18. body fluids and circulation

Chapter-18BODY FLUIDS AND

CIRCULATIONPresented by

B.PrabhakarPrincipal

JNV. Panchmahal (Guj)

• The food material which is digested in human alimentary canal will be transported to each & every part of the body. How Is this possible?

• By the circulatory system

– What is the organ that pumps the blood to different body parts

Water pumping station Blood pumping station

electrical impulse that originates in the pacemaker region (sinoatrial node) of the heart and initiates contractions of cardiac muscle

Conducting pathways of heart beat

SA Node Atria Atrial systole

AV Node

AV bundle

Right & left bundle branches

Purkinji branches

Ventricular muscles

Ventricular systole

Picture of Pacemaker After InstallationPicture of Pacemaker Before Installation

Heart BeatThe heart beats approximately 75 times per minute in an adult, at rest. However, this can change with exercise, emotional stress or disease. The resting heart rate also varies slightly with age, fitness and genetics.  At rest, the average heart rate (beats per minute) for infants is 100-120, for children aged 6-10 it is 80-100 for adults it is 60-80.  

Cardiac cycle

• The cardiac cycle is the sequence of events that occurs when the heart beats.

• It involves three steps• 1. Atrial systole• 2. Ventricular systole• 3. Joint diastole

Atrial systole

• Contraction of the auricles

• AV Valves will be opened

• Blood flows from auricles to ventricles

Ventricular systole

Contraction of the ventricles

Semilunar valves are opened

AV Valves are closed

Blood flows from ventricles to great arteries

JOINT DIASTOLE

• Auricles are receiving the blood from veins

• Opening of AV valves

• Blood comes from auricles to ventricles

• Closing of Semi lunar valves

Lup & Dup sounds

These Two sounds are together known as Heart beat

• Why there is a delay in the contraction of the Ventricles