Lecture 18 Circulatory System I 1 Blood Matrix

Lecture 18 Circulatory System I 1

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 2

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) 3

Systemic Circulation: Arteries • Aorta – From which all arteries are derived either directly or indirectly – Parts • Ascending aorta, aortic arch, descending aorta (thoracic and abdominal) 4

Branches of the Ascending Aorta Fig. 22. 9 • Coronary arteries – Supply the heart’s cardiac muscle with oxygen and nutrients 5

Branches of the Aortic Arch Right common carotid artery • First branch – Brachiocephalic trunk – Right common carotid and right subclavian • Second branch Vertebral artery Right subclavian artery Brachiocephalic trunk Left common carotid artery Left subclavian artery Aortic arch Descending thoracic aorta Fig. 23. 12 – Left common carotid • Third branch – Left subclavian 6

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 7

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 Internal carotid artery External carotid artery Common carotid artery Vertebral artery Brachiocephalic trunk Subclavian artery Fig. 23. 10 8

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) Subclavian artery Vertebral artery Axillary artery Brachial artery Radial artery Ulnar artery Fig. 23. 19 9

Branches of the Descending Aorta: Arteries of the Abdominal Aorta Celiac trunk Right renal artery Descending abdominal aorta Inferior mesenteric artery Left renal artery Superior mesenteric artery Common iliac artery Left internal iliac artery Left external iliac artery Fig. 23. 12 Left femoral artery • Three major branches (in order from superior to inferior along abdominal aorta) – Celiac trunk – Superior mesenteric artery – Inferior mesenteric artery 10

Branches of the Descending Aorta: Pelvis and Lower Limb Anterior view • Abdominal aorta divides into: Posterior view Common iliac artery External iliac artery – Common iliac arteries Internal iliac artery Femoral artery • Common iliac arteries divide into: – External iliac arteries – Internal iliac arteries Popliteal artery Anterior tibial artery Posterior tibial artery • Popliteal artery • Anterior and posterior tibial arteries Fig. 23. 20 11

Points 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 12

Questions? 13