VESSELS general overview - Univerzita Karlovaanatomie.lf3.cuni.cz/centralni_prezentace/Cevy_eng.pdf · Muscular artery (arteria musculotypica) • Tunica intima –thin –lamina

VESSELS

general overview

© David Kachlík 30.9.2015

• tunica intima

• subedothelial layer of connective tissue

• membrana elastica interna

• tunica media

• membrana elastica externa

• tunica adventitia= tunica externa

GENERAL STRUCTURE OF VASCULAR WALL


General structure of vascular wall

• tunica intima

• tunica media

• tunica

adventitia

(externa)


Tunica intima

• endothelial cells (endotheliocyti)

– simple flat/squamous epithelium

– on basal lamina

• subendothelial layer (stratum subendotheliale)

– loose connective tissue

– some smooth muscle cells

• lamina elastica interna

– elastin


Endothelial cells (Endotheliocyti)

• mesenchymal origin

• zonulae occludentes, desmosomes, nexuses

• intermediate filaments, microfilaments

(contraction)

• corpora multitubularia (Weibel-Palade‘s

bodies)

• f. VIII – vWF, P-selectin

• receptors: adrenergic, histaminic, ADH

• synthesis of vasoactive substances: NO, PG


Tunica media

• smooth muscle cells

– spiral arrangement

• elastic a collagen fibers (type III)

• lamina elastica externa

– only in thicker arteries


Tunica adventitia (externa)

• fibroblasts

• collagen fibers (type I)

• elastic fibers

• vasa vasorum

• nervi vasorum



Vessel types

• arteries (arteriae) - aer + térein

– muscular x elastic x mixed

– microcirculation: small arteries – less than 1 mm

– arterioles (arteriolae)• less than 100 μm

• several layers of smooth muscle cells

• principal source of peripheral resistance !!!

– metarterioly• one smooth muscle cell layer, precapillary sphincter

• capillaries (vasa capillaria)– no nerve fibers

– endotheliocyte + pericyte (Rouget‘ s cell)

– caliber ± 7 μm © David Kachlík 30.9.2015

Vessel types

• veins (venae)

– few muscle cells, more valvules

– venules (venulae)

• capacity part of circulation (70% of blood)

• lymph vessels (vasa lymphatica)

– lymph capillaries (vasa lymphocapillaria)

• originate as cul-de-sac

– lymphatic trunks and ducts (trunci et ductus

lymphatici)

• collectors in limbs

• valvules© David Kachlík 30.9.2015

Elastic arteriesaorta, truncus pulmonalis, a. subclavia,

axillaris, iliaca, femoralis, thoracica int.


Elastic artery

(Arteria elastotypica)

• Tunica intima

– lamina elastica interna – incoherent

• Tunica media

– elastic membranes with fenestrations – elastin

– smooth muscle cells

– lamina elastica externa

• Tunica adventitia (externa)

– frequent vasa vasorum

• supply outer 2/3 of wall© David Kachlík 30.9.2015

Elastic artery (van Gieson + elastin)


Elastic artery (elastin)


Muscular artery (arteria musculotypica)

• Tunica intima

– thin

– lamina elastica interna – obvious

• Tunica media

– circular smooth muscle cell layer (up to 40 layerss)

• each cell is covered with basal lamina – communication

• synthesis of extracellular matrix

– lamina elastica externa – several elastic membranes

• Tunica externa

– nerve bundles – contraction


Muscular artery

(HE) (van Gieson + elastin)


Arterioles = Arteriolaecaliber < 0.5 mm

• Tunica intima

– Weibel-Palade‘ s bodies within endothelail cells

(not in capillaries!)

– lamina elastica int. – absent in smallest arterioles

• Tunica media

– 1-3 layers of smooth muscle cells

– lamina elastica ext. – absent

• Tunica adventitia (externa) – very thin

principal source of peripheral resistance© David Kachlík 30.9.2015

Arteriola (HE)


Arteriola (HE)


Sensory structures in arteries

• Glomera supracardiaca (aortica) – sup., medium,

inf. - baroreceptors

• Sinus caroticus - baroreceptor

– thicker, richly innervated tunica adventitia

– thinner tunica media

• Glomus caroticum - chemoreceptors

– oval structures - 3-5 mm

• glomus cells – large nucleus, vesicles with catecholamines

• shield cells – cover neural endings as glia


Capillaries (Vasa capillaria)

• microvascular part of circulation

– vas capillare arteriale, intemredium, venosum

– site of gas and nutrients exchange

• capillary– caliber 7-9 μm

– length 1 mm (50 mm in renal glomerulus)

– total length approximately 96 000 km

– formed by endothelial cells on basal lamina


Capillaries – wall structures

• Endothelial cell (Endothelicytus)

• Basal lamina (Lamina basalis)

• Pericyte (Pericytus; Rouget‘s cells)

– mesenchymal cells with long processes

– stem, supporting and transporting cell

– proper lamina basalis

– contractile proteins (replaces tunica media)


Capillary bed

(HE)


Capillary types

• somatic capillaries– muscle, conncetive tissue, exocrinne glands (pinocytar

vesicle in the wall), nervous tissue (no vesicles)

• fenestrated (visceral) capillaries with diaphragms– fenestrations 60-80 nm (quick metabolic exchange)

– kidneys, gut, endocrinne glands

• fenestrated capillaries without diaphragms– glomeruli in kidney

• sinusoids– caliber 30-40 μm, often without lamina basalis

– hematopoetic organs – liver, spleen, bone marrow, dental pulp

• glomus, glomi n. (vessel glomerule) – ball of fingers, nailbeds, auricle, penis / clitoris, uterus © David Kachlík 30.9.2015

Capillaries - function

• permeability

– exchanger vessels (diffusion, pores, fenestration, vesicles)

• metabolic function

– activation of angiotensin I angiotensin II (lungs)

– inactivation of bradykinin, serotonin, prostaglandins

– lipolysis

• antithrombotic function

– inhibition of tissue thromboplastin© David Kachlík 30.9.2015

Somatic capillary (EG)


Somatic capillary (EG)


Fenestrated capillary (EG)


Fenestrated capillary

(EG)


Other structures of vascular wall

• vasa

vasorum

• vasa

nervorum

• nervi

vasorum



Other peculiar vascular structures

• vas anastomoticum (anastomosis)

• vas collaterale (collateral)

• rete mirabile = portal system

– 2 capillary beds series-connected

• anastomosis arteriovenosa (arteriolovenularis)

– endothel bulges of intimal cushions with myoepitheloid cells

• simple (skin, lungs, kidneys)

• composed (glomus coccygeum)© David Kachlík 30.9.2015

Vessel network arrangement

• terminal (retina, spleen, kidney)

• functionally terminal (heart, brain)

• anastomotic

angiogenesis – hypoxia is the strongest

factor !


Clinical relevance

• aneurysma

• atherosclerosis (athere + skleros)

• necrosis, infarctus

• air embolism in large cervical veins

• varices


Blood distribution in vessels

• veins 64%

• arteries 13%

• capillaries 7%

• heart 7%

• lungs 9%


Blood distribution in organs

• heart (coronary arteries) 5%

• brain 15%

• muscles 15%

• viscera 35%

• kidneys 20%

• skin, skeleton 10%

according to Stingl


Development of arterial system


Developmental arteries

• Saccus aorticus (aortal sac)

• Aa. arcuum pharyngeorum (pharyngeal arch arteries; „aortal arches“)– 5 pairs develop and change successively

• Aorta dorsalis (original 2 merge into 1)– a.a segmentales ventrales ( a. omphalomesenterica,

unpaired branches from AA)

– truncus umbilicalis ( a. iliaca communis + int.)

– a. umbilicalis

– aa. segmentales laterales ( paired branches from AA)

– aa. intersegmentales dorsolaterales ( branches from a. subclavia)

– a. sacralis mediana© David Kachlík 30.9.2015


Day 20-22



Pharyngeal arch arteries derivates

• 1st pair – arteria maxillaris + carotis externa

• 2nd pair – arteria stapedia

• 3rd pair – central – arteria carotis communis

– peripheral – arteria carotis interna



• 4th pair

– left – part of the arcus aortae

– right – a. subclavia dx.

• peripheral part of a. subclavia dx. is derived from aorta dorsalis

dextra

– a. subclavia sin. is NOT derived from the 4th aortic

arch but from 7th intersegmental artery



• 5th – Ø

• 6th pair

– left central left pulmonary artery

peripheral ductus arteriosus (Botali)

– right central right pulmonary artery

peripheral Ø



Arteriae omphalomesentericae

(vitellinae)

• number of paired arteries

• supply yolk sac

• develop in vascular supply of gut → truncus

coeliacus, arteria mesenterica superior et inferior


Arteriae umbilicales

• paired branches

– central: truncus umbilicalis from aorta dorsalis

– peripheral: within mass of diverticulum allantoicum

• to placenta (originally to allantois) in embryonic

(connective) stalk or later in umbilical cord

• persist as arteriae iliacae internae and vesicales

superiores

– central: pars patens)

– peripheral: ligamentum umbilicale mediale = pars

occlusa


Malformation of arteries

• Ductus arteriosus patens

• Coarctatio aortae

• Arcus aortae duplex

• Arcus aortae dexter

• Arteria lusoria

– abnormal origin of the right subclavian artery –

obliteration of right aortic arch – origin of 7th

segmental artery





Malformation of arteries

• course changes

• clinically relevant:

– a. radialis

• a. brachioradialis (14%)

– a. ulnaris

• a. brachioulnaris superficialis (3%)


Development of venous system


Developmental veins

vv. somaticae

• v. cardinalis communis = ductus Cuvieri

• v. precardinalis ( v. jugularis int.+ ext.)

• v. postcardinalis ( v. azygos + hemiazygos)

• anastomosis subcardinalis– vv. subcardinales

• vv. intersegmentales – v. marginalis membri + v. axialis m.s./m.i.( vv. subclaviae + superficial and deep limb veins)

vv. viscerales

• vv. omphalomesentericae (vitellinae)

• v. umbilicalis (originally 2, right one disappears)

• v. pulmonalis communis© David Kachlík 30.9.2015


Vena cava inferior

• v. omphalomesenterica intraembryonica

pars hepatica VCI

• anastomosis subcardinalis + v.

subcardinalis dx. pars subcardinalis VCI

• developmental anomalies 1-2%

– infrarenal duplication


Vena portae

• vv.

omphalomesentericae

intraembryonicae

• vv. afferentes hepatis

• ductus venosus lig.

venosum)

• vv. efferentes hepatis

vv. hepaticae


Vena portae

preduodenalis

rare


Documents

VESSELS general overview - Univerzita Karlovaanatomie.lf3.cuni.cz/centralni_prezentace/Cevy_eng.pdf · Muscular artery (arteria musculotypica) • Tunica intima –thin –lamina