kuliah kardio blok4.o9


Arteries Elastic arteries Muscular arteries Arterioles

Capillaries Continuous Fenestrated Sinusoidal

Veins Veins, venules


Structure of Blood Vessels

Composed of three layers (tunics) Tunica intima – composed of simple squamous

epithelium Tunica media – sheets of smooth muscle

Contraction – vasoconstrictionRelaxation – vasodilation

Tunica externa – composed of connective tissue Lumen

Central blood-filled space of a vessel


Structure of Arteries, Veins, and Capillaries

Figure 19.1a


Types of Blood Vessels

Arteries – carry blood away from the heart Capillaries – smallest blood vessels

The site of exchange of molecules between blood and tissue fluid

Veins – carry blood toward the heart


Types of Arteries

Elastic arteries – the largest arteries Diameters range from 2.5 cm

to 1 cm Includes the aorta and its

major branches Sometimes called

conducting arteries High elastin content dampens

surge of blood pressure

Aorta, brachiocephalic, common carotid, subclavian, vertebral, pulmonary, common iliac


Types of Arteries

Muscular (distributing) arteries Lie distal to elastic arteries Capable of grater vasoconstriction and

vaodilation to adjust the blood flow Diameters range from 1 cm to 0.3 mm Includes most named arteries Tunica media is thick Many of the arteries anastomose Unique features Internal and external elastic laminae Distribute blood to skeletal muscles &

internal organs Ex: external carotid, brachial, mesenteric,

femoral

Figure 19.2b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 19.2c

Types of Arteries

Arterioles Smallest arteries Diameters range from 0.3 mm to 10 µm Larger arterioles possess all three tunics Diameter of arterioles controlled by

Local factors in the tissues (02 levels)

Sympathetic nervous system hormonal stimulation


Arterioles

Arterioles are small arteries that deliver blood to capillaries.

Also have the three layers as an artery. Tunica media 1-2 layers of smooth muscle fibers A change in diameter of arterioles can significantly

affect blood pressure. Through constriction and dilation, arterioles assume

a key role in regulating blood flow from arteries into capillaries and in altering arterial blood pressure.


Arteriole: structure

1. Metarteriole

2. Arteriole

3. Capillary

Activity 3


Capillaries

Smallest blood vessels Diameter from 8–10 µm

Red blood cells pass through single file

Site-specific functions of capillariesLungs – oxygen enters blood,

carbon dioxide leaves Small intestines – receive digested

nutrientsEndocrine glands – pick up

hormonesKidneys – removal of nitrogenous

wastes


Capillaries

Tempat pertukaran material nutrien antara darah dan jaringan.

Tempat terjadinya mikrosirkulasi:aliran darah dari arteriole menuju venule malaui kapiler.

capiller tidak berpori (continuous Capillaries) dan berpori ( fenestrated).

Precappilary sphincters mengatur aliran darah melalui capillaries.

Pada liver berupa sinusoid


Capillaries

Capillary walls are made of a single layer of endothelial cells and a basement membrane. They have no tunica media or tunica externa.

Body tissues with high metabolic requirements, such as muscles, kidneys, liver and nervous system, have an extensive network of capillaries.

Tissues with low metabolic requirements have fewer capillaries-tendons and ligaments.

All covering and lining epithelia, cornea and lens of the eye-lack capillaries.


Types of Capillaries

True capillaries:emerge from arterioles and metarterioles.

Continuous capillaries-found in skeletal and smooth muscle, connective tissues and the lungs.

Fenestrated capillaries-kidneys, villi os the SI, choroid plexuses in brain, ciliary process, endocrine glands.

Sinusoids:are wider and more winding than other capillaries. Present in liver, red bone marrow, pleen, ant.pit. Gland, and parathyroid glands.


RBCs in a Capillary

Figure 19.3


Capillary Beds

Network of capillaries running through tissues Precapillary sphincters

Regulate the flow of blood to tissues

Tendons and ligaments – poorly vascularized Epithelia and cartilage – avascular

Receive nutrients from nearby CT


Capillary Beds

Figure 19.4a


Capillary Beds

Figure 19.4b


Local control of blood vessels

Sphincters contract or relax based on demand for: nutrients (AA, glucose, fatty

acids) Dissolved gases (O2, CO2 load,

lactic acid) Additional capillaries grow in

to area to satisfy increased energy demands


Capillary Permeabillity

Endothelial cells – held together by tight junctions and desmosomes

Intercellular clefts – gaps of unjoined membrane Small molecules can enter and exit

Two types of capillary Continuous – most common Fenestrated – have pores


Structure of Capillaries – Cross Section

Figure 19.5a


Structure of Capillaries – Cross Section

Figure 19.5b


Routes of Capillary Permeability

Four routes into and out of capillaries Direct diffusion Through intercellular clefts Through cytoplasmic vesicles Through fenestrations


Low Permeability Capillaries

Blood-brain barrier Capillaries have complete tight junctions No intercellular clefts are present Vital molecules pass through

Highly selective transport mechanisms

Not a barrier against Oxygen, carbon dioxide, and some anesthetics


Sinusoids

Wide, leaky capillaries found in some organs Usually fenestrated Intercellular clefts are wide open

Occur in bone marrow and spleen Sinusoids have a large diameter and twisted course


Sinusoids

Figure 19.5c


Veins

Conduct blood from capillaries toward the heart Blood pressure is much lower than in arteries Smallest veins – called venules

Diameters from 8 – 100 µm Smallest venules – called postcapillary venules

Venules join to form veins Tunica externa is the thickest tunic in veins

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 19.6

Mechanisms to Counteract Low Venous Pressure

Valves in some veins Particularly in limbs

Skeletal muscle pump Muscles press against

thin-walled veins


Vascular Anastomoses

Vessels interconnect to form vascular anastomoses Organs receive blood from more than one arterial

source

Neighboring arteries form arterial anastomoses Provide collateral channels

Veins anastomose more frequently than arteries


Vasa Vasorum

Tunica externa of large vessels have Tiny arteries, capillaries, and veins

Vasa vasorum vessels of vessels Nourish outer region of large vessels

Inner half of large vessels receive nutrients from luminal blood


Arteries

Sympathetic fibers of the ANS innervate vascular smooth muscle. An inc. in sympathetic stimulation typically stimulates the smooth muscle to contract-vasoconstriction.

When sympathetic stimulation decreases, or in presence of certain chemicals-NO, K+, H+ and lactic acid, they relax-vasodilation.


JANTUNG

RUANGAN ATRIUM DEXTER ET SINISITER VENTRICULUS DEXTER ET SINISTER

LAPISAN DINDING ENDOCARDIUM MYOCARDIUM PERICARDIUM ( 2 LAPIS) (Berasal dari sebuah kantong berisi cairan)

LAMINA VISCERALIS PERICARDII ( EPICARDIUM ) LAMINA PARIETALIS PERICARDII

STRUKTUR TAMBAHAN RANGKA FIBROSA VALVULA M. PAPILLARIS CHORDAE TENDINEAE

SISTEM KONDUKSI


JANTUNG

DINDING JANTUNG


LAPISAN ENDOCARDIUM

SEL ENDOTEL: POLIGONAL GEPENG BERLANJUT DENGAN ENDOTEL PEMBULUH DARAH

LAPISAN SUBENDOTEL LAPISAN JARINGAN PENGIKAT LONGGAR TIPIS: FIBROBLAS,

SERAT KOLAGEN DAN SEDIKIT SERAT ELATIS LAPISAN JARINGAN PENGIKAT PADAT TEBAL: LEBIH BANYAK

SERAT ELASTIS, DAN SEDIKIT BERKAS OTOT POLOS

LAPISAN SUB-ENDORKARDIAL JARINGAN PENGIKAT LONGGAR MENGANDUNG PEMBULUH DARAH, SARAF DAN SISTEM KONDUKSI

JANTUNG MENGIKAT ENDOKARDIUM DENGAN MIOKARDIUM


LAPISAN ENDOCARDIUM


MYOCARDIUM

UMUM: LAPISAN PALING TEBAL: OTOT-OTOT JANTUNG

SEL KONTRAKTIL (UTAMA) SEL BERFUNGSI KONDUKSI

ANYAMAN SERABUT ELASTIS DI ANTARA SEL-SEL OTOT JANTUNG

DINDING ATRIUM TERDAPAT ANYAMAN SERABUT ELASTIS ANTARA

BERKAS OTOT JANTUNG DINDING VENTRICULUS

LEBIH TEBAL DARIPADA DINDING ATRIUM SEDIKIT SERABUT ELASTIS TRABECULAE CARNEAE : TONJOLAN-TONJOLAN

BERKAS OTOT JANTUNG KE DALAM RONGGA


DINDING JANTUNG

MYOCARDIUM

MYOCARDIUM

DINDING JANTUNG

MYOCARDIUM

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin CummingsCopyright 2009, John Wiley & Sons, Inc.

Cardiac Muscle Tissue and the Cardiac Conduction System

Histology Shorter and less circular than skeletal muscle fibers Branching gives “stair-step” appearance Usually one centrally located nucleus Ends of fibers connected by intercalated discs Discs contain desmosomes (hold fibers together) and gap

junctions (allow action potential conduction from one fiber to the next)

Mitochondria are larger and more numerous than skeletal muscle

Same arrangement of actin and myosin


PERICARDIUM

PEMBUNGKUS SEROSA BERBENTUK KANTONG PERMUKAAN BEBAS DILAPISI OLEH MESOTEL BERISI CAIRAN 2 LAPISAN:

LAMINA PARIETALIS LAPISAN TIPIS JARINGAN PENGIKAT: SERABUT ELASTIS,

SERABUT KOLAGEN, FIBROBLAS, SEL MAKROFAG DAN SELAPIS SEL-SEL MESOTEL

LAMINA VISCERALIS (EPICARDIUM) MENEMPEL PADA MYOCARDIUM PERMUKAN BEBAS DITUTUPI OLEH SELAPIS SEL-SEL

MESOTEL DI BAWAH MESOTEL: JARINGAN PENGIKAT LONGGAR

TIPIS MENGANDUNG SERABUT ELASTIS, PEMBULUH DARAH (CABANG PEMB. DARAH JANTUNG), SER. SARAF


Pericardium and Heart Wall


MESOTHELIUM

EPICARDIUM

PEMBENTUKAN PERICARDIUM


RANGKA FIBROSA

KOMPONEN: SEPTUM MEMBRANACEUM (BAG. DARI SEPTUM

VENTRICULORUM) TRIGONUM FIBROSUM

TRIGONUM FIBROSUM DEXTER TRIGONUM FIBROSUM SINISTER

ANULUS FIBROSUS MEMBATASI OSTIUM ATRIOVENTRICULARIS

MIKROSKOPIS: JARINGAN PENGIKAT PADAT SERABUT KOLAGEN KASAR KE BERBAGAI ARAH

FUNGSI TEMPAT ORIGO-INSERSI OTOT JANTUNG PANGKAL VALVULA JANTUNG


Fibrous skeleton Dense connective tissue that forms a structural foundation,

point of insertion for muscle bundles, and electrical insulator between atria and ventricles


RANGKA FIBROSA

TRIGONUM FIBROSUM

ANULUS FIBROSUS

A. CORONARIA DEXTER

A. CORONARIA SINISTRA

A. PULMONALIS

AORTA

VALVULA MITRALISVALVULA

TRICUSPIDALIS


VALVULA

VALVULA TRICUSPIDALIS OSTIUM ATRIOVENTRICULARE DEXTER

VALVULA BICUSPIDALIS (MITRALIS) OSTIUM ATRIOVENTRICULARE SINISTER

MIKROSKOPIS: LEMPENG JARINGAN PENGIKAT (JARINGAN

KHONDROID PADAT DENGAN SEL-SEL BULAT) YANG BERPANGKAL PADA ANULUS FIBROSUS

PADA PANGKAL: MYOCARDIUM MASUK KE VALVULA MYOCARDIUM SISI ATRIUM LEBIH TEBAL DP SISI VENT KEDUA PERMUKAAN DILAPISI OLEH ENDOCARDIUM ENDOCARDIUM SISI ATRIAL LEBIH TEBAL DP SISI VENT PADA TEPI BEBAS KETIGA LAPISAN INI BERTEMU


VALVULA ATRIO-VENTRICULARIS

SISI ATRIUM

SISI VENTRIKEL


MUSCULUS PAPILLARIS

BENTUK: TONJOLAN KEDALAM DINDING VENTRIKEL

MENYERUPAI KERUCUT PUNCAK KERUCUT TERDAPAT BENANG-BENANG

CHORDAE TENDINEAE MENUJU TEPI BEBAS VALVULA LOKASI:

PADA BEBERAPA TEMPAT PERMUKAAN DALAM DINDING VENTRICULUS DEXTER ET SINISTER

MIKROSKOPIS LANJUTAN MYOCARDIUM : OTOT JANTUNG PERMUKAAN BEBAS DILAPISI OLEH ENDOCARDIUM

TIPIS


CHORDAE TENDINEAE

BENTUK: BENANG-BENANG MENGHUBUNGKAN PUNCAK M. PAPILLARIS DAN

TEPI VALVULA MIKROSKOPIS

JARINGAN PENGIKAT PADAT DISELUBUNGI OLEH ENDOTEL


HUBUNGAN VALVULA, CHORDAE TENDINEAE DAN MUSCULUS PAPILLARIS,

MUSCULUS PAPILLARIS

CHORDAE TENDINEAEVALVULA

VENTRICULUS DEXTER

A. PULMONALIS

A. CORONARIA DEXTRA

A. CORONARIA SINISTRA

VALVULA AORTAE

VALVULA MITRALIS

SERPTUM INTERVENTRICU

LARIS

M. PAPILLARIS ANTERIOR

M. PAPILLARIS POSTERIOR


SISTEM KONDUKSI

NODUS SINOATRIALIS TEMPAT: BATAS ATRIUM DEXTER DAN V. CAVA SUPERIOR UKURAN: 1 cm X 3-5 mm MIKROSKOPIS: ANYAMAN PADAT SERABUT PURKINJE FUNGSI:

PACE MAKER, AWAL DARI IMPULS MENGAKTIFKAN OTOT-OTOT ATRIUM

TRACTUS INTERNODUS: MENGHUBUNGKAN NODUS NODUS ATRIOVENTRICULARIS TRACTUS ATRIOVENTRICULARIS HIS

MENEMBUS TRIGONUM FIBROSUM : KE APEX CORDIS DALAM LAMINA SUBENDOCARDIUM CABANG BERKAS KIRI

BERKAS POSTERIOR BERKAS ANTERIOR

CABANG BERKAS KANAN

SISTEM PURKINJE : SEL PURKINJE (MODIFIKASI OTOT JANTUNG)


SISTEM KONDUKSI

NODUS SINO-

ATRIALIS

NODUS ATRIO-VENTRICULARIS

SERABUT PURKINJE

CABANG KIRI DARI BERKAS

BERKAS DEPAN


Coronary circulation

Myocardium has its own network of blood vessels Coronary arteries branch from ascending aorta

Anastomoses provide alternate routes or collateral circuits

Allows heart muscle to receive sufficient oxygen even if an artery is partially blocked

Coronary capillaries Coronary veins

Collects in coronary sinus Empties into right atrium


Coronary Circulation


Normal Coronary Artery Cross Section


60% Narrowing of Coronary Artery


90% Blockage of Coronary Artery

calcified arearemaining lumen


Atherosclerotic Plaque Histology

cholesterol crystal (cleft) foam cells


Thrombus Causing MI

“Needle-Like” white spots are cholesterol crystals

Thrombus ocluding artery Likely site of plaque rupture


Myocardial Infarction Histology

necrosed muscle cells red blood cells


Myocardial Infarction Histology

normal muscle cells remaining macrophages and the beginnings of scar tissue

kuliah kardio blok4.o9

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