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Lecture 18

Circulatory System ICirculatory System I

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Blood• Matrix between the

cells is liquid• Hemopoiesis

– Process of formation of blood cells

– Tissue found in marrow cavity and spongy bone

• Yellow

• Red

Table 4.13

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Blood Vessel Structure• Arteries

– Elastic, muscular, arterioles, capillaries

• Capillaries– Most of exchange between blood and

interstitial spaces (filled with interstitial fluid) occurs across the walls

– Blood flows from capillaries to venous system

• Aneurysm– Weak point in artery or wall of heart– May rupture (hemorrhage)

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Systemic Circulation: Arteries

• Aorta– From which all arteries are derived either

directly or indirectly– Parts

• Ascending aorta, aortic arch, descending aorta (thoracic and abdominal)

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Branches of the Ascending Aorta

• Coronary arteries– Supply the heart’s cardiac muscle with oxygen

and nutrients

Fig. 22.9

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Branches of the Aortic Arch

• First branch– Brachiocephalic

trunk– Right common

carotid and right subclavian

• Second branch– Left common

carotid

• Third branch– Left subclavian

Right common carotid artery

Right subclavian arteryVertebral artery

Brachiocephalic trunk

Descendingthoracic aorta

Aortic arch

Left subclavianartery

Left commoncarotid artery

Fig. 23.12

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Review Question

An interruption in blood flow that resulted in less blood reaching the right shoulder and right neck (but not affecting the opposite side) could indicate a partial blockage in the

(a) Right subclavian artery(b) Brachiocephalic artery(c) Right common carotid artery(d) Ascending aorta(e) Coronary arteries

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Branches of the Aortic Arch:Head and Neck Arteries

• Branches of common carotid arteries– Internal carotid

arteries

– External carotid arteries

• Branches of the subclavian arteries– Left and right

vertebral arteries

• Internal carotids and vertebral arteries supply brain Fig. 23.10

Brachiocephalic trunk

Internal carotid arteryExternal carotid artery

Common carotid arteryVertebral artery

Subclavian artery

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Branches of the Aortic Arch:Arteries of Upper Limb and Shoulder

• Three major arteries– Subclavian– Axillary– Brachial

• Subclavian is posterior to clavicle

• Axillary is within axillary region (armpit)

• Brachial is within brachium (arm)

Fig. 23.19

Subclavian artery

Axillary artery

Brachial artery

Radial artery Ulnar artery

Vertebral artery

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Branches of the Descending Aorta: Arteries of the Abdominal Aorta

• Three major branches (in order from superior to inferior along abdominal aorta)– Celiac trunk– Superior mesenteric artery– Inferior mesenteric artery

Right renal artery

Descending abdominalaorta

Inferior mesenteric artery

Left femoral artery

Left external iliac arteryLeft internal iliac artery

Common iliac artery

Superior mesenteric artery

Left renal artery

Celiac trunk

Fig. 23.12

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Branches of the Descending Aorta: Pelvis and Lower Limb

• Abdominal aorta divides into:– Common iliac arteries

• Common iliac arteries divide into:– External iliac arteries

– Internal iliac arteries

• Popliteal artery

• Anterior and posterior tibial arteries

Fig. 23.20

Posterior tibial artery

Anterior tibial artery

Popliteal artery

Femoral artery

Internal iliac artery

Common iliac artery

Anterior view Posterior view

External iliac artery

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Points to RememberPoints to Remember

• Arteries transport blood away from the heart• Branches of aorta supply heart, head and

neck, shoulder and upper limb, trunk, abdomen, pelvis and lower limb

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Questions?