CVS lecture one

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    • >hollow, cone fist size, cone shaped organ
    • >enclosed within the mediastinum
    • >rests on diaphragm at the 5th intercostal space
    • >encased in a double walled sac called pericardium
    • >4 hollow chamber
    • >2 artia and 2 ventricles
    • >act as a double pump
    • >divided by interventricular septum
  2. Pericardium
    • > double walled sac surround the heart
    • >2 layers > Fibrous & serous
    • >Serous pericardium consists of 2 layers>Parietal & visceral layer
    • >Visceral layer is part of the wall of heart called epicardium
  3. Muscle layers of the heart

    Endocardium - Inner layer
    >lines each 4 chambers of heart to ensure blood flows freely through the heart
  4. muscle layer

    Myocardium - middle layer
    • >consists of thick cardiac muscle that contract
    • >responsible for the majority of the work that occurs in the heart.
  5. Muscle layer 

    Epicardium - outer layer
    >also visceral layer of pericardium>Produce serous fluid to ensure the heart beats without any friction or resistance>without fluid, friction will occurs>loss of serous fluid results in inflammation of percardium causing pericarditis.
  6. Atria
    >receiving chambers where blood flows passively into them
  7. Ventricles
    • >discharging chambers that force blood out of the heart into the circulation during contraction
    • >left ventricle has the thickest walls because it has to pump the blood throughout the entire body and back to the heart.
  8. Valves
    • >ensure blood flow in one direction
    • >4 valve to prevent backflow of blood into the heart chambers
    • >attached to valve are flaps
  9. Av valve
    • >located between atrial and ventricular chambers
    • include
    • >bicupsid (mitral)(L atria)
    • >Tricupsid (R atria)
  10. Semi Lunar valves
    >located in chambers of ventricles
  11. Pulmonary circulation (right side)
    • >deoxygenated blood rushes into R atrium via superior/interior vena cavae
    • >heart pumps blood into R ventricl via pulmonary trunk
    • >blood leaves the heart through the R ventricle vai pulmonary trunk
    • >Pulmonary trunk divides nto L & R pumonary arteries
    • >Blood travel through arteries to capillaries at the lungs to collect O2 and dispose of CO2
    • >Oxygenated blood returns to the heart via pulmonary veins
  12. Systemic circulation ( left side)
    Function is to provide the body with needed oxygen and nutrients.

    L ventricle is musch more powerful than R ventricl becuase it has to travle from the body's tissues over a long distance.

    • >blood returns to L side of the heart rich in O2/nutrients and low in CO2 via pulmonary veins
    • >blood enters the heart in L atrium into L ventricles 
    • >oxygenated blood leaves the heart via L ventricle and enters the aorta
    • >Aorta branches into systemic arteries into capillaries 
    • >O2 diffuses from capillaries into capillary beds in body's tissues.
    • > at the same time CO2 diffuses from tissues's capillary beds into the blood
    • >deoxygenated blood enters the R side of the heart via vena cavae
  13. Conduction of heart
    • >cardiac muscle initiates own contraction to ensure heart functions as a whole
    • >diferent cells maintain different rhythms
    • >Atria cell 60 x min
    • >Ventricular cell 20 - 40 x min
    • >nervous system aid in maintaining some form of unity 
    • >autosome NS
    • >intrin conduction system
  14. Autonomic nervous system
    >acts to decrease or increase heart rate
  15. Intrinsic conduction system
    • >found in heat tissue
    • >responsible for the rate of contraction and for setting rhythm via electrical current taht constitues a pulse
    • >consists of SA node (most important), Av node (pacemaker), Atrioventricular bundle, bundle branches, Purkinje fibres
  16. cardia/Coronary circulation ( serves the heart)
    • >heart needs 5% of output ot supply to self.
    • >C.C deliever O2 rich blood into myocardium for processing
    • >As heart relaxs, oxygenated blood leave L ventricle via the aorta
    • >blood enters R & L coronary arteries located at the base of the aorta
    • >blood enters anterior and posterior brances
    • >oxygen is delieverd to mayocardium
    • >deoxygenated blood returns to the heart via caridac veins into coronary sinus and empites into R atrium.
  17. Vascular system: the vessels
    • >Blood leaves the heart and force into arteries then arterioles as the heart beats
    • >blood moves into capillary beds found within tissues
    • >movement of nutrients, O2, CO2 occurs within capillaries via diffusion
    • >blood move from capillaries into venule then larger veins
    • >once in vein blood rushes back into the heart.
  18. Arteries (single - arteriole)
    • Drain oxgenated blood away from the heart
    • >3 layers (tunica or lumen)
    • >closer to heart
    • >Thicker walls due to tunia media is heavier
    • >Capable of expansion and recoil to normal size
    • >Strong stretchy walls
    • >high pressure
  19. Veins (single. Venule)
    • Return deoxygenated blood to the heart
    • >3 layers (tunica or lumen)
    • >further from heart
    • >Thinner walls especially in tunia media
    • >low pressure
    • >capable of returning equal amount of blood back to heart
    • >valve work to return blood back to heart
  20. Capillaries
    • >branch thru tissues, connecting the arterioles to the venules
    • >only vessel that move between tissues by weaving and winding causing exchange of gases & nutrients between blood and tissue
    • > 1 thin layer
    • >thinness allows diffusion of nutrients between capillaries and tissue to occurs
    • >Form capillary beds
    • >sphincters that allow blood to bypass tissue cells
  21. Layers of vein and artery

    Tunica intima
    • >inner layer
    • > lines the interior wall to reduce friction as blood flows thru the vessel
  22. Tunica Media
    • >middle layer of smooth muscle and elastin
    • >allows vessels to constrict/dilate
  23. Tunia externa
    • >outer layer
    • >consists of  collagen that support and protect the vessels
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CVS lecture one
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