Circulatory Flashcards
Heart and Lung: series
systemic: parallel
series: constant volume (flow stays same, pressure changes)
parallel: problem in one place doesn’t affect others
pressure in pulmonary and systemic circulation
15 mmHg, 100 mmHg
pulmonary vessels able to decrease resistance why
- greater in diameter
- distensible
- thinner
- less smooth muscle
Tunics of arteries and veins
- Tunica intima: endothelium, loose CT, elastic lamina
- tunica media: smooth muscle, collagen
- tunica adventitia: elastic fibers, collagen fibers
coronary circulation
circulation of blood within the blood vessels of the cardiac tissue
role of lymphatic system in preventing edema
fluid filters out of arterial end of capillary, fluid is reabsorbed at the venous end (different pressures)
- any excess is picked up by lymphatic vessel
organs with dual circulation
- redundant blood supply, can receive oxygen from second source if first is compromised
- Liver and Lungs
End circulation organs
- most everything but liver and lungs
- i.e. kidneys, spleen
- Blockage of vessels can be disastrous
anastomosis
- provide alternative pathways for blood flow
- i.e. response to cold weather - blood divert through anastomosis near skin to prevent flow at skin surface where it would lose heat
cardiac output
volume blood pumped by heart in one minute
- stroke volume x heart rate
arteries and what they serve
brachiocephalic trunk: brain and head common carotid: head and neck subclavian: mainly arms thoracic: all body except head neck upper extremities abdominal: in retroperitoneum common iliac: pelvis and lower limbs celiac: liver, stomach, spleen, pancreas mesenteric: SI and large intestine
edema
abnormal increase in interstitial fluid within tissues (between cells)
pleural effusion
fluid collection in pleural cavity
anasarca
severe and generalized edema with widespread subcutaneous tissue swelling
ascites
fluid accumulation in abdominal cavity (effusion)
causes of edema
- increased hydrostatic pressure
- reduced plasma osmotic pressure
- sodium and water retention
- lymphatic obstruction
hyperemia vs. congestion
hyperemia shouldn’t cause hypoxia, congestion can
hyperemia
active process in which arteriolar dilation leads to increased blood flow
congestion
passive process resulting from reduced outflow of blood from a tissue
pulmonary edema (imaging and microscopically)
- uniform opacity on radiograph
- microscopically, cell swelling and clearing and separation of ECM
hepatic chronic passive congestion
nutmeg liver
- due to right heart failure
L heart failure
causes edema in lungs
hemorrhage vs. hematoma
active bleeding (usually in tissue itself) vs. accumulation, usually clotted (in space between serosa and parenchyma)
- into extravascular space
petechiae
- 1 to 2 mm hemorrhages into skin
purpura
slightly larger hemorrhages than petechiae (> 3 mm)
ecchyomses
> 1 to 2 cm hematomas
thrombus
blood clot formation within intact vessels
Virchow’s Triad
- endothelial injury
- stasis or turbulent flow
- hypercoagulability
Fates of thrombus
- propogation
- embolization
- dissolution
- organization and recanalization
embolus
detached thrombus carried to site distant from origin
- Venous source: lodges in lung bed
- Arterial source: any location systemically
red infarct
- area of ischemic necrosis, venous occlusions (i.e. testicular or ovarian torsion)
- previously congested tissues
- tissues with dual circulation (liver and lung)
- bowel
white infarct
- area of ischemic necrosis with arterial occlusions in solid organs with end-arterial circulation
- i.e. heart, spleen, kidney
atheroma
accumulation of swelling in artery walls made of up macrophage cells, debris, lipids, calcium, fibrous connective tissue
