term
| Renin–angiotensin–aldosterone (RAA) system |
|
Definition
- Stims water reabsorption
- Increases total blood volume, which increases blood pressure |
|
|
Term
| Epinephrine and norepinephrine |
|
Definition
- Increase cardiac output by increasing the rate and force of heart contractions.
- Cause vasoconstriction of arterioles and veins in the skin and abdominal organs and vasodilation of arterioles in cardiac and skeletal muscle
- Helps increase blood flow to muscle during exercise. |
|
|
Term
|
Definition
- ADH promotes movement of water from the lumen of kidney tubules into the bloodstream.
- Results in increase in blood volume and decrease in urine output |
|
|
Term
| Autoregulation of Blood Pressure |
|
Definition
| The ability of a tissue to automatically adjust its blood flow to match its metabolic demands |
|
|
Term
| Types of Stimuli that Cause Autoregulatory Changes in Blood Flow |
|
Definition
| Warming promotes vasodilation, and cooling causes vasoconstriction. |
|
|
Term
|
Definition
| Smooth muscle in arteriole walls contract more forcefully when stretched and relax when stretching lessens |
|
|
Term
| Vasodilating and Vasoconstricting Chemicals |
|
Definition
- White blood cells, platelets, smooth muscle fibers, macrophages, and endothelial cells
- Release wide variety of chemicals that alter blood-vessel diameter |
|
|
Term
|
Definition
| Aalternate expansion & recoil of elastic arteries after each systole of the left ventricle creates a traveling pressure wave |
|
|
Term
| Systolic Blood Pressure (SBP) |
|
Definition
| Force of blood pressure on arterial walls just after ventricular contraction |
|
|
Term
| Diastolic Blood Pressure (DBP |
|
Definition
| Force exerted by the blood remaining in arteries during ventricular relaxation |
|
|
Term
|
Definition
| The various sounds that are heard while taking blood pressure |
|
|
Term
|
Definition
- Difference between systolic and diastolic pressure is called
- Normally about 40 mmHg
- Provides info about condition of the cardiovascular system |
|
|
Term
|
Definition
- Failure of cardiovascular system to deliver enough O2 and nutrients to meet cellular metabolic needs
- Inadequate oxygen delivery, cells switch from aerobic to anaerobic production of ATP, and lactic acid accumulates in body fluids. |
|
|
Term
|
Definition
- Decreased blood volume
- Common cause is acute (sudden) hemorrhage |
|
|
Term
|
Definition
- Poor heart function
- Heart fails to pump adequately b/c heart attack |
|
|
Term
|
Definition
- Inappropriate vasodilation
- Anaphalaxis |
|
|
Term
|
Definition
| Obstruction of blood flow (embolism) |
|
|
Term
| Homeostatic Responses to Shock - 1 |
|
Definition
| Negative feedback systems that work to return cardiac output and arterial blood pressure to normal. |
|
|
Term
| Homeostatic Responses to Shock - 2 |
|
Definition
1. Activation of the renin–angiotensin–aldosterone system.
2. Secretion of antidiuretic hormone
3. Activation of the sympathetic division of the ANS
4. Release of local vasodilators |
|
|
Term
| Signs and Symptoms of Shock |
|
Definition
| Systolic blood pressure is lower than 90 mmHg |
|
|
Term
|
Definition
| Arteries, arterioles, capillaries, venules, and veins are organized into circulatory routes that deliver blood throughout the body |
|
|
Term
|
Definition
| Includes all arteries and arterioles that carry oxygenated blood from the left ventricle to systemic capillaries, plus the veins and venules that carry deoxygenated blood returning to the right atrium after flowing through body organs |
|
|
Term
| Hepatic Portal Circulation |
|
Definition
| Extends from gastrointestinal tract to the liver |
|
|
Term
|
Definition
| When blood returns to heart from systemic route -> pumped out of the right ventricle through the pulmonary circulation to the lungs |
|
|
Term
|
Definition
| Carries oxygen and nutrients to body tissues and removes carbon dioxide and other wastes and heat from the tissues |
|
|
Term
|
Definition
| Inflammation of a vein, often in a leg |
|
|
Term
|
Definition
- Inflammation of a vein involving clot formation
- Superficial thrombophlebitis occurs in veins under the skin, especially in the calf. |
|
|
Term
| White coat (office) hypertension |
|
Definition
A stress-induced syndrome found in patients who have elevated blood pressure when being examined by
health-care personnel, but otherwise have normal blood pressure. |
|
|
