160 likes | 435 Views
Arteries. Away from the heartThick, muscular wallsVery elasticArteriolesDiameter varies in response to neural stimuli and local chemical influences.. CapillariesConsist of a single tunica internaGas, nutrient, and waste exchangeBrain capillariesBlood-brain barrierCapillary bedsPrecapillary sphincterShunting of bloodDigestion.
E N D
1. Blood Vessels Closed circulatory system
Arteries
Arterioles
Capillaries
Venules
Veins
3 tunics
Lumen Tunica interna
Endothelium
Connective tissue
Tunica media
Smooth muscle
Elastin
Vasoconstriction
Vasodilation
Tunica externa
Collagen fibers
Nerve fibers
Lymphatic vessels
Elastin fibers
3. Arteries Away from the heart
Thick, muscular walls
Very elastic
Arterioles
Diameter varies in response to neural stimuli and local chemical influences. Capillaries
Consist of a single tunica interna
Gas, nutrient, and waste exchange
Brain capillaries
Blood-brain barrier
Capillary beds
Precapillary sphincter
Shunting of blood
Digestion
4. Venous System Toward the heart
Venules—porous—free movement of fluids and white blood cells.
Veins
3 tunics—but thin
Venous valves
Varicose veins
Incompetent valves
hemorrhoids Maintenance of Blood Pressure
Neural control
Shunting and vasoconstriction.
Vasomotor center
Baroreceptors
Carotid and aorta
Chemoreceptors
Higher brain centers
Hormones
Catecholoamines
Atrial natrietic peptide
ADH
Alcohol
Histamine—other vasodilators
5. Hypertension 30% of people over 50
Damages arteries
Causes heart failure, vascular disease, renal failure, stroke, and blindness.
Enlargement falled by hypertrophy of the myocardium Contributing factors:
Diet (sodium, saturated fat, cholesterol.)
Obesity
Age
Race
Heredity
Stress
Smoking—nicotine is a vasoconstrictor.
6. Atherosclerosis Damage to the tunica interna
Viral
Bacterial
Hypertension
Reinjury
Inflammation
LDLs—”bad cholesterol”
Foam cells
Fatty streak stage Arteriosclerosis
Hypertension
Stroke
Heart attack
Coronary bypass
Angioplasty
tPA—tissue plasminogen activator
Clot buster
HDL—removes cholesterol from vessel walls.
7. Arteries Aorta—largest artery
Ascending
Descending
Right and left coronary arteries
Common carotid arteries—branch to form internal and external carotids
External—supply tissues of the head except the brain and orbits.
Internal—supply the orbits and most of the cerebrum.
Vertebral arteries—branch to the cervical spinal cord, neck, cerebellum, pons, and inner ear.
10. Arteries to Know Know the arteries on the proceeding chart plus:
Arteries of the arm—brachial, radial, ulnar
Arteries of the leg—femoral, popliteal, anterior tibial, posterior tibial
Be able to identify these arteries on a diagram like that on page 631. Also know the locations served by these arteries.
11. Veins Dural sinuses—veins of the brain drain into these enlarged chambers and drain to the internal jugular veins.
External jugular veins—superficial head structures.
Vertebral veins—cervical vertebrae & neck muscles.
Brachiocephalic—mammary glands and first 2 or 3 intercostal spaces.
14. Veins to Know Know the veins on the preceding chart plus:
The veins of the arms—cephalic, axillary, brachial, radial, ulnar.
The veins of the legs—external iliac, femoral, popliteal, anterior tibial, posterior tibial, great saphenous vein, hepatic portal vein.
The great saphenous vein is a superficial vein. Connect with many of the deep veins of the legs and thighs.
Be able to identify these veins on a diagram like that on page 638. Also know the locations served by these arteries.