Midterm 2 Flashcards
1st heart sound:
Caused by tricuspid & bicuspid valves (AV valve closure)
2nd heart sound
Caused by closure of pulmonary and aortic valves (semilunar valves)
3rd heart sound
- Heard only among children and young adults
- Best heard when ask patient to lie on left side
- Disappears in 30’s
- If present in older adults may signify heart failure @ Erb’s point or mitrovalve area
- Caused by ventricular filling
- Vibration of ventricles
- Blood rushing from atria to ventricles
4th heart sound:
- Heard after 1st heart sound
- Heard in people w/ heart disease or MI
Projection Areas of Valve Sound:
- Pulmonic:
- Aortic:
- Tricuspid:
- Mitral:
- Erb’s point:
- 2nd left intercostal space lateral to sternum
- 2nd right intercostal space lateral to sternum
- over lower portion of sternum
- 5th left intercostal ½ inch medial to the midclavicular line
- S2 sound- in 3rd left intercostal space
Mapping out the Heart:
-Superior border:
- Right border:
- Inferior border:
- Left border:
– a line connecting the inferior margin of the 2nd left costal cartilage and superior margin of 3rd right costal cartilage
- line connecting 3rd right costal cartilage to 6th right costal cartilage
- line connecting 6th right costal cartilage to apex beat are (3.5inches from midline at left 5th intercostal space)
- connects left ends of superior and inferior border
Nerve Supply of the Heart
Cardiac Plexus of Nerves Contain:
- Preganglionic parasympathetic fibers (vagus nerve)
- Vagal afferent fibers-concerned with cardiac reflexes
- Postganglionic sympathetic fibers (T1-T4/5)
- Sympathetic afferent fibers-detects ischemic pain
- NOT sensitive to touch, cutting, cold, or heat
Cardiac Conduction System:
SA node:
SA node:
- Superior end of sulcus terminalis
- In subepicardium (under epicardium)
- Near opening of SVC
- Natural pacemaker of the heart
- 70-80bpm
AV node:
- If SA node is damaged or destroyed AV node takes over as the pacemaker
- Provides impulses 40-60bpm
Purkinje fibers
-Ends in sub-endocardium
FUN FACTS CLINICALLY
- IF SA node & AV node are both damaged- will have multiple pacemakers= ventricular fibrillation- heart quivers =doesn’t pump efficiently-must force multiple pacemakers to synchronize.
- Transplant=DENERVATED- no more nerve supply from the vagus nerve or sympathetic nervous system-when exercise doesn’t pump any harder= DELAYED RESPONSE; when resting, then starts to increase through adrenal glands= LONG DURATION
“SKELETON OF THE HEART”
Composed of fibrous or fibrocartilaginous tissue
-Forms the central support of the heart
- Fibrous rings that give circular form and rigidity to
- the AV orifices and roots of pulmonary trunk and aorta
- Provide attachment to valves and prevent the outlets from becoming dilated
- Also provides attachment to cardiac muscle fibers
Venus Drainage:
Coronary Sinus:
- Anterior Cardiac Veins: drain directly to RA
- Vena Cordis minimi: drains directly into atria
- Great cardiac vein-accompanied by anterior interventricular artery
- Middle cardiac vein- accompanied by posterior interventricular artery
- Small cardiac vein-accompanied by right marginal artery
- Left marginal vein-accompanied by left marginal artery
- Left posterior interventricular vein-accompanied by left posterior ventricular artery
Right Coronary Artery:
RA & RV
Circumflex-
LA and LV
Pericardium:
- Located in the middle mediastinum
- Posterior to the body of the sternum
- 2nd-6th costal cartilages
- Anterior to T5-T8 vertebrae
- Double-walled fibrous sac which encloses the heart and root of the great vessels: conical in shape
- It is bound by pericardiacophrenic and sternopericardial ligaments
- Cavity contains 5-30ml of serous fluid
- Arterial supply: branches from the internal thoracic, pericardiacophrenic, musculophrenic, and inferior Phrenic arteries, and the thoracic aorta
- Nerve supply: phrenic and vagus nerves, sympathetic trunks
Fibrous and serous pericardium
Fibrous pericardium: outer tough fibrous layer made up of dense irregular CT
o Serous pericardium: parietal layer and visceral layer (epicardium)
Pericarditis:
inflammation of the pericardium; causes increased secretion of serous fluid-surface becomes rough
Pericardial effusion:
increased secretion of fluid-due to infection
Cardiac tamponade
blood coming out to sac but still in pericardium-starts to compress the heart and therefore compression of great vessels especially SVC
Pericardiocentesis:
put needle into pericardium then extract
External Features of the heart:
- Pyramidal shape; fibrous framework
- External sufaces: sternocostal, diaphragmatic, & pulmonary; a base; apex
- Coronary sulcus: groove that separates atria from ventricles (aka AV sulcus)
- Interventricular sulcus: b/w ventricles
- Sulcus terminalis: along inferior/superior vena cava (right side) – inside is crista terminalis
Coronary arteries and branches
- RCA: marginal and posterior interventricular arteries
- LCA: anterior interventricular and circumflex arteries
Coronary sinus and cardiac veins
- Posterior cardiac veins drain directly into coronary sinus
- Anterior cardiac veins drain directly into RA
- Coronary sinus drains into RA