Lecture Outline #21: CV Heart Flashcards
functions of the blood
transport of:
- gases O2 & CO2
- nutrients (digested food)
- hormones to target organs
- wastes to kidneys/lungs
regulate blood ph & electrolyte composition
defend against pathogens
restrict blood loss @ injury sites (sealant/clotting)
stabilize body temp
how does blood stabilize body temp
blood has a radiator system: deep & superficial veins
deep veins pushes blood to superficial veins when hot
blood composition
plasma = 55%
plasma proteins
formed elements = 45%
plasma
non-cellular fluid matrix of blood
- water, electrolytes, nutrients, metabolic wastes
modified into CSF, aqueous humor, peri/endolymph, urine, lymph
plasma proteins
transport of hormones & lipids
framework for clots
formed elements
RBCs - 99.9% - O2 & CO2 transport
recycled by spleen b/c of iron
20-30 trillion cells
WBCs - immunological defense
Platelets - cell fragments that aid blood clotting
2 systems that branch off the heart
- Pulmonary - lungs
- Systemic - everything else
basic structure of the heart
4 chambered muscular pump with 2 circuits - separate oxy-/de-oxygenated blood, ventricles - pump blood, atria - receive blood
interatrial septa - thin tissue wall btw atria
interventricular septa - muscular wall btw vents
atrioventricular septa - btw. atria & vents
base - attachment site of large vessels
apex - bottom part, ventricle area
valves - allow blood flow in one direction
myocardium
cardiac m. cells (single nuclei, striated, branched)
have intercalary discs to relay action potentials, help chemical signals travel
Is thick on the left side because it pumps blood for whole body
endocardium
smooth inner surface made up elastic & collagen fibers, covering the surface of chambers & valves
epicardium (visceral pericardium)
serous membrane on outer surface, stuck to myocardium
parietal pericardium
serous membrane that surrounds the heart, encases the paricardial cavity.
pericardial sac
inner layer - visceral pericardium
outer layer - parietal pericardium
serous fluids secreted by membrane oppose friction
mediastinum
space btw lungs that contain esophagus, trachea, great vessels, NAVLs & heart
pericardial cavity
space btw parietal & visceral pericardia containing serous fluid
pericarditis
inflammation of pericardia
cardiac tamponade
pericardial cavity fills with blood because coronary vessels leak
the heart keeps contracting until the sac can’t fill anymore and the heart becomes compressed
right atrium
contains
- superior & inferior vena cava
- coronary sinus
- pectinate m.s - on the lateral wall of each auricle for contraction
- right atrioventricular valve/tricuspid valve
right ventricle
contains
- right atrioventricular valve/tricuspid valve (blood flow from RA to RV)
- chordae tendineae - fibrous strand anchored to papillary m.s that allow valves to open and close
- trabeculae carneae - ventricular walls that slow blood down to prevent splashing.
- pulmonary semilunar valve (has 3 cusps)
- pulmonary trunk
left atrium
- 4 pulmonary veins
- pectinate m.s
- left atrioventricular valve/bicuspid/mitral valve
left ventricle
- left atrioventricular valve/bicuspid/mitral valve
- chordae tendineae - fibrous strand anchored to papillary m.s that allow valves to open and close
- trabeculae carneae - ventricular walls that slow blood down to prevent splashing.
- left aortic valve (3 cusps) and aorta
coronary valves
respond to pressure, where there is pressure, blood will flow from.
insure 1-way flow of blood
if there is a bad seal - back flow/regurgitation - reduces heart efficiency, makes gurgling/fluttering sounds = heart murmur (mechanical failure of a heart valve)
mitral valve prolapse
failure of chords/papillary m.s to stabilize bicuspid valve
systole
diastole
contraction of myocardium (pump)
relaxation of myocardium (fill)
systole-diastole flow of blood
- Atrial systole injects blood into ventricles
- Vents fill - AV valves start closing
- Atrial diastole
- ventricular systole injects blood into aorta & pulmonary a.
- AV valves slam shut (lubb sound)
- back pressure in aorta & pulmonary trunk builds up
- semilunar valves slam shut (dupp sound)
- Ventricular diastole
what opens & closes coronary valves
pressure because these valves are passive
sino-atrial node
medial wall of RA
nodal (pacemaker) cells are responsible for heart rate (90-100 bpm)
response for atrial contraction
atrio-ventricular node
junction between atria & vents
connected to SA node
40-50 bpm
AV bundle (Bundle of His)
runs from AV-node through interventricular septum (between vents)
purkinje fibers/cells branch out in ventricular walls
control of heartrate
SA node - heart initiates its own heartline (baseline)
Heart slows - parasym ANS - acetylcholine
- CN X
heart accels - sym ANS - norepinephrine
- Sym ganglia (T1-4)
angina pectoris
referred pain assoc. w/ an MI, T1-4
embolus
drifting clot in the circulation, not problematic
embolism
blockage due to clot so blood can’t pass
pulmonary embolism - kills part of lung, #1 killer of women post-birth
coronary ischemia
restricted blood supply to myocardium when embolism occurs
myocardial infarction
localized cell death in myocardium because blood can’t get to heart
bradycardia & tachycardia
slower than normal HR
faster than normal HR
anemia
poor O2 delivery, low #s of RBCs & low hemoglobin
right coronary artery (RCA)
brings in blood
contains:
- anterior ventricular a. (AVA) right side of heart
- right marginal a. (RMA) side of apex
- posterior interventricular a. (PIA)
left coronary artery (LCA)
brings in blood
- anterior interventricular a. (AIA or widow maker)
- circumflex branch - continues around left side around heart, LMA & PVA branch off)
- left marginal a. (LMA) side of apex
- posterior ventricular a. (PVA) on left side
venous drainage of myocardium - anterior side
great cardiac vein (anterior interventricular vein) and anterior cardiac veins
venous drainage of myocardium - posterior side
posterior cardiac vein & middle cardiac vein (posterior interventricular vein)
coronary sinus
where cardiac veins combine
all blood flows to this, venous blood starts here
drains into RA
