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8 08, 2018

Types of Blood Vessels – Structure And Function of Arteries, Arte¬rioles, Capillaries, Venules, And Veins

By Dr. Joseph H Volker | 2018-08-30T09:18:03+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

There are three basic types of blood vessels: arteries, capillaries, and veins. They form a closed system of tubes that carry blood from the heart to the tissue cells and back to the heart. Comparison of Arteries, Capillaries, And Veins Type of Vessel Function Structure Arteries Carry blood from the heart to the capillaries Control [...]

8 08, 2018

Pain and Reflex Pathways of The Heart

By Dr. Joseph H Volker | 2018-08-30T09:38:31+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

Pain Pathways The sensations of pain arising because of the ischemia of the heart go through the sympathetic fibres to reach the upper 5 thoracic spinal segments (T1-T5) via cervical andthoracic sympathetic ganglia and follow the usual somatosensory pathway to the central nervous system. The pain fibres pass from thoracic ganglia to the spinal nerves [...]

8 08, 2018

Cardiac Electrophysiology

By Dr. Joseph H Volker | 2018-08-30T08:51:08+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

Cardiac tissue has distinctive electrical characteristics. Intercalated disks allow action potentials to pass to adjacent cells. Myocardial cells can spontaneously depolarize, a process called automaticity. This spontaneous depolarization generates a pacemaker potential or prepotential and is caused by decreasing K+ and increasing Ca++ and Na+ permeability. This occurs at the fastest rate in sinoatrial (SA) [...]

8 08, 2018

Mechanism of Blood Circulation – Blood Flow

By Dr. Joseph H Volker | 2018-08-30T09:19:49+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

Blood circulates because of differences in blood pressure. Blood flows from areas of higher pressure to areas of lower pressure. Blood pressure is greatest in the ventricles and lowest in the atria. Contraction of the ventricles creates the blood pressure that propels the blood through the arteries. However, the pressure declines as the arteries branch [...]

8 08, 2018

Action of the Heart – Cardiac Cycle

By Dr. Joseph H Volker | 2018-09-11T09:44:41+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

The heart is actually a double sided muscular pump. The right side pumps blood to the lungs and left side pumps blood to all the parts of the body. Every pump is created from an atrium and a ventricle. Cardiac Cycle The contraction of heart followed by relaxation is 1 cardiac cycle. The [...]

8 08, 2018

Myocardial Physiology

By Dr. Joseph H Volker | 2018-08-30T08:57:08+00:00 August 8th, 2018|Cardiovascular System, General, Physiology|0 Comments

Myocardial cells have distinctive anatomic and physiologic characteristics. Under a microscope, striations are visible owing to the arrangement of actin and myosin as in skeletal muscle. T tubules increase the contact area of the cell membrane and extracellular fluid space. At rest, cardiac muscle obtains 99% of its energy from aerobic metabolism. Myocardial cells have [...]

8 08, 2018

Blood Pressure – Systolic And Diastolic Blood Pressure And Its Regulation

By Dr. Joseph H Volker | 2018-08-30T09:21:01+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

The term blood pressure, the force of blood against the wall of the blood vessels, usually refers to arterial blood pressure in the systemic circuit-in the aorta and its branches. Arterial blood pressure is greatest during ventricular contraction (systole) as blood is pumped into the aorta and its branches. This pressure is called the systolic [...]

8 08, 2018

Pulmonary Circuit

By Dr. Joseph H Volker | 2018-08-30T10:54:03+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

The cardiovascular system is categorized into the pulmonary circuit as well as the systemic circuit. The blood among the heart and the lungs is transported by pulmonary circuit, which is made up of arteries and veins. The circuit starts at the right ventricle and terminates at the left atrium. The arteries of the systemic circuit [...]

8 08, 2018

Disorders of The Blood – RBC, WBC And Hemostasis

By Dr. Joseph H Volker | 2018-08-30T08:58:14+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

Blood disorders may be grouped as red blood cell disorders, white blood cell disorders, and disorders of hemostasis. Normal values for common blood tests are located on the inside back cover. Blood tests are valuable in diagnosing a variety of disorders. Note that many of the disorders described below are associated with abnormal values of [...]

8 08, 2018

Circulation Pathways- Systemic And Pulmonary Circuits.

By Dr. Joseph H Volker | 2018-08-30T09:22:42+00:00 August 8th, 2018|Cardiovascular System, Physiology|0 Comments

The heart is a double pump that serves two distinct circulation pathways: the pulmonary and systemic circuits. Pulmonary Circuit The pulmonary circuit carries deoxygenated blood to the lungs, where oxygen and carbon dioxide are exchanged between the blood and the air in the lungs. The right ventricle pumps deoxygenated blood into the pulmonary trunk, a [...]