Term
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Definition
inner most
- lined with simple squamous epithelium (endothelium),contacts the lumen
- basement membrane lies beneath endothelium
- the "internal elastic lamina" (elastic tissue)surrounds the basement membrane |
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Definition
middle layer
- usually the thickest of the three layers
- consists of smooth muscle and elastic fibers |
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Definition
outer layer
- mostly elastic and collagen fibers |
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Term
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Definition
- tunica media contains a higher proportion of elastic fibers
- the larger arteries ex. Aorta
- these propel blood towards smaller arteries |
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Term
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Definition
- the tunica media contains a higher proportion of smooth muscle, this allows for vasoconstriction which helps direct blood flow
- these arteries carry blood to the organs |
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Term
| - ex. Sympathetic response - |
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Definition
| gastric arteries constrict which direct blood to skeletal muscle |
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Term
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Definition
- vessels that transport blood to the capillaries
- smooth muscle predominates, regulates blood flo |
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Term
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Definition
- composed of basement membrane and simple squamous epithelium (1 thin layer of cells)
- Connect arterioles to venules
- permits exchange of substances between the blood and tissue cells (via interstitial fluid) |
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Term
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Definition
- drain capillaries
- the outer two layers reappear as the venule lead into veins |
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Term
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Definition
- transport blood towards the heart
- contains the same three layers as arteries, less smooth muscle is present
- the lumen is larger (greater surface area) than the corresponding artery
- contain valves to prevent the back flow of blood (these valves are folds of tunica interna that project into the lumen, muscular action helps move blood towards the heart) |
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Term
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Definition
| weakened valves cause veins to become dilated and twisted |
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Term
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Definition
| varicosity of a vessel around the anus |
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Term
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Definition
| the joining together of vessels (provides collateral circulation) |
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Term
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Definition
| the movement of substances between the blood and interstitial fluid |
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Term
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Definition
| - provides movement for substances like oxygen, carbon dioxide, glucose, amino acids and some hormones |
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Term
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Definition
| - larger substances (like insulin) pass through the capillary wall via endocytotic vesicles |
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Term
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Definition
| - a passive process where large numbers of dissolved and suspended particles in a fluid move together in the same direction |
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Term
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Definition
| - a passive process where large numbers of dissolved and suspended particles in a fluid move together in the same direction |
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Term
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Definition
| pressure driven movement of fluid and solutes from the capillaries into interstitial fluid. |
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Term
| Reabsorption (Resorption) - |
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Definition
| pressure driven movement from interstitial fluid into capillaries. |
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Term
| Net Filtration Pressure - |
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Definition
| The net pressure that promotes fluid outflow at the arterial end of a capillary, and fluid inflow at the venous end of a capillary. |
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Term
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Definition
| An abnormal increase in interstitial fluid volume, ie. filtration exceeds absorption. |
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Term
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Definition
| factors affecting blood flow |
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Term
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Definition
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Definition
| The volume of blood that flows through any tissue in a given period of time. Determined by the force of the heartbeat and the resistance through the body. |
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Term
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Definition
The expansion and elastic recoil of arteries after systole of the left ventricle. The pulse is best felt in arteries that are close to surface, and run over a firm structure (ex. bone).
Normal range - 70 to 80 b.p.m. |
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Term
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Definition
| Rapid heart rate. >100 b.p.m |
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Term
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Definition
| Slow resting heart rate. <60 b.p.m |
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Term
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Definition
| The exerted by the blood against the walls of blood vessels due to the contraction of the left ventricle. |
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Term
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Definition
| The force in the vessels during ventricular systole. |
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Term
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Definition
| The pressure remaining in the vessels during ventricular diastole. |
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Term
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Definition
Persistently high blood pressure.
- Systolic > 140 mmHg
- Diastolic < 90 mmHg |
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Term
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Definition
Idiopathic hypertension
- cause unknown |
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Term
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Definition
has an identifiable underlying cause.
ex. Renal hypertension assoc. with decreased blood flow through the Kidneys |
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Term
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Definition
| the opposition of blood flow due to friction between the blood and the walls of the blood vessels |
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Term
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Definition
| the volume of blood flowing back to the Heart through systemic veins |
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Term
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Definition
- located in the Medulla Oblongata, helps regulate stroke volume and heart rate
- Sympathetic stimulation increases the heart rate and volume (BP). Sympathetic stimulation increases also causes vasoconstriction which increases peripheral resistance, raising BP.
- Parasympathetic stimulation decreases heart rate |
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Term
| Baroceptors and Chemoceptors |
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Definition
- receptors that respond to pressure and chemical changes
ex. High carbon dioxide concentration in the blood causes amore force full heartbeat, increasing BP. |
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Term
| Renin-Angiotensin-Aldosterone System |
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Definition
(1) Juxtaglomerular cells in the Kidneys release Renin when BP is low (decreased blood flow through the Kidneys)
(2) Renin leads to the production of Angiotensin II. Angiotensin II causes vasoconstriction, and stimulates aldosterone secretion.
(3) Aldosterone (released from the Adrenal Cortex) increases sodium absorption (and water) in the Kidneys which increases blood volume. |
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Term
| Antidiuretic Hormone (ADH) - |
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Definition
| Released by the Posterior Pituitary Gland. ADH causes vasoconstriction, and reabsorption of water by the Kidneys. |
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Term
| Epinephrine and Norepinephrine |
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Definition
- released from Adrenal Medulla in response to sympathetic stimulation
- these increase the rate and force of cardiac contraction |
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Term
| Atrial Natriuretic Peptide (ANP) |
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Definition
- released when Atria is overstretched
- inhibits aldosterone production lowering BP
- causes excretion of Na+ by the kidneys |
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Term
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Definition
= failure of the cardiovascular system to deliver adequate oxygen and nutrients to meet cellular metabolic needs.
- the type of shock is named after the cause.
e.g. Hypovolemic shock (low volume, ex. bleeding)
Cardiogenic (heart origin, ex. MI)
Vascular (vessel dilation, ex. anaphylaxis)
Obstructive |
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Term
| The body's response to mild shock, i.e. between 10 to 20%loss of blood: |
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Definition
a. Activation of the Renin-Angiotensin-Aldosterone System
b. Secretion of ADH
c. Sympathetic stimulation, i.e. vasoconstriction, increased heart rate
d. Release of local vasodilators (to try to bring blood/nutrition to deprived cells) |
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Term
| Signs and symptoms of shock: |
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Definition
a. Systolic BP below 90mmHg
b. Rapid pulse (heart rate), weak (thready)
c. Cool, clammy, pale skin
d. Sweating
e. Altered mental state (decreasing LOC)
f. Reduced Urine formation
g. Thirst
h. Nausea |
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Term
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Definition
- caused from a weakened vessel wall that bulges outward
- area can enlarge and burst causing internal bleeding
- can lead to hypovolemic shock |
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Term
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Definition
1. Loss of vessel elasticity.
2. Cardiac muscle fibers become smaller and have decreased strength. This reduces CO. Systolic reading tends to increase with age._ |
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