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

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

Inner layer:_________

Middle layer:_________

Outer layer:_________

Connective tissue

Endothelium

______

________

________

________

_______

Direction ofblood flow

Tissuecells

_________

Smooth muscle

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

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

Capillary Beds

Figure 18.4a

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Figure 8.3a Capillaries.

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Figure 8.3b Capillaries.

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Figure 8.3c Capillaries.

• 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

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

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Superior vena cava

Pulmonarysemilunar valveRight atrium

Right AV valveRight 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

Brachiocephalic trunkLeft subclavian artery

Left carotid artery

Three arteries branching from the aortic arch

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Brachiocephalic trunk

Left carotid arteryRight carotid artery

Left subclavian arteryRight subclavian artery

Aorta and Major Arteries

Figure 18.20b

Arteries of the Head and Neck

Figure 18.21b

Arteries of the Upper Limbs and Thorax

Figure 18.22b

Arteries of the Abdomen 1

Figure 18.22c

Arteries of the Abdomen 2

Opening for esophagus

Arteries of the Lower Limbs

Figure 18.23b, c

Pulmonary Circulation

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Figure 19.21b Major arteries of the systemic circulation.

Internal carotid artery

Common carotid arteries

Subclavian artery

Subclavian artery

Aortic archAscending aortaCoronary arteryThoracic aorta (abovediaphragm)

Renal artery

Superficial palmar arch

Radial arteryUlnar artery

Internal iliac artery

Deep palmar arch

Vertebral artery

Brachiocephalic trunk

Axillary artery

Brachial artery

Abdominal aortaSuperior mesenteric artery

Gonadal arteryCommon iliac artery

External iliac artery

Digital arteries

Femoral artery

Anterior tibial arteryPosterior tibial artery

(b) Illustration, anterior view

Inferior mesenteric artery

Celiac trunk

External carotid artery

Arteries of the head and trunk

Arteries that supply the upper limb

Arteries that supply the lower limb

Figure 18.20d

Arteries of the Brain

Veins of Systemic Circulation

Figure 18.26b

Veins of the Upper Limbs and Thorax

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

Figure 18.27c

Veins of the Abdomen

Figure 18.27b

Veins of the Abdomen

Veins of the Pelvis and Lower Limbs

Fibular veinFibular vein