Electrocardiogram and Disorders of Heart

Electrocardiogram
Electrocardiograms (ECGs) are a simple way of checking the electrical activity and rhythm of the heart. Each time your heart beats, there are sensors attached to your skin that detect the electrical signals it produces. Doctors study these signals to determine whether they are abnormal, using a machine that records them. ECGs are requested by doctors who suspect that you might ha…

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Regulation of Blood Pressure and Pulse

Regulation of blood pressure
To regulate systemic blood pressure, two mechanisms are needed: intrinsic mechanisms and nervous mechanisms. In the nervous mechanisms, the nervous system is involved, while in the intrinsic mechanisms, nerve impulses are not required.

Intrinsic mechanism
"Intrinsic," as the term implies, is what happens within certain organs. As the first of these organs, the …

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Heart Regulation by Autonomic Nervous System, Cardiac Output and Cardiac Cycle

Heart regulation by the autonomic nervous system
Sinoatrial Node (SAN) - the pulse generator of the heart muscle - is responsible for establishing the heart rate. Without influences, it can be assumed that the SAN pacing rate is 100 bpm; however, the heart rate and cardiac output will vary based on individual requirements. A nerve impulse or hormone can influence the speed with which the SAN produ…

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Elements of Conduction System of Heart and Heartbeat

Elements of the conduction system of the heart
Hearts are characterized by an autorhythmic ability, in which they generate electricity and beat on their own without being governed by nervous or hormonal input, i.e. they are not dependent on external mechanisms for every heartbeat. Although the intrinsic heart rate increases and decreases with sympathetic and parasympathetic nerve fibers respective…

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Structure and Functions of Artery, Vein and Capillaries

Artery
Structure
During a heartbeat, blood travels from the heart to capillaries via arterioles, which are smaller arteries. Arteries are divided into three layers (or tunics) of tissue, each of which has a specific function.

A vessel's only part in contact with blood is its innermost layer, the tunica intima. It is also known as endothelium, composed solely of simple squamous epithelium cells.…

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Blood Circulation and Blood Vessels

Blood circulation
Blood circulates continuously around the body, but its efficient description can be divided into two parts:
1. Pulmonary circulation
2. Systemic or general circulation

The right ventricle is responsible for pulmonary circulation, whereas the left ventricle is responsible for systemic circulation.

1. Pulmonary circulation
Blood from the right ventricle of the heart enters the left atri…

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Anatomy of Heart

A heart is a hollow muscular organ roughly shaped like a cone. It measures about 10 centimeters in length, about the size of someone's fist. In women, it weighs about 225 g, while in men, it weighs more.

The heart has its base in the mediastinum that is present in the thoracic cavity (It is present in between two lungs). There is a base and an apex above it, and it lies obliquely, slightly to …

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Structure and Functions of Nose & Tongue and Their Disorders

Structure and function of the tongue
Structure
There is a muscular organ inside the mouth called the tongue. The mucosa is the pink, moist tissue covering the tongue. A tongue's rough texture is caused by the presence of papillae, which are small bumps on its surface. On the surfaces of the papillae, there are thousands of taste buds. Several nerve-like cells are found in taste buds and are con…

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Structure and Functions of Eye & Ear and their Disorders

Structure of an eye
Light rays penetrating your eye are focused on the retina's receptors by an ocular refracting system.

Eyelids and lacrimal glands
A skeletal muscle is located at the base of each eyelid, which controls how the eyelids close and cover the eyeball. It is made possible by the eyelashes that line the eyelids that keep dust from entering the eyes. In addition to covering the whit…

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Origin and Functions of Spinal and Cranial Nerves

Spinal nerves
Nerves in the spinal cord send signals to the muscles, bones, and internal organs of the body via peripheral nerves. There are different spinal nerves for different parts of the body.

A spinal nerve is formed when sensory and motor nerve roots merge together to form a relatively large nerve. The nerve roots emerge directly from the spinal cord both ways in both directions, the motor r…

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Structure and Functions of Sympathetic and Parasympathetic Nervous System

The autonomic nervous system (ANS) provides motor functions for some cranial and spinal nerves, which makes it part of the peripheral nervous system. An autonomic nervous system is comprised of visceral motor neurons that send signals to smooth muscle, cardiac muscle, and glands plus, Muscles and glands possess these visceral effectors, with muscles either contracting or relaxing, and glands eith…

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Classification of Peripheral Nervous System

The peripheral nervous system consists of the following components: The spine has 31 pairs of nerves, the cranium has 12 pairs of nerves, and the autonomic nervous system has 12 pairs of nerves. The peripheral nervous system is mainly made up of sensory nerves that send afferent signals from sensory organs to the brain, and motor nerves that send efferent signals to effector organs, e.g., skelet…

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Lymphatic Vessels, Lymph Circulation and Functions of Lymphatic System

Lymph
Despite its different composition from plasma, lymphoid fluid is a clear, watery fluid with comparable characteristics to interstitial fluid, except for plasma proteins. Proteins from the plasma are transported back to the bloodstream by the lymphatic system. Larger particles, including bacteria, or cells from damaged tissues are also taken away by the lymph nodes, which filter them out and …

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