Platelets

Neutrophils Lymphocyte

Erythrocytes Monocyte

2.5 µm

7.5 µm

Side view (cut)

Top view

Stem cell

Hemocytoblast ProerythroblastEarlyerythroblast

Lateerythroblast Normoblast

Phase 1Ribosomesynthesis

Phase 2Hemoglobinaccumulation

Phase 3Ejection ofnucleus

Reticulo-cyte

Erythro-cyte

Committedcell

Developmental pathway

Formedelements

Platelets

Leukocytes

Erythrocytes

DifferentialWBC count(All total 4800 –10,800/l)

Neutrophils (50 – 70%)

Lymphocytes (25 – 45%)

Eosinophils (2 – 4%)

Basophils (0.5 – 1%)

Monocytes (3 – 8%)

Agranulocytes

Granulocytes

(a) Neutrophil; multilobed nucleus

(b) Eosinophil; bilobed nucleus, red cytoplasmic granules

(c) Basophil; bilobed nucleus, purplish-black cytoplasmic granules

(d) Small lymphocyte; large spherical nucleus

(e) Monocyte; kidney-shaped nucleus

Stem cell Developmental pathway

Hemocyto-blast Megakaryoblast

PromegakaryocyteMegakaryocyte Platelets

Collagenfibers

Platelets

Fibrin

Step Vascular spasm• Smooth muscle contracts, causing vasoconstriction.

Step Platelet plugformation

• Injury to lining of vessel exposes collagen fibers; platelets adhere.

• Platelets release chemicals that make nearby platelets sticky; platelet plug forms.

Step Coagulation• Fibrin forms a mesh that traps red blood cells and platelets, forming the clot.

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2

3

Superiorvena cava

Left lung

AortaParietalpleura (cut)

Pericardium(cut)

Pulmonarytrunk

DiaphragmApex ofheart

Fibrous pericardiumParietal layer

Pericardial cavityEpicardium(visceral layer)

MyocardiumEndocardium

Pulmonarytrunk

Heart chamber

PericardiumMyocardium

Brachiocephalic trunk

Superior vena cava

Right pulmonaryarteryAscending aortaPulmonary trunk

Right pulmonaryveins

Right atriumRight coronary artery(in coronary sulcus)Anterior cardiac veinRight ventricle

Right marginal artery

Small cardiac vein

Inferior vena cava

Left common carotidarteryLeft subclavian artery

Ligamentum arteriosumLeft pulmonary artery

Left pulmonary veins

Circumflex artery

Left coronary artery(in coronary sulcus)

Left ventricle

Great cardiac veinAnterior interventricularartery (in anteriorinterventricular sulcus)Apex

Aortic arch

Auricle ofleft atrium

AortaLeft pulmonaryarteryLeft pulmonaryveinsAuricle of leftatriumLeft atriumGreat cardiacveinPosterior veinof left ventricleLeft ventricle

Apex

Superior vena cavaRight pulmonary arteryRight pulmonary veins

Right atrium

Inferior vena cava

Right coronary artery(in coronary sulcus)

Coronary sinus

Posteriorinterventricularartery (in posteriorinterventricular sulcus)Middle cardiac veinRight ventricle

AortaLeft pulmonaryarteryLeft atriumLeft pulmonaryveins

Mitral (bicuspid)valve

Aortic valvePulmonary valveLeft ventricle

Papillary muscleInterventricularseptumEpicardiumMyocardiumEndocardium

Superior vena cavaRight pulmonaryarteryPulmonary trunkRight atrium

Right pulmonaryveinsFossa ovalisPectinate musclesTricuspid valveRight ventricle

Chordae tendineaeTrabeculae carneaeInferior vena cava

Oxygen-rich,CO2-poor bloodOxygen-poor,CO2-rich blood

Capillary bedsof lungs wheregas exchangeoccurs

Capillary beds of allbody tissues wheregas exchange occurs

Pulmonary veinsPulmonary arteries

PulmonaryCircuit

SystemicCircuit

Aorta and branches

Left atrium

HeartLeft ventricleRight atrium

Right ventricle

Venae cavae

Rightventricle

Rightcoronaryartery

Rightatrium

Rightmarginalartery Posterior

interventricularartery

Anteriorinterventricularartery

Circumflexartery

Leftcoronaryartery

Aorta

Anastomosis(junction ofvessels)

Leftventricle

Superiorvena cava

The major coronary arteries

Left atrium

Pulmonarytrunk

Superiorvena cava

Anteriorcardiacveins

Small cardiac veinMiddle cardiac vein

GreatcardiacveinCoronarysinus

The major cardiac veins

Sinoatrialnode

Atrioventricularnode

Atrialdepolarization

QRS complex

Ventriculardepolarization

Ventricularrepolarization

P-QInterval

S-TSegment

Q-TInterval

Large veins(capacitancevessels)

Largelymphaticvessels

Arteriovenousanastomosis

Lymphaticcapillary

Postcapillaryvenule

Sinusoid

MetarterioleTerminal arteriole

Arterioles(resistance vessels)

Muscular arteries(distributingvessels)

Elastic arteries(conductingvessels)

Small veins(capacitancevessels)

Lymphnode

Capillaries(exchange vessels)

Precapillary sphincterThoroughfarechannel

Lymphaticsystem

Venous system Arterial systemHeart

(a) Sphincters open—blood flows through true capillaries.

(b) Sphincters closed—blood flows through metarteriole thoroughfare channel and bypasses true capillaries.

Precapillarysphincters Metarteriole

Vascular shunt

Terminal arteriole Postcapillary venule

Terminal arteriole Postcapillary venule

Thoroughfare channel

True capillaries

Internal carotid artery

Common carotid arteries

Subclavian artery

Subclavian artery

Aortic archAscending aortaCoronary arteryThoracic aorta (abovediaphragm)

Renal artery

Superficial palmar arch

Radial arteryUlnar artery

Internal iliac artery

Deep palmar arch

Vertebral artery

Brachiocephalic trunk

Axillary artery

Brachial artery

Abdominal aortaSuperior mesenteric artery

Gonadal arteryCommon iliac artery

External iliac artery

Digital arteries

Femoral arteryPopliteal arteryAnterior tibial arteryPosterior tibial artery

Arcuate artery

Inferior mesenteric artery

Celiac trunk

External carotid artery

Arteries of the head and trunk

Arteries that supply the upper limb

Arteries that supply the lower limb

• Superficial temporal artery• Maxillary artery• Occipital artery• Facial artery• Lingual artery• Superior thyroid artery

Ophthalmic artery

LarynxThyroid gland(overlying trachea)Clavicle (cut)BrachiocephalictrunkInternal thoracicartery

Basilar artery

Vertebral arteryInternalcarotid artery

SubclavianarteryAxillaryartery

Arteries of the head and neck, right aspect

Externalcarotid arteryCommoncarotid arteryThyrocervicaltrunkCostocervicaltrunk

Branches ofthe external carotid artery

Frontal lobeOptic chiasma

Middlecerebral arteryInternalcarotid arteryMammillarybody

Temporallobe

Occipital lobe

Cerebral arterialcircle (circle of Willis)

• Posterior cerebral arteryBasilar arteryVertebral artery

Cerebellum

• Posterior communicating artery

Major arteries serving the brain (inferior view, right side of cerebellum and part of right temporal lobe removed)

Pons

• Anterior cerebral artery

• Anterior communicating artery

Posterior

Anterior

Vertebral artery

Costocervical trunkThoracoacromial arteryAxillary artery

Subscapular artery

Radial arteryUlnar artery

Brachial artery

Suprascapular arteryThyrocervical trunk

Posterior circumflexhumeral arteryAnterior circumflexhumeral artery

Deep artery of armCommoninterosseousartery

Deep palmar archSuperficial palmar archDigital arteries

Common carotidarteries

Right subclavian arteryLeft subclavian artery

Brachiocephalic trunkPosterior intercostalarteriesAnterior intercostalarteryInternal thoracic artery

Lateral thoracic arteryDescending aorta

Illustration, anterior view

Renal vein

Splenic vein

Basilic veinBrachial veinCephalic vein

Dural venous sinusesExternal jugular veinVertebral veinInternal jugular vein

Superior vena cava

Right and leftbrachiocephalic veins

Axillary vein

Great cardiac veinHepatic veins

Hepatic portal vein

Superior mesentericveinInferior vena cava

Ulnar veinRadial vein

Common iliac vein

External iliac vein

Internal iliac vein

Digital veins

Femoral veinGreat saphenous veinPopliteal veinPosterior tibial veinAnterior tibial veinSmall saphenous veinDorsal venous arch

Illustration, anterior view. The vessels of the pulmonary circulation are not shown.  Dorsal metatarsal veins

Inferior mesenteric vein

Median cubital vein

Subclavian vein

Veins of the head and trunk Veins that drainthe upper limb

Veins that drainthe lower limb

Veins of the head and neck, right superficial aspect

Vertebral vein

Ophthalmic vein

Externaljugular vein

Superficial temporalvein

Facial veinOccipital veinPosteriorauricular vein

Internal jugularveinSuperior and middlethyroid veinsBrachiocephalicveinSubclavian veinSuperiorvena cava

Right subclavian veinBrachiocephalic veins

Axillary veinBrachial veinCephalic veinBasilic vein

Median cubital vein

Median antebrachialvein

Basilic vein

Internal jugular veinExternal jugular veinLeft subclavian veinSuperior vena cavaAzygos vein

Inferior vena cavaAscending lumbar vein

Accessory hemiazygosveinHemiazygos veinPosterior intercostals

Ulnar veinDeep palmar venous archSuperficial palmar venous archDigital veins

Cephalic veinRadial vein

Anterior view

The hepatic portal circulation.

Hepatic veins

Liver

SpleenGastric veins

Inferior vena cava

Inferior vena cava(not part of hepaticportal system)

Splenic vein

Right gastroepiploicveinInferiormesenteric veinSuperiormesenteric veinLarge intestine

Hepatic portal vein

Small intestine

Rectum