SJSU SP24 BIOL-65 Chapter 21 - Blood Vessels

Arteries

Efferent vessels carrying blood away from heart

Veins

Afferent vessels carrying blood toward heart

Capillaries

Microscopic vessels connecting small arteries to small veins that are important and in gas and nutrient exchange in organs; contain only a wall of endothelium and the basal lamina/basement membrane

tunica interna (intima)

inner layer; jmade of simple squamous endothelium; slick lining for smooth blood flow; selectively permeable barrier

tunica media

middle layer; thick layer with smooth muscle, collagen, sometimes elastin; responsible for vasoconstriction and vasodilation

tunica externa/adventitia

outer layer; loose connective tissue; anchors vessel to its surroundings

vaso vasorum

network of small vessels for large vessels (aorta/vena cava)

conducting (elastic) arteries

biggest arteries; absorb some pressure but also maintain it; i.e. aorta

distributing (muscular) arteries)

midsized arteries; distribute blood to specific organs; i.e. femoral artery or hepatic artery

resistance arteries or arterioles

smallest arteries; smallest artery leading to capillary bed; contain a precapillary sphincter allowing only a certain amount of blood into capillaries at any given time

metarterioles

subtype that link arterioles and capillaries

continuous capillary

endothelial cells joined by tight junctions; some intercellular clefts present; found in most organs of the body

fenestrated capillary

endothelial cells have filtration pores facilitating exchange; commonly found in kidneys

sinusoid (discontinuous capillary)

irregular passages with wide gaps between endothelial cells; commonly found in the liver and spleen

capillary beds

when tissue is active precapillary sphincters open and capillaries fill it with blood; when tissue is inactive precapillary sphinters close and blood flows from metarteriole to throroughfare channel

capacitance vessels

contain most of the blood at any given time in the circulatory system

postcapillary venules

very porous, allow for some exchange

muscular venules

have smooth muscle in wall (tunica media)

medium veins

individually named veins; contain valves

large veins

have smooth muscle in all tunics

skeletal muscle pump

muscle activity squeezes veins and forces blood through one-way valves toward heart

simple path

artery to capillary to vein

portal system

sequence of two capillary beds

anastomosis

vessel merger without intervening capillary bed

Pulmonary Circuit

Pulmonary trunk, unpaired vessel, and from R. ventricle; Pulmonary arteries, carry oxygen-poor blood, one on each side; lobar arteries; alveolar capillaries; pulmonary veins carry oxygen-rich blood, two from each side enter L. atrium

Ascending aorta branches

L. & R. Coronary artery

Aortic arch branches

Braciocephalic artery, L. common carotid artery, L. subclavian artery

Descending aorta branches

Thoracic aorta, abdominal aorta

Selected Arteries of the Head and Neck

Common carotid artery; external carotid artery; internal carotid artery; vertebral artery, basilar artery; cerebral arterial circle (of Willis), anterior cerebral artery, anterior communicating artery, posterior cerebral artery, posterior communicating artery

Selected Veins of the Head and Neck

Vertebral v., Internal jugular v., External jugular v., Subclavian v., Brachiocephalic v.

Arteries of the Thorax

Braciocephalic trunk/a., Subclavian a., Internal thoracic a., Anterior/Posterior intercostal a., Descending Aorta, Bronchial aa., Esophageal aa.

Selected Veins of the Thorax

Azygous v. (only on R.), Hemiazygous v. (only on L.), Subclavian v., Braciocephalic v., Superior vena cava

Selected Arteries of the Abdomen and Pelvic Region

Celiac trunk -- unpaired stump to three branches, common hepatic a., L. gastric a., Splenic a.; Superior mesenteric a. (unpaired); Renal a. (paired); Inferior mesenteric a. (unpaired); Gonadal a. (paired), Common iliac a. (paired), External iliac a. (paired), Internal iliac a. (paired)

Selected Veins of the Abdomen and Pelvic Region

Common iliac v., External Iliac v., Internal iliac v., Gonadal v., Renal v., Hepatic vv., Inferior vena cava

Hepatic portal vein

blood from GI tract sent to liver before going back to the heart; formed by the superior mesenteric vein and the splenic vein.

Hepatic Portal System

Superior mesenteric v., Splenic v., Inferior mesenteric v., Cystic v., Gastric v., Pancreatic v.

Arteries of the Upper Limb

Subclavian a., Axillary a., Brachial a., Radial a., Ulnar a., Palmar arches

Veins of the Upper Limb

Venous palmar arches, Radial v. and ulnar v., Medial cubital v., Brachial v., Basilic v., Cephalic v., Axillary v., Subclavian v.

Arteries of the Lower Limb

External iliac a., Femoral a., Popliteal a., Anterior tibial a., posterior tibial a., fibular a., Dorsal a., Arcuate a.

Veins of the Lower Limb

Medial plantar v. and lateral plantar v., Anterior tibial vv., posterior tibial vv., and fibular vv., popliteal v., great & small saphenous v.

Changes at Birth 1

Foramen ovale closes and becomes fossa ovalis

Changes at Birth 2

Ductus arteriosus constricts and becomes ligamentum arteriosum

Changes at Birth 3

The two umbilic arteries degenerate and become median umbilical ligaments

Changes at Birth 4

Umbilical vein constricts and becomes round ligament of liver

Changes at Birth 5

Ductus venosus degenerates and becomes ligamentum venosum of liver

Changes at Birth 6

Blood returning to the heart is now oxygen-poor, systemic blood only

Arteriosclerosis

the stiffening of vessels that generally occurs due to old age

Atherosclerosis

the growth of lipid deposits in the arterial walls often due to poor lifestyle choices, hereditary diseases, or aging