Mechanism of circulatory system, Biology

MECHANISM -

1.      AURICULAR SYSTOLE -

First of all from complete body impure blood comes in R.A. by superior and inferior vena cava or pre and post cavals.

Pure blood comes in L.A. by pulmonary veins.

Both auricles contract, so their blood comes in respective ventricles by tricuspid and bicuspid valve.

2.      VENTRICULAR SYSTOLE -

Both ventricles contract.

Tricuspid & bicuspid valves are closed.

First sound of lubb is heard which is slow and for long time.

Blood enters into pulmonary aorta and carotico systemic arch, so semilunar valves are closed, second sound of dup is heard which is loud and for short period.

Cardiac out put depends on coming out of blood from L.V. only.

3.      HEART DIASTOLE -

Volume of heart starts to increase.

By sucking pressure blood comes in auricles by veins.

688_heart structure.png

144_circulatory system.png

4.      HEART BEAT -

The spontaneous and rhythmic contraction & relaxation of heart to pump out and receive blood is called heart beat.

So systole and diastole are collectively known as heart beat.

Started from S.A. node which stimulate A.V. node, A.V. node with the help of Bundle of His and purkenje fibres stimulate ventricles.

Heart beat is of 2 types -

(i) Neurogenic - Controled by nerve e.g. lower animals - Arthropoda, Mollusca. (ii) Myogenic - By own muscles. e.g. Vartebrates, Anopheles.

In rabbit and man it is myogenic. Neurogenic part is less. It is under control of upper part of medulla.

Sympathatic accelerate heart beat. Pera sympathatic or vagal inhibit heart beat. Adrenal, thyroxine increases heart beat.

Heart beat is - 210/ minute in rabbit. 72 / minute in man. 500 / minute in mice. 800 / minute in shrew. 25 / minute in elephant. 8 / minute in belenoptera.

In left ventricle pressure is 115-125 mm Hg. In right ventricle pressure is 25-30 mm Hg.

In man cardiac cycle is of 0.8 sec.

Heart beat is below normal is brachae cardia. Heart beat is above normal is tachae cardia.

1512_heart beat.png

222_heart beat1.png

Posted Date: 10/2/2012 2:52:16 AM | Location : United States







Related Discussions:- Mechanism of circulatory system, Assignment Help, Ask Question on Mechanism of circulatory system, Get Answer, Expert's Help, Mechanism of circulatory system Discussions

Write discussion on Mechanism of circulatory system
Your posts are moderated
Related Questions
Etiology -Although this approach less desirable, it is useful, short-term option if the etiology of the condition remains unknown. - The patient must inform about what will

MENSTRUAL CYCLE - It occurs only in Primates. Start at the age of 13 yrs. upto menopouse. During this period, generally one egg is released every 28 dyas or so alternately f

Which are the germ layers present in cnidarians? Which tissues of the animal do they originate? These beings there ectoderm and endoderm, two germ layers. Animals with only two


P ANCREAS It is an elongated, leaf like, yellowish or orangish in colour. Lying partly behind stomach. 16 cm long, 2.5 cm. wide & weight about 60 gms. It consists of hea

The structure of leaves Borrow a microscope from another school, a doctor, or a hospital. Study the under- side of leaves and locate the breathing pores or stomata with the two

Q. What are the modes of transmission, main signs and symptoms and treatments of hepatitis C? The Hepatitis C is caused by the RNA virus and transmitted through blood (like hep

Q. Can you explain Abdominal Aortography? The abdominal aorta starts at the level of diaphragm (T12). Here too, prior to performing an abdominal aortogram, a sound knowledge of

Q. Pathophysiology of Cardiac tamponade? Progressive increase in pericardial fluid results in progressive increase in intrapericardial pressure, till a critical volume is reach

Q. How do zygote and fecundation formation occur in these plants? Do these processes depend on water? The microsporangia in the male strobile rupture at the right time of the y