Figure 8.1 The structures of blood vessels in the human body.

Figure 8.1 The structures of blood vessels in the human body. Direction of blood flow Outer layer: _________ Middle layer: _________ Inner layer: _________ ______ ________ Connective tissue Smooth muscle Endothelium ________ ________ _______ _________ Tissue cells

Tunics Tunica interna = tunica intima = inner layer Endothelial layer that lines the lumen of all vessels Tunica media = middle layer Smooth muscle and elastic fiber layer, controls constriction/dilation of vessels Tunica externa = tunica adventitia = outer layer Contains collagen fibers that protect and reinforce vessels

Lumen central blood-containing space surrounded by tunics

Figure 8.4 The general pattern of movement between capillaries, the interstitial fluid, and cells.

Capillary Beds Figure 18.4a

Figure 8.3a Capillaries.

Figure 8.3b Capillaries.

Figure 8.3c Capillaries.

To return blood to the heart, veins have special adaptations Veins have much lower blood pressure and thinner walls than arteries; larger lumen To return blood to the heart, veins have special adaptations Large-diameter lumens, offer little resistance to flow Valves which prevent backflow of blood Respiratory “pump” – pressure changes created during breathing suck blood toward the heart by squeezing local veins Muscular “pump” – contraction of skeletal muscles “milk” blood toward the heart

Factors Aiding Venous Return Figure 18.6

Fetal Circulation 1 Umbilical vein carries blood (highly oxygenated) from the placenta to the fetal heart. Umbilical arteries carry blood from fetal heart to placenta.

Fetal Circulation 2 Blood in the umbilical vein is shunted past the liver, to right atrium, via the ductus venosus. Blood is shunted past the lungs, from the right atrium into the left atrium, via the foramen ovale in the interatrial septum. Blood that does enter the right ventricle is shunted past the lungs, from the pulmonary trunk to the aorta, via the ductus arteriosus.

Fetal Circulation 3 The foramen ovale closes at birth and becomes the fossa ovalis; a depression in the septum The ductus arteriosus collapses and becomes the ligamentum arteriosum Remnants of the umbilical vessels exist as ligaments in the adult

Microscope slides

Figure 8.9 Some of the major arteries and veins in the human body.

Three arteries branching from the aortic arch Left carotid artery Left subclavian artery Brachiocephalic trunk Superior vena cava Pulmonary semilunar valve Right atrium Right AV valve Right ventricle Inferior vena cava Pulmonary trunk Left pulmonary veins Left atrium Left AV valve Aortic semilunar valve Chordae tendineae Papillary muscles Left ventricle Septum Right pulmonary artery Left pulmonary artery Aorta

Left carotid artery Right carotid artery Left subclavian artery Right subclavian artery Brachiocephalic trunk

Aorta and Major Arteries

Arteries of the Head and Neck Figure 18.20b

Arteries of the Upper Limbs and Thorax Figure 18.21b

Arteries of the Abdomen 1 Figure 18.22b

Arteries of the Abdomen 2 Opening for esophagus Figure 18.22c

Arteries of the Lower Limbs Figure 18.23b, c

Pulmonary Circulation

Figure 19.21b Major arteries of the systemic circulation. Arteries of the head and trunk Internal carotid artery Arteries that supply the upper limb External carotid artery Common carotid arteries Subclavian artery Vertebral artery Axillary artery Subclavian artery Brachiocephalic trunk Brachial artery Aortic arch Ascending aorta Radial artery Coronary artery Ulnar artery Thoracic aorta (above diaphragm) Deep palmar arch Celiac trunk Superficial palmar arch Abdominal aorta Digital arteries Superior mesenteric artery Arteries that supply the lower limb Renal artery Gonadal artery External iliac artery Common iliac artery Femoral artery Inferior mesenteric artery Anterior tibial artery Internal iliac artery Posterior tibial artery (b) Illustration, anterior view

Arteries of the Brain Figure 18.20d

Veins of Systemic Circulation

Veins of the Upper Limbs and Thorax Figure 18.26b

The cephalic vein is an example of a badly named body part, and a thus confusing medical word, based on a translator’s mistake. The Canon of Avicenna ( 980-1037 CE) collected the medical knowledge of his times. This vein of the arm was named al-kifal, which means “the outer vein of the arm”. When this was translated into Latin in A.D. 1564, the translator thought al-kifal was related to the Latin word cephalicus, ‘pertaining to the head’. He was wrong, but the naming error stuck.

Veins of the Head and Neck

Veins of the Abdomen Figure 18.27c

Veins of the Abdomen Figure 18.27b

Veins of the Pelvis and Lower Limbs Fibular vein Fibular vein