Physiology Flashcards
Cardiovascular system major elements
The heart
the blood vessels
the blood
How many chambers in the heart
4 chambers right atrium right ventricle left atrium Left ventricle
Pathway of blood in the cardiovascular system
Superior and inferior vena cava Right atrium tricuspid valve right ventricle semi lunar pulmonary valve Pulmonary arteries Lungs pulmonary veins left atrium mitral valve left ventricle aortic semilunar valve Aorta Body and organs
Pulmonary circuit
Bloods pathway between right side of the heart to the lungs and back to the left side of the heart
Systemic circuit
That way between the left and the right side of the heart
Type of blood vessels
Arteries
arterioles
capillaries
veins
venules
Arteries
A lot of collastin
Help fluids to move down the gradients
lots of elastic tissue
maintain pressure
Arterioles
Majority of Smooth muscle To allow dilation and constriction
Arterioles
A lot of nerves which help vary flow of blood to tissues
Capillaries
Fenestration
One cell layer thick of endothelium
Allow exchange with environment
Vein /venules
A lot of collagen and smooth muscle
Very distensible to carry a lot of blood
One way flow
Skeletal muscle
Blood composition
Plasma
red blood cell
white blood cells
Thrombocytes
Plasma blood
Liquid portion of the blood Contains : clotting factors hormones antibodies dissolved gases nutrients waste
Erythrocytes red blood cells
Carrie hemoglobin and oxygen
no nucleus
live for 90 to 120 days
Cannot repair themselves
Leukocytes white blood cells
Fight infection forms in the bone marrow five types : neutrophils lymphocytes Eosinophils basophils monocytes
Thrombocytes platelets
Self recommends forms in the bone marrow from megakaryocytes
Klutz blood by sticking together via fibrin
Anemia
Lack of iron in the blood
low red blood cell counts
Leukemia
White blood cell wild proliferation causing anemia
Hemophilia
Lack of fibrinogen in Thrombocytes leading to heavy bleeding
Heart murmur
Abnormal heart beat caused by valve issues
Heart attack/ myocardial infarction
Blood vessels around heart become blocked with plaque
Heart Blood supply
Right coronary artery anterior interventricular coronary artery great cardiac vein Middle cardiac vein Posterior interventricular artery Small cardiac vein Right marginal artery
Heart functions
Generates blood pressure
routing blood
ensuring oneway bloodflow with presence of valves
regulates blood supply
Pericardium
Composed of fibrous pericardium and serous pericardium
Serous pericardium
Parietal pericardium
Visceral pericardium
Three layers of tissue of heart
Epicardium => serous membrane, smooth, outermost
myocardium => middle layer , cardiac muscle cells, make heart contract
endocardium => smooth inner surface of heart chamber
Role of desmosomes in cardiac muscles
Hold cells together
Role of gap junctions in cardiac muscles
Allow action potential’s
Conducting system of the heart components
Sino atrial node atrioventricular node atrioventricular bundle left and right bundle branches Purkinje fibers
2 systems of the heart
Conducting
Contractile
Conducting system function
Induce impulse to conduct information.
Has excitable cells ( cells with variable resting membrane potential )
Contractile system
Impulse transmitted through movement of ions across leaky channels or gated channels
Action potential in SA nodes phases
Prepotential
Depolarization
Repolarization phase
Two types of refractory period
Absolute
Relative
Absolute refractory period
Cardiac muscle completely insensitive to further stimulation
Relative refractory period
Reduced sensitivity to additional stimulation
Component of ECG
P wave
QRS complex
T wave
P wave of ECG
Atrial depolarization
QRS complex
Ventricular depolarization
Atrial depolarization
T wave
Ventricular repolarization
Tachycardia
Fast heart rate above 100bpm
Bradycardia
Heart rate less than 60bpm
Sinus arrythmias
Irregular heartbeat
Premature atrial contraction
Shortened interval between one contraction and next one
ECG change in complete heart block
Small uncoordinated p and QRS wave
ECG change in premature ventricular contraction
No p waves before QRS
Bundle branch block ECG changes
Prolonged QRS complex
Atrial fibrillation ECG changes
No clear p waves
Rapid QRS
Ventricular fibrillation ECG changes
Ahh no p wave, QRS or T wave
Cardiac cycle
ISOVOLUMIC CONTRACTION
Systole -> both semilunar and AV valves closed
EJECTION
sysTole -> semilunar valve open and av valve closed
ISOVOLUMIC RELAXATION
diastole -> both types of valve closed —> atrium Filling
VENTRICULAR FILLING
diastole —> passive ventricular filling followed by active ventricular filling —> semi lunar valves closed and AV valve opened
mean arterial blood pressure equation
MAP= COxPR
Cardiac output equations
CO = HRx PR
Peripheral resistance
Total resistance against which blood must be pumped
Intrinsic regulation of the heart
Normal functional characteristics
Starlings law of the heart
Extrinsic regulation
Involves neural and hormonal control
Parasympathetic stimulation ( vagus nerve , decreased HR, Acetylcholine)
Sympathetic stimulation ( cardiac nerves, increase HR and contraction, epinephrine and norepinephrine)
Baroreceptor reflex
Blood pressure increases -> detected by baroreceptor in internal carotid arteries and aorta -> cardio regulatory center increases parasympathetic and decreases sympathetic -> decreased heart rate and stroke volume -> BP decreased mes
Blood pressure decreases too low -> detected by baroreceptor in internal carotid artery and aorta -> decreased parasympathetic , increased sympathetic -> increased HR and SV -> BP increases because of high CO and He
Chemoreceptor reflex pH
Blood pH high ( low CO2) -> detected by chemoreceptors in medulla oblongata-> cardio regulatory center increases parasympathetic and decrease sympathetic -> decreases HR and SV -> decreased blood flow to the lungs-> decreased blood pH (increased CO2) ->
Blood pH low (high CO2) -> detected by chemoreceptors -> cardio regulatory center decreases sympathetic and parasympathetic-> increased HR and SV -> CO increased -> decreased CO2 -> increased blood pH
Changes of the heart due to aging
Hypertrophy of left ventricle
Max heart rate decreases
More andnormality of valves
3 layers of blood vessels
Tunica intima
Tunica media
Tunica external
Bulk flow
Large number of ions molecules or particles move together in sand direction
Systolic BP
Highest pressure during systole
Diastolic BP
Lowest arterial pressure in diastole
Vascular resistance
Resistance to blood flow
Factors affecting vascular resistance
Size of lumen -> vasoconstriction lead to higher resistance
Blood viscosity -> higher viscosity means higher resistance
Blood vessel length -> proportion to resistance
Venous return
Volume of blood flowing back to heart
Skeletal muscle pump
Blood goes in one direction due to valves
Respiratory pump
Due to pressure changes in thoracic and abdominal cavities
Factors that can increase venous return
Increase blood volume
Skeletal muscle pump
Respiratory pump
Venoconstriction
Factors that increase SV
Increased venous return
Increased sympathetic
Hormones from adrenal medulla
Factors that can Increased heart rate
Decreased parasympathetic
Increased sympathetic impulses
Hormones form adrenal medulla
Propioreceptors
Monitor joint movement
Provide input during physical activity
Carotid sinus reflex regulate
Blood pressure in Brain
Aortic reflex regulates
Systemic blood pressure
Salt sensitivity percentage in essential hypertension
60%
Percentage of essential up retention with high renin
15%
How can cell membrane defect cause high blood pressure
Because accumulation of calcium in the cells
Transport of sodium impaired
Syndrome X
Central obesity
dyslipidemia
rise in blood pressure
Is insulin resistance part of syndrome X
Yes
Consequence of insulin resistance
Rise in renal sodium Rise in sympathetic activity rise in arterial pressure vascular smooth muscle hypertrophy rise in calcium due to modification of membrane transport
Percentage of genetic heritability of hypertension
30%
Factors that play into essential hypertension
Age race sex smoking excessive alcohol intake serum cholesterol glucose intolerance inappropriate weight gain
