Skip to main content

What happens in you in a Heartbeat?



Today we'll study something interesting. We want to peep into our hearts and see what really happens each time we feel our hearts beating. It is called the CARDIAC OR HEART CYCLE.

--------------------------------------------------------------------
The Cardiac Cycle.

Describes all the activities of the heart through one complete heartbeat; that is through one contraction and relaxation of the ventricles and atria.

Phases of the Cardiac Cycle.
The cardiac cycle is majorly divided into two known as the systole and diastole.

The Diastole is the phase where the atria and ventricles are in a relaxed mode.
- During this phase blood is pumped into both straight from the large veins of systemic circulation; ( superior and inferior Vena Cava) and the pulmonary veins.

- Blood fills the ventricles passively as both the mitral and tricuspid valves that are at located between the ventricles and atria are lifted.

- The left atrium receives oxygenated blood from the pulmonary veins while the right receives deoxygenated from the superior and inferior vena cava.

- At the end stage of the diastolic phase the atria begin to contract and propel additional blood into the respective ventricles.


The Systole.
This phase refers to the period during which the ventricles contract and eject blood into the aorta for circulation and pulmonary arteries for oxygenation respectively.

- This phase begins with the closure of the valves between the atria and ventricles and that closure is what is responsible for the first heart sound you hear.

The heart beats in a 'lub-dub' fashion, the 'lub' being the first heart sound and the second which is happens as a result of the closure of the aortic and pulmonary valves following the pumping of blood.

All these activities take place in just a heartbeat.
So each time you feel your heart beat. Just remember that is what happens during those split seconds.

Credits:
Science direct.com
The physiologist.org
Cliff notes.com
Lumenlearning.com
cvphysiology.com




Comments

Popular posts from this blog

How much do you know about hernia?

Hello friends. How has the week been for you? Today we'll be looking at something we are familiar with in terms of the name but hardly know what it is and what is responsible for it. I'm talking about hernia. I remember discussing with someone not long ago and he was completely ignorant on what this hernia was all about and that really inspired me to write on it. Hope you enjoy reading as you get informed. ......……..…................................................................. What is Hernia? Hernia simply put, is a condition where there is a weakness in a surrounding muscle or tissue which causes the surrounding organs, mostly the gut to push through it. It could also mean the abnormal be protrusion of tissue or organ such as the bowel through the wall of the cavity in which it normally resides. Hernias are most common in the abdomen but can occur in the upper thigh and groin areas. Hernias can range from being asymptotic to life threatening dependi

Things to note about Constipation.

Today we'll look at a condition that is common to most of us, constipation. ---- ----- ----- ------ ------ -------- ------- ------- --------- --- What is constipation? Constipation is condition of the digestive system where an individual faces infrequent bowel evacuation, or where the faeces are hard and small or where passage of stool is hard and painful. This occurs because the colon has absorbed too much water from the food in the colon ( large intestine). Causes of Constipation. - Lack of dietary fibre in food. - Physical inactivity. - Dehydration. -Medications eg narcotics, anticonvulsants, antidepressants. -Consumption of diary products by others. - Over use of laxatives. - Pregnancy. - Resisting the urge to poop. - An underactive thyroid. - Problems with nerves and muscles of the digestive system. - Ageing. Symptoms. - Few bowel movements of less than three times a week. - Hard or small stools. - Bloating. - A feeling that everything didn'

What to do when you have 'PINK EYE'( Conjunctivitis).

Conjuctivitis popularly known as the 'Pink eye' or 'apollo' as it is popularly called in Nigeria is an infection of the white part of the eye ball.  This infection is most times caused by bacteria, viruses and allergies.  The most common type is the viral infection. According to the University College of Medicine, Ibadan, Nigeria, about 1.5 million cases of conjuctivitis are seen yearly.  MODE OF SPREAD. Conjuctivitis can be extremely contagious and can be spread through the following ways; * Through skin to skin contact eg handshake with an infected person. * By touching a surface contaminated with secretions from an infected eye.  *Almost all age groups can be affected by this ailment but the most vulnerable group are children between the age of 3-13years.  * Though contagious it rarely damages the eye especially when treated on time. SYMPTOMS OF 'PINK EYE'. -  Redness. - Thick yellowish discharge that c