The CARDIO: Vessels and Circulation


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  • In liver and bone marrow
  • The CARDIO: Vessels and Circulation

    1. 1. CH 22: The Cardiovascular System: Vessels & Circulation <ul><li>Describe the histological similarities and differences of the blood vessels </li></ul><ul><li>Explain the pattern and names of the major arteries and veins of the pulmonary & systemic circulations </li></ul><ul><li>Describe the circulatory changes that occur at birth, and the ones occurring with exercise. </li></ul>Keyconcepts :
    2. 2. <ul><li>1 aorta & 1 pulmonary trunk </li></ul><ul><li>~ 2.5 cm </li></ul><ul><li>10 bio capillaries (~ length 5,000 miles) </li></ul><ul><li>? </li></ul>
    3. 3. Histology of Blood Vessels <ul><li>Tunica interna or intima (endothelium + c.t.) </li></ul><ul><li>Tunica media (muscle + c.t.) </li></ul><ul><li>Tunica externa or adventitia (thick layer of c.t.) </li></ul>
    4. 4. Distinguishing Arteries from Veins : <ul><li>Artery walls thicker (more muscle and elastic fibers) </li></ul><ul><li>Additional: internal & external elastic membranes </li></ul><ul><li>Artefacts when fixing slides: </li></ul><ul><li>Arterial walls contract; endothelium cannot contract: pleated appearance </li></ul><ul><li>Veins collapse </li></ul>Fig 22.1 Compare to Fig 22.1
    5. 5. <ul><li>elastic arteries </li></ul><ul><li>muscular arteries </li></ul><ul><li>arterioles </li></ul>capillaries large vein medium-sized vein venules Arteries – ALWAYS carry blood away from heart Veins – ALWAYS return blood to heart, contain about 2/3 body's blood at any given time
    6. 6. Pulmonary trunk & aorta and their major branches Superior & inferior vena cava and their tributaries Largest, conducting arteries – lead directly from heart, subject to high pressures
    7. 7. External and internal carotids, brachial & femoral arteries External and internal jugular, brachial & femoral veins  2 - 9 mm  ~ 4 mm
    8. 8.  ~ 10-50 µm  ~ 30 µm
    9. 9. Capillaries Intestinal mucosa Choroid plexus, endocrine glands, kidneys Most body regions Only endothelium Variably permeable somewhat permeable Characterized by circular fenestrae or pores that penetrate the endothelium -permit exchange of larger molecules.  ~ 8 µm
    10. 10. Sinusoids <ul><li>Resemble fenestrated capillaries, yet </li></ul><ul><ul><li>irregular shapes </li></ul></ul><ul><ul><li>have longer pores </li></ul></ul><ul><ul><li>thinner (or no) basement membranes </li></ul></ul><ul><li>Blood movement very slow </li></ul><ul><li>Found in the liver, heart, etc. sometimes called sinusoidal capillary. </li></ul>
    11. 11. Capillary Bed <ul><li>= Capillary region supplying a body area </li></ul><ul><li>Metarteriole – shunt - preferred channel through a capillary bed </li></ul><ul><li>Precapillary sphincter - closes bed temporarily to redistribute blood flow </li></ul><ul><li>Arteriovenous anastomosis: interconnections , alternative routes of supply </li></ul>Fig 22.4
    12. 12. Normal: From capillary bed into veins and back to heart <ul><li>3 exceptions </li></ul><ul><li>Hypophysis _________________ </li></ul><ul><li>Liver _________________ </li></ul><ul><li>In kidney nephrons </li></ul>Fig 19.6 Fig 22.26
    13. 13. ?
    14. 14. Uneven Distribution of Blood <ul><li>Total blood volume: ? </li></ul><ul><li>65 -70% in veins (= blood reservoir) lumen is larger than in corresponding arteries </li></ul><ul><li>30-35% in heart, arteries and capillaries </li></ul>Table 22.7
    15. 15. <ul><li>Why are valves found in veins but not in arteries? </li></ul><ul><li>Do all veins have valves? </li></ul>Venous valve pathology ?
    16. 16. Blood Vessel Pathologies <ul><li>Aneurysms </li></ul><ul><li>Atherosclerosis = type of Arteriosclerosis) thickening and toughening of arterial walls </li></ul><ul><ul><li>Pathogenesis covered in Physiology </li></ul></ul>
    17. 17. Cerebral aneurysms Most common type: berry aneurysm Usually occur at the bifurcations and branches of the large arteries located at the Circle of Willis Abdominal Aortic Aneurysm Repair
    18. 18. Gross Anatomy of Circulatory System Pulmonary & Systemic Circulations
    19. 19. Pulmonary Circuit Fig 22.9 Right ventricle into pulmonary trunk to pulmonary arteries to lungs Return by way of 4 pulmonary veins to left atrium
    20. 20. Left common carotid 2 Aortic Arch Systemic Circuit Brachiocephalic trunk 1 Left subclavian 3
    21. 21. Circle of Willis = Cerebral Arterial Circle <ul><li>= Ring of vessels surrounding pituitary gland - supplies cerebrum and cerebellum </li></ul><ul><li>Brain can receive blood from carotids or vertebrals (significance?) </li></ul>v ic Fig 22.13
    22. 22. Circle of Willis
    23. 23. Descending aorta • thoracic aorta •  abdominal aorta Abdominal aorta Common iliac External iliac Femoral
    24. 24. Descending Aorta - Thoracic Area <ul><li>Bronchial arteries - supply bronchi and lungs </li></ul><ul><li>Pericardial arteries - supply pericardium </li></ul><ul><li>Mediastinal arteries - supply mediatinal structures </li></ul><ul><li>Esophageal arteries - supply esophagus </li></ul><ul><li>Paired intercostal arteries- thoracic wall </li></ul><ul><li>Superior phrenic arteries - supply diaphragm </li></ul>Fig 22.17
    25. 25. Descending Aorta - Abdominal Area <ul><li>Celiac trunc - 3 branches – to liver, gallbladder, esophagus, stomach, duodenum, pancreas, and spleen </li></ul><ul><li>Superior mesenteric– to pancreas and duodenum, small intestine and colon </li></ul><ul><li>Paired suprarenal - to adrenal glands </li></ul><ul><li>Paired renal – to kidneys </li></ul><ul><li>Paired gonadal – to testes or ovaries </li></ul><ul><li>Inferior mesenteric – to terminal colon and rectum </li></ul><ul><li>Paired lumbar – to body wall </li></ul>Fig 22.17
    26. 26. Circulation Changes at Birth <ul><li>No blood coming from placenta </li></ul><ul><li>Ductus venosus becomes ligamentum venosus (=ligamentum teres) </li></ul><ul><li>Foramen ovale closes & becomes fossa ovale </li></ul><ul><li>Ductus arteriosus closes and becomes ligamentum arteriosum </li></ul><ul><li>Umbilical vein and arteries degenerate </li></ul>
    27. 27. Patent foramen ovale For more congenital circulatory problems see p. 606 The End