Human Physiology and Immunology

 Gamma globulins are antibodies produced in blood, and not in liver.

Albumin is the most abundant plasma protein.

 T  lymphocytes are a type of white blood cells involved in cell mediated immunity.

 Antibodies belong to immunoglobulins which are glycoproteins in blood plasma used in immunity and contain oligosacharride chains.

 Immature B cells which are never exposed to an antigen express only IgM antibody isotype  but express IgD too,when they are mature.

It is the only antibody isotype which can cross the placenta of the foetus to provide passive immunity.

 IgE antibodies bind to allergens and trigger release of histamine from mast cells and thus gets involved in allergies.

 IgE isotype is found only in mammals and is involved in allergies.

 Presence of rhesus factor in a person's Rh blood group system is denoted by the presence of D antigen on red blood cells surface.

 Alloimmune condition refers to a condition when the body gains immunity from another individual of the same species. In erythroblastocis foetalis, some  maternal antibodies pass through placenta and attack red blood cells of the foetus causing anaemia and other life threatening symptoms in the newborn.

 Menarche refers to the first menstrual cycle in the life of a female and is not a phase in menstrual cycle.

 Narrowing of heart vessels may occur due to clogging by cholesterol or other reasons and abnormal narrowing is called stenosis.

 Accumulation of lipids in arteries causes reduced blood supply to the heart due to the formation of  atheromatous plaques [lipids,macrophages] and this condition may give rise to heart attack and  is termed as atherosclerotic heart disease.

 Amniotic sac is protected to the inner side by a membrane called amnion and towards the outer side is protected by a membrane called chorion.

 This hormone is secreted by the trophoblast cells of the embryo, so its presence confirms the presence of a foetus and thus it imples that pregnancy has set in.

 Vitelline duct also called umbilical duct appears in human embryo at the end of fourth week and it connects the yolk sac of embryo to the mid-gut.

 Gastrula stage follows after blastula and during this stage the cells of blastula develop into a tri-laminar structure and the three germ layers namely ectoderm,mesoderm and endoderm develop.

 Many types of cell movements occur during gastrula stage of human embryo and ingression is one such stage when cells leave an epithelial sheet to become freely migrating mesenchyme cells.

Mammalian zygote undergoes total cleavage as yolk is less in amount and thus holoblastic .

 Cartilage is formed from condensed mesenchyme tissue during organogenesis and this is called chondrogenesis.

Inner cell mass of blastocyst  or emryoblast lies as a mass of cells in blastocyst  and give rise to embryonic stem cells and this part is used in stem cell research.

 Archenteron is formed during gastrulation and is a cavity formed by invagination of cells of vegetal pole of blastula and at the end of gastrulation develops into the digestive tube and thus is considered as the primitive gut.

 Foramen ovale ia a passage between the two atria in foetus through which blood passes and it closes to form fossa ovalis in adult heart.

 Cells lose their totipotency during this stage which means that cell differentiation initiates leading to development of organs eventually.

 Haldane effect named after the scientist who first described it and it states that deoxygenated haemoglobin has more affinity for carbon-di-oxide than oxygenated haemoglobin.