Blood vessels: Plumbing of the people Chapter 20 A&P

Types of Blood Vessels Artery  Arteriole  Capillary  Venules  Veins Stretch out for 100,000 km or 60,000 miles!

Structure of Blood Vessel Consists of three layers: 1.Tunica adventitia/externa- “coming from outside”; outermost layer; fibrous connective tissue; prevents tearing 2.Tunica media- “middle coat”; smooth muscle tissue and elastic tissue; change b.v. diameter 3.Tunica intima/interna- “innermost coat”; endothelium tissue; smooth lining; helps make up semilunar valves in veins

Lumen – central blood-containing space 1.Arteries  distribute; use precapillary sphincters to regulate flow 2.Capillaries  transport essential materials to and from cells by diffusion 3.Veins  collect; use capacitance or stretch to catch all blood; sinuses- reservoirs of blood

Blood vessel structure

Arteries: Close Up

Blood pressure: Hydrostatic force that blood exerts against the wall of a vessel 1.Arterial blood pressure- highest; from cardiac output (heart rate & contractions) and peripheral resistance (blood viscosity & diameter of arterioles) 2.Capillary blood pressure- lowest; thin walls for diffusion and filtration 3. Venous blood pressure- medium; from pressure gradient of skeletal muscle contractions & total blood volume

Nervous Control of CV System

Circulation Routes: 1. Systemic- WHOLE BODY; blood flow from left ventricle to all parts of body and back to right atrium 2.Pulmonary- LUNGS; blood flow from right ventricle to lungs, get O2, release CO2, and go back to left atrium 3.Hepatic Portal- DIGESTION; blood flow from digestive organs into liver 1st through hepatic portal vein  blood leaves liver through hepatic vein into inferior vena cava. Liver can remove excess glucose and store it as glycogen; also it can detoxify blood (alcohol). 4.Fetal- FETUS; gets O2 and food through diffusion from mother’s blood and receives it from placenta through umbilical arteries and veins; ductus venosus allows blood to by-pass fetal liver; also by-passes lungs; foramen ovale opens from right atrium into left atrium in septum; ductus arteriosus lets blood enter aorta from pulmonary artery; No maternal blood actually mixes with the fetus. After birth, lungs function and extra vessels are not needed.

Circulation Routes 1. Systemic- WHOLE BODY; blood flow from left ventricle to all parts of body and back to right atrium

Circulation Routes 2.Pulmonary- LUNGS; blood flow from right ventricle to lungs, get O2, release CO2, and go back to left atrium

Circulation Routes 3.Hepatic Portal-DIGESTION blood flow from digestive organs into liver 1st through hepatic portal vein  blood leaves liver through hepatic vein into inferior vena cava. Liver can remove excess glucose and store it as glycogen; also it can detoxify blood (alcohol).

Circulation Routes 4.Fetal- FETUS gets O2 and food through diffusion from mother’s blood and receives it from placenta through umbilical arteries and veins ductus venosus allows blood to by-pass fetal liver; also by- passes lungs foramen ovale opens from right atrium into left atrium in septum ductus arteriosus lets blood enter aorta from pulmonary artery No maternal blood actually mixes with the fetus After birth, lungs function and extra vessels are not needed.

The aorta branches into 3 main arteries: 1.Brachiocephalic 2.Subclavian 3.Carotid VI. Blood vessels of the body

Arteries:Veins: Carotids – C, I, EJugular – I, E BrachiocephalicBrachiocephalic – R, L Abdominal aortaVena Cava – I, S Iliac – C, I, EIliac – C, E Femoral Popliteal ArcuateDorsal venous arch Subclavian – R, L AortaHepatic Portal/ Hepatic Palmar archDigital Pulmonary Plantar arch Splenic Renal Axillary Mesenteric – S, I Tibial – A, P Brachial Radial Ulnar Coronary

Arterial System

Venous System