Generalidades Flashcards
What is the myocardium composed of?
Células musculares estriadas conectadas por uniones comunicantes
What are sarcomeres?
La unidad de contracción muscular formada por estructuras que se repiten en serie
What proteins are involved in muscle contraction?
Actina, miosina, troponina y tropomiosina
What role does tropomyosin play in relaxed muscle?
Impide la interacción entre actina y miosina
In a cross-section, how are thick and thin filaments arranged?
Cada filamento grueso está rodeado por seis filamentos finos
What are the dark and light bands in muscle fibers called?
Bandas oscuras (A) y bandas claras (I)
What is the Z line in a sarcomere?
Punto de unión entre los filamentos finos de una sarcómera con los de la sarcómera adyacente
What happens to the A band and I band during muscle contraction?
La banda A no varía de longitud; la banda I se acorta
What are T-tubules?
Invaginaciones de la membrana de la célula muscular estriada hacia el citosol
What triggers calcium release from the sarcoplasmic reticulum?
La propagación del potencial de acción a través de los túbulos T
What is the role of calcium in muscle contraction?
Se une a la troponina C, lo que permite la interacción entre actina y miosina
What are the two consequences of calcium influx in cardiac muscle?
- Mayor duración de la contracción del músculo cardíaco
- Mayor sensibilidad a la concentración de calcio
What happens during muscle relaxation in cardiac muscle?
El calcio se almacena en el retículo sarcoplasmático a través de una bomba ATPasa
Fill in the blank: ATP is required for _______.
disociar actina y miosina
True or False: The energy expenditure occurs during muscle contraction.
False
What is the function of the Na+/Ca2+ exchanger during relaxation?
Permite que una pequeña proporción de calcio salga al exterior
What does the term ‘zona H’ refer to in a sarcomere?
Zona en la banda A donde no existen filamentos finos
What happens to the sarcomeres during contraction?
Se acortan debido al deslizamiento de los filamentos de actina hacia el centro de la banda A
What is the main function of the heart?
To receive and pump blood to various organs and tissues of the body.
Where does deoxygenated blood enter the heart?
Through the superior and inferior vena cava and coronary sinus.
What is the pathway of blood starting from the right atrium?
Right atrium → Tricuspid valve → Right ventricle → Pulmonary valve → Pulmonary artery.
What happens to blood in the pulmonary bed?
Blood gets oxygenated.
What is the pathway of oxygenated blood starting from the pulmonary veins?
Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aortic valve → Systemic circulation.
What are the phases of the cardiac cycle?
Isovolumetric contraction, ejection period, isovolumetric relaxation, filling phases.
What initiates systole in the cardiac cycle?
Contraction of the ventricles.
What is the first heart sound associated with?
Closure of the AV valves.
What occurs during isovolumetric contraction?
Ventricular pressure increases, closing AV valves.
What is the second heart sound associated with?
Closure of the semilunar valves.
What are the three filling phases of the ventricles?
- Rapid filling
- Diastasis
- Atrial contraction.
How does heart rate affect diastole?
Diastole shortens with increased heart rate.
What is the role of diastole in myocardial perfusion?
It is the period during which the myocardium is perfused.
What are the three factors that determine stroke volume?
- Preload
- Contractility
- Afterload.
What does preload refer to?
The volume of blood in the ventricles at the end of diastole.
What is the Frank-Starling law?
The stroke volume is directly proportional to the initial length of cardiac muscle fibers.
What factors can decrease cardiac contractility?
- Hypoxia
- Hypercapnia
- Acidosis
- Negative inotropic drugs.
What is the effect of sympathetic nervous system stimulation on contractility?
It increases contractility.
Fill in the blank: The initial phase of ventricular filling is called _______.
Rapid filling.
True or False: The diastolic phase is the first to be affected during myocardial ischemia.
True.
Fases de la diastole
Relacion entre precarga, contractilida y poscarga con el volumen sistolico
Pulso salton
Pulso Anacroto
Pulso hipocinegico
Pulso bisferens
Pulso alternate
Pulso paradojico y sgno de kussmaul
Pulso venoso
R1 y r2
Bloqueos de rama y ruidos cardiacos
Estenosis valvular y ruidos cardiacos
R3 y r4
Maniobras que aumentan el retorno venoso
Signos radiologicos de crecimiento de cavidades toracicas
Que se registra con la ergometria
Para que se utiliza la ergometria
Vias de realizar el ecocardio
M ecocardio
Ecocardio 2d
Ecocardio 3d
Ecocardio doppler
Como se realiza el acateterismo y angiofrafia diagnosticoterapeutica
Para que se realiza la rmn cardiaca
Limitaciones rmn cardiaca
En que consiste el estudio electrofisiologico
Uso estudio electrofisiologico
Angiotac uso
Angiotac y calcium score
