Diagram of Heart

What is Heart?

The heart is one of the principal human body organs that play a crucial role in the circulatory system as it is in charge of the circulation of blood in the body to facilitate aeration, supply nutrients and expulsion of metabolic wastes. Knowing the human heart is necessary for comprehending the simple vital and ruling life procedures and their importance in the clinical analysis and treatment of diseases. Appreciation of these ideas is essential, especially for individuals seeking to become healthcare professionals as they determine how the patient’s clinical signs present, how to handle the patients, and how to manage the patients’ conditions appropriately.

Functions of the Human Heart

The functions of the human heart are discussed below:

• The force and rate of the contractions of the heart helps to avoid inadequate blood flow and hence maintains blood pressure in the body..

• The circulatory system transports material such as glucose and amino acids in their developed forms to cells and embraces products such as carbon dioxide and urea.

• It also plays the role of an endocrine gland because it has the capability of secreting hormones that control other activities in the body. Atrial Natriuretic Factor (ANF) is released from the atria of the heart when blood volume and pressure are high.

Anatomy of Human Heart

The human heart is a muscular organ located in the chest that consists of four chambers and which pumps blood to and from the body. The anatomy of the human heart is discussed below:

Location And Size

• The human heart is situated in the mediastinum, more specifically in the thoracic cavity and in front of the lungs in coordination with the left side of the sternum axis.

• It is situated behind the sternum and above the diaphragm.

• An average human heart is as large as a fist and weighs between 250-350gm (9-12oz) in an adult.

Pericardium

• The overall structure in which the heart is surrounded is called the pericardium and is made up of two elementary structures, the fibrous pericardium and the serous pericardium.

• Serous pericardium is subdivided into the parietal and visceral layers.

• The pericardium acts as a shield to the heart, it holds the heart in position and acts as a constraint to the heart’s ventricular filling.

Chambers of the Heart

The heart's major parts include:

Atria

• Right Atrium: Gathers deoxygenated blood from the body and directs it to the right atrium of the heart through this S-shaped tube.

• Left Atrium: Recovers O2-rich blood from the lungs and pumps it into the left ventricle chamber.

Ventricles

• Right Ventricle: Pumps deoxygenated blood to the lungs for oxygenation increasing the level of oxygen in the bloodstream.

• Left Ventricle: Kills off low-oxygenated blood in the pulmonary veins and pumps oxygenated blood to all parts of the body.

Valves of the Human Heart

There are four valves that ensure unidirectional blood flow including the tricuspid, pulmonary, mitral, and aortic ones.

• Tricuspid Valve: It is located between the right atrium and right ventricle and this prevents the backflow of blood towards the atrium.

• Pulmonary Valve: It is located in between the right ventricle and the pulmonary artery; its function is to stop the blood from flowing back into the right ventricle.

• Mitral Valve: Located between the left atrium and left ventricle, its purpose is to avoid the backflow coming into the atrium.

• Aortic Valve: It is situated between the left ventricle and aorta and it closes to prevent backflow into the ventricle.

Layers of the Heart Wall

The heart wall is composed of three distinct layers:

• Epicardium: The outer layer, the outermost layer of very loose connective tissue that protects the target tissue.

• Myocardium: The second layer is a middle layer that is a thicker portion of the cardiac muscle including the layers that cause the contractions of the heart.

• Endocardium: They are grouped into four layers with layer one being the thinnest layer and the inner layer of the heart walls It is also found on the heart valves where it gives a smooth surface to the blood flow.

Disorders

Caring for our hearts is among the core values for the quality of life free from diseases, mishaps, and untimely deaths.

• Coronary Artery Disease (CAD) is a condition that affects the blood vessels called the coronary arteries leading into the heart muscle and which get blocked thus limiting the amount of blood that is delivered to the muscle.

• Heart attack happens when a section of the heart does not get an adequate amount of blood and nutrients hence becoming damaged.

• Heart failure is a state in which the heart is not able to pump blood as it should, hence accumulating fluids within the body.

Heart NEET MCQs (With Answers & Explanations)

Types of questions asked from this topic are:

• Anatomy of Human heart

• Disorders related to heart

Practice Questions for NEET

Q1. The human heart is derived from

1. Ectoderm

2. Mesoderm

3. Endoderm

4. Both 1 and 3

Correct answer: 2) Mesoderm

Explanation:

Early embryonic mesoderm gives rise to the heart through a region known as the cardiogenic mesoderm. Initially, the heart is shaped as two separate tubes which merge to create a single tubular structure. This tube undergoes folding and dividing processes to develop into the atria and ventricles, along with other heart components. The mesoderm is the primary origin of the heart's tissue and structure during embryonic development.

Hence, the correct answer is option 2) Mesoderm.

Q2. The right aortic arch is found in

1. Mammals

2. Mammals and reptiles

3. Birds

4. Amphibians

Correct answer: 2) Mammals and reptiles

Explanation:

The aortic arch, the arch of the aorta or the transverse aortic arch is a part of the aorta between the ascending and descending aorta. The arch travels backwards so that it ultimately runs to the left of the trachea.

The right-sided aortic arch is a rare anatomical variant in which the aortic arch is on the right side rather than on the left.

Hence, the correct answer is option 2) Mammals and reptiles.

Q3. The pericardium and the pericardial fluid help in

1. Protecting the heart from friction, and shocks and keeping it moist

2. Pumping the blood

3. Receiving the blood from various parts of the body

4. None of these

Correct answer: 1) Protecting the heart from friction, and shocks and keeping it moist

Explanation:

The pericardium is a double-layered membrane surrounding the heart, consisting of an outer fibrous layer and an inner serous layer. It protects the heart, anchors it within the chest cavity, and prevents overexpansion during blood volume changes. The pericardial fluid, found between the serous layers, acts as a lubricant to reduce friction as the heart beats. This fluid also helps distribute mechanical forces evenly across the heart. Together, the pericardium and pericardial fluid ensure the heart functions efficiently within a stable and protective environment.

Hence, the correct answer is option 1) Protecting the heart from friction, and shocks and keeping it moist.

Also Read:

• MCQs on Human Heart

• Components of Blood

• Functions of Blood

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