Blood Composition and Properties

Study Notes

Komposisi Darah

Komponen Utama:
- Plasma: Sekitar 55% dari darah, terdiri dari air (90%), protein, elektrolit, dan zat lainnya.
- Sel Darah: Sekitar 45% dari darah, dibagi menjadi sel darah merah, sel darah putih, dan trombosit.

Sifat Fisik Darah

Warna: Merah akibat hemoglobin; warna bisa bervariasi dari merah terang (arteri) ke gelap (vena).
Viskositas: Lebih kental dibandingkan air; dipengaruhi oleh kandungan sel darah dan protein.
pH: Rentang normal sekitar 7.35-7.45; bersifat sedikit basa.
Suatu cairan: Berdampak pada mobilitas dan distribusi dalam tubuh.

Jenis Sel Darah

Sel Darah Merah (Eritrosit):
- Fungsi: Mengangkut oksigen dari paru-paru ke seluruh tubuh dan karbon dioksida kembali.
- Memiliki bentuk cakram cekung; tidak memiliki inti.
Sel Darah Putih (Leukosit):
- Fungsi: Melawan infeksi dan berperan dalam sistem imun.
- Terdiri dari berbagai jenis, termasuk neutrofil, limfosit, monosit, basofil, dan eosinofil.
Trombosit (Platelet):
- Fungsi: Berperan dalam proses pembekuan darah untuk mencegah perdarahan.
- Mungkin berasal dari fragmen sel raksasa yang disebut megakariosit.

Fungsi Darah

Transportasi:
- Mengangkut oksigen, karbon dioksida, nutrisi, hormon, dan limbah.
Regulasi:
- Mengatur suhu tubuh, pH, dan keseimbangan cairan.
Perlindungan:
- Melindungi tubuh dari infeksi dan perdarahan melalui sistem imun dan pembekuan darah.

Pengaturan Suhu Tubuh

Sistem Sirkulasi:
- Darah berfungsi mendistribusikan panas yang dihasilkan oleh metabolisme ke seluruh tubuh.
Vasodilatasi dan Vasokonstriksi:
- Pembuluh darah melebar (vasodilatasi) untuk meningkatkan aliran darah ke kulit saat panas, dan menyempit (vasokonstriksi) saat dingin untuk mengurangi kehilangan panas.

Blood Composition

Blood is composed of plasma and blood cells.
Plasma accounts for 55% of blood volume and is mostly water with dissolved proteins, electrolytes, and other substances.
Blood cells make up 45% of blood volume and include red blood cells, white blood cells, and platelets.

Physical Properties of Blood

Blood is red due to hemoglobin, with a brighter red in arteries and a darker red in veins.
Blood is more viscous than water, influenced by cell and protein content.
Blood's pH is slightly basic, ranging from 7.35 to 7.45.
Its fluid nature allows for mobility and distribution within the body.

Blood Cell Types

Red Blood Cells (Erythrocytes):
- Transport oxygen from the lungs to the body and carbon dioxide back to the lungs.
- Shaped like biconcave discs, lacking a nucleus.
White Blood Cells (Leukocytes):
- Fight infections and play a role in the immune system.
- Include neutrophils, lymphocytes, monocytes, basophils, and eosinophils.
Platelets (Thrombocytes):
- Crucial for blood clotting to prevent bleeding.
- May originate from fragments of giant cells called megakaryocytes.

Functions of Blood

Transportation:
- Carries oxygen, carbon dioxide, nutrients, hormones, and waste products.
Regulation:
- Regulates body temperature, pH, and fluid balance.
Protection:
- Defends against infections and prevents bleeding through the immune system and blood clotting processes.

Regulation of Body Temperature

Circulatory system:
- Blood distributes heat generated by metabolism throughout the body.
Vasodilation and vasoconstriction:
- Blood vessels widen (vasodilate) to increase blood flow to the skin during heat, and narrow (vasoconstrict) during cold to reduce heat loss.

Blood Plasma Composition

Blood plasma is primarily composed of water (92%), with remaining components consisting of plasma proteins (7%) and other miscellaneous substances (1%).
Plasma proteins are a critical element of blood plasma, accounting for approximately 7% of its total volume.
Albumin, the most abundant plasma protein (55-60%), is synthesized in the liver and plays a vital role in maintaining blood osmotic pressure.
Globulins, comprising 35% of plasma proteins, are further categorized into alpha and beta globulins (synthesized in the liver) and gamma globulins (synthesized in lymphoid tissues). Alpha and beta globulins serve as carriers for lipids, hormones, and other substrates, while gamma globulins are crucial for immune function.
Fibrinogen, a vital protein for blood clotting, accounts for 4% of plasma proteins and is synthesized in the liver.
The miscellaneous substances found in blood plasma can be broadly categorized into organic and inorganic components, as well as dissolved gases.
Organic substances include glucose, amino acids, lipids, urea, and creatinine, all of which are essential for various metabolic processes.
Inorganic substances include minerals like phosphorus, magnesium, sodium chloride, and sodium bicarbonate, which play critical roles in maintaining electrolyte balance and pH.
Dissolved gases in blood plasma include oxygen and carbon dioxide, which are essential for respiration.

Description

This quiz covers the main components of blood, including plasma and different blood cells. It explores the physical properties of blood such as color, viscosity, and pH levels. Additionally, it includes detailed functions of red and white blood cells.