KOMPOSISI DARAH dan FUNGSINYA,KOMPOSISI DARAH dan FUNGSINYA,HEMATOPOETIK dan PENGONTROLANNYAHEMATOPOETIK dan PENGONTROLANNYA

Fakultas KedokteranFakultas Kedokteran

Universitas AndalasUniversitas Andalas

PadangPadang

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Fungsi Utama DarahFungsi Utama Darah

1. Respirasi;

pengangkutan O2 dan CO2

2. Nutrisi; pengangkutan hasil absorpsi usus

3. Ekskresi; pengangkutan sisa metabolik ke ginjal,

paru-paru, kulit, & usus

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Fungsi Utama DarahFungsi Utama Darah

4. Keseimbangan asam-basa

5. Keseimbangan air; antara sirkulasi darah dan jaringan

6. Pengaturan suhu tubuh

7. Pertahanan terhadap infeksi; oleh sel darah putih & antibodi

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Fungsi Utama DarahFungsi Utama Darah

8. Pengangkutan hormon &

pengaturan metabolisme

9. Pengangkutan metabolit

10. Koagulasi

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Blood ComponentBlood Component

– 5-6 L in an adult

– 70 mL/kg of body weight

– Suspension of cells in a carrier fluid (plasma)• Cells - 45% by volume• Plasma - 55% by volume

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Plasma CompositionPlasma Composition

– Water - 90% of plasma volume

– Proteins - 7% of plasma volume

– Inorganic - 1% of plasma volume

• Na+, K+, Mg2+, Ca2+, PO43-…

– Organic - 2% of plasma volume

• urea, fats, cholesterol, glucose ...

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CellsCells

– Red cells (erythrocytes)• 5x106/L

– White cells (leukocytes)• 7x103/L

– Platelets (thrombocytes)• 3x105/L

• Hematocrit (% volume that is red cells): - 40-50% in males

- 35-45% in females

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Red Cells

– 40 - 50% of blood volume

– 5 x 106 cells /L

– “bag” of hemoglobin

• non-nucleated

• no proliferation

– Shape

• Biconcave disc

• Diameter is 6 - 8 μm

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Red Cells

– The production can be stimulated & controled by the hormone erythropoietin.

– This hormone produces in kidney (85%) and It’s level will be rise in anemia.

– Erythrocytes develop from stem cells through reticulocytes to mature erythrocytes in about 7 days and live a total of about 120 days.

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Red Cells

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HemoglobinHemoglobin

• Satu mol. Hb dewasa (HbA) mempunyai; - 4 gugus heme - Setiap heme mengandung 1 ion Fe2+

- 4 subunit protein globin

- Setiap subunit mengikat 1 mol. O2

- 1 mol. Globin mengikat 1 mol. CO2

• Subunit rantai terdiri dari 2 dan 2 - masing-masing=141 asam amino - masing-masing = 146 asam amino

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UNSUR SELULAR DALAM RESPON IMUNUNSUR SELULAR DALAM RESPON IMUN

1. Jalur limfoid yang membentuk limfosit dan subsetnya

2. Jalur mieloid yang membentuk sel-sel fagosit mononuklear & polimorfonuklear (PMN).

PMN terdiri dari:

neutrofil, eosinofil, basofil

Differential WBC Count (Leukosit)

• Detection of changes in numbers of circulating WBCs (percentages of each type)– indicates infection, poisoning, leukemia,

chemotherapy, parasites or allergy reaction

• Normal WBC counts– neutrophils 60-70% (up if bacterial infection)– lymphocyte 20-25% (up if viral infection)– monocytes 3 - 8 % (up if fungal/viral infection)– eosinophil 2 - 4 % (up if parasite or allergy reaction)– basophil <1% (up if allergy reaction or hypothyroid)

Half time WBC + 6 hours

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• Function– Defense against foreign invaders

• bacteria• viruses• foreign materials (including biomaterials)

• Phagocytosis– Move to foreign particle by chemotaxis

• Chemicals induce migration• Toxins, products of inflamed tissues

– Response is extremely rapid (approx 1 h)– Monocytes in tissue become macrophages

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LymphocytesLymphocytes

– B cells - responsible for humoral immunity– T cells - responsible for cell mediated

immunity

• B cells responsible for production of antibodies – Receptor matches antigen– Cells multiply– Antibodies

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• T cells– Cytotoxic T cells (Killer T cells)

• Bind to cytotoxic cells (eg infected by virus)

– Helper T cells• Most numerous• Activate B cells & Killer T cells• Stimulate macrophages

– Suppressor T cells• Regulate activities of other cell types

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PlateletsPlatelets

• Non-nucleated disk shaped cells• 3-4 m diameter• Volume 10 x 10-9 mm3

• 250 000 cells/L• 10 day circulation time

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• Function:

– Initially arrest bleeding through formation of platelet plugs

– Stabilize platelet plugs by catalyzing coagulation reactions leading to formation of fibrin

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Protein PlasmaProtein Plasma

- Bagian utama unsur padat dalam plasma.

- Konsentrasi total protein plasma + 7-7,5 g/dl.

- Berbagai protein plasma dapat dipisahkan menurut karakteristik kelarutannya.

- Metode pemisahan tsb antara lain;

1. Salting-out (Na2SO4 23%, dll)

2. Elektroforesis

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Protein PlasmaProtein Plasma

1. Sebagian besar disintesis di hepar.2. Umumnya disintesis sbg preprotein pada

poliribosom terikat membran. Preprotein akan mengalami modifikasi pascatranslasi.

3. Hampir semuanya berupa glikoprotein, kecuali albumin.

4. Bersifat polimorfisme (ciri bawaan pd populasi dgn sedikitnya 2 macam fenotipe).contoh; gol. Darah ABO

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Plasma ProteinsPlasma Proteins

• More than 200

• Most abundant

– Albumin - 4-5 g/100 mL

--globulins - ~1 g/100 mL

– fibrinogen - 0.2-0.4g/100 mL

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AlbuminAlbumin

- Merupakan protein utama dalam plasma.

- Mempertahankan 75-80% tekanan osmotik.

- Berfungsi mengikat berbagai macam ligand, seperti; asam lemak bebas, Ca, Cu, Zn, hormon steroid, bilirubin, metheme

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AlbuminAlbumin

- Albumin juga dapat mengikat obat-an,

seperti; sulfonamid, penisilin-G,

dikumarol, aspirin

- Penyakit hepar akan memperlihatkan rasio albumin/globulin yang menurun.

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TransferinTransferin

• Adalah 1-globulin berbentuk glikoprotein yang disintesis di hepar.

• Berfungsi sebagai alat transpor besi (Fe3+) untuk dibawa ke jaringan.

• Jika besi tidak diikat oleh transferin, maka akan menjadi prooksidan.

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CeruloplasminCeruloplasmin

• Protein ini adalah 2-globulin yang mengandung 90% Cu plasma.

Tetapi 10% Cu terikat longgar pd albumin, sehingga mudah dilepas ke jaringan.

• Ceruloplasmin mengandung ferroksidase yang mengkatalisis ion Fe2+ --> Fe3+,

karena hanya ion Fe3+ yang mampu berikatan dgn apotransferin.

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-Globulins-Globulins

• 20% of plasma proteins

• “” refers to electrophoretic mobility

• Represents a group of proteins of variable structure

– immunoglobulins

• Main functional task is immunochemical

– Antibodies - combine with specific antigens

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Imunoglobulin PlasmaImunoglobulin Plasma

• Disintesis dalam sel plasma.

• Sel plasma adalah turunan Sel- yang mensintesis dan mensekresikan imuno- globulin sebagai respon terhadap pajanan berbagai antigen.

• Semua imunoglobulin mengandung paling kurang 2 rantai ringan dan 2 rantai berat.

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Classes of ImmunoglobulinsClasses of Immunoglobulins

• IgG – Identifies microorganisms for engulfment or lysis

• IgE – Inhibits parasite invasion; involved in allergic reactions

• IgD – Unknown• IgA – Basis for passive immunity provided by

breast milk, agglutinates infectious agents in secretions outside the body, present in tears, mucous

• IgM – Identifies microorganisms for engulfment or lysis

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• Basic 4 chain structural unit– MW = 2x55000 +2x27000 = 160000

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FibrinogenFibrinogen– Function: Blood coagulation (clotting)Function: Blood coagulation (clotting)

Fibrinogen FibrinThrombin

Fibrin Degradation (FDP)Plasmin

Plasmin is end product of fibrinolytic Plasmin is end product of fibrinolytic systemsystemClot needs to be removedClot needs to be removed

Not needed foreverNot needed foreverCould embolize to lungs, brainCould embolize to lungs, brain

Plasmin is end product of fibrinolytic Plasmin is end product of fibrinolytic systemsystemClot needs to be removedClot needs to be removed

Not needed foreverNot needed foreverCould embolize to lungs, brainCould embolize to lungs, brain

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KepustakaanKepustakaan

• Ganong, WF. Sirkulasi cairan tubuh. Dalam: HM Djauhari Widjajakusumah. Review Of Medical Physiology. 20th ed. McGraw-Hill Companies, New York, 2001: 495 - 501.

• Rand, ML., Murray, RK. Protein plasma, imunoglobulin, dan pembekuan darah. Dalam: Andry Hartono, penerjemah. Harper’s Biochemistry. 25th ed. Eds. R.K. Murray, D.K. Granner, P.A. Mayes, V.W. Rodwell. McGraw-Hill Companies, New York, 2003: 702 - 11.

• Sheardown, H. Blood Biochemistry. McMaster University. Download 20-05-2007.