PACEMAKER(CONTINUE)

PACEMAKER(CONTINUE)

PACEMAKER

FUNCTIONS OF BLOOD

Functions of Blood:

You take a last, deep, calming breath before plunging into a
dark, vessel-like tube. The water transports you down the slide
much like the way blood carries substances to all parts of your
body. Blood has four important functions.
1. Blood carries oxygen from your lungs to all your body cells. Carbon dioxide diffuses from your body cells into your blood. Your blood carries carbon dioxide to your lungs to be exhaled.
2. Blood carries waste products from your cells to your kidneys to be removed.
3. Blood transports nutrients and other substances to your body cells.
4. Cells and molecules in blood fight infections and help
heal wounds.
Anything that disrupts or changes these functions affects all the
tissues of your body. Can you understand why blood is sometimes
called the tissue of life?

Parts of Blood:
Blood is a tissue made of plasma (PLAZ muh), platelets (PLAYT luts), and red and white blood cells. Blood makes up about eight percent of your body’s total mass. If
you weigh 45 kg, you have about 3.6 kg of blood moving through your body. The amount of blood in an adult would fill five 1-L bottles.

Types of Blood:

CONTINUE CLASSIFICATION OF NUTRIENTS

>Vitamins:
Organic nutrients needed in small quantities for growth, regulating body functions, and preventing some diseases are called vitamins. For instance, your bone cells need vitamin D to use calcium, and your blood needs vitamin K in order to clot. Most foods supply some vitamins, but no food has them all. Some people feel that taking extra vitamins is helpful, while others feel that eating a well-balanced diet usually gives your body
all the vitamins it needs. Vitamins are classified into two groups,Some vitamins dissolve easily in water and are called watersoluble vitamins. They are not stored by your body so you have to take them daily. Other vitamins dissolve only in fat and are called fat-soluble vitamins. These vitamins are stored by your body. Although you eat or drink most vitamins, some are made by your body. Vitamin D is made when your skin is exposed to sunlight. Some vitamin K and two of the B vitamins are made
with the help of bacteria that live in your large intestine.



>Minerals:
Inorganic nutrients—nutrients that lack carbon and regulate many chemical reactions in your body—are called minerals. Your body uses about 14 minerals.Minerals build cells, take part in chemical reactions in cells, send nerve impulses throughout your body, and carry oxygen to body cells.
In Figure, you can see how minerals can get from the soil into your body.

Of the 14 minerals, calcium and phosphorus are used in the largest amounts for a variety of body functions. One of these functions is the formation and maintenance of bone. Some minerals, called trace minerals, are required only in small amounts. Copper and iodine usually are listed as trace minerals. Several minerals, what they do, and some food sources for them are listed in Table

>Water:

Water is important for your body.Next to oxygen, water is the most important factor for survival. Different organisms need different amounts of water to survive.You could live for a few weeks without food but for only a few days without water because your cells need water to carry out their work. Most of the nutrients you have studied in this chapter can’t be used by your body unless they are carried in a solution. This means that they have to be dissolved in water. In cells, chemical reactions take place in solutions. The human body is about 60 percent water by weight. About two thirds of your body water is located in your body cells.Water also is found around cells and in body fluids such as blood. your body loses water as perspiration.When you exhale, water leaves your body as water vapor.Water also is lost every day when your body gets rid of wastes. To replace water lost each day, you need to drink about 2 L of liquids. However, drinking liquids isn’t the only way to supply cells with water. Most foods have more water than you realize. An apple is about 80 percent water, and many meats are 90 percent water.

CLASSIFICATION OF NUTRIENTS

>Carbohydrates:

Carbohydrates (kar boh HI drayts) usually are the main sources of energy for your body. Each carbohydrate molecule is made of carbon, hydrogen, and oxygen atoms. Energy holds the atoms together.When carbohydrates are broken down in the presence of oxygen in your cells, this energy is released for use by your body.

Three types of carbohydrates are sugar, starch, and fiber. Sugars are called simple carbohydrates. You’reprobably most familiar with table sugar. However, fruits, honey, and milk also contain forms of sugar.Your cells break down glucose, a simple sugar. The other two types of carbohydrates— starch and fiber—are called complex carbohydrates. Starch is found in potatoes and foods made from grains such as pasta. Starches are made up of many simple sugars in long chains. Fiber, such as cellulose, is found in the cell walls of plant cells. Foods like whole-grain breads and cereals, beans, peas, and other vegetables and fruits are good sources of fiber. Because different types of fiber are found in foods, you should eat a variety of fiber-rich plant foods.

>Fats:

The term fat has developed a negative meaning for some people. However, fats, also called lipids, are necessary because they provide energy and help your body absorb vitamins. Fat tissue cushions your internal organs. A major part of every cell membrane is made up of fat. A gram of fat can release more than twice as much energy as a gram of carbohydrate can. During the digestion process, fat is broken down into smaller molecules called fatty acids and glycerol (GLIH suh rawl). Because fat is a good storage unit for energy, excess energy from the foods you eat is converted to fat and stored for later use.

Fats are classified as unsaturated or saturated based on their chemical structure. Unsaturated fats are usually liquid at room temperature. Vegetable oils as well as fats found in seeds are unsaturated fats. Saturated fats are found in meats, animal products, and some plants and are usually solid at room temperature. Although fish contains saturated fat, it also has some unsaturated fats that your body needs. Saturated fats have been associated with high levels of blood cholesterol. Your body makes cholesterol in your liver. Cholesterol is part of the cell membrane in all of your cells. However, a diet high in cholesterol may result in deposits forming on the inside walls of blood vessels. These deposits can block the blood supply to organs and increase blood pressure. This can lead to heart disease and strokes.

NUTRIENTS & CLASSIFICATION

>NUTRIENTS:

Nutrients (NEW tree unts) are substances in foods that provide energy and materials for cell development, growth, and repair.

>CLASSES OF NUTRIENTS:

Six kinds of nutrients are available in food.

1) Proteins

2) Carbohydrates

3) Fats

4) Vitamins

5) Minerals

6) Water

Proteins, carbohydrates, vitamins, and fats all contain carbon and are called organic nutrients. In contrast, inorganic nutrients, such as water and minerals, do not contain carbon. Foods containing carbohydrates, fats, and proteins need to be digested or broken down before your body can use them. Water, vitamins, and minerals don’t require digestion and are absorbed directly into your bloodstream.

>PROTIENS:

Your body uses proteins for replacement and repair of body cells and for growth. Proteins are large molecules that contain carbon, hydrogen, oxygen, nitrogen and sometimes sulfur. A molecule of protein is made up of a large number of smaller units, or building blocks, called amino acids. Your body needs only 20 amino acids in various combinations to make the thousands of proteins used in your cells.Most of these amino acids can be made in your body’s cells, but eight of them cannot. These eight are called essential amino acids. They have to be supplied by the foods you eat. Complete proteins provide all of the essential amino acids. Eggs, milk, cheese, and meat contain complete proteins. Incomplete proteins are missing one or more of the essential amino acids. If you are a vegetarian, you can get all of the essential amino acids by eating a wide variety of protein-rich vegetables, fruits, and grains.

BIOELECTRODE

Bioelectrodes function as an interface between biological structures and electronic systems. Electrical activity within the biological structure is either sensed or stimulated. The electrical systems are either passively sensing (measuring) or actively stimulating (inducing) electrical potentials within the biological structure or unit.

Electrical currents are generated by many biological structures. Currents give rise to potential differences that can be measured using electrodes and can be interpreted to gain insight in the functioning of the source structure. Conversely, current can be applied to the biological structure through electrodes to affect the target.

The same electrode may function either passively or actively, depending on the purpose and the electronic system controls. An example seen on TV is the large defibrillation paddles used by paramedics to resuscitate people in cardiac distress. When the paddles are applied to a patient, the electrical system is programmed to first passively sense the electrical activity (or lack of) within the heart. Then the electrical system uses algorithms to determine if a stimulation (shock) is required, and finally to provide the appropriate electrical stimulation.

The size of bioelectrodes ranges from microscopic intra-cellular research electrodes to large (3 x 5-inch) defibrillation paddles.

Most bioelectrodes are made of metal, but the microscopic intra-cellular research electrodes are glass capillary tubes filled with a conductive saline solution.

The following table gives some examples of applications, characteristics, and materials.

* has a conductive gel applied
Perhaps one of the most infamous applications of bioelectrodes is the “Electric Chair,” used for executing criminals in certain localities. A voltage is applied with so much power that the nervous system, including the pacing of the heart, are overwhelmed and cease to function, causing death.
Neurophysiology techniques are used to measure variations in electrical potentials for understanding the pathways and functions of the nervous system. Bioelectrodes provide the interface.

RADIOTHERAPY

FEEDBACK CONTROL SYSTEM IN HUMAN

RESISTORS

INDUCTORS

AMAZING FACTS OF HUMAN BODY

-> When you sneeze all body functions stop, even your heart




-> Your brain is 80% water



-> A human has 60,000 miles of blood vessels in their body




-> The lining of your digestive system is shed every 3 days


-> More than half the bones in your body are found in your hands and feet

-> Everyone is colour blind at birth

-> 1.7 litres of saliva is produced each day

-> Within a tiny droplet of blood, there are some 5 million red blood cells, 300 000 platelets and 10 000 white cells.

-> About 8 million blood cells die in the human body every second, and the same number are born each second .

-> There are 206 Bones in Human Body.

-> When you were born, your skeleton had around 350 bones. By the time you become an adult, you will only have 206 bones. This is because, as you grow, some of the bones join together to form one bone.

-> Most of the calcium in your body is stored in your bones

-> There are about 60 muscles in the face.

-> There are 640 muscles in our body.

-> The small intestine in the human body is about 2 inches around, and 22 feet long.

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