hematologi

ANATOMI FISIOLOGI MANUSIA

HEMATOLOGI

Oleh:NADIA FARHANAH SYAFHAN M.Si, Apt

• Blood separates into two main parts: plasma and formed elements.

• Plasma accounts for 55% and formed elements 45% of blood volume.

• Plasma contains mostly water (90–92%) and plasma proteins (7–8%), but it also contains nutrients and wastes.

BLOOD

BLOOD

• 8% total body weight

• 5 L pada wanita dan 5,5 L pada pria

• 3 Tipe elemen sel : eritrosit, leukosit, platelet

• Albumin is a large plasma protein that transports bilirubin; globulins are plasma proteins that transport lipoproteins.

Composition of blood

Blood constituents and its functions

Blood constituents and its functions

HEMOPOESIS

• Hemopoesis atau hematopoesis ialah proses pembentukan darah.

• Pranatal di hati dan limpa• Pascanatal terbatas di sumsum tulang

• Untuk kelangsungan hemopoesis diperlukan sel induk hemopoetik (hematopoetic stem cell).

• A stem cell is capable of dividing into new cells that differentiate into particular cell types.

HEMOPOESIS

• Sel induk yang paling primitif disebut sebagai pluripotent stem cell.

• Sel induk pluripotent mempunyai sifat (Bakta IM, 2006):– self renewal: kemampuan memperbarui diri sendiri sehingga

tidak akan pernah habis meskipun terus membelah;– proliferatif: kemampuan membelah atau memperbanyak diri;– diferensiatif: kemampuan untuk mematangkan diri menjadi

sel-sel dengan fungsi tertentu.

HEMOPOESIS

• Sel induk sel progenitor yang semakin terspesialisasi sel matur perifer :

- sel darah merah,

- granulosit,

- monosit,

- trombosit dan limfosit

(Mehta AB dan Hoffbrand V, 2006)

Blood cell formation in red bone marrow

Hemopoesis

The Red Blood Cells

• Normally there are 4 to 6 million RBCs per mm3 of whole blood.

• Red blood cells contain the pigment hemoglobin for oxygen transport;

• hemogobin contains heme, a complex iron-containing group that transports oxygen in the blood.

Physiology of red blood cells

• Red blood cells (erythrocytes or RBCs) are made in the red bone marrow of the skull, ribs, vertebrae, and the ends of long bones.

• The kidneys produce the hormone erythropoietin to increase blood cell production when oxygen levels are low.

The Red Blood Cells

Epo enters bone marrow through blood vessel

(4). Epo is in bone marrow, surrounded by millions

of cells including stem cells

The Red Blood Cells

• The air pollutant carbon monoxide combines more readily with hemoglobin than does oxygen, resulting in oxygen deprivation and possible death.

• Red blood cells lack a nucleus and have a 120 day life span.

• When worn out, the red blood cells are dismantled in the

liver and spleen.

• Iron is reused by the red bone marrow where stem cells continually produce more red blood cells;

• the remainder of the heme portion undergoes chemical degradation and is excreted as bile pigments into the bile.

• Lack of enough hemoglobin results in anemia.

The Red Blood Cells

The White Blood Cells

• White blood cells (leukocytes) have nuclei and defend against disease.

• Leukocytes are divided into granular and agranular based on appearance.

• Granular leukocytes (neutrophils, eosinophils, and basophils) contain enzymes and proteins that defend the body against microbes.

• The agranular leukocytes (monocytes and lymphocytes) have a spherical or kidney-shaped nucleus.

White Blood Cellular Elements

• Monocytes can differentiate into macrophages that phagocytize microbes and stimulate other cells to defend the body.

• Lymphocytes are involved in immunity.

• An excessive number of white blood cells may indicate an infection or leukemia;

HIV infection drastically reduces the number of lymphocytes.

The White Blood Cells

RES (Reticulo Endothelial Systems)

• Sel yang berasal dari monosit yang tersebar di seluruh tubuh dalam banyak organ dan jaringan.

• Fungsi:- Memfagositosis dan menghancurkan patogen dan debris

selular

- Memproses dan menyajikan antigen ke sel limfoid (antigen presenting cell) yang bereaksi dengan sel T dalam kelenjar limfe, limpa, timus, sumsum tulang dan jaringan.

- Menghasilkan sitokin (misal IL-1) yang mengatur dan berperan dalam jaringan kerja dan gf hemopoesis, peradangan dan respon selular.

Macrophage engulfing bacteria

The Platelets and Blood Clotting

• Red bone marrow produces large cells called megakaryocytes that fragment into platelets at a rate of 200 billion per day.

Trombosit

HEMOSTASIS

Tujuan: • Mempertahankan darah tetap cair• Berada di dalam pembuluh darah• Membeku darah saat keluar pembuluh darah

Koordinasi :• Pembuluh darah• Trombosit• Faktor-faktor pembekuan• Natural inhibitor (penghambat alamiah)• Protein fibrinolitik

Hemostasis

Hemostasis normal membutuhkan 3 tanggapan:• Tanggapan normal pembuluh darah• Pembentukan sumbat trombosit• Pembentukan sumbat fibrin yang insoluble

Selanjutnya, sistem fibrinolisis berperan :• Mengontrol trombosis• Mengontrol fibrinolisis & inflamasi• Menghancurkan dan menyingkirkan kelebihan

fibrin

Pembuluh darah

• Peran utama → mencegah perdaraha Vasokostriksi

• Endotel utuh → trombosit & eritrosit terpisah sekresi zat yg mencegah pembekuan• Trauma → trombosit menggumpal → proses pembekuan dimulai

→ Disebut mekanisme hemostatik primer• Mekanisme hemostatik sekunder → mengontrol

pembentukan bekuan fibrin.• Mekanisme hemostatik primer dan sekunder berjalan

simultan.

Trombosit

• Segera setelah jejas, trombosit menggumpal dan mencegah perdarahan lebih lanjut.

• Adesi• Agregasi Membentuk fibrin • Sekresi prokoagulan

Blood clotting

• Trapped red blood cells make a clot appear red.

FIBRINOLISIS

• Setelah fibrin terbentuk → FIBRINOLISIS.• Fungsi : menyingkirkan bekuan dan menjamin

darah mengalir kembali.

Plasmin ← Plasminogen

t-PA

• Fibrin akan diubah menjadi FDPs