BMS100 Lecture Notes - Lecture 11: Internal Bleeding, Macrophage, Malaria
BMS 100- Lecture 11
Introduction to Blood
Blood Composition
• Plasma
• Formed elements
• Erythrocytes (red blood cells, or RBCs)
• Leukocytes (white blood cells, or WBCs)
• Platelets
Physical Characteristics and Volume
• Properties
– Sticky, opaque fluid
– Colour scarlet to dark red
– pH 7.35–7.45
– 38C
– ~8% of body weight
Average volume: 5–6 L for males, and 4–5 L for females
Functions of blood
1. Distribution of:
– O2 and nutrients to body cells
– Metabolic wastes
– Hormones
2. Regulation of:
– Body temperature by absorbing and distributing heat
– Normal pH using buffers
3. Protection against:
– Blood loss
– Infection
Blood Plasma
• 90% water
• Proteins are mostly produced by the liver
– 60% albumin
– 36% globulins
– 4% fibrinogen
• Nitrogenous by-products
– lactic acid, urea, creatinine
• Nutrients
• Electrolytes
• Respiratory gases
• Hormones
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Formed Elements
• Only WBCs are complete cells
• RBCs have no nuclei or organelles
• Platelets are cell fragments
• Most formed elements survive in the bloodstream for only a few days
• Most blood cells originate in bone marrow and do not divide
• Blood cell formation is Hematopoiesis (hemopoiesis)
– Occurs in red bone marrow of axial skeleton, girdles and proximal epiphyses
of humerus and femur
Erythrocytes
• Structural characteristics contribute to gas transport
– Biconcave shape—huge surface area relative to volume
– >97% hemoglobin (not counting water)
– No mitochondria
– ATP production is anaerobic
Erythrocyte Function
• Hemoglobin structure
– Protein globin: two alpha and two beta chains
– Heme pigment bonded to each globin chain
• Iron atom in each heme can bind to one O2 molecule
• Each Hb molecule can transport four O2
• 2x Alpha + 2x Beta chains = 4x Iron atoms = 4 O2 molecules
Erythropoiesis
• Erythropoiesis: red blood cell production
– A hemocytoblast is transformed into a proerythroblast
Platel
Neutrop
Lypho
Erythro
Moo
Ste
Heoytol
Proerythr
o-last
Early
erythrol
Late
erythro
Norol
Phase
Rioso
Phase
Heogloi
Phase
Ejetio
Retiu
loyte
Erythr
oyte
Coitt
ed
Developetal
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find more resources at oneclass.com
Document Summary
Blood composition: plasma, formed elements, erythrocytes (red blood cells, or rbcs) Leukocytes (white blood cells, or wbcs: platelets. Average volume: 5 6 l for males, and 4 5 l for females. Body temperature by absorbing and distributing heat. Normal ph using buffers: protection against: Blood plasma: 90% water, proteins are mostly produced by the liver. 4% fibrinogen: nitrogenous by-products lactic acid, urea, creatinine, nutrients, electrolytes, respiratory gases, hormones. Occurs in red bone marrow of axial skeleton, girdles and proximal epiphyses of humerus and femur. Ly(cid:373)pho: structural characteristics contribute to gas transport. Biconcave shape huge surface area relative to volume. Iron atom in each heme can bind to one o2 molecule: each hb molecule can transport four o2, 2x alpha + 2x beta chains = 4x iron atoms = 4 o2 molecules. A hemocytoblast is transformed into a proerythroblast. Regulation of erythropoiesis: balance between rbc production and destruction depends on.
