Blood and CirculationBlood and Circulation

Anatomy and PhysiologyAnatomy and Physiology

BloodBloodFunctions:Functions:

Transports: oxygen for CR, carbon dioxide Transports: oxygen for CR, carbon dioxide away, nutrients, ions, immune cells and away, nutrients, ions, immune cells and antibodiesantibodies

Distributes heatDistributes heat

I. Blood composition I. Blood composition (connective tissue – (connective tissue – cells in a liquid matrix - ~6 L/personcells in a liquid matrix - ~6 L/personA. Liquid = Plasma – 54%A. Liquid = Plasma – 54%

H2OH2O proteins (clotting, Ab, hormones, osmotic proteins (clotting, Ab, hormones, osmotic

balance)balance) salts (maintain pH, osmotic balance, need for salts (maintain pH, osmotic balance, need for

muscle contraction)muscle contraction)

Blood Composition ContinuedBlood Composition ContinuedB. CellsB. Cells

1. RBC’s – 45% (erythrocytes – mainly 1. RBC’s – 45% (erythrocytes – mainly hemoglobin, have no nucleus or hemoglobin, have no nucleus or mitochondria so don’t use the O2 they mitochondria so don’t use the O2 they carry)carry)2. WBC’s – 1% (leukocytes – immunity and 2. WBC’s – 1% (leukocytes – immunity and platelets – blood clotting)platelets – blood clotting)

a. Granulocytes – made in bone a. Granulocytes – made in bone marrow, marrow, their names are based on their names are based on stains, non-stains, non- specificspecific

• Neutrophils – phagocytes , 1Neutrophils – phagocytes , 1stst reaction reaction• Basophils – histamine producers for Basophils – histamine producers for

inflammation and allergic reactionsinflammation and allergic reactions• Eosinophils - ?? – to fight parasites? Eosinophils - ?? – to fight parasites?

Mediate allergic reactionMediate allergic reaction

Blood composition ContinuedBlood composition ContinuedCellsCells

b. Lymphocytes – specific b. Lymphocytes – specific immunity – immunity – made in lymph glands, made in lymph glands, spleen, and spleen, and thymus thymus

B cells – make antibodiesB cells – make antibodies T cells – Helper – increase B cells and T killersT cells – Helper – increase B cells and T killers T cells - Cytotoxic – killers – kill bacteria, viruses, T cells - Cytotoxic – killers – kill bacteria, viruses,

tumorstumors

c. Monocytes – made in bone c. Monocytes – made in bone marrow – marrow – phagocytosis – when phagocytosis – when activated activated become become macrophagesmacrophages

d. Platelets – make d. Platelets – make thromboplastin, thromboplastin, serotoninserotonin

Blood Composition ContinuedBlood Composition Continued

Relative Abundance of WBC’s:Relative Abundance of WBC’s: Never Let Monkeys Eat BananasNever Let Monkeys Eat Bananas

Leukocytes are recruited and activated Leukocytes are recruited and activated by cell damage or foreign tissueby cell damage or foreign tissue

Cytokines (chemical attractors of Cytokines (chemical attractors of WBC’s) are released by T helpers WBC’s) are released by T helpers causing chemotaxis – cells go to causing chemotaxis – cells go to chemicalschemicals

Blood FormationBlood Formation

Forms in red marrow in flat bones Forms in red marrow in flat bones and little in the ends of long bonesand little in the ends of long bones

Erythropoietin (produced by the Erythropoietin (produced by the kidney controls RBC production)kidney controls RBC production) Low O2 causes release of erythropoietin Low O2 causes release of erythropoietin

from kidney – increased RBC production from kidney – increased RBC production – better oxygen carrying cabability – – better oxygen carrying cabability – shuts off release of erythropoietinshuts off release of erythropoietin

Blood Clotting – 2-6 minutesBlood Clotting – 2-6 minutes Platelets stick to endothelium only when Platelets stick to endothelium only when

there is a tearthere is a tear Platelets produce serotonin Platelets produce serotonin

(neurotransmitter) which acts on smooth (neurotransmitter) which acts on smooth muscle causing it to contract and narrows muscle causing it to contract and narrows the vessel so blood flow is shut off to that the vessel so blood flow is shut off to that areaarea

Platelets produce thromoboplastin (enzyme) Platelets produce thromoboplastin (enzyme) which cleaves prothrombin (inactive) to which cleaves prothrombin (inactive) to thrombin (active)thrombin (active)

Thrombin links fibrinogen proteins together Thrombin links fibrinogen proteins together (small soluble fibrous proteins) and it (small soluble fibrous proteins) and it become fibrin – which is large fibers that act become fibrin – which is large fibers that act like a meshlike a mesh

Fibrin covers over the hole in the bv and Fibrin covers over the hole in the bv and traps the RBC’straps the RBC’s

Blood TypesBlood Types

Blood Blood TypeType

Antigens Antigens on blood on blood

cellscells

Body will Body will make Ab make Ab againstagainst

Person Person can can

Donate Donate to:to:

Person Person can can

Receive Receive From:From:

AA AA B, ABB, AB A, ABA, AB A, OA, O

BB BB A, ABA, AB B, ABB, AB B, OB, O

ABAB A AND A AND BB

NONENONE ABAB ALLALLUniversal Universal recipientrecipient

OO NONENONE ALLALL ALLALLUniversal donorUniversal donor

OO

Blood DiseasesBlood Diseases Anemia – decreased O2 carrying abilityAnemia – decreased O2 carrying ability

Sickle cell anemia – genetic point mutation in hemoglobinSickle cell anemia – genetic point mutation in hemoglobin Aplastic Anemia – cancer – can’t produce RBC’sAplastic Anemia – cancer – can’t produce RBC’s Iron Deficiency AnemiaIron Deficiency Anemia Hemolytic Anemia – blood cells are being destroyedHemolytic Anemia – blood cells are being destroyed

Polycythemia – bone marrow cancer – make too Polycythemia – bone marrow cancer – make too many RBC’smany RBC’s

Leukemia – over production of WBC’s – immature Leukemia – over production of WBC’s – immature and don’t work – metatstasize to liver, spleen – use and don’t work – metatstasize to liver, spleen – use up all metabolic substrates and cause tissue up all metabolic substrates and cause tissue destructiondestruction

Thrombus – clotThrombus – clot Emobolus – clot that has broken off – may cause Emobolus – clot that has broken off – may cause

strokestroke Hemophilia – lack of a clotting factor – blood clots Hemophilia – lack of a clotting factor – blood clots

slowly on internal bleeds – 1 hour vs. 6-8 minutesslowly on internal bleeds – 1 hour vs. 6-8 minutes

Parts of the Circulatory Parts of the Circulatory SystemSystem

Heart – pumps blood - ~6000 quarts/dayHeart – pumps blood - ~6000 quarts/day

Blood vessels – pipes blood travel throughBlood vessels – pipes blood travel through

Lymphatics – cleanse leaked blood of Lymphatics – cleanse leaked blood of bacteria, viruses, etc. and rejoins blood bacteria, viruses, etc. and rejoins blood vessels where veins enter the hearvessels where veins enter the hear

Heart Parts – From outside to Heart Parts – From outside to inin

Membranes (from outside to inside)Membranes (from outside to inside) Pericardium – serous membrane – Pericardium – serous membrane –

epithelial over areolar with visceral and epithelial over areolar with visceral and parietal membranes – protects heart and parietal membranes – protects heart and anchors it to sternum and diaphramanchors it to sternum and diaphram

Epicardium – outside connective tissue Epicardium – outside connective tissue layers of the heart – can be considered layers of the heart – can be considered visceral pericardium)visceral pericardium)

Myocardium – cardiac muscle interwoven Myocardium – cardiac muscle interwoven with dense fibrous connective tissuewith dense fibrous connective tissue

Endocardium – sheet of epithelium Endocardium – sheet of epithelium surrounding the open cavities (has some surrounding the open cavities (has some connective tissue underlying itconnective tissue underlying it

Membranes of the HeartMembranes of the Heart

Heart Parts ContinuedHeart Parts ContinuedChambersChambers Atria – two cavities on top – right Atria – two cavities on top – right

receives blood from body, left receives receives blood from body, left receives blood from the lungsblood from the lungs

Ventricles – the inferior and larger Ventricles – the inferior and larger cavities – right pumps blood to the cavities – right pumps blood to the lungs, left lungs, left pumps blood to the bodypumps blood to the body

Septum – divides the heart into right Septum – divides the heart into right and leftand left

Heart Parts continued - Heart Parts continued - ValvesValves Atrioventricular Valves (AV valves)Atrioventricular Valves (AV valves)

Between the atria and ventriclesBetween the atria and ventricles As the ventricles contract it forces the flap of As the ventricles contract it forces the flap of

the valve to close and open during ventricular the valve to close and open during ventricular relaxationrelaxation

Left valve = bicuspid or mitral valveLeft valve = bicuspid or mitral valve Right valve = tricuspidRight valve = tricuspid

Semilunars Semilunars (look like half moons)(look like half moons) Cover the pulmonary and aortic arteriesCover the pulmonary and aortic arteries Open up into the arteryOpen up into the artery Open when the ventricles are contracting so Open when the ventricles are contracting so

that blood goes to the body or lungsthat blood goes to the body or lungs Back flow closes them so that blood doesn’t Back flow closes them so that blood doesn’t

flow back into the heartflow back into the heart

Path of Blood Through the Path of Blood Through the HeartHeart

1.1. Rt. Atrium receives oxygen poor blood from the Rt. Atrium receives oxygen poor blood from the vena cava.vena cava.

2.2. Flows to the rt. Ventrical through the right AV Flows to the rt. Ventrical through the right AV valve (tricuspid)valve (tricuspid)

3.3. Rt. Ventricle pumps to lungs thru pulmonary Rt. Ventricle pumps to lungs thru pulmonary semilunar valve into the pulmonary arteries.semilunar valve into the pulmonary arteries.

4.4. Blood returns to the heart through the Blood returns to the heart through the pulmonary veins into the left atrium (oxygen pulmonary veins into the left atrium (oxygen rich blood from the lungs)rich blood from the lungs)

5.5. Blood flows to left ventricle through left AV Blood flows to left ventricle through left AV valve (bicuspid or mitral valve) and is pumped valve (bicuspid or mitral valve) and is pumped out to body through the aorta thru the aortic out to body through the aorta thru the aortic semilunar valve.semilunar valve.

6.6. Blood circulates to the heart thru coronary Blood circulates to the heart thru coronary arteries - only when it is relaxedarteries - only when it is relaxed

Blood Vessel StructureBlood Vessel Structure Basic blood vessel structure:Basic blood vessel structure:

Internal lining (Tunica Intima)Internal lining (Tunica Intima) Epithelium - endotheliumEpithelium - endothelium

Middle of wall (Tunica Media)Middle of wall (Tunica Media) Smooth muscleSmooth muscle

Outside (Tunica Externa)Outside (Tunica Externa) Fibrous connective tissueFibrous connective tissue

Capillaries – just one single cell layer thick for Capillaries – just one single cell layer thick for diffusiondiffusion

EpitheliuEpitheliumm

ConnectiConnectiveve

Smooth Smooth musclemuscle

CirculationCirculation

Heart Heart → Arteries → Arterioles →→ Arteries → Arterioles →

(less lumen and smooth muscle)(less lumen and smooth muscle)

Capillaries → Venules → Veins → HeartCapillaries → Venules → Veins → Heart (just epithelium)(just epithelium)

Arteries vs. VeinsArteries vs. Veins ArteriesArteries

More smooth More smooth musclemuscle

Smaller lumen due Smaller lumen due to pressureto pressure

A lot of pressureA lot of pressure No valvesNo valves

VeinsVeins Little smooth Little smooth

musclemuscle Bigger lumen due Bigger lumen due

to less muscleto less muscle Low pressureLow pressure ValvesValves

Veins are under low pressure so it is difficult for blood to get back to the heart from the feet – need help:

Valves prevent backflow

Skeletal muscle helps push blood back

Pressure in chest from breathing

Blood PressureBlood Pressure

Usually measure the pressure in the Usually measure the pressure in the brachial artery – measure during brachial artery – measure during ventricular systole and ventricular diastoleventricular systole and ventricular diastole

Normal b.p. = 110-140/75-80Normal b.p. = 110-140/75-80 Top # is the systolic pressure, bottom # is Top # is the systolic pressure, bottom # is

the diastolic pressurethe diastolic pressure Hypertention – sustained b.p. of 140/90 Hypertention – sustained b.p. of 140/90

and above – damages epithelial lining and and above – damages epithelial lining and accelerated atherosclerosisaccelerated atherosclerosis

What controls resistance in What controls resistance in blood vessels?blood vessels?

Kidneys monitor blood volume – if too high - Kidneys monitor blood volume – if too high - ↑ water ↑ water output – if too low – retain salt which causes water retentionoutput – if too low – retain salt which causes water retention

Blood vessel constriction/dilationBlood vessel constriction/dilation Cold – bv constrictionCold – bv constriction Fight or flight – stress hormones cause vasoconstriction Fight or flight – stress hormones cause vasoconstriction

except to skeletal muscleexcept to skeletal muscle If lose blood – vasoconstriction to combat pressure lossIf lose blood – vasoconstriction to combat pressure loss When stand up – pressure drops since it is hard to return When stand up – pressure drops since it is hard to return

blood to the heart against gravity – pressure receptors blood to the heart against gravity – pressure receptors signal brain to cause vasoconstriction and increase heart signal brain to cause vasoconstriction and increase heart rate so blood pressure is maintainedrate so blood pressure is maintained

Nitric oxide has been found to be the major regulator of bv Nitric oxide has been found to be the major regulator of bv relaxationrelaxation

Alcohol lowers bpAlcohol lowers bp Nictotine raises bpNictotine raises bp

AtherosclerosisAtherosclerosis

Cardiac Cycle and Heart Cardiac Cycle and Heart SoundsSounds

1. Relaxing heart (atrial and ventricular 1. Relaxing heart (atrial and ventricular diastole ) diastole )

- AV valves open/ SL valves closed- AV valves open/ SL valves closed2. Atrial systole (ventricles still in diastole) – 2. Atrial systole (ventricles still in diastole) –

pushes any blood still in atria to pushes any blood still in atria to ventricles before they contractventricles before they contract- Valves are the same- Valves are the same

3. Ventricular systole (atria are relaxing – 3. Ventricular systole (atria are relaxing – already contracted)already contracted)- AV valves close so blood doesn’t squirt - AV valves close so blood doesn’t squirt back into the atria, SL open to let blood back into the atria, SL open to let blood go to lungs and the bodygo to lungs and the body

Electricity Thru the Electricity Thru the HeartHeart1.1. SA (sinoatrial node – pacemaker) gets SA (sinoatrial node – pacemaker) gets

the signal from the brain and sends the the signal from the brain and sends the electrical impulse through the atria to electrical impulse through the atria to the AV (atrioventricular) node. The atria the AV (atrioventricular) node. The atria then contract.then contract.

2.2. AV node delays the impulse – allows atria AV node delays the impulse – allows atria to finish contractingto finish contracting

3.3. AV node sends the pulse down the AV AV node sends the pulse down the AV bundle to the bundle branches to the bundle to the bundle branches to the Purkinje fibers in the walls of the Purkinje fibers in the walls of the ventriclesventricles

4.4. Heart contracts from the apex up Heart contracts from the apex up sending blood up and out thru the aorta sending blood up and out thru the aorta or pulmonary trunkor pulmonary trunk

EKG or ECG – measurement of the EKG or ECG – measurement of the electrical wave that sets off muscle electrical wave that sets off muscle

contractioncontractionP-wave – preceeds the contraction of the atria

Atria are depolarizing (Na+ is flowing into T-tubules)

QRS wave – preceeds ventricular systole – Ventricles are depolarizing

T wave – the ventricles repolarizing – returning Na and K to normal

Can’t see the atria repolarizing since it is behind the QRS wave

Can tell if heart beats too fast or slow if heart is abnormally large due to overwork by size of waves

tachycardiatachycardia