Translate

LubDup sound of the heart



The “LubDub” sound of the heartbeat is caused by the closing of the heart’s valves.
Lub Sound is caused by the closing of the A-V valves (tricuspid, bicuspid). Dub Sound is caused by the closing of the semilunar valves. 

The heart is caused to beat regularly by a structure called the Sinoatrial Node (S - A node) or the PACEMAKER.

 

Control of heart beat

The heart is caused to beat regularly by a structure called the Sinoatrial Node (S - A node) or the PACEMAKER. 

How it happens

An electrical impulse from the brain is received by the S-A node (pacemaker) in the right atrium. The SA node sends a signal to the A-V
node (atrioventricular node) in the right ventricle.  This electrical impulse causes the heart (ventricles) to contract.
The pacemaker controls the heartbeat for a human from the time they are born until they die or the pacemaker gives out. 

What happens if the pacemaker gives out?

The person’s heart will stop beating because the ventricles are not receiving electrical impulses causing them to contract. A person whose pacemaker gives out can get an artificial one inserted into their chest.

Control of the heart rate

The heart rate (speed) at which the heart beats is controlled by two nerves. Medulla Oblongata (Sometimes called the Cardioaccelerator nerve): Nerve in the brain that causes the heart to speed up when needed. Vagus nerve: Nerve in the brain that causes the heart to slow down when needed. The medulla sends a message to the SA node to cause an impulse to be sent to the AV node causing the heart to contract more or less in an attempt to set the heart rate.

How is blood pressure measured?  

Blood pressure is measured using a blood pressure cuff or Sphygmomanometer. It measures the pressure in an artery while the heart is contracting (systolic pressure) and the pressure while the heart is resting (diastolic pressure).  A simple fraction is calculated using the following formula:
Blood Pressure =    Systolic Pressure
                             Diastolic Pressure

For example: A person with a pressure 120/80 means that the person has a pressure of 120 while the heart is contracting and 80 when the heart is relaxing. P.S.   Normal blood pressure is different for each person but is usually around 120/80. 

Divisions of circulation

There are two types of circulation that happen in the human organism: Pulmonary Circulation and Systemic circulation



PULMONARY CIRCULATION: This is circulation of blood from the heart and to the lungs and vice versa. This type of circulation adds oxygen and removes carbon dioxide from the blood.

 SYSTEMIC CIRCULATION: This is circulation of blood between the heart and the body. This type of circulation brings blood to the cells and from the cells. Systemic circulation has three subdivisions. They are: Coronary Circulation, Hepatic-portal circulation and renal circulation
Coronary circulation is circulation that supplies blood and nutrients directly to the heart muscle.

Hepatic - portal circulation is circulation that carries nutrients and blood from the digestive system to the liver to maintain glucose levels in the body.

Renal Circulation is circulation that carries blood to and from the kidneys so that nitrogenous wastes may be removed from the blood and excreted by the kidneys.

              


LubDup sound of the heart LubDup sound of the heart Reviewed by gafacom on October 29, 2019 Rating: 5

No comments:

Powered by Blogger.