Slide 88, elastic artery (aorta), (10x obj.)Slide 88, elastic artery (aorta), (10x obj.)TITI

TMTM

TATA

elastic fiberselastic fibers

Slide 36, elastic artery (aorta), trichrome (10x obj.)Slide 36, elastic artery (aorta), trichrome (10x obj.)

TITI

TMTM

TATA

elastic fiberselastic fibers

NOT vasa NOT vasa vasorumvasorum

Slide 36, elastic artery (aorta), trichrome (40x obj.)Slide 36, elastic artery (aorta), trichrome (40x obj.)

TMTM

TATA

elastic fiberselastic fibers

vasa vasorum

vasa vasorum

Slide 30, muscular artery (4x obj.)Slide 30, muscular artery (4x obj.)

Vessel TunicsA. Tunica Intima

•endothelium•subendothelium

connective tissuesmooth muscle(longitudinal fibers)

•internal elastic lamina

B. Tunica Media•vascular smooth muscle•external elastic lamina(circular fibers)

C. Tunica Adventitia•connective tissue(longitudinal)

Slide 30, muscular artery (40x obj.)Slide 30, muscular artery (40x obj.)

Slide 92, muscular artery w/ intimal thickening (40x obj.)Slide 92, muscular artery w/ intimal thickening (40x obj.)

Vessel TunicsA. Tunica Intima

•endothelium•subendothelium

connective tissuesmooth muscle(longitudinal fibers)

•internal elastic lamina

B. Tunica Media•vascular smooth muscle•external elastic lamina(circular fibers)

C. Tunica Adventitia•connective tissue(longitudinal)

Slide 95, muscular artery, trichrome (4x obj.)Slide 95, muscular artery, trichrome (4x obj.)

Slide 95, muscular artery, trichrome (40x obj.)Slide 95, muscular artery, trichrome (40x obj.)

tunica media

internal elastic lamina

elastic fibers

tunica tunica adventitiaadventitia

external elastic lamina

Slide 95, medium vein, H&E (4x obj.)Slide 95, medium vein, H&E (4x obj.)

Slide 95, medium vein, H&E (10x obj.)Slide 95, medium vein, H&E (10x obj.)

Tunica media• 3-15 layers of VSMCs• no external elastic lamina

•Tunica adventitiaTunica adventitia• thicker than tunica mediathicker than tunica media• larger veins have larger veins have

longitudinal smooth longitudinal smooth muscle in adventitiamuscle in adventitia

• Tunica intima • endothelium• subendothelium• IEL generally not evident

Slide 95, medium vein, trichrome (4x obj.)Slide 95, medium vein, trichrome (4x obj.)

tunica adventitia

tunica media

Slide 95, medium vein, trichrome (10x obj.)Slide 95, medium vein, trichrome (10x obj.)

tunica adventitiatunica adventitia

tunica mediatunica media

elastic fiberselastic fibers

Note: IEL sometimes evident w/ trichrome stain

Arterioles•Tunica intima

very thin subendothelial layergenerally lacking distinct internal elastic lamina

•Tunica media1-3 layers of VSMCsno external elastic lamina

•Tunica adventitiathin and ill-defined

Venules•Tunica intima

endotheliumpericytes

•Tunica media1-2 sparse layers of VSMCsno external elastic lamina

•Tunica adventitiathicker than tunica media

Slide 95, arteriole and venule, H&E (40x obj.)Slide 95, arteriole and venule, H&E (40x obj.)

Slide 95, arterioles and venules, trichrome (40x obj.)Slide 95, arterioles and venules, trichrome (40x obj.)

arteriole

venulevenule

Slide 95, arteriole and venule (?), trichrome (40x obj.)Slide 95, arteriole and venule (?), trichrome (40x obj.)

arteriole?

venule?

Remember, the change in vessel size is gradual, so you’ll find intermediate sizes. To make classification easy, focus on vessels that are clearly one type or another.

Slide 95, arteriole and venule (?), trichrome (40x obj.)Slide 95, arteriole and venule (?), trichrome (40x obj.)

arteriole?(sectioned obliquely)

venule?

Slide 95, small vein & Slide 95, small vein & artery, H&E (40x obj.)artery, H&E (40x obj.)

veinvein

arteryartery

Slide 95, small vein & Slide 95, small vein & artery, trichrome (40x obj.)artery, trichrome (40x obj.)

veinvein

arteryartery

Slide 30, Slide 30, lymphaticlymphatic vessel (10x obj.) vessel (10x obj.)

Note number of white blood cells in lumen

valve

Slide 40, trachea (10x obj.)Slide 40, trachea (10x obj.)

Look in this layer for arterioles and venules

Slide 40, trachea (40x obj.)Slide 40, trachea (40x obj.)

venulevenule

arteriolearteriole

Slide 102, capillaries in myocardium (40x obj.)Slide 102, capillaries in myocardium (40x obj.)

Slide 98, H&E (orientation)Slide 98, H&E (orientation)

epicardiumepicardium

ventricular myocardiumventricular myocardium

papillary musclepapillary muscle

A-V valve leafletA-V valve leaflet

coronary vessels

atrial m

yocardium

atrial m

yocardium

Look under endocardium to find Purkinje fiberschorda tendinae

Slide 98, H&E, (20x obj.)Slide 98, H&E, (20x obj.)

endocardiumendocardium

Purkinje fibersPurkinje fibersin “subendocardium”in “subendocardium” (note perinuclear space (note perinuclear space and large fiber size)and large fiber size)

cardiac musclecardiac muscle

myocardiummyocardium

Slide 98, H&E (orientation)Slide 98, H&E (orientation)

epicardiumepicardium

ventricular myocardiumventricular myocardium

papillary muscle

A-V valve leafletA-V valve leaflet

coronary vessels

atrial m

yocardium

atrial m

yocardium

Look under endocardium to find Purkinje fibers

chorda tendinae

Slide 98, trichrome (20x obj.)Slide 98, trichrome (20x obj.)

endocardium

Purkinje fibers Purkinje fibers (note perinuclear space (note perinuclear space and large fiber size)and large fiber size)

cardiac musclecardiac muscle

Slide 98, trichrome (20x obj.)Slide 98, trichrome (20x obj.)

papillary muscle

A-V valve leafletA-V valve leaflet

chorda tendinae

to atrium to ventricle

Note that distribution of elastic fibers faces blood flow.

Slide 99, H&E (orientation)Slide 99, H&E (orientation)

look here for A-V bundle of His

ventricular myocardiumventricular myocardium

atrial myocardiumatrial myocardium

aortic valve aortic valve leafletleaflet

A-V valve A-V valve leafletleaflet

cardiac skeleton

Slide 99, H&E (4x obj.)Slide 99, H&E (4x obj.)

A-V bundle of His

ventricular myocardiumventricular myocardium

cardiac skeleton

Slide 99, H&E (20x obj.)Slide 99, H&E (20x obj.)

A-V bundle of His

cardiac skeleton

Slide 99, trichrome (orientation)Slide 99, trichrome (orientation)

look here for A-V bundle of His

ventricular myocardiumventricular myocardium

atrial myocardiumatrial myocardium

aortic valve aortic valve leafletleaflet

A-V valve A-V valve leafletleaflet

cardiac skeleton

Slide 99, trichrome (4x obj.)Slide 99, trichrome (4x obj.)

A-V bundle of His

ventricular myocardiumventricular myocardium

cardiac skeleton

Slide 99, trichrome (20x obj.)Slide 99, trichrome (20x obj.)

A-V bundle of His

cardiac skeleton

Slide 100, H&E (orientation)Slide 100, H&E (orientation)

ventricular myocardiumventricular myocardium

atrial atrial myocardiummyocardium

aortic valve aortic valve leafletleaflet

Slide 100, Weigert (orientation)Slide 100, Weigert (orientation)

ventricular myocardiumventricular myocardium

atrial atrial myocardiummyocardium

aortic valve aortic valve leafletleaflet

Slide 100, Weigert (4x obj)Slide 100, Weigert (4x obj)

to ventricle

to aorta

Note that distribution of elastic fibers faces blood flow.

aortic valve aortic valve leafletleaflet

Slide 100, Weigert (4x obj)Slide 100, Weigert (4x obj)

aortic side of leaflet ventricular side of leaflet

aortic valve aortic valve leafletleaflet

Note that distribution of elastic fibers faces blood flow.

Slide 102, H&E (orientation)Slide 102, H&E (orientation)

ventricular myocardiumventricular myocardium

aortic valve aortic valve leafletleaflet

epicardium

epicardium

coronary vessels

atrial atrial myocardiummyocardium