1330
Apex of the heart
Tip of left ventricle, lies above the diaphragm at 5th intercostal space
2/3 of the heart lies where?
To the left between the 2nd & 6th ribs
Transfers nutrients and waste products
capillary system
sympathetic division (fight or flight)
central control mechanism
Responds to change in blood chemistry
chemoreceptors
3 tissue layers
endoderm, mesoderm, ectoderm
Capillary System
exchange vessels. works against gravity daily.
4 Key properties of heart muscle
excitability, conductivity, contractibility, inherent rhythmicity
If ejection fraction falls below 30%
exercise tolerance becomes limited
Gas moving in and out of lungs
external respiration
Pericardial Fluid
fluid that separates the parietal and visceral layers
Fetal blood has a ____ hemoglobin & _____ hematocrit VS _____ blood.
higher, increased, adult
IVC
inferior vena cava
Pericarditis
inflammation of the pericardium
Inherent Rhythmicity
initiation of spontaneous electrical impulse
Parietal
inner lining of fibrous pericardium
Coronary Sinus
large vessel that collects blood from heart muscle (myocardium)
Arterial System
large, elastic, low resistance, small muscular. Distribution and regulation of BP.
MAP values below 60 mmHg may cause ?
perfusion to brain and kidneys, organ failure in minutes.
SVR (formula)
(MAP - RAP) / CO
PVR formula
(MPAP-LAP)/CO
Right Coronary Artery (RCA)
branches into the right posterior descending (RPD)
ADH begins to rise/HR increase
10% blood loss
Normal EDV
110-120 ml
How many main coronary arteries are there?
2 (right and left)
ADH increase/HR increase/Vascular tone
20% blood loss
Immature surfactant begins to appear in lung fluid
24-26 week of gestation
The semilunar valves consist of...
3 half mooned shaped cusps
BP starts to fall during
30% blood loss
How many chambers does the heart have?
4 (2 atria, 2 ventricles)
Normal Cardiac Output (CO)
5 L/min
Normal ejection fraction range
65%
Normal SV
70 mL
Normal MAP value
80-100 mmHg
Pericardial Effusion
Abnormal amount of accumulated fluid
Begins at 32 weeks of gestation
Alveolar Stage
3 components of systemic vasculature
Arterial system, Capillary system, and Venous System
type 1 and type 2 pneumocytes begin to appear and replicate
At 20-24 weeks of gestation
Responds to pressure changes
Baroreceptors
Mitral valve aka
Bicuspid valve
MAP formula
CO x SVR
20 - 24 week gestation period
Canalicular Stage
Contractibility
Contraction in response to electrical impulse
Visceral
Covers outer surface of heart and great vessels
Pericardium
Double-walled sac that encloses the heart
SV formula
EDV - ESV
Forms the nervous system of the respiratory tract (forms within mesoderm)
Ectoderm
Begins at conception and end at 8 weeks of gestation
Embryonic development
Forms the mucous and gas exchange membranes of the entire respiratory system.
Endoderm
Visceral aka
Epicardium
3 layers of the heart wall
Epicardium, Myocardium, Endocardium
Occurs during remaining 32 weeks of gestation
Fetal respiratory phase
L/S Ratio for low risk of respiratory distress
Greater than 2
CO formula
HR x SV
Plays secondary role in regulating blood flow?
Heart
Tissue cells & Capillary blood
Internal respiration
Indicates risk for development of respiratory distress syndrome after birth.
L/S Ratio
Forms the supporting structures, muscle and connective tissue of the tracheobronchial tree.
Mesoderm
2 inner serous layers
Parietal & Visceral
What do the AV valves do?
Prevent back flow into atria when ventricles contract
what do SV valves do?
Prevent backflow of blood into the ventricles during diastole
Produced by type 2 pnuemocytes & hormonally regulated
Pulmonary Surfactant
Promotes lung inflation & protects alveolar surface.
Pulmonary Surfactant
Semilunar valves
Pulmonary artery and Aorta
2 most common valve problems
Regurgitation and Stenosis
Cardiac Tamponade
Result of a large pericardial effusion, affects pumping of heart
Ejection Fraction Formula
SV/EDV
Conductivity
Spreads impulses quickly
26 week gestation period
Terminal Saccular Stage
Extrauterine life is possible with life support during which stage of fetal development
Terminal Saccular Stage
Organized into 23 stages
The Carnegie Stages
Marks the final stage of lung development
The alveolar period
Frank-Starling Law
The greater the stretch, the stronger is the heart's contraction.
Atrioventricular Valves
Tricuspid and Mitral valves
Alveoli are lined with what?
Type 1 & 2 Pneumocytes
Pneumocytes that produce surfactant
Type 2
Diastole
Valves close
Systole
Valves open
Conducts blood back to heart
Venous system
Reservoir for circulatory system, holds 3/4 of body's blood volume
Venous system
Excitability
ability to respond to stimuli
primary function of the respiratory system
absorption of O2 and excretion of CO2
thebesian veins
anatomical shunt
Left Coronary Artery (LCA)
branches into left anterior descending (LAD)
S2 "dubb" what valves close?
aortic and pulmonic (SV)
What controls local blood flow into capillaries?
arterial system
Upper chambers of the heart
atria (right and left)
Systemic vasculature
begins with the aorta on the left ventricle and ends in the right atrium
Pulmonary Vasculature
begins with the pulmonary trunk out of the right ventricle and ends in the left atrium
The most muscular chamber of the heart is the __________.
left ventricular
Premature infants less than what amount of weeks are at greater risk of developing respiratory distress?
less than 32 weeks
cardiovascular system tells the heart how much to pump by?
local and central mechanisms
myogenic and metabolic regulation
local control mechanisms
S1 "lubb" what valves close?
mitral and tricuspid (AV)
mitral valve stenosis
narrowing of the mitral valve from scarring, usually caused by episodes of rheumatic fever
Lower chambers of the heart
right and left ventricles
Cardiac Tamponade may lead to
shock or death
SVC
superior vena cava
The AV valves close during
systole
Pericardium Structure
tough, fibrous outer layer, lined by a delicate serous membrane
