Chapter 1 Flashcards
(95 cards)
Atria
Two upper chambers of the heart (singular, atrium)
Atrial kick
Blood pushed into the ventricles because of atrial contraction
Afterload
Pressure or resistance against which the ventricles must pump to eject blood
Cardiac output
Amount of blood pumped into the aorta each minute by the left ventricle. Defined as the stroke volume multiplied by the heart rate
What influences heart size?
Age, body weight and build, physical exercise frequency, heart disease
Location of heart?
Lies in the space between the lungs ( mediastinum I in the chest). About 2/3 of the heart lies to the left of the midline of the sternum
What are the surfaces of the heart?
Anterior, inferior, posterior, base, apex
Anterior
- Lies behind sternum and costal cartilages
- Right ventricle lies most directly behind sternum
Inferior
l. Aka diaphragmatic surface
2. Formed by the left ventricle
Base
- upper portion of the heart
- Left atrium
- Small portion of the right atrium
- Proximal portions of the superior and interior venacava and the pulmonary reins
Apex
- Lower portion of the heart
- Formed by the tip of the left ventricle
What are the three layers of the heart?
- Pericardium ( parietal pericardium - outer/ visceral pericardial )
- Myocardium
- Endocardium
Pericardium
- Parietal pericardium - tough outer layer
- Serous pericardium
- Pericardial space contains serous fluid
Organ has to be hollow to pump blood. Layers of heart importance holding heart in position and wall for protection of infection
Endocardium
- Innermost layer
- Lines the hearts inner chambers
- Continuous with innermost layers of vessels
Direct contact with flood. Connected with arteries.
Myocardium
I. Thickest
2. The one that contracts
3. Responsible for pumping action
Epicardium
- outermost layer of heart
- Contains blood capillaries, lymph capillaries, nerve fibers, and fat
Cardiac muscle
- Aka Myocite
- Heart halls formed by cardiac muscle fibers
- myofibrils
-myosin
- actin
- intercalated disks
- gap junctions
Those filaments create the contraction and relaxation
Myosin and actin do the most
Heart chambers
- 4 chambers
- Right and left atria
- Right and left ventricles
Which chambers are bigger?
- Atria - smaller
- Ventricles - bigger
Left ventricle is the biggest chamber. Needs space to hold blood to pump to the rest of the body.
Function of the heart skeleton?
l. Provides secure attachments for heart values
2. Provides for the attachment of the myocardium
3. Helps form the partitions (septa) that separate Tre atria from the ventricles.
4. Part in the middle is septum separates left and right side ( oxygen from CO2)
How many heart valves? What are their functions?
- 4 heart values. 2 sets of atrioventricular valves (AV) and 2 sets of semilunar valves (sl)
- Ensure blood flow in one direction through heart chambers prevent back flow.
Atrioventricular valves (AV)
l. AV separate atria from ventricles
2. Tricuspid valve - lies between right atrium and right ventricle.
3. Valves only allow blood to go one way (one direction)
Mitral value has only 2 cusps. Lies between left and right ventricle
Semilunar value
I. Prevent back flow of blood from the aorta and pulmonary arteries into the ventricles.
Pulmonic Valve - right
Aortic valve - left
Acute coronary syndrome (Acs)
Temporary or permanent blockage of a coronary artery. Excessive demand or inadequate supply of oxygen and nutrients to the heart muscle associated with plaque disruption, thrombus formation, and vast constriction.
3 major syndromes: unstable angina, non-st-elevation myocardial infraction, and ST- elevation myocardial infraction