hematopoeisis

• means formation of bloodcells
• starts in intrauterine life
• then liver takes over
• later in life bone marrow takes over as main production site

cell lines in blood cell formation

• all blood cells originate in bone marrow from blood stem cells
• lymphoid stem cells -->lymphocytes
• myeloid stem cells -->all other blood cells

Genesis of 

erythrocytes

• committed cells are proerythroblasts
• remain in the reticulocyte stage for 1-2 days in circulation
• makeup 1-2% of all erythrocytes

production of red blood cells and synthesis of hemoglobin depends on

• iron
• B12
• folic acid

formation of leukocytes

• granulocytes form from myeloblasts
• monoblasts enlarge and form monocytes
• platelet forming cells from megakaryoblasts that break apart into platelets

polycythemia

• abnormal excess of RBC (erythrocytes)
• abnormality of bone marrow produces excess RBC
• excess platelets cause RBC to accumulate and could cause stroke

polycythemia (excess RBC) can cause what chain of events?

excess RBC can cause hypertension which stimulates the medulla oblongata and can cause

1. acromegaly
2. hepatomegaly
3. splenomegaly

blood throughout life

• 1st blood cells develop in early blood vessels
• mesenchyme cells cluster into blood islands
• late in 2nd month liver & spleen take over production
• at 7 months, bone marrow becomes major hematopoeitic site

What is sickle cell anemia?

• abnormal hemoglobin causes a change in the RBC shape
• RBC now cannot cross capillary wall and loses elasticity

How can sickle cell anemia cause ulcers?

lack of elasticity can cause destruction of wall of blood vessels which causes rupture of capillary and small hemorrhage which can cause an ulcer

What is leukemia?

when bone marrow makes abnormal WBC which do NOT function normal, grow faster than normal WBC, and do not stop growing when they should!

signs and symptoms of a patient with leukemia?

• fever
• infection
• weak immune system

What is lymphocytic leukemia?

leukemia that affects the WBC and produces large number of mature WBC (lymphocytes)

What is myelogenous leukemia?

affects WBC called myelocytes and produces large number of immature and mature WBC (myelocytes)

Name the 3 layers of blood vessels

1. Tunica intima - simple squamous
2. Tunica media - sheets of smooth muscle
3. Tunica externa - composed of connective tissues 

lumen

central blood filled space of vessel

elastic arteries

• largest arteries
• high elastin
• diameters 1cm-2.5cm (aorta & other large vessels)
• also called conducting arteries

Name the 4 differences between arterial and venous systems

1. Wall of artery is thicker than venous system
2. Wall of artery has more elastic fiber
3. Pressure in artery (100mm/Hg) is higher than venous system (4mm/Hg)
4. The amount of blood which circulates in arterial system is slightly less because of the thickness of wall of the artery.

Describe the mechanisms that help blood circulation in the venous system due to the low pressure.

1. Contraction of surrounding muscles can constrict venous system & increase blood circulation
2. By having a valve, the position & direction of valve helps blood circulation
3. Some small veins are connected to bigger veins that are perpendicular to small veins. The circulation of blood in small veins creates pressure to aid in blood circulation
4. Parallel to the vein (bilateral) are 2 arteries, the pulse from arteries is transferred to the venous system.

capillary bed

network of capillaries running through tissues

sinusoids

wide, leaky capillaries found in the spleen and liver

Name the functions of the circulatory system.

• transportation
• gasses & nutrients
• regulation
• hormones & temperature
• protection
• like clotting

percent of hematocrit in men 

42-52%

percent of hematocrit in women

37-47%

blood plasma contains...

• sodium
• nutrients
• hormones
• enzymes
• antibodies
• wastes
• proteins

3 main blood plasma proteins

1. albumin
2. globulins
3. fibrinogen

• 60-80% of the blood
• produced by the liver & provide osmitic pressure needed to draw fluid from the surrounding tissue into the capillaries

production of RBC

• is a hormonal mechanism
• O2 deficiency initiates and releases erythropoietin
• -->stimulates RBC production in the bone marrow

left ventricle

• is the largest chamber of the heart
• chamber walls are only about a 1/2" thick, but they have enough force to push blood through the aortic valve and into your body.

between the left atrium and left ventricle is the ...

atrialventricular valve (AV valve) 

or

mitral valve

between the right atrium and right ventricle is the...

tricuspid valve

tricuspid valve

regulates blood flow between the right atrium and right ventricle

pulmonary valve 

controls blood flow from the right ventricle into the pulmonary arteries, which carry blood to your lungs to pick up O2 

mitral valve

valve lets oxygen-rich blood from your lungs pass from the left atrium into the left ventricle

aortic valve

opens the way for oxygen-rich blood to pass from the left ventricle into the aorta, your body's largest artery, where it is delivered to the rest of your body. 

Superior and inferior vena cava take deoxygenated blood from entire body to the right atrium by contraction of the right atrium, the deoxygenated blood gets into the right ventricle and later on by contraction of the right ventricle the deoxygenated blood is ejected into the pulmonary artery. Pulmonary artery takes deoxygenated blood to the lungs and then we have gas exchange. After this, 4 pulmonary veins take the oxygenated blood from the lungs to the left atrium. By contraction of the left atrium the oxygenated blood gets ino the left ventricle and later on by contraction of the left ventricle, fresh oxygenated blood is ejected into the aorta. Aorta takes fresh blood to organs, tissues and cells

Systemic Circulation

the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart. 

Pulmonary Circulation

the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.

• deliver oxygenated blood to the tissues.
• are thick-walled, with extensive elastic tissue and smooth muscle.
• are under high pressure.The blood volume contained in  the arteries is called the stressed volume.

Arterioles

• are the smallest branches of the arteries
• site of highest resistance in the cardiovascular system
• have a smooth muscle wall that is extensively innervated by autonomic nerve fibers
• regulated by ANS

Alpha1 - Adrenergic receptors are found on the arterioles of the...

• skin
• splanchnic
• renal circulations.

Beta 2 - Adrenergic receptors are found on arterioles of...

skeletal muscle

Capillaries 

• consist of a single layer of endothelial cells surrounded by basal lamina
• are thin-walled, lack smooth muscle
• site of exchange of nutrients, gasses & H2O

Venules

formed from merged capillaries

Veins

• progressively merge to form larger veins.
• largest vein (vena cava) returns blood to the heart
• thin-walled
• under low pressure
• contain the highest proportion of the blood in the cardiovascular system

the blood volume  contained in the veins is called the

unstressed volume

Q stands for 

cardiac output (ml/min)

P stands for

Pressure gradient (mm/Hg)

R stands for

resistance or total peripheral resistance
(mm Hg/ml/min)

What drives blood flow?

P, the pressure gradient

blood flow is inversely proportional to...

the resistance of blood vessels

Blood flow depends on...

1. Pressure
2. Location
3. Resistance
   (by decreasing of diameter of capillary and by having of intersectional area in the capillary itself builds up a resistance to the blood flow) 

Poiseuille’s equation 

• Resistance depends on the viscosity of blood. More concentrated means more viscosity and can add to resistance. Length of the blood vessel – it takes time to flow through.
• The smaller radius has higher resistance to the blood.

Capacitance

• depends on the elastic fibers (amount) in the arterial system
• the wall of the artery has more elastic fiber than the venous system and it makes the wall thicker because of the thickness of artery wall, it occupies & reduces the radius of lumen of artery. 

mean pressure of the aorta

100mm/Hg

mean pressure of the arterioles

50mm/Hg

mean pressure of capillaries

20mm/Hg

mean pressure of vena cava 

4mm/Hg

• is the highest arterial pressure during a cardiac cycle
• is measured after the heart contracts (systole) and blood is ejected into the arterial system

Diastolic pressure

• is the lowest arterial pressure during a cardiac cycle
• is measured when the heart relaxed (diastole) and blood is returning to the heart via the veins

Pulse pressure

difference between the systolic and diastolic pressures

primary hypertension causes

are unknown 

• Sympathetic nervous system and renin-angiotensin-aldosterone system have received the most attention for the pathophysiology of hypertension, both can increase cardiac output and total peripheral vascular resistance (CO & TPR)

factors that can influence hypertension

• obesity
• sodium salt
• endocrine hormone disorder
• metabolic disorder
• ix syndrome 
• stress

cardiac output

the amount or volume of blood which is ejected into blood vessel by the contraction of ventricle per minute which is about 5L/min 

total peripheral resistance (TPR)

comes from capillary and by having a small diameter and intersectional area, the pressure is reduced and it builds up resistance to the blood flow

secondary hypertension is cause by

conditions that affect your kidneys, arteries, heart or endocrine system

Secondary hypertension can also occur during pregnancy 

How does adrenal gland disorders affect secondary hypertension?

How can an auto-immune disease cause secondary hypertension?

Conn’s Disease 

Pheochromocytoma

the name of the tumor that is in the adrenal medulla of adrenal gland.

This is the cancer of the adrenal medulla. Then we have overproduction of adrenaline and noradrenaline and so then we have constrction of smooth muscle increasing the BP.

P wave

• represents the wave of depolarization that spreads from the SA node throughout the atria, and is usually 0.08 to 0.1 seconds (80-100 ms) in duration
• represents atrial depolarization.
• contraction of atrium

PR interval

• The period of time from the onset of the P wave to the beginning of the QRS complex
• which normally ranges from 0.12 to 0.20 seconds in duration.  
• the time between the onset of atrial depolarization and the onset of ventricular depolarization 
• depolarization of AV node

ST segment

• is the segment from the end of the S wave to the beginning of the T wave
• represents the period when the ventricles are completely depolarized

• important in the diagnosis of ventricular ischemia or hypoxia because under those conditions, the ST segment can become either depressed or elevated. 

T wave

• represents ventricular repolarization and is longer in duration than depolarization (i.e., conduction of the repolarization wave is slower than the wave of depolarization). 

QT interval

• the beginning of the Q wave to the end of the T wave
• Q-T interval represents the time for both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential.
• This interval can range from 0.2 to 0.4 seconds depending upon heart rate

Action potential of ventricles, atrium and Purkinje system

• have stable resting membrane potentials of about 90mV
• This value approaches the K+ equilibrium potential.
• Action potentials are long duration, especially in Purkinje fibers, where they last 300 msec
• has 5 phases

Phase 0 of cardiac action potential

• is the upstroke of the action potential.
• Na+ inflow is caused by a transient increase in Na+ conductance. This increase results in an inward Na+ current that depolarizes the membrane.
• At the peak of the action potential, the membrane potential approaches the Na+ equilibrium potential. (45-65)

Phase 1 of cardiac action potential

• is a brief period of initial repolarization
   
• Opening of a few K channels and K leaves the cell (slowly)
• Initial repolarization is caused by an outward current, in part because of the movement of K+ ions 

Phase 2 of cardiac action potential

• is the plateau of action potential
• right after phase 1 we have opening of Ca channels
• caused by an increased in Ca conductance and and increase in K+ conductance
• During phase 2, outward and inward currents are approximately equal, so the membrane potential is stable at the plateau level

Phase 3 of cardiac action potential

• repolarization phase
• opening  of the rest of K channels and K leaves the cell
• Ca conductance decreases, K conductance increases
• high K conductance results in hyperpolarization 

Phase 4 of cardiac action potential

• is resting membrane potential phase
• the period during which inward and outward current (Ik1) are equal and the membrane potential approaches the K= equilibrium potential

   

Conduction velocity

• reflects the time required for excitation to spread throughout cardiac tissue.
• depends on the size of the inward current, larger current = higher conduction veolcity
• fastest in Purkinje system
• slowest in AV node

excitability

• the ability of cardiac cells to initiate action potential in response to inward, depolarizing current
• reflects the recovery of channels that carry the inward current
• changes over the course of action potential.
• these changes in excitability are described by refractory periods.

1. Preload
2. Afterload
3. sarcomere length
4. velocity of contration at a fixed muscle length
5. Frank-Starling relationship

Length-tension relationship in the ventricles

PRELOAD

• is equivalent to end-diastolic volume, which is related to right atrial pressure
• when venous return increases, end diastolic volum increases and stretches or lengthens the ventricular muscle fibers

Length-tension relationship in the ventricles

AFTERLOAD

• for the left ventricle the afterload is equivalent to aortic pressure. Increase in aortic pressure cases an increase in afterload on the left ventricle.
• for the right ventricle is equivalent to pulmonary atrtery pressure. increase in pulmonary artery pressure causes an increase in afterload on the right ventricle

Length-tension relationship in the ventricles

SARCOMERE LENGTH

• determines the maximum number of cross-bridges that can form between actin and myosin
• determines the maximum tension, or force, of contraction

Length-tension relationship in the ventricles

VELOCITY of CONTRACTION

• velocity of contraction is maximal when the afterload is 0
• velocity of contraction is decreased by increase in afterload

Length-tension relationship in the ventricles

FRANK-STARLING RELATIONSHIP

• Greater venous return leads to greater end diastolic volume and causes greater cardiac output
• increases in end diastolic volume canse an increase in ventricular fiber length which increases tensionn

Frank-Starling relationship

increase in contractility causes...

Frank-Starling relationship

decrease in contractility causes...

Steps 1-2  isovolumetric contraction 

Steps 2-3 ventricular ejection

Steps 3-4 isovolumetric relaxation

Steps 4-1 ventricular filling

• in point 1 the pressure is very close to 0
• closure of aortic, pulmonary, tricuspid and bicuspid valves
• end diastolic volume

• intraventricular pressure increases
• high pressure pushes up the aortic and pulmonary valve, then the ventricle has a strong contraction and ejects 70ml stroke volume of blood into aorita or pulmonary trunk of artery
• the pressure in ventricle increases & we have ejection of stroke volume

• intraventricular pressure drops to 0
• amount of blood in ventricle is 70ml end systolic volume
• ventricle is relaxed 
• atrial pressure is higher than ventricular pressure
• meanwhile the atrium receives large amount of blood from venous system such as superior/inferior VC on the right side and pulmonary veins on the left side.

• the pressure in ventricle is lower than atrial pressure
• atrial pressure is increased by receiving large amounts of blood from venous system
• b/c of intra-atrial pressure, the AV valves (mitral and tricuspid) are pushed down and by contraction of atrium, large amount of blood (70mL) is released intro ventricles and we have ventricular filling
• it contains 140ml again which is end diastolic volume
• point 4 is exactly 70ml, the atrium released 70ml of blood into ventricle and it goes back to 140ml 

• is directly related to the amount of tension developed by the ventricles
• is increased by
• increased afterload (^ aortic pressure)
• increased size of heart
• increased contractility
• increased HR

• atherosclerosis (plaque builds up)
• stress
• male
• diabetes
• history of coronary artery disease
• high blood pressure
• smoking 
• unhealthy cholesterol levels (high LDL and low HDL)
• chronic kidney disease

• chest pain #1
• can be severe or minor but usually lasts longer than 20 minutes
• sweating
• anxiety
• cough
• fainting
• dizziness
• nausea/vomiting
• palpitations
• dyspnea

• inflammation of the inside lining of the heart chambers and heart valves (endocardium)
• is usually the result of a blood infection like bacteria
• artificial heart valves
• congenital heart disease
• heart valve problems
• history of rheumatic heart disease

• alpha & beta are produced by the liver & function in transporting lipids and fat soluble vitamins
• function in immunity

• important clotting factor
• produced by liver
• fluid from clotted blood is called serum

Blood comes from superior/inferior

VC --> right atrium --> tricuspid valve -->

right ventricle -->pulmonary valve--> pulmonary arteries--> lungs!! --> pulmonary capillaries --> 

left atrium --> mitral valve -->

left ventricle --> aortic valve --> aorta!