Anaphy Finals

• Blood vessels outside the heart

  • Pulmonary vessels
  • Systemic vessels
• Pulmonary vessels


  Transport blood from the right ventricle of the heart through the lungs and back to the left atrium
• Systemic vessels


  Transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium
• Blood vessel functions


  • Carry blood
  • Exchange nutrients, waste products, gases within tissues
  • Transport substances
  • Regulate blood pressure
  • Direct blood flow to tissues
• Vessel structures


  • Arteries: carry blood away from heart, thick with a lot of elastic tissue
  • Veins: carry blood toward heart, thick with less elastic tissue
  • Capillaries: exchange occurs between blood and tissue fluids
• Blood flow


  1. Blood flows from arteries into arterioles

  2. Arterioles into capillaries

  3. Capillaries into venules

  4. Venules to small veins

  5. Veins return to heart
• Blood vessel wall layers

  • Tunica intima: innermost layer, simple squamous
  • Tunica media: middle layer, smooth muscle with elastin and collagen fibers
  • Tunica adventitia: outermost layer, connective tissue
• Elastic arteries


  • Largest in diameter, thickest walls, Example - aorta and pulmonary trunk
• Muscular arteries


  • Medium to small size, thick in diameter, contain smooth muscle cells, can control blood flow to body regions
• Capillaries


  Blood flows from arterioles into capillaries, Capillaries branch to form networks, Blood flow is regulated by smooth muscle cells, precapillary sphincters
• Types of veins


  • Small veins: all 3 tunics present
  • Medium sized veins: collect blood from small veins and deliver to large veins
  • Large veins: contain valves
• Pulmonary circulation vessels


  • Pulmonary trunk: carries blood from right ventricle towards lung
  • Pulmonary veins: exit lungs and carry O2 rich blood to left atrium
• Parts of the aorta

  • Ascending: passes superiorly from left ventricle
  • Aortic arch: contains 3 major arteries which carry blood from aorta to head and upper limbs
  • Descending: extends through thorax and abdomen to pelvis
  • Thoracic: part of descending aorta that extends through thorax to diaphragm
  • Abdominal: descending aorta that extends from diaphragm where it divides at the common iliac arteries
• Branches of the aortic arch

  • Brachiocephalic artery
  • Left common carotid artery
  • Left subclavian
• Arteries of the head and neck

  • Brachiocephalic artery: first branch off aortic arch, supplies blood to right side of head and neck
  • Left common carotid artery: 2nd branch off aortic arch, supplies blood to the left side of head and neck
  • Left subclavian artery: 3rd branch off aortic arch, supplies blood to left upper limbs
  • Right common carotid artery: branches off brachiocephalic artery, supplies blood to right side of head and neck
  • Right subclavian artery: branches off brachiocephalic artery, supplies blood to right upper limbs
• Cerebral arterial circle
• Arteries of the upper limbs

  • Axillary arteries: continuation of subclavian in the axilla (armpits)
  • Brachial arteries: continuation of axillary artery that extends into the arm where blood pressure measurements are taken
  • Ulnar arteries: branch of brachial artery near elbow
  • Radial arteries: branch of brachial artery, supply blood to forearm and hand, pulse taken here
• Abdominal aorta branches


  • Celiac trunk arteries: supply blood to stomach, pancreas, spleen, liver, upper duodenum
  • Superior mesenteric arteries: supply blood to small intestines and upper portion of colon
  • Inferior mesenteric arteries: supply blood to colon
  • Renal arteries: supply blood to kidneys
  • Hepatic arteries: supply blood to liver
  • Testicular arteries: supply blood to testes
  • Ovarian arteries: supply blood to ovaries
  • Inferior phrenic arteries: supply blood to diaphragm
  • Lumbar arteries: supply blood to lumbar vertebra and back muscles
• Arteries of the pelvis

  • Common iliac arteries: branches from abdominal aorta, divides into external and internal iliac arteries
  • External iliac arteries: division of common iliac artery, supply blood to lower limbs
  • Internal iliac arteries: division of common iliac, supply blood to pelvic area
• Arteries of the lower limbs

  • Femoral arteries: supply blood to thigh
  • Popliteal arteries: supply blood to knee
  • Anterior and posterior arteries: supply blood to leg and foot
  • Fibular arteries: supply blood to lateral leg and foot
• Veins


  In the systemic circulation, the blood returning to the heart is deoxygenated. In the pulmonary circulation, the blood returning to the heart in the pulmonary veins is oxygenated.
• Major veins


  • Superior vena cava: returns blood from head, neck, thorax, and right upper limbs, empties into right atrium of heart
  • Inferior vena cava: returns blood from abdomen, pelvis, lower limbs, empties into right atrium of heart
• Veins of the head and neck

  • External jugular vein: drain blood from head and neck, empties into subclavian veins
  • Internal jugular vein: drain blood from brain, face, neck, empty into subclavian veins
  • Subclavian veins: forms brachiocephalic veins
  • Brachiocephalic veins: join to form superior vena cava
• Veins of the upper limbs

  • Brachial veins: empty into axillary vein
  • Cephalic veins: empty into axillary vein and basilic vein
  • Median cubital veins: connects to cephalic vein near elbow
• Veins of the thorax


  • Right and left brachiocephalic veins: drain blood from thorax into superior vena cava
  • Azygos veins: drain blood from thorax into superior vena cava
  • Internal thoracic veins: empty into brachiocephalic veins
  • Posterior intercostal veins: drain blood from posterior thoracic wall, drains into azygos vein on right side
  • Hemiazygos vein: receives blood from azygos vein of left side
• Veins of the abdomen and pelvis

  • Common iliac vein: formed from external and internal iliacs, empty into inferior vena cava
  • External iliac vein: drains blood from lower limbs, empty into common iliac vein
  • Internal iliac vein: drains blood from pelvic region, empties into common iliac vein
  • Renal vein: drains blood from kidneys
• Hepatic portal system


  Vascular system that begins with capillaries in viscera and ends with capillaries in liver, uses splenic vein and superior mesenteric vein
• Veins of the lower limbs

  • Femoral veins: drain blood from thigh and empty into external iliac vein
  • Great saphenous veins: drain from foot and empty into femoral vein
  • Popliteal veins: drain blood from knee and empty into femoral vein
• Blood pressure


  Measure of force blood exerts against blood vessel walls, Systolic pressure: contraction of heart, Diastolic pressure: relaxation of heart, Average Blood Pressure: 120/80
• Pulse pressure


  Difference between systolic and diastolic blood pressures, Example - 120 for systolic / 80 for diastolic; pulse pressure is 40 mm Hg, Pulse pressure points can be felt near large arteries
• Body locations to evaluate pulses
• Capillary exchange


  Most exchange across capillary wall's occurs by diffusion, Blood pressure, capillary permeability and osmosis affect movement of fluids across capillary walls, Net movement of fluid from blood into tissues, Fluid gained in tissues is removed by lymphatic system
• Local control of blood flow

  Achieved by relaxation and contraction of precapillary sphincters, Sphincters relax blood flow increases, Precapillary sphincters controlled by metabolic needs of tissues, Concentration of nutrients also control blood flow, Blood flow increases when oxygen levels decrease
• Nervous control of blood flow

  Vasomotor center: in pons and medulla oblongata, sympathetic division, controls blood vessel diameter, Vasomotor tone: state of partial constriction of blood vessels, increase causes blood vessels to constrict and blood pressure to go up
• Hormonal control of blood flow

  Sympathetic division regulates hormonal control through release of epinephrine and norepinephrine from the adrenal medulla, In most blood vessels these hormones cause constriction, reducing blood flow, In some tissues like skeletal and cardiac muscle they cause dilation, increasing blood flow
• Mean arterial pressure (MAP)


  Reflects an average arterial pressure in various vessels of the body, MAP = CO × PR, Changes in response to changes in HR, SV, or PR, About 70 mm Hg at birth, Maintained at about 95 mm Hg from adolescence to middle age, May reach 110 mm Hg in a healthy older person
• Baroreceptor reflexes


  Activate responses to blood pressure in normal range, Baroreceptors respond to stretch in arteries due to increased pressure, Located in carotid sinuses and aortic arch, Change peripheral resistance, heart rate, stroke volume in response to blood pressure
• Baroreceptor reflex mechanisms
• Baroreceptor effects on blood pressure
• Chemoreceptor reflex


  Chemoreceptors are sensitive to changes in blood oxygen, carbon dioxide, and pH, Located in carotid bodies and aortic bodies, Send action potentials along sensory nerve to medulla oblongata