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BODY FLUIDS & CIRCULATION - Coggle Diagram
BODY FLUIDS & CIRCULATION
Components of Blood
Plasma
Straw coloured
Viscous
Constitutes 55% of blood volume
90-92% is water
6-8% is made of proteins
Main proteins are: Fibrinogen, Globulins, Albumins
Fibrinogen
: Prevents coagulation of blood
Globulins
: Defend against foreign microbes
Albumins
: Prevent plasma leakage into interstitial spaces and hence, maintain the osmotic balance of blood
Minerals like Ca++, Mg++, HCO3-, Cl-
Serum is plasma without the clotting factors
Formed Elements
Erythrocytes
Most abundant
5-5.5 million per cubic mm
Formed in red bone marrow
Devoid of nucleus
Biconcave in shape
Red coloured due to presence of Haemoglobin
Life span of 120 days
Destroyed in Spleen
Leucocytes
Colourless due to absence of Haemoglobin
Nucleated
Less in number (6000-8000 per cubic mm)
Short life span (around 12-14 days)
Granulocytes
: Have grain-like structures in cytoplasm
Neutrophil
(most abundant)
Phagocytic cell which destroys foreign microbes
Easinophil
Resist infections
Associated with allergic reactions
Basophil
(least abundant)
Secrete histamine, serotonin, heparin
Involved in inflammatory reactions
Agranulocytes
: Don't have grain-like structures in cytoplasm
Lymphocytes
B and T lymphocytes
B lymphocyte stimulates direct immune response while T lymphocyte produces antibodies and helps in defense mechanism
Monocytes
Phagocytic cell which destroys foreign microbes
Thrombocytes
Formed by Megakaryocytes
Help in coagulation of blood
Irregular in shape
Blood Grouping Systems
ABO Grouping
Based on presence or absence of A and B antigens on RBC's
A, B, AB and O blood groups
O is the universal donor (both A and B antibodies and no antigens)
AB is the universal recipient (both A and B antigens and antibodies)
Blood transfusion of incompatible blood group results in RBC clumping (destruction of RBC's)
Rh Grouping
Based on presence or absence of Rhesus (Rh) antigen
Rh negative (presence of Rh) and Rh positive (absence of Rh)
Rh negative mother with Rh positive foetus leads to
Erythroblastosis Foetalis
in subsequent pregnancies.
Erythroblastosis Foetalis
Rh+ foetus blood is exposed to Rh- maternal blood
Maternal blood prepares antibodies against Rh antigens
The Rh antibodies, during future pregnancies leak to the Rh+ foetal blood leading to clumping of foetal RBC's
This causes severe anaemia and jaundice
This is prevented by administering anti-Rh injections to the mother after her first pregnancy
Coagulation of Blood
At the site of injury, clumped platelets and tissues release
Thromboplastin
Thromboplastin
forms
Thrombokinase
by activating
Prothrombinase
Thrombokinase
activates
Prothrombin
to
Thrombin
. This is catalysed by
Ca2+
Thrombin
converts
Fibrinogen
(soluble) to
Fibrin
(insoluble)
Fibrin
traps
dead and damaged elements
forming a
coagulum
(clot)
Lymph
Interstitial fluid
Escapes through walls of capillaries
Has similar composition to that of plasma
Contains water & lymphocytes from blood
Drains into major veins from the lymphatic vessels
Lymphatic System
Capillaries: Contain epithelial cells
Lymphoid cells: Defend against foreign particles
Lymphoid macrophages: Destroy foreign antigens by activating T-lymphocytes
Functions
Helps in immune responses
Important carrier for nutrients, hormones, etc
Fats are absorbed through lymph in the lacteals present in the intestinal villi
Circulatory Pathways
Open Circulatory System
Present in Arthropods & Molluscs
Blood passes through large vessels into open spaces/body cavities called
sinuses
Closed Circulatory System
Present in Annelids & Chordates
Heart is circulated through a closed network of blood vessels
Fishes
have a
2 chambered heart
with an atrium and ventricle
Single Circulation
: Blood passes through the heart only once during one cardiac cycle
Amphibians
&
Reptiles
(except crocodiles) have a
3-chambered heart
with 2 atria and 1 ventricle
Incomplete Double Circulation
: Venous & arterial blood get mixed up in the single ventricle
Crocodiles, Mammals & Birds
have a
4 chambered heart
with 2 atria and 2 ventricles
Complete Double Circulation
: The venous & arterial blood are pumped separately by the respective atria and ventricles