Refractory period of a muscle fibre in mammals is
0.8001 sec
0.002 sec
0.004 sec
0.005 sec
B.
0.002 sec
After an action potential initiates, the cardiac cell is unable to initiate another action potential for some duration of time (which is slightly shorter than the "true" action potential duration). This period of time is referred to as the refractory period, which is 250ms in duration and helps to protect the heart.
Assertion : Mast cells in the human body release excessive amounts of inflammatory chemicals which cause allergic reactions.
Reason : Allergens in the environment on reaching human body stimulate mast cells in certain individuals.
If both Assertion and Reason are true and the reason is the correct explanation of the assertion
If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
If Assertion is true statement but Reason is false
If both Assertion and Reason are false statements
Which of the following cytoplasmic granules contain histamine
Basophils
Acidophils
Eosinophils
Neutrophils
Squeezing of leucocytes out from the endothelium of capillaries to fight foreign agents. is known as
haemolysis
diapaedesis
phagocytosis
rouleaux
Which organ is considered as "Graveyard of RBC" where most of them are destroyed by macrophages
Red bone marrow
Spleen
Kidney
Intestine
Which of the following is not immunised by triple antigen ?
Typhoid
Tetanus
Diptheria
Whooping cough
Liver damage caused by excessive drinking of alcohol is called
hepatitis
dematitis
liver cirrhosis
liver diarrhoea
Only one of the following four ways through which AIDS can spread?
Infected needles and syringes
Through mosquito bites
Looking after AIDS patient
Shaking hands, coughing, sneezing, hugging
