Please enable JavaScript.

Coggle requires JavaScript to display documents.

CARDIOVASCULAR (Clinical Terms (Stroke volume: Amount of blood pumped…

- - - - Pulmonary trunk: splits into pulmonary arteries and transports blood from right ventricle
      - Aorta: transports blood from left ventricle
    - - Superior/Inferior vena cava: drain deoxygenated blood into right atrium
      - Pulmonary veins: drain oxygenated blood into left atrium
  - - - Right AV valve (tricuspid)
      - Left AV valve (bicuspid)
    - - Aortic sl valve: located between left ventricle and the aorta.
        
        Opens to allow blood flow through the heart
        
        Closes to prevent backflow
      - Pulmonary sl valve: located between right ventricle and pulmonary trunk.
        
        Opens to allow blood flow through the heart
        
        Closes to prevent backflow
  - - - Papillary muscles found on internal ventricle wall
      - Trabeculae carneae are the irregular muscular ridges inside the ventricle wall
      - Chordae tendineae are thin strands of collagen fibers attaching to the AV valve.
    - - Pectinate muscles are the ridges on the anterior wall and within auricle.
      - The fossa ovalis is the oval depression in interatrial septum
  - - - Intercalated discs connect cells
      - Gap junctions electrically join cells (allow ion flow) to make each heart chamber a functional unit
      - Desmosomes mechanically join cells with protein filaments
    - - The sarcolemma increased structural stability of myocardium and facilitates communication between cells
- - - - Depolarization --- Changing of membrane potential triggers the opening of fast voltage gated Ca2+ channels. Ca2+ flows into the nodal cell changing the membrane potential from -40 mv to around 0 (making it slightly positive).
      - Reaching threshold --- Slow voltage Na+ channels open. Na+ flows into into the nodal cells and change RMP from -60 mV to -40 mV (threshold value).
        
        No outside stimuli
      - Repolarization --- Ca2+ channels close and voltage gated K+ channels open, changing the membrane potential from about 0 to -60 mV (RMP). Na+ channels open and the cycle continues.
    - - Action potential is delayed at the AV node before it passes to the AV bundle within the intervenrticular septum.
      - The AV bundle conducts the action potential along the left and right bungle branches to Purkinje fibers.
      - Action potential that is generated in the SA node spreads between cardiac muscle cells (by gap junctions) throughout the atria to the AV node.
      - Action potential is spread (gap junctions) between cardiac muscle cells throughout ventricles.
  - - - Plateau --- Voltage gated K+ channels open, causing K+ to leave cardiac muscle cells (changing membrane potential).
        Slow voltage gated Ca2+ channels in the sarcolemma open (Ca2+ flows into the cardiac muscle cells from the interstitial fluid).
        The simultaneous release of K+ and entrance of Ca2+ into cardiac muscle cells causes no electrical change (both are positive).
      - Repolarization --- Ca2+ channels close, while K+ channels remain open and exit the cardiac muscle cell. Membrane potential changes back to -90 mV. Muscle cells propagate and the cycle may continue when when the cardiac muscle is stimulated again.
      - Depolarization --- Action potential (via gap junctions or conduction system) triggers the opening of fast voltage gated Na+ channels in the sarcolemma. RMP in muscle cells changes from -90 mV to +30 mV. Voltage gated Na+ channels close to an inactive state.
    - - Crossbridge cycling --- the entry of Ca2+ into the sarcoplasm (from IF or SR) initiates muscle contractions.
        
        Ca ions bind to troponin.
        
        Voltage gated Ca2+ channels close and Ca2+ is taken into the sarcoplasmic reticulum, but removed from the cell by plasma membrane pumps (decreases levels in the sarcoplasm)
        
        Ca ions are released by troponin causing the crossbridge between thick and thin filaments to decrease and relaxing the cardiac muscle.
        
        Muscle cannot contract until the sarcolemma has been repolarized and the RMP is reestablished.