Biology 2nd Half Test

Which one of the following statements best describes the function of sino atrial node?

• It sends out electrical impulses to atrial muscles causing both atria to contract

• It consists of small number of diffusely oriented cardiac fibers

• It sends out electrical impulses to ventricular muscles causing both ventricles to contract

• It is present at upper end of left atrium

The heart beat cycle starts when electrical impulses are generated from?

• AV node

• SV node

• SA node

• PQ node

One complete heart beat consists of one systole and one diastole and lasts for about?

• 0.8 sec

• 0.4 sec

• 0.2 sec

• 0.5 sec

The flaps of tricuspid valves are attached to muscular extensions of right ventricle known as?

• Smooth muscles

• Papillary muscles

• Inter costal muscles

• Skeletal muscles

Right atrium is separated from right ventricle by?

• Bicuspid valve

• Semilunar valves

• Tricuspid valve

• Interatrial septum

Diastolic blood pressure is?

• 120mmHg

• 80mmHg

• Mid point of both these values

• None of these

Which of the following condition will reduce the flow of blood?

• Vasodilation

• Vasoconstriction

• Vasoconstant

• None of these will reduce blood flow

Sertoli  cells are found in?

• Pancreas and secrete cholecystokinin

• Ovaries and secrete progesterone

• Adrenal cortex and secrete adrenalin

• Seminiferous tubules and provide nutrition to germ cells

Which of the following is just unpaired?

• Testes

• Prostate

• Bulbo urethral gland

• Cowpers gland

What is the location of interstitial cells in testes?

• Inside the seminiferous tubules

• Between the seminiferous tubules

• Among the germinal epithelial cells

• Around the testes