When we exercise our body parts, we are exercising our heart. Exercising increases the efficiency of contraction and output of the heart per beat. The heart of a physically fit person has an increase in blood output per heartbeat. Therefore, such an individual’s heart does not need to beat as fast during exercise. The demand on the heart output (blood pumped per minute) remains constant while resting. Therefore, the heart rate that is needed to maintain this output is less in a physically fit person.
During Rest: Blood Flow per Minute
Brain__ ½ pint (0.25 liter)
Skin__ 1 pint (0.5 liter)
Muscles__ 2 pints (1 liter)
Coronary arteries ½ pint (0.25 liter)
Digestive system /liver__ 3 pints (1.5 liters)
Kidneys 1 ½ pints (0.75 liter)
Your body makes enormous demands on your heart under different conditions. At rest, the total blood volume is pumped in about one minute.
During Exercise: Blood Flow per Minute
Brain__ ½ pint (0.25 liter)
Skin___ 4 pints (2 liters)
Muscles__ 24 pints (12 liters)
Coronary arteries __ 1 ½ pints (0.75 liter)
Digestive System /liver__ 1 pint (0.5 liter)
Kidneys__ 1 ½ pints (0.75 liter)
During strenuous exercise, there is a major change in the rate of blood flow through different parts of the body. This is brought about by changes in the degree of constriction of the small arteries.
Source of information:
American Medical Association
To put it simple, Anatomy is the structure of the body parts, and Physiology is how each of the body parts function. Let’s start with the inner parts of the body, called the systems which are the structure of the body parts, and after which, we will list the function of each system. The body is built like a sophisticated machine that only its creator completely understand its operations. After studying Anatomy and Physiology, I understood clearly what the writer of Psalm 139: 14
meant by his statement as noted below.
“I am fearfully and wonderfully made: marvelous are thy works; and that my soul knoweth right well.”
We can conclude that the body systems are an organized group of organs or cells related to each other. Where as each organ performs a specific or a certain function. Let’s begin with the Circulatory System.
The heart is a hollow muscular contractible organ that is the center of the Circulatory System. It is divided into 4 chambers. There are two upper champers with thin walls and two lower chambers with thick walls.
The two upper chambers are called the atria (left and right). The two lower chambers are called ventricles.
The two sides of the heart are separated by a strong muscular wall known as the septum. There are several valves in the heart. They are; Pulmonary, Tricuspid, Mitral, and Aortic. Each valve is lined with a membrane called Endocardium.
The muscle of the heart is called, Myocardium. Inside of this muscle, there are fibers that forms a network of branches called arteries and veins. The Aorta, is the largest artery in the body. It leads from the left ventricle and supplies the body with oxygenated blood.
The Pulmonary artery leads from the right ventricle. It divides into two branches that supply used blood to the right and left lungs.
Inside of the heart is lined with a smooth membrane called the Endocardium.
Pericardium is a tough membrane that is double-layered covering the heart as a bag.
There is a space between the two layers of Pericardium and Endocardium that contains a thin layer of fluid that lubricates and allows free movement of the heart muscle within the outer bag.
Being that the heart works hardest of all the muscles in the body, it has large energy requirements that need an adequate supply of fresh oxygenated blood to maintain its actions, as all of the muscles in the body do.
The heart has a network of branches which is its own system of arteries, capillaries, and veins exclusively for its own blood supply. This system is call the Coronary. The reason behind the name is due to the arteries surround the upper portion of the heart like a crown. The word “Corona” in Latin mean crown. Both the right and left Coronary arteries arise from the beginning of the Aorta. From that point, smaller branches pass into the heart. The left artery is divided into two large branches; Right Coronary artery and left Coronary artery.
1. The heart rate is approximate 70 beats per minute at rest for an adult.
2. During strenuous exercise, the heart rate can become 200 beats per minute.
3. The heart contracts about 100,000 times per day and more than 2.5 billion time in an average lifetime.
4. The heart pumps at least 9 pints (4.5 liters) of blood per minute.
5. The heart pumps about 1,500 gallons (6,000 liters) of blood daily.
6. The heart generates enough power in a day to drive a truck 20 miles.
The Body Systems:
1. circulatory – circulates body fluids. It includes both cardiovascular
(heart and blood vessels) and the lymphatic systems
2. digestive – is defined as the Alimentary Canal. This includes the mouth, teeth, tongue,
pharynx, esophagus, stomach, small and large intestines, accessory glands (salivary glands, liver, pancreas)
3. endocrine- ductless glands that produces an internal secretion discharged into the blood
or lymph. It is then circulated into all of the body parts.
4. hematopoietic _ has to do with the production and development of blood cells.
5. integumentary- consists of the skin, hair and nails and its appendages.
6. lymphatic-circulates lymph. It includes lymph vessels, lymphatic organs
(lymph nodes, ducts, tonsils, thymus, spleen)
7. muscular- includes all of the muscles (smooth, cardiac, striated, and skeletal)
8. nervous – consists of the brain, ganglia, spinal cord and nerves
9. reproductive-includes the gonads, their structure association and ducts.
10. respiratory- consists of the air passageway and organs (nasal cavities, oral cavity
pharynx, trachea, and lungs (bronchi, bronchioles, alveolar ducts, and alveoli.
11. skeletal- The bony framework of the body.
12. urinary – Secreting or containing urine.
___ Ellen J. Barrier
Source for diagram of the heart:
The American Medical Association