Chapter 9 Chapter 9 Circulatory Circulatory

systemsystem

---Closed tubular system

---Blood circulatory or cardiovascular S

---Lymph vascular S

The cardiovascular S

• heart

• artery

• vein

• capillary

1.    Capillaries1.    Capillaries

1) LM: • endothelium: • basement membrane: • pericyte:

/flattened with processes

/function:

i.  support

ii. undifferentiated cell

endothelial cell: • processes –microvilli-like, finger-liked• vesicle /60-70nm, constitute about 25-35% of total vol

ume /transendothelial channel function: transport large molecules and storag

e of membrane (for enlarge, enlongated, pore-formed and microvilli)

EM: classification①Continuous capillary: ---Structural feature: • endothelial cell: -more vesicles -tight junction• basal lamina: complete ---Distribution: CT, MT,

lung and CNS

② Fenestrated capillary

---Structural feature:

• endothelial cell: -have fenestrae or pore (60-80nm in D, with 4-6 nm diaphragm)

• basal lamina: complete

---Distribution: gastrointestinal tract, endocrine gland and renal glomerulus

③Sinusoid capillaries (enlarge capillary)

---Structural feature:

• endothelium: gap, pore

• basal lamina: incomplete or no (absent)

---Distribution: liver, spleen and bone marrow

2.     Artery2.     Artery---large A: aorta, pulmonary trunk

---medium-sized A: all named A, the diameter > 1mm (radial A, ulnar A)

---small A: 300um<D<1mm

1) Medium-sized A – muscular A---Tunica intima• endothelium• subendothelial layer: CT -collagenous F -elastic F -smooth muscle• internal elastic membrane: wa

ve-liked, pink-colored band- elastin

---Tunica media: thickest layer

• smooth muscle: 10-40 layers of, circularly

• elastic F: produced by SM• collagenous F: produced b

y SM---Tunica adventitia: • LCT –with small BV-vasa

vasorum, NF and LV• external elastic M

2) Large A: elastic A

---Structural features:

a. Tunica intima is thick, and internal elastic M is not prominant

b.   Tunica media: consists of 40-70 layers of elastic membrane, CF and SM

Large ALarge A

elastic M

SM

3) Small A:

---large SA: • internal EM• 3-4 layers SM• no external M

---small SA: • no internal M • 1-2 layers SM

2.       Veins2.       Veins---three type

---correspond with A except for LV

---three layers

---structural features: a. larger diameter, thinner walls- collapsedb.  no internal and external elastic membrane, s

o the boundaries between three tunica are not very clear

c. contains more CT, less smooth M, SM are arranged in bundles

d.   vein valve: /infolding of tunica intima /semilunar-liked /prevent back flow of blood

4.      Heart4.      Heart

---atrium(right and left)

---ventricle (right and left)

The wall of heartThe wall of heart

ESE

subendocardial layer

endocardium

myocardium

epicardium

1) The wall of heart

---endocardium:

• endothelium

• subendothelial layer: more dense CT- contain fibroblast, CF, EF, SM

• subendocardial layer: LCT, with BV, N and conducting S- Purkinje fiber

---myocardium: • cardiac M:

a.    atrial muscle:

/atrial granules: 0.3-0.4um in D, contain atrial natriuretic polypeptide or cardionatrin

b.   ventricular M: thick, long, branches• LCT: rich in capillaries

*atrioventricular fibrous annulus: DCT

---epicardium: visceral layer of pericardium- serous membrane:

• mesothelium • LCT: more fat cell- sub

epicardial layer

---cardiac valve: • formed by infolding of

endocardium: endothelium + DCT

• prevent the back flow of blood

2) Conducting S

① components:

---sinoatriol node (SA node): located in epicardium of right atrium

---atrioventricular node (AV node) and bundles (AV bundles): located in subendocardial layer

---network of Purkinje fiber:

② three types of cells a. pacemaker cell ( P cell):• mainly distributed in SA and AV node• small, fusiform or polygonal in shaped• enclosed by DCT• less organelle: myofibril, plasmalemma

l vesicles and more glycogen

b. transitional cell:

• mainly distributed in periphery of SAN or AVN and AV bundle

• The structure is between pacemaker cell and cardiac M

• thinner and shorter than CM

• more myofibril than P cell

c. Purkinje cell:• mainly constitute AV bundle and

branches• shorter, boarder than CM, with 1-2

centrally located nuclei• rich in mitochondria, glycogen, less

myofibril• well-developed intercalated disks

Chapter 10 Chapter 10 Immune system Immune system

1. Components1. Components

1)  Cells

① Lymphocyte: a. T-lymphocytes: • cytotoxic T cell: Tc C- kill the tumor cell,

virus infective cell and foreign cell• helper T cell: Th C- promotes activity of

BLC and Tc C• suppressor T cell: Ts C –regulate the fu

nction of BLC and TCb. B-lymphocytes: become into plasma cel

lc. NK cell: counteract virus infective cell a

nd tumor cell

②Plasma cell③antigen presenting

cell: a. dendritic cell: • Blood DC• Langerhans cell• interstitial cell• veiled cell• interdigitating cellb.macrophage: Mononuclear phagocyti

c system

④other cells: • granulated cell• mast cell• blood platelet• blood-borne stem cell*Function: i.      immunologic defence functionii.     immune surveillance functioniii.    immune homeostasis

2)     Lymphoid tissue

---reticular T:

• reticular cell: stellate-shaped with processes to form network

• reticular fiber

---lymphocytes, macrophage,

plasma cell

and mast cell

a. Diffuse LT:

• no clear boundary

• mainly consists of TLC

• postcapillary venules:

-high endothelial venules

-opening for LC enter LT from blood

b. Lymphoid nodule:

• spherical or ovoid

• have clear boundaries

• mainly composed of BLC

• germinal center: stained pale

* primary LN → secondary LN

3) Lymphoid organs

a. Central lymphoid organs:

thymus, bone marrow• developed earlier• blood-borne stem cell comes from yolk sac• microenvironment → proliferation

promoting• send LC to PLD and LT two weeks before

borne

b. Peripheral lymphoid organs: lymph node, spleen and palatine tonsil

• developed later

• LC come from CLO

• cell proliferation need antigen stimulating - antigen dependent

• place for immune reactions

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