Blood physiology

1
(No Transcript)
2
Blood physiology

• Andres Soosaarhttp//biomedicum.ut.ee/andress
• September 2003

3
Body water

• Adult person contains 60 of water, i.e. 70 kg
  weighting person 42 L
• 2/3 (28 l) of body water is intracellular fluid
  ja 1/3 (14 l) extracellular fluid
• 4/5 of extracellular fluid (11 l) is
  interstitial fluid and 1/5 (3 l ) the blood
  plasma
• Extracellular fluid also contains transcellular
  fluids cerebrospinal fluid (CSF), secretions of
  exocrine glands, etc
• Additional information http//www.uhmc.sunysb.edu
  /internalmed/nephro/webpages/Part_C.htm

4
Body fluids

• Glandular secretions, filtrates or composites of
  several simultaneously running processes
• Body fluids usually contain many components
• Body fluids have several functions based on their
  component properties.

5
Transfer of substances between different fluid
compartments

• Inside of the compartment concentration or
  pressure gradient
• Between compartments
• Extracellular space cells ordinary and
  osmotic diffusion
• Blood plasma interstitial space diffusion ja
  filtration (see the Starling equation by
  microcirculation or ultrafiltration in kidneys)

6
Estimation of the fluid compartment volume

• The most popular way to estimate those volumes is
  the dilution method, which takes into account a
  decrease of indicator substantce content in a
  new common volume.
• D2O as an indicator is good to measure total body
  water
• Inulin is good to measure volume of extracellular
  fluid compartmet, because it can penetrate
  capillaries but not cell membranes.
• Evans blue or radioactive 131I are good to
  measure blood plasma volume, because they well in
  circulation.

7

8
Daily water balance
9
Blood

• lt kr haima
• Hematolology and many other special terms
• lt ld sanguis
• Sanguinity
• Blood has a holy reputation, other body fluids do
  not serve so good attitudes

10
Blood circulation
11
Blood, general features

• Fluid connective tissue, amount 7-8 of body
  weight, 5 L
• 55 of blood volume is plasma and 45 cells
• Blood is a temporary home for its constituents,
  they have different ways and mechanisms to appear
  and leave blood.

12
Main functions of blood

• A giant transportation system
• Milieu or homeostatic funtion. Organism tries to
  keep blood composition stable and it help to hold
  interstitial environment stability
• Defense
• 3.1. Defense against blood loss or bleeding
  hemostasis, blood coagulation.
• 3.2. Defense against foreign biological material
  or immunological defense
• NB! To realise those functions blood has to be
  permanently circulating

13
Physical and chemical properties of blood

• Total blood density 1050-1060 g/L
• Plasma density 1024-1030 g/L
• Density of blood cells 1089-1097 g/L
• Osmotic pressure 7,4-7,6 atm
• Colloidosmotic or oncotic pressure 25-30 mmHg
  0,002 atm
• Freezing temperature -0,55 C
• Pindpinevus 67-77 mN/m
• Total relative viscosity 4,0-5,0
• Plasma relative viscosity 1,8

14
Hematocrit

• The ratio of blood cells to total blood volume

15
(No Transcript)
16
Blood plasma

• 90-92 water
• 6-8 plasma proteins
• 1-2 heterogenic group of low molecular weight
  substances

17
Plasma proteins

• Albumins (60), globuliins fibrinogen (40)
• Electrophoresis is classical method to separate
  proteins
• See biochemistry course

18
Albumins

• A homogeneous group of proteins produced by
  hepatocytes
• Molekular weight 70 000 D
• Functions nonspecific transport vehicle (also
  endogenous regulatory substances and drugs), main
  part of the colloidosmotic or oncotic pressure
  (25 mmHg), nutritional function

19
Globulins

• A heterogeneous group of proteins, produce by
  hepatocytes and plasma cells (antibodies)
• a-, ß- ja ?-globulins
• Functions transport (e.g. metals, lipids etc),
  clotting factors, antibodies agains antigenes.

20
The synthesis of plasma proteins

• 17 g albumins and 5 g globulins per day.
• The half life time of albumins is 10-15 days and
  globulins 5 days

21
The heterogeneous group of low molecular weight
substances (I)

• Members of this group have different structure,
  metabolisam and funtions, but their blood
  contents are relatively
• The initial, intermediate and final products of
  cell metabolism.
• Initial products glucose, amino acids, lipids,
  O2
• Intermediate products lactate
• Final products CO2, urea, uric acid, H2O

22
The heterogeneous group of low molecular weight
substances (II)

• Ions
• Cations Na, K, Ca2 jt
• Anions Cl-, HCO3-
• Protons (H) , pH7,35-7,40
• Their contents have held very constant which is
  important for body homeostasis
• Bioregulators hormones, transmitters etc
• Vitamines

23
Blood cells
24
Hematopoiesis
25
Main principles of hematopiesis

• All cells are originated from the pluripotent
  hematopoietic stem cells in red bone marrow
• Only mature blood cells can reach circulation
• When level of cell diffrentiation is higher, then
  their ability for mitosis is less. Mature blood
  cells are not able to divide
• Hematopoiesis needs very careful regulation to
  keep numbers of cells on stable level. It means
  that birth and death of cells must be balanced.

26
Hematopoiesis
27

• Programmed cell death is a normal physiological
  form of cell death that plays a key role both in
  the maintenance of adult tissues and in embryonic
  development. In adults, programmed cell death is
  responsible for balancing cell proliferation and
  maintaining constant cell numbers in tissues
  undergoing cell turnover. For example, about 5
  1011 blood cells are eliminated by programmed
  cell death daily in humans, balancing their
  continual production in the bone marrow.
• http//www.ncbi.nlm.nih.gov/books/bv.fcgi?toolboo
  kshelfcallbv.View..ShowSectionsearchtermcellr
  idcooper.section.2281

28
Red blood cells or erythrocytes

• Number is 4-5X1012 per liter
• Without nuclei, 1/3 of mass is hemoglobin
• Main function is to carry oxygen
• Clinically important are blood groups ABO and
  Rh systems

29
Erythrocytes
30
Hemoglobin

• Content in men 130-160 g/l, in women 120-160 g/l
• The Hb molecul contains 4 subunits, everyone
  with heme and globin

31
hemoglobin
32
heme
33
The ABO blood groups
34
(No Transcript)
35
Rhesus system

• A person is Rh (85) when he or she has on
  erythocytes D antigene, otherwise they are Rh-.
• Initially plasma doesnt have antibodies.
• Anti D antibodies are produced during
  sensibilization when D antigenes reach Rh-
  organism
• The RH system is important by haemotransfusion
  and mother-fetus Rh conflict

36
White blood cells or leucocytes

• Normal amount is 4-10 x 109 WBCs in 1 L blood.
• Main function immunological defense
• Heterogenous group of cells and exceptionally big
  number of WBCs are outside of circulation

37
Leucocyte formula

• Granulocytes
• Neutrophilic granulocytes 50-70
• Eosinophilic granulocytes 2-4
• Basophilic granulocytes 0,5-1
• B. Agranulocytes
• Lymphocytes 25-40 (T- and B-lymphocytes)
• Monocytes 4-8

38
Leucocytes
39
Classification of immunological defense mechanisms

• Unspecific mechanisms
• - humoral mechanisms the complement system -
  cellular mechanisms phagocytosis, very potent
  phagocytotic potential have neutrophils and
  monocytes
• Specific mechanisms - humoral mechanisms
  antibodies from plasma cells, antigene-antibody
  reaction - cellular mechanisms cytotoxic
  effect of T-lymphocytes