Ch 14 Cardiovascular System Flashcards
Desmosomes
Allow force to pull on adjacent cells
Autorhythmic cells
control heart rate
- pacemaker potential
- Start action potential
Pacemaker potential
Unstable membrane potential, drifts towards 0
Contractile cells
smaller than skeletal muscle
-1 nucleus per cell, shorten in response to stimulus
Septum
separates left and right sides of heart so they function independently
Valves
prevent backwards flow of blood
- AV
- RST
- Left side biscuspid valve
- Semilunar valves
Atrioventricular Valves (AV)
between atria and ventricles
- Passive movement, blood is pushed up when ventricle contracts closing valve
- Chordae Tendineae
Chordae Tendineae
Connects valve to ventricle
-connected to papillary muscles for stability
Right Side Tricuspid Valve (RST)
3 flaps
Left Side Bicuspid or Mitral Valve
2 flaps
Semilunar valves
b/w ventricles and arteries
- aortic on left and pulmonary on right
- concave shape so no connective tissue is needed
Pulmonary Circuit
Heart to lungs and back
Oxygen poor blood leaves–> oxygen rich returns
Systemic Circuit
Heart to body and back
Oxygen rich blood leaves–>oxygen poor returns
Starling law of the heart
Heart pumps out all the blood that is returned to it
Inotropic Agent
Chemical that affects contractility
Contractility
Controlled by nervous and endocrine systems
Positive Inotropic Effect
Increases contractility
Negative Inotropic Effect
Decreases contractility
Plateau
- Contractile cells action potential
- Complete opening of Ca channels, closing of some K channels
Autorhythmic cells action potential
- Does not require innervation
- Signal spreads to contractile cells via gap junctions
- Action potential spreads across membrane to t tubules
- Opens Voltage gated Ca channels
Na-Ca Exchanger (NCX)
Exports Ca from cell after contraction
Graded Contraction
Force is proportional to # of formed crossbridges
-How much Ca is bound to troponin
Cardiac Refractory Period
Much longer than in skeletal muscle
-ensures that heart relaxes (fills with blood) and contracts (sends blood away)
Pericardium
Sac made of connective tissue that encases the heart
-filled w/ fluid for lubrication
Fibrous and Serous
- Fibrus
2. Serous
- Outer layer of pericardium
2. Inner layer
Capillaries
Exchange nutrients/wastes w/ tissues
ECG
Measures electrical activity of the heart
Valves-portions above or below baseline
Segments-baseline b/w waves
Intervals-Combos of waves and segments
Pwave
ECG
-atrial depolarization
QRS Complex
-ECG
Ventricular depolarizaton and atrial repolarization
T wave
ECG
-Ventricular repolarization
Junctions that attach myocardial cells together
Intercalated disks
How does Ca get removed from cell
Ca-ATPase
Na-Ca exchanger (NCX)
