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Chapter 13 (13.1 Types of Blood Vessels (Venules & Veins (1. Carry…

Chapter 13

13.1 Types of Blood Vessels

Arteries

  1. Carry blood away from the heart
  2. Strong & thick walled vessels. 
  3. 3 distinct layers
       1. Tunica Interna (Intima) - surrounds lumen  
             Composed of:
             a. Layer of endothelium
             b. Basement membrane
             c. Internal elastic lamina
       2. Tunica Media- the thickest layer 
              Composed of:
             a. Smooth muscle cells
             b. Elastic fibers
       3. Tunica Externa (adventitia) - outermost layer 
            Composed of:
             a. Elastic Fibers
             b. Collage Fibers

  4. Carries blood that is under great pressure.
  5. High in oxygen and low in carbon dioxide, **except the pulmonary arteries.**
  6. Branches & gives rise to thinner vessels (arterioles)
  7. Can unite with branches of other arteries 
  8. Supplies the same region forming anastomoses.

Capillaries

  1. The smallest and thinnest blood vessels. 
  2. Permit the exchange of gases, nutrients, and wastes between blood & tissues
  3. Connect arterioles to venules
  4. Are composed of only a single layer of endothelium & basement membrane
  5. **Capillary Arrangement** varies by tissue supplied
        a. Higher cellular needs (brain, muscle) = more elaborate network
        b. Lower cellular needs= less branching
  6. Regulation of Capillary Blood Flow
        a. Smooth muscles control blood entry into capillary beds
        b. Metabolic need controls precapillary sphincter

Capillary Exchange

  Gases, nutrients, & wastes are exchanged between blood in capillaries & tissues in 3 ways

 2. Vesicular Transport (endocytosis and exocytosis)

 3. Bulk Flow (filtration & absorption)
      a. Filtration
           - Hydrostatic (blood) pressure pushes small solutes & fluid out of capillaries
           - Colloid osmotic pressure (osmosis) - draws fluid back into capillary
           - Net affect is fluid loss at the beginning of capillary bed (most is regained by the end of the capillary bed)
           - Fluid not regained enters lymphatic vessels

 1. Diffusion
      a. Most common
      b. Includes oxygen, CO2, glucose, & hormones
      c. Lipid-soluble substances pass directly through endothelial cell membranes
      d. Water-soluble substances must pass through gaps between endothelial cells.

Venules & Veins

 2. Venules are composed of a tunica externa and tunica intima
      a. Extend from capillaries & merge together to form veins

 3. Veins Thin- walled vessels with 3 tunics:
      a. Tunica Intima = endothelium & basement membrane
      b. Tunica Media = thin layer of smooth muscle; much thinner than artery
      c. Tunica Externa = elastic & collagen fibers

 5. Contain valves; in medium sized veins & in the limbs.

 6. Carry blood that is high in carbon dioxide & low in oxygen, **except the pulmonary veins**
 7. Veins are large & serve as a blood reservoir, especially in the skin.

Arterioles

 1. Small arteries
 2. Delivers blood to capillaries in tissues
 3. Plays a major role in regulating blood flow and blood pressure. 
      a. Vasoconstriction (Contraction) = decrease vessel volume = decreased blood flow = increased blood pressure. 
      b. Vasodilation = increases vessel volume = increased blood flow = decreased blood pressure.

 Blood Distribution 
 1. 60-70% in systemic veins & venules
 2. 10-12% in systemic arteries & arterioles
 3. 10-12% in pulmonary vessels
 4. 8-11% in heart
 5. 4-5% in systemic capillaries

13.3 Control mechanisms that interact to regulate BF & BP in tissues

 Mechanisms involved in regulation of cardiovascular function
        i. Autoregulation (Local Changes)
       ii. Neural mechanisms (Short Term)
       iii. Endocrine mechanisms (Long Term)

Autoregulation

 Precapillary Sphincters alter peripheral resistance (Local changes)
      a. Based on local tissue concentrations (O2, CO2, pH)
           i.  Vasodilators: Increase Bloodflow
           ii. Vasocontriction: Less Blood

Neural Regulation

 2. When BP increases:
      1. Vasomotor dilate (inhibited)
      2. Cardioinhibitory center stimulated
           a. Parasympathetic
      3. Cardioacceleratory center inhibited
           a. Sympathetic
 3. When BP decreases;
      1. Vasomotor constrict (stimulated)
      2. Cardioinhibitory center inhibited
           a. Parasympathetic
      3. Cardioacceleratory center stimulated

 -The Cardiovascular (CV) Center & Vasomotor Center are located in the medulla oblongata.
           a. Nerve impulses sent to centers from 3 areas:
                i. Higher brain centers;
                ii. Baroreceptors (or pressoreceptors) that detect changes in BP in aorta & carotid arteries
                iii. Chemoreceptors that detect changes in key blood chemical concentrations (H+, CO2, & O2)

Hormonal Control/Endocrine

 -Several hormones affect BP by acting on the heart, altering blood vessel diameter, or adjusting blood volume.

  1. Hormones that increase BP:
        a. Epinephrine & Norepinephrine
           i. Increases CO & causes vasoconstiction of arterioles.
             b. Antidiuretic Hormone (ADH) (Posterior pituitary gland)
           i. increases reabsorption of water by the kidneys (DCT), and causes vasoconstriction of arterioles during diuresis (Have to pee a lot) and during hemorrhafe, because of angiotensin II.
      c. Angiotensin II (Renin released from kidneys)
           i. has 4 different targets that cause vasoconstriction of arterioles & causes the secretion of aldosterone, ADH & stimulus cardiac output.
      d. Aldosterone
           i. increases Na+ & water reabsorption in the kidneys
      e. EPO
           i. stimulates RBC production

 2. Hormones that decrease BP: 
      a. Atrial Natriuretic Peptide (ANP) 
           i. causes vasodilation of arterioles & promotes the loss of salt & water in urine
      b. Histamine
           i. causes vasodilation of arterioles (plays a key role in inflammation)

13.7 The major arteries & veins of the systemic circulation.

 B. Systemic Circuit -  the vessels that carry blood from the heart to body cells & back to the heart. 
      1. Arterial System:
           a. The aorta is divided into the following regions:
                -Ascending aorta;
                -Aortic arch;
                -Thoracic aorta;
                -Abdominal aorta;
                     *The abdominal aorta terminates at the brain of the pelvis & branches into each legs
           b. PRINCIPAL BRANCHES OF THE AORTA 
                -Branches of the ascending Aorta:
                     1. Right coronary a. (Myocardium)
                     2. Left coronary a. (Myocardium)

 -Branches of the aortic arch:
                     1. Brachiocephalic (Right side of head & arm);
                          a. Right common carotid (Right side of head)
                               -External carotid (Scalp)
                               -Internal carotid (Brain) 
                               -Vertebral (Cervical vertebrae/skull)
                                   a. Basilar (Brain)
                                         b. Circle of Willis (Brain)
                          c. Right Subclavian (Right arm)
                          d. Axillary (Armpit)
                          e. Brachial (Upper arm)
                          f. Radial (Lateral forearm)
                          g. Ulnar (Medial forearm)
                          h. Palmar arches (Palm)
                               i. Digital (Fingers)

           2. Left Common Carotid Artery (Left side of head):
                a. External carotid
                b. Internal carotid
           3. Left Subclavian Artery (Left arm):
Follows the same pattern as right subclavian artery

 BRANCHES OF THORACIC AORTA:
      1. Intercostals (chest muscles)
      2. Superior phrenics (Superiod diaphragm)
      3. Bronchial arteries (Bronchi of lungs)
      4. Esophageal arteries (Esophagus)
 BRANCHES OF ABDOMINAL ARTERY:
      1. Inferior phrenics (Inferior diaphragm)
      2. Celiac trunk (artery)
           a. Common hepatic (Liver)
           b. Left gastric a. (Left stomach)
           c. Splenic artery (Spleen)
      3. Superior Mesenteric (Small intestine, colon, & pancreas)
      4. Suprarenals (Adrenals)
      5. Renal Arteries (Kidneys)
      6. Gonadal Arteries (Ovarian/Testicular)
      7. Inferior Mesenteric (Descending colon, rectum)

 BRANCHES OF COMMON ILIAC ARTERIES
      1. External Iliac (Lower extremities)
           a. Femoral (Thigh)
                -Popliteal
                     1. Posterior Tibial (Lower leg)
                          a. Plantar arteries (heel, foot, & toes)
                     2. Anterior tibial
                          a. Dorsalis pedis (Foot & toes)

 1. Venous System:
      a. Jugular Veins (Head)
           -External jugular vein (Face)
           -Internal jugular vein (Brian)
      b. Median Cubital Vein (Venipuncture site)
      c. 2 brachiocephalic veins
      d. Superior vena cava (Formed by left & right brachiocephalic veins - head & upper limbs)
      e. Coronary Sinus (Cardiac veins)
           -Cardiac veins
      f. Hepatic vein
           -Hepatic portal vein (Drains gastric, mesentery, & spleen veins)
                1. Gastric vein (Stomach)
                2. Mesentery veins (Intestines)
                3. Splenic Vein (Spleen)
      g. Great saphenous vein - the longest vein in the body. From the medial ankle to the external iliac vein. 
      h. Inferior vena cava (Drains veins from abdominal & lower (limbs)
      j. Azygous system - azygous vein (R) & hemiazygous (L) 
           -Drains intercostal veins & lumbar veins

13.2 Regulating blood flow through blood vessels, & Regulating the movement of fluids between capillaries & interstitial spaces

  1. Factors affecting blood flow

  a. Pressure
        1. Liquids cannot be compressed (hydrostatic pressure)
              a. Liquid flow from high to low 
        2. Circulatory pressure at the base of the aorta (Pressure gradient)
              a. Needed to force blood through arterioles & into capillaries
                    1. Arterial pressure (BP) measured from arm
                    2. Capillary pressure
                    3. Venous pressure

  2. Peripheral Resistance

        1. Total peripheral resistance
              a. Vascular resistance, viscosity, & turbulence
              b. Blood flow- circulatory pressure must increase
                    2. Resistance (R) is the opposition to blood flow primarily due to friction.                                                                                 3. Friction depends on 3 things: 
              c. Blood viscosity (thickness of blood) 
              -Normally constant
              -Direct relationship
              d. Total blood vessel length
              -Normally constant 
              -Direct relationship
              e. Blood vessel radius
                    1. MOST significant factor in determining BP
                    2. Indirect relationship

  3. Cardiovascular pressures within the systemic circuit

        a. BP- the pressure exerted by blood on the wall of blood vessels. 
        b. Pulse- the pressure wave that travels through arteries following left ventricular systole

  1. Strongest in arteries that are closest to the heart
  2. Usually measure BP in radial artery at wrist
  3. Normal pulse = 70-80 bpm
        -Tachycardia > 100bpm
        -Bradycardia < 60bpm

        c. Pulse pressure - the difference between systolic & diastolic pressures
              1. Lessens as distance from the heart increases

        d. Measuring BP: 
              1. Use an instrument called a sphygmomanometer
              2. Brachial artery is usually used

        e. Arterial Pressure (BP)
              1. Usually refer to arterial BP, because the BP in the veins are insignificant
              2. The arterial BP rises to its maximum during systole (contraction) & falls to its lowest during diastole (relaxation)
              3. In a normal adult at rest, BP= 120mm Hg/80 mm Hg

        f. Capillary pressures & Capillary Exchange
              1. Capillary pressure pushes on capillary walls
                    a. Permeable to ions, nutrients, organic wastes, dissolved gasses & water
                    b. Capillary hydrostatic pressure vs Blood osmotic pressure
                          1. 100mm Hg (aorta)
                          2. 35mm Hg (arterial side capillary)
                                i. Arterial difference 100mm Hg - 35mm Hg= 65mm Hg
                          3. 18mm Hg (venule side of capillary)
                          4. 2mm Hg (vena cava)
                          5. Pressure of veins 18mm Hg - 2mm Hg = 16mm Hg
                    c. CHP ^ BOP (arterial side) fluid moves into tissues
                    d. BOP ^ CHP (venule side) fluid moves into vessels 
                    e. CHP = BOP no net fluid movement 
              2. Capillary exchange has 4 parts;
                    a. Communication between plasma & interstitial fluid
                    b. Speeding distribution throughout tissues
                    c. Assisting the movement of insoluble lipids & tissue proteins
                    d. Flushing bacterial toxins & chemical stimuli to the lymphatic system

13.4 How the cardiovascular system responds to stresses of exercise & hemorrhage.

 A. Exercise & the cardiovascular system
      a. Rest- 5.8 liters per minute
      b. Exercise
           1. Extensive vasodilation (Thighs/calves)
                a. Peripheral resistance drops
                b. Capillary flow increases
           2. Venous return increases
                a. Skeletal muscle contractions
                b. Increased respiration rate (Respiratory pump)
           3. Cardiac output increases
                a. Frank Starling principle (Ventricle pump)
                b. Bainbridge reflex (Atrial reflex)

      c. Hemorrhage
           1. Short term
                a. Blood donation 500ml 10%
                     1. Vasometer enough to restore pressure & flow
                b. Venous reserve
                     1. Slow moving blood (Liver, bone marrow, & skin)
                          a. Restore 15-20% loss
                c. Sympathetic stimulation (Major loss of blood)
                     1. E, NE, ADH, Renin (Starts to get blood levels back up)

Kahoot 13.1

 1. The muscular layer of blood vessels is the TUNICA MEDIA
 2. Compared to veins, arteries ARE MORE ELASTIC
 3. The blood vessels that carry blood at the highest pressure are the ARTERIES
 4. The blood vessels that have only a tunica intima are the CAPILLARIES
 5. Which of the following blood vessels hold the greatest volume of blood? VEINS
 6. Blood flow has the highest velocity in the ARTERIES
 7. The brachial artery would be classified as a(n) MUSCULAR artery
 8. The outermost layer of the arterial wall is the TUNICA EXTERNA
 9. Which of the following is lesser amount? THE NORMAL BLOOD VOLUME OF THE VENOUS SYSTEM
 10. The vessels that permit exchange of material between the cells & the blood are termed CAPILLARIES

13.2 Kahoot:

 1. Plasma proteins that remain in the blood capillaries help MAINTAIN THE OSMOTIC PRESSURE OF THE BLOOD
 2. Blood flow through the cardiovascular system is affected by ALL OF THE ABOVE
 3. Which of the following conditions would completely stop all NET filtration? THE BLOOD HYDROSTATIC PRESSURE & THE BLOOD OSMOTIC PRESSURE ARE EQUAL IN MAGNITUDE BUT OPPOSITE IN DIRECTION
 4. As blood travels from the aorta toward the capillaries the RESISTANCE INCREASES
 5. Which of the following is a normal pressure within capullaries? 20-30MM HG
 6. Transport mechanisms used by capillaries include ALL OF THE ABOVE
 7. Swelling of a tissue is due to INCREASED PERMEABILITY OF CAPILLARIES
 8. Blood moves forward through veins ALL OF THE ABOVE
 9. The third and fourth heart sounds are caused by TURBULENCE
 10. Edema would be likely to form when THE HEART IS AN INSUFFICIENT PUMP

13.3 Kahoot:

 1. Which of the following will cause a decrease in blood pressure? INCREASED LEVELS OF ANP 
 2. Which of the following changes will result in increased nutrient delivery to a specific tissue? RELAXATION OF PRECAPILLARY SPHINCTERS
 3. Baroreceptors that function in the regulation of BP are located in the CAROTID SINUS & AORTA
 4. Blood pressure in the systemic arteries is greatest during VENTRICULAR SYSTOLE
 5. Angiontensin increases BP by INCREASING PERIPHERAL RESISTANCE
 6. Which of the following factors is most likely to result in an increase in BP? DECREASED BLOOD FLOW TO THE KIDNEYS
 7. Causes a direct increase in blood volume. ADH
 8. Which of the following is greater? BP WHEN SYMPATHETIC STIMULATION TO THE HEART INCREASES
 9. When a capillary bed decreases in blood flow due to locally high oxygen levels, it is caused by AUTOREGULATION
 10. Blood pressure is lowest in which of the following structures? VEIN
 11. The baroreceptor reflex causes changes in ALL OF THE ABOVE (BP, STROKE VOL., HR)
 12. A decrease in vessel diameter is called VASOCONSTRICTION

Kahoot 13.4 - 13.10

 1. The celiac artery provides blood to the LIVER & SPLEEN
 2. Which of the following supplies blood to parts of the intestinal tract? SUPERIOR MESENTERIC ARTERY
 3. An important artery that supplies blood to the brain is the INTERNAL CAROTID
 4. Blood from the face returns to the heart by way of the EXTERNAL JUGULAR VEIN
 5. The pulse point on the wrist is actually the RADIAL artery
 6. After passing the axilla, the axillary artery becomes the BRACHIAL ARTERY
 7. In the forearm, the brachial artery becomes the BOTH A & B (RADIAL & ULNAR ARTERY)
 8. The internal carotids and the basilar artery are interconnected by an anastomosis called the CIRCLE OF WILLIS
 9. The DIAPHRAGM divides the aorta into a superior thoracic aorta & an inferior abdominal aorta
 10. Near the level of vertebra L4, the aorta branches to form the COMMON ILIAC ARTERIES
 11. The vessel that receives blood from below diaphragm is the INFERIOR VENA CAVA
 12. Small veins of the brain empty into the DURAL SINUSES

 13. After receiving the internal jugular vein, the subclavian vein becomes the BRACHICEPHALIC VEIN
 14. The fusion of the brachiocephalic veins forms the SUPERIOR VENA CAVA
 15. The two common iliac veins form the INFERIOR VENA CAVA
 16. Which of the following is a remnant of a fetal blood vessel? LIGAMENTUM ARTERIOSUM
 17. Elderly individuals are more prone to suffer from ALL OF THE ABOVE then younger adults.
 18. Factors that increase the risk of atherosclerosis include OBESITY
 19. Vicki has a disabled posterior pituitary. What type of cardiovascular affects might you expect? DECREASED BLOOD VOLUME
 20. In response to hemorrhage, there is MOBILIZATION OF THE VENOUS RESERVE
 21. Symptoms of shock include ALL OF THE ABOVE
 22. Which of the following is greater? HEART RATE DURING CARDIOVASCULAR SHOCK
 23. Which is a branch of the pulmonary trunk? PULMONARY ARTERY

13.5 The 3 general functional patterns in pulmonary & systemic circuit.

 A. Cardiovascular is divided into
      1. Pulmonary Circuit
      2. Systemic Circuit
 B. Distribution of arteries & veins on Lleft & right are identical 
 C. Vessels may undergo several changes
 D. Tissues & organs are service by several arteries & veins

13.6 The major arteries & veins of the pulmonary circuit.

 A. Pulmonary Circuit - the vessels that carry blood from the right ventricle to the lungs, & the vessels that return the blood to the left atrium: 
      1. Pulmonary trunk
      2. Right and left pulmonary arteries (Deoxygenated blood)
      3. Capillaries in lungs 
      4. Right & left pulmonary veins (Oxygenated blood)

13.8 The differences between fetal & adult circulation pattern & the changes in the patterns of blood flow that occur at birth.

 A. Embryonic lungs collapse
 B. Placental blood supply
      1. Umbilical Arteries (2)
           a. Rise from internal iliac arteries
      2. Placenta
           a. Exchange of nutrients
      3. Umbilical Vein (1)
           a. Liver
           b. Ductus Venous
                1. Inferior vena cava
 C. Fetal circulation in the heart & great blood vessels
      1. Foramen ovale (1 way valve thru the interatrial septum)
      2. Ductus arteriosus (Pulmonary & aortic trunks)
 D. Circulatory changes at birth
      1. Foramen ovale closes
      2. Ductus arteriosus become Ligamentum arteriosum

13.9 The effects of aging on the cardiovascular system

 A. Blood
      1. Decreased hematocrit (less red blood cells)
      2. Constriction or blockage (thrombus or embolism)
      3. Pooling of blood (valves don't work as well)
 B. Heart
      1. Reduced cardiac output
      2. Changes in nodal or conducting cells
      3. Reduced elasticity of fibrous skeleton
      4. Atherosclerosis
      5. Scar tissue
 C. Blood vessels
      1. Inelastic walls
           a. Aneurysm, stroke, MI, or massive blood loss
      2. Calcium deposits