Circulatory System and Blood

• Function of Circulatory System

  • Pumps and direct blood cells and substances carried in blood to all tissues of the body
  • Transport
  • Excretory
  • Protection: Aid on fighting off pathogenic microorganism
• Components of Cardiovascular System

  • Heart
  • Blood vessels
  • Arteries
  • Capillaries
  • Vein
  • Blood
  • RBC
  • WBC
  • Platelets
• Tunica media

  • An intermediate predominantly muscular layer, contains alternating smooth muscle and collagen or elastic lamellae
• Tunica adventitia

  • outer supporting tissue layer , contains connective tissue, small vessels and nerves and vasa vasorum
• Tissues of the vascular walls

  • Endothelium
  • Smooth muscle
  • Connective Tissue
• Endothelium

  • internal surface of all components of cardiovascular and lymphatic system
  • Simple squamous epithelium
  • maintain selectively permeable and antithrombogenic barrier
  • They also determine when and where white blood cells leave the circulation for the for the interstitial space of tissues
  • Secretes paracrine factors- signal vessel dilation, constriction and growth adjacent cells
• Smooth muscle

  • occur in the walls of all vessels larger than capillaries and arranged helically in layers
  • permit regulated vasoconstriction and vasodilation
• Connective Tissue

  • Collagen: found in subendothilial layer
  • Elastic fiber: provide resiliency to blood vessel
• It is hollow muscular organ?

  Heart
• Located in central mediastinum of thoracic cavity?

  Heart
• Modified artery that has pumping capacity that propels blood to the arteries of both the systematic and pulmonary circulations?

  Heart
• Endothelium and fibroelastic tissue, smooth muscle fibers and modified cardiac muscle?

  Endocardium or Tunica intima
• Contractile cardiac muscle fibers arranged spirally around each heart chamber?

  Myocardium or Tunica media
• Compose of simple squamous mesothelium supported by a layer of connective tissue containing blood vessels and nerves?

  Epicardium or Tunica serosa or Visceral pericardium
• It is thicker than endocardium and epicardium since it requires strong force to pump blood for circulation?

  Myocardium
• Cardiac skeleton

  • Forms base for all cardiac valves
  • Separates atria from ventricles and provide points of insertion for cardiac muscle in the atria and ventricles
  • Composition: Dense Irregular Connective Tissue
  • Helps coordinate the heartbeat by acting as electrical insulation between atria and ventricles
• Cardiac Conducting System

  • specialized to generate and conduct waves of depolarization which stimulates rhytmic contractions
  • Consists of modified cardiac muscle fibers
  • Composition
  • Sinoatrial nodes (pacemaker)
  • Atrioventricular node
  • Atrioventricular bundle of his
  • Purkinjie fibers
  • Contractile bundles
  • Abundant glycogen
  • Sparse bundles of myofibrils
• Blood vessels

  • Forms closed circuit to and from heart
  • Walls of all blood vessels except capillaries contain smooth muscle and connective tissue and endothelial lining
• Permit and regulate metabolic exchange between blood and surrounding tissues?

  Capillaries
• The most common type of capillary?

  Continous capillary
• Continuous capillaries

  • Locations:
  • Muscle
  • Connective tissue
  • Lungs
  • Exocrine glands
  • Nervous tissue
• These smallest blood vessels always function in network ?

  Capillary beds
• With well-developed occluding junctions; allow cellular exchange?

  Continuous capillaries
• Have a sieve-liked that allow more extensive molecular exchange across endothelium?

  Fenestrated capillaries
• found in organs with rapid interchange of substance between tissues and blood?

  Fenestrated capillaries
• Fenestrated capillaries

  • Locations
  • Kidneys
  • Intestines
  • Choroid plexus
  • Endocrine glands
• Permit maximal exchange of macromolecules as well as allow easier movement of cells between tissues and blood?

  Discontinued capillaries or sinusoids
• Highly discontinued basement membranes and much larger diameters, often 30-40, which slows blood flows?

  Discontinued capillaries or sinusoids
• Discontinued capillaries or sinusoids

  • Locations:
  • Liver
  • Spleen
  • Bone marrow
  • Some endocrine organs
• Resist control blood flow to capillaries?

  Arterioles
• Major determinant of systemic blood pressure?

  Arterioles
• Exchange metabolites by diffusion to and from cells?

  Capillaries
• Drain capillary beds?

  Venules
• Site of leukocyte exit from vasculature?

  Venules
• Veins

  • Carry blood back to the heart from microvasculature all over the body
  • Most veins are classified as small and medium veins that are usually located close and parallel to corresponding muscular arteries
• Collect blood from venules?

  Small veins
• Carry blood to larger veins; with no backflow?

  Medium veins
• Return blood to the heart?

  Large veins
• blood vessels that bring oxygen-rich blood from your heart to your body are called?

  arteries
• Conduct blood from heart and with elastic recoil help move blood forward under pressure?

  Large elastic arteries