According to Ayurveda the body comprises of three primary life forces or humors. In Ayurvedic terminology they are calleddoshas. The state of balance or equilibrium between these three doshas in the body is called health and the state of imbalance or disequilibrium is disease. The imbalance may be in one, two or all the three doshas. For example excess of vatacauses arthritis and excess of pitta causes acidity, ulcer and liver disorders.

All causative factors of disease internal or external directly or indirectly create an imbalance in these doshas first and only then do the symptoms of the disease manifest. The causative factors can be the food, life style or other activities. All these factors are affecting one , two or all the three doshas. So if you want to stay healthy, you must know what are these factors which create an imbalance of doshas. As said earlier these factors could be your diet, life style or daily activities. You will soon discover that majority of foods and activities we practise in the modern world are increasing one or moredoshas. They are discussed briefly as below.

MUSCULAR SYSTEM

The human body contains more than 650 individual muscles which are attached to the skeleton, which provides the pulling power for us to move around. The main job of the muscular system is to provide movement for the body. The muscular system consist of three different types of muscle tissues : skeletal, cardiac, smooth. Each of these different tissues has the ability to contract, which then allows body movements and functions. There are two types of muscles in the system and they are the involuntary muscles, and the voluntary muscles. The muscle in which we are allow to control by ourselves are called the voluntary muscles and the ones we can? control are the involuntary muscles. The heart, or the cardiac muscle, is an example of involuntary muscle.

 

CARDIAC MUSCLE:

The cardiac muscle is the muscle of the heart itself. The cardiac muscle is the tissue that makes up the wall of the heart called the mydocardium. Also like the skeletal muscles, the cardiac muscle is striated and contracts through the sliding filament method. However it is different from other types of muscles because it forms branching fibers. Unlike the skeletal muscles, the cardiac muscle is attached together instead of been attach to a bone.

SKELETAL MUSCLE:
The skeletal muscle makes up about 40 % of an adults body weight. It has stripe-like markings, or striations. The skeletal muscle is composed of long muscle fibers. Each of these muscles fiber is a cell which contains several nuclei. The nervous system controls the contraction of the muscle. Many of the skeletal muscle contractions are automatic. However we still can control the action of the skeletal muscle. And it is because of this reason that the skeletal muscle is also called voluntary muscle.

SMOOTH MUSCLE:
Much of our internal organs is made up of smooth muscles. They are found in the urinary bladder, gallbladder, arteries, and veins. Also the digestive tract is made up of smooth muscle as well. The smooth muscles are controlled by the nervous system and hormones. We cannot consciously control the smooth muscle that is why they are often called involuntary muscles.

Muscle and Tendon Disorders
1)  Baker’s cyst
2)  Bursitis
3)  Carpal tunnel syndromem
4)  Tendinitis and Tenosynovitis
5)  Fibromyalgia
6)  Marfan Syndrome
7)  Muscle Cramp
8)  Muscular Dystrophy
9)  Repetitive Strain Injury
10)  Tendonitis
11)  Tennis elbow
12)  Whiplash Injury

Nervous System
The nervous system of the human being is responsible for sending, receiving, and processing nerve impulses throughout the body. All the organs and muscles inside your body rely upon these nerve impulses to function. It could be considered as the master control unit inside your body. Sense organs provide the nervous system with information about the environment by means of such senses as sight, hearing, smell, taste, tough, pressure, and pain. Nerves are connected throughout the whole body to the brain. They carry the information throughout the body in the form of electrochemical signals called impulses. These impulses travel from the brain and spinal cord to the nerves located throughout the body.
For example, if we touch something, impulses travel through the nerve network to the brain at a rate of 350 feet per second. This message is sent along the functional component of the nervous system called the neuron or nerve cell. It takes the cooperation of three sub-divisions of the nervous system to carry out the mission of the nervous system . They are the central, the peripheral, and the autonomic nervous systems.
Although divided for discussion purposes, these systems are connected and function together. OK, the nervous system is divided into:

1)The Central Nervous System which has has the responsibility for issuing nerve impulses and analyzing sensory data, and includes the brain and spinal cord.
2) Peripheral Nervous System which is responsible for carrying these nerve impulses to and from the body and many structures, including the many craniospinal nerves which branch off the brain and the spinal cord, and the<
3)Autonomic nervous system which is composed of the sympathetic and parasympathetic systems and is responsible for regulating and coordinating the functions of vital organs in the body.

Development of the Nervous Systemwretwert
Almost all neurons are generated during prenatal life, and they are not replaced by new neurons during postnatal life. Structurally, the nervous system first appears about 18 days after conception. Functionally, it appears with the first sign of reflex activity during the second prenatal month, when stimulation by touch of the upper lip has been shown to evoke an avoidance-withdrawal response of the head. Many reflexes of the head, trunk, and extremities can be elicited in the third month.

During its development the nervous system undergoes remarkable changes to attain its complex organization. In order to produce the estimated one trillion neurons present in the mature brain, an average of 2.5 million neurons must be generated per minute during the entire prenatal life. This includes the formation of neuronal circuits comprising 100 trillion synapses, as each potential neuron is ultimately connected with either a selected set of other neurons or specific targets such as sensory endings.

The nervous system can be divided into “systems”.

1)  They release different transmitter substances (neurotransmitters), usually triggering opposite reactions.
2)  The vegetative nervous system is controlled by the hypothalamus in the brain (cerebrum), where the information arrives, coordinating the interaction and functions of the organs.
3)  If, for example, increased physical exertion leads to an oxygen deficiency, the depth and rate of the breaths taken automatically increase. This leads to an increase in cardiac activity and an increased supply of oxygenated blood.

Nervous System Disorders
1)   Stroke
2)  Warning Signs of Dementia
3)  Caring for Someone Who Has Dementia
4)  Parkinson’s Disease
5)  Migraines
6)  Tension Headaches
7)  Cluster Headaches
8)  Rebound Headaches
9)  Epilepsy
10)  Epilepsy and Pregnancy
11)  Cervical Spondylotic Myelopathy
12)  Herniated Disk
13)  Lumbar Spinal Canal Stenosis
14)  Essential Tremor
15)  Bell’s Palsy
16)  Trigeminal Neuralgia
17)  Multiple Sclerosis
18)  Medicines to Treat Multiple Sclerosis
19)  Living with Multiple Sclerosis
20)  Multiple Sclerosis and Pregnancy

Endocrine System

The endocrine system is a collection of glands that secrete chemical messages we call hormones. These signals are passed through the blood to arrive at a target organ, which has cells possessing the appropriate receptor. The hormone in other words acts as a switch or a trigger for a certain action to take place. Exocrine glands (not part of the endocrine system) secrete products that are passed outside the body. Sweat glands, salivary glands, and digestive glands are examples of exocrine glands.

The endocrine glands are under the control of the nervous system.
The endocrine system of human beings consists of the following glands:

1)  Hypothalamus And Pituitary Gland
2)  The Pineal Gland
3)  The Thyroid Gland
4)  The Parathyroid Glands
5)  The Adrenal Glands
6)  Islets Of Langerhans (Pancreas)
7)  Ovaries (Female)
8)  Testes (Male)

Endocrine Disorders
1)  Acromegaly
2)  Adrenal Gland Disorders
3)  Amyloidosis
4)  Diabetes
5)  Empty Sella Syndrome
6)  Fertility and Infertility
7)  Galactorrhea
8)  Growth Disorders
9)  Hirsutism
10)  Hyperinsulinemia
11)  Hyperparathyroidism
12)  Hypoparathyroidism
13)  Hypopituitarism
14)  McCune-Albright Syndrome
15)  Menstruation Problems & Concerns
16)  Metabolic Syndrome
17)  Multiple Endocrine Neoplasia
18)  Osteoporosis
19)  Pancreatic Cancer
20)  Pancreatitis
21)  Pituitary Gland Disorders
22)  Polycystic Ovary Syndrome
23)  Precocious Puberty
24)  Prolactinoma
25)  Thyroid Diseases
26)  Turner’s Syndrome
27)  Cardiovascular System

Cardiovascular System
The cardiovascular system includes the heart and the blood vessels. The heart pumps blood, and the blood vessels channel and deliver it throughout the body. Arteries carry blood filled with nutrients away from the heart to all parts of the body. The blood is sometimes compared to a river, but the arteries are more like a river in reverse. Arteries are thick-walled tubes with a circular covering of yellow, elastic fibers, which contain a filling of muscle that absorbs the tremendous pressure wave of a heartbeat and slows the blood down. This pressure can be felt in the arm and wrist – it is the pulse. Eventually arteries divide into smaller arterioles and then into even smaller capillaries, the smallest of all blood vessels. One arteriole can serve a hundred capillaries. Here, in every tissue of every organ, blood’s work is done when it gives up what the cells need and takes away the waste products that they don’t need. Now the river comparison really does apply. Capillaries join together to form small veins, which flow into larger main veins, and these deliver deoxygenated blood back to the heart. Veins, unlike arteries, have thin, slack walls, because the blood has lost the pressure which forced it out of the heart, so the dark, reddish-blue blood which flows through the veins on its way to the lungs oozes along very slowly on its way to be reoxygenated. Back at the heart, the veins enter a special vessel, called the pulmonary arteries, into the wall at right side of the heart. It flows along the pulmonary arteries to the lungs to collect oxygen, then back to the heart’s left side to begin its journey around the body again.

Cardiovascular Disorders

1)  Acute coronary syndrome (unstable angina and non-ST elevation MI)
2)  Angina (chronic stable)
3)  Atrial fibrillation (acute onset)
4)  Atrial fibrillation (chronic)
5)  Cardiovascular medication: improving adherence
6)  Heart failure
7)  Myocardial infarction (ST-elevation)
8)  Peripheral arterial disease
9)  Primary prevention of CVD: diet and weight loss
10)  Primary prevention of CVD: physical activity
11)  Primary prevention of CVD: treating dyslipidaemia
12)  Primary prevention of CVD: treating hypertension
13)  Raynaud’s phenomenon (primary)
14)  Secondary prevention of ischaemic cardiac events
15)  Stroke management
16)  Stroke: secondary prevention
17)  Thromboembolism
18)  Varicose veins

The Human Respiratory System

The Pathway

1)  Air enters the nostrils
2)  Apasses through the nasopharynx
3)  the oral pharynx
4)  through the glottis
5)  into the trachea
6)  into the right and left bronchi, which branches and rebranches into
7)  bronchioles, each of which terminates in a cluster of
8)  alveoli

Only in the alveoli does actual gas exchange takes place. There are some 300 million alveoli in two adult lungs. These provide a surface area of some 160 m2 (almost equal to the singles area of a tennis court and 80 times the area of our skin!).

Breathing
In mammals, the diaphragm divides the body cavity into the
1)  abdominal cavity,which contains the viscera (e.g., stomach and intestines)
2)  thoracic cavity,which contains the heart and lungs.
The inner surface of the thoracic cavity and the outer surface of the lungs are lined with pleural membranes which adhere to each other. If air is introduced between them, the adhesion is broken and the natural elasticity of the lung causes it to collapse. This can occur from trauma. And it is sometimes induced deliberately to allow the lung to rest. In either case, reinflation occurs as the air is gradually absorbed by the tissues.
Because of this adhesion, any action that increases the volume of the thoracic cavity causes the lungs to expand, drawing air into them.
3)  During inspiration (inhaling).
i)  The external intercostal muscles contract, lifting the ribs up and out.
ii)  The diaphragm contracts, drawing it down .
4)  During expiration (exhaling), these processes are reversed and the natural elasticity of the lungs returns them to their normal volume. At rest, we breath 15-18 times a minute exchanging about 500 ml of air.
5)  In more vigorous expiration.
i)  The internal intercostal muscles draw the ribs down and inward.
ii)  The wall of the abdomen contracts pushing the stomach and liver upward.

The table shows what happens to the composition of air when it reaches the alveoli. Some of the oxygen dissolves in the film of moisture covering the epithelium of the alveoli. From here it diffuses into the blood in a nearby capillary. It enters a red blood cell and combines with the hemoglobin therein.
At the same time, some of the carbon dioxide in the blood diffuses into the alveoli from which it can be exhaled.

The ease with which oxygen and carbon dioxide can pass between air and blood is clear from this electron micrograph of two alveoli (Air) and an adjacent capillary from the lung of a laboratory mouse. Note the thinness of the epithelial cells (EP) that line the alveoli and capillary (except where the nucleus is located). At the closest point, the surface of the red blood cell is only 0.7 µm away from the air in the alveolus. (Reproduced with permission from Keith R. Porter and Mary A. Bonneville, An Introduction to the Fine Structure of Cells and Tissues, 4th. ed., Lea & Febiger, 1973.)

 

Central Control of Breathing
The rate of cellular respiration (and hence oxygen consumption and carbon dioxide production) varies with level of activity. Vigorous exercise can increase by 20-25 times the demand of the tissues for oxygen. This is met by increasing the rate and depth of breathing.

It is a rising concentration of carbon dioxide — not a declining concentration of oxygen — that plays the major role in regulating the ventilation of the lungs. The concentration of CO2 is monitored by cells in the medulla oblongata. If the level rises, the medulla responds by increasing the activity of the motor nerves that control the intercostal muscles and diaphragm.

However, the carotid body in the carotid arteries does have receptors that respond to a drop in oxygen. Their activation is important in situations (e.g., at high altitude in the unpressurized cabin of an aircraft) where oxygen supply is inadequate but there has been no increase in the production of CO2.

Local Control of Breathing
The smooth muscle in the walls of the bronchioles is very sensitive to the concentration of carbon dioxide. A rising level of CO2 causes the bronchioles to dilate. This lowers the resistance in the airways and thus increases the flow of air in and out.

Respiratory Disorders
1)  Pneumonia
2)  Asthma
3)  Emphysema
4)  Chronic Bronchitis
5)  Chronic Obstructive Pulmonary Disease (COPD)
6)  Lung Cancer

Digestive System
The digestive system is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. Inside this tube is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. There are also two solid digestive organs, the liver and the pancreas, which produce juices that reach the intestine through small tubes. In addition, parts of other organ systems (for instance, nerves and blood) play a major role in the digestive system.

 

Why Is Digestion Important?

When we eat such things as bread, meat, and vegetables, they are not in a form that the body can use as nourishment. Our food and drink must be changed into smaller molecules of nutrients before they can be absorbed into the blood and carried to cells throughout the body. Digestion is the process by which food and drink are broken down into their smallest parts so that the body can use them to build and nourish cells and to provide energy.

How Is Food Digested?
Digestion involves the mixing of food, its movement through the digestive tract, and chemical breakdown of the large molecules of food into smaller molecules. Digestion begins in the mouth, when we chew and swallow, and is completed in the small intestine. The chemical process varies somewhat for different kinds of food.

 

The large, hollow organs of the digestive system contain muscle that enables their walls to move. The movement of organ walls can propel food and liquid and also can mix the contents within each organ. Typical movement of the esophagus, stomach, and intestine is called peristalsis. The action of peristalsis looks like an ocean wave moving through the muscle. The muscle of the organ produces a narrowing and then propels the narrowed portion slowly down the length of the organ. These waves of narrowing push the food and fluid in front of them through each hollow organ.

 

The first major muscle movement occurs when food or liquid is swallowed. Although we are able to start swallowing by choice, once the swallow begins, it becomes involuntary and proceeds under the control of the nerves.

The esophagus is the organ into which the swallowed food is pushed. It connects the throat above with the stomach below. At the junction of the esophagus and stomach, there is a ringlike valve closing the passage between the two organs. However, as the food approaches the closed ring, the surrounding muscles relax and allow the food to pass.

 

The food then enters the stomach, which has three mechanical tasks to do. First, the stomach must store the swallowed food and liquid. This requires the muscle of the upper part of the stomach to relax and accept large volumes of swallowed material. The second job is to mix up the food, liquid, and digestive juice produced by the stomach. The lower part of the stomach mixes these materials by its muscle action. The third task of the stomach is to empty its contents slowly into the small intestine.

Several factors affect emptying of the stomach, including the nature of the food (mainly its fat and protein content) and the degree of muscle action of the emptying stomach and the next organ to receive the stomach contents (the small intestine). As the food is digested in the small intestine and dissolved into the juices from the pancreas, liver, and intestine, the contents of the intestine are mixed and pushed forward to allow further digestion.

Finally, all of the digested nutrients are absorbed through the intestinal walls. The waste products of this process include undigested parts of the food, known as fiber, and older cells that have been shed from the mucosa. These materials are propelled into the colon, where they remain, usually for a day or two, until the feces are expelled by a bowel movement.

Digestive System Disorders
1)  Colon and Rectal Cancer
2)  Stomach Cancer
3)  Diarrhea
4)  Diverticular Disease
5)  Gas in the Digestive Tract
6)  Heartburn
7)  Hepatitis
8)  Inflammatory Bowel Diseases
9)  Irritable Bowel Syndrome
10)  Lactose Intolerance
11)  Stomach and Duodenal Ulcers

Cardiovascular System

The Immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have specialized functions. The cells of the immune system can engulf bacteria, kill parasites or tumor cells, or kill viral-infected cells. Often, these cells depend on the T helper subset for activation signals in the form of secretions formally known as cytokines, lymphokines, or more specifically interleukins. The purpose of this article is to review the organs, cell types and interactions between cells of the immune system as a commentary on their importance and interdependence on the T helper subset. Such an understanding may help comprehend the root of immune deficiencies, and perceive potential avenues that the immune system can be modulated in the case of specific diseases.

 

The Organs of the Immune System

Bone Marrow — All the cells of the immune system are initially derived from the bone marrow. They form through a process called hematopoiesis. During hematopoiesis, bone marrow-derived stem cells differentiate into either mature cells of the immune system or into precursors of cells that migrate out of the bone marrow to continue their maturation elsewhere. The bone marrow produces B cells, natural killer cells, granulocytes and immature thymocytes, in addition to red blood cells and platelets.

Thymus —

The function of the thymus is to produce mature T cells. Immature thymocytes, also known as prothymocytes, leave the bone marrow and migrate into the thymus. Through a remarkable maturation process sometimes referred to as thymic education, T cells that are beneficial to the immune system are spared, while those T cells that might evoke a detrimental autoimmune response are eliminated. The mature T cells are then released into the bloodstream.

Spleen —

The spleen is an immunologic filter of the blood. It is made up of B cells, T cells, macrophages, dendritic cells, natural killer cells and red blood cells. In addition to capturing foreign materials (antigens) from the blood that passes through the spleen, migratory macrophages and dendritic cells bring antigens to the spleen via the bloodstream. An immune response is initiated when the macrophage or dendritic cells present the antigen to the appropriate B or T cells. This organ can be thought of as an immunological conference center. In the spleen, B cells become activated and produce large amounts of antibody. Also, old red blood cells are destroyed in the spleen.

Lymph Nodes —

The lymph nodes function as an immunologic filter for the bodily fluid known as lymph. Lymph nodes are found throughout the body. Composed mostly of T cells, B cells, dendritic cells and macrophages, the nodes drain fluid from most of our tissues. Antigens are filtered out of the lymph in the lymph node before returning the lymph to the circulation. In a similar fashion as the spleen, the macrophages and dendritic cells that capture antigens present these foreign materials to T and B cells, consequently initiating an immune response.

 

The Immune Response

An immune response to foreign antigen requires the presence of an antigen-presenting cell (APC), (usually either a macrophage or dendritic cell) in combination with a B cell or T cell. When an APC presents an antigen on its cell surface to a B cell, the B cell is signalled to proliferate and produce antibodies that specifically bind to that antigen. If the antibodies bind to antigens on bacteria or parasites it acts as a signal for pmns or macrophages to engulf (phagocytose) and kill them. Another important function of antibodies is to initiate the “complement destruction cascade.” When antibodies bind to cells or bacteria, serum proteins called complement bind to the immobilized antibodies and destroy the bacteria by creating holes in them. Antibodies can also signal natural killer cells and macrophages to kill viral or bacterial-infected cells.

 

If the APC presents the antigen to T cells, the T cells become activated. Activated T cells proliferate and become secretory in the case of CD4+ T cells, or, if they are CD8+ T cells, they become activated to kill target cells that specifically express the antigen presented by the APC. The production of antibodies and the activity of CD8+ killer T cells are highly regulated by the CD4+ helper T cell subset. The CD4+ T cells provide growth factors or signals to these cells that signal them to proliferate and function more efficiently. This multitude of interleukins or cytokines that are produced and secreted by CD4+ T cells are often crucial to ensure the activation of natural killer cells, macrophages, CD8+ T cells, and PMNs is listed in the chart below.

Immune System Disorders
1)  Allergy and asthma – inappropriate immune responses to substances that are usually harmless.
2)  Graft-vs.-host disease – a life-threatening reaction in people receiving organ transplants.
3)  Immune deficiency diseases – disorders in which your resistance to disease becomes dangerously low.
4)  Autoimmune diseases – diseases causing your immune system to attack your own body’s cells and tissues by mistake.

Urinary System

The organs, tubes, muscles, and nerves that work together to create, store, and carry urine are the urinary system. The urinary system includes two kidneys, two ureters, the bladder, two sphincter muscles, and the urethra.

How does the urinary system work?

Front view of urinary tract.

 

Your body takes nutrients from food and uses them to maintain all bodily functions including energy and self-repair. After your body has taken what it needs from the food, waste products are left behind in the blood and in the bowel. The urinary system works with the lungs, skin, and intestines—all of which also excrete wastes—to keep the chemicals and water in your body balanced. Adults eliminate about a quart and a half of urine each day. The amount depends on many factors, especially the amounts of fluid and food a person consumes and how much fluid is lost through sweat and breathing. Certain types of medications can also affect the amount of urine eliminated.

 

The urinary system removes a type of waste called urea from your blood. Urea is produced when foods containing protein, such as meat, poultry, and certain vegetables, are broken down in the body. Urea is carried in the bloodstream to the kidneys.

The kidneys are bean-shaped organs about the size of your fists. They are near the middle of the back, just below the rib cage. The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries, called a glomerulus, and a small tube called a renal tubule. Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney.

 

From the kidneys, urine travels down two thin tubes called ureters to the bladder. The ureters are about 8 to 10 inches long. Muscles in the ureter walls constantly tighten and relax to force urine downward away from the kidneys. If urine is allowed to stand still, or back up, a kidney infection can develop. Small amounts of urine are emptied into the bladder from the ureters about every 10 to 15 seconds.

 

The bladder is a hollow muscular organ shaped like a balloon. It sits in your pelvis and is held in place by ligaments attached to other organs and the pelvic bones. The bladder stores urine until you are ready to go to the bathroom to empty it. It swells into a round shape when it is full and gets smaller when empty. If the urinary system is healthy, the bladder can hold up to 16 ounces (2 cups) of urine comfortably for 2 to 5 hours.

 

Circular muscles called sphincters help keep urine from leaking. The sphincter muscles close tightly like a rubber band around the opening of the bladder into the urethra, the tube that allows urine to pass outside the body.

 

Nerves in the bladder tell you when it is time to urinate, or empty your bladder. As the bladder first fills with urine, you may notice a feeling that you need to urinate. The sensation to urinate becomes stronger as the bladder continues to fill and reaches its limit. At that point, nerves from the bladder send a message to the brain that the bladder is full, and your urge to empty your bladder intensifies.

 

When you urinate, the brain signals the bladder muscles to tighten, squeezing urine out of the bladder. At the same time, the brain signals the sphincter muscles to relax. As these muscles relax, urine exits the bladder through the urethra. When all the signals occur in the correct order, normal urination occurs.

 

What causes problems in the urinary system?

Problems in the urinary system can be caused by aging, illness, or injury. As you get older, changes in the kidneys’ structure cause them to lose some of their ability to remove wastes from the blood. Also, the muscles in your ureters, bladder, and urethra tend to lose some of their strength. You may have more urinary infections because the bladder muscles do not tighten enough to empty your bladder completely. A decrease in strength of muscles of the sphincters and the pelvis can also cause incontinence, the unwanted leakage of urine. Illness or injury can also prevent the kidneys from filtering the blood completely or block the passage of urine.

 

How are problems in the urinary system detected?

Urinalysis is a test that studies the content of urine for abnormal substances such as protein or signs of infection. This test involves urinating into a special container and leaving the sample to be studied.

 

Urodynamic tests evaluate the storage of urine in the bladder and the flow of urine from the bladder through the urethra. Your doctor may want to do a urodynamic test if you are having symptoms that suggest problems with the muscles or nerves of your lower urinary system and pelvis—ureters, bladder, urethra, and sphincter muscles.

 

Urodynamic tests measure the contraction of the bladder muscle as it fills and empties. The test is done by inserting a small tube called a catheter through your urethra into your bladder to fill it either with water or a gas. Another small tube is inserted into your rectum or vagina to measure the pressure put on your bladder when you strain or cough. Other bladder tests use x-ray dye instead of water so that x-ray pictures can be taken when the bladder fills and empties to detect any abnormalities in the shape and function of the bladder. These tests take about an hour.

Urinary system disorders
1)  Benign prostatic hyperplasia (BPH)
2)  Painful bladder syndrome/Interstitial cystitis (PBS/IC)
3)  Kidney stones
4)  Prostatitis
5)  Proteinuria
6)  Renal (kidney) failure
7)  Urinary tract infections (UTIs)
8)  Urinary incontinence
9)  Urinary retention

Reproductive System

Male Reproductive System

The male reproductive system is illustrated to the right. Sperm are produced in the testes located in the scrotum. Normal body temperature is too hot thus is lethal to sperm so the testes are outside of the abdominal cavity where the temperature is about 2° C (3.6° F) lower. Note also that a woman’s body temperature is lowest around the time of ovulation to help insure sperm live longer to reach the egg. If a man takes too many long, very hot baths, this can reduce his sperm count. Undescended testes (testes are supposed to descend before birth) will cause sterility because their environment is too warm for sperm viability unless the problem can be surgically corrected.

From there, sperm are transferred to the epididymis , coiled tubules also found within the scrotum, that store sperm and are the site of their final maturation.

 

In ejaculation, sperm are forced up into the vas deferens (plural = vasa deferentia). From the epididymis, the vas deferens goes up, around the front of, over the top of, and behind the bladder. A vasectomy is a fairly simple, outpatient operation that involves making a small slit in each scrotum, cutting the vasa deferentia near where they begin, and tying off the cut ends to prevent sperm from leaving the scrotum. Because this is a relatively non-invasive procedure (as compared to doing the same to a woman’s oviducts), this is a popular method of permanent birth control once a couple has had all the children they desire. Couples should carefully weigh their options, because this (and the corresponding female procedure) is not designed to be a reversible operation.

 

The ends of the vasa deferentia, behind and slightly under the bladder, are called the ejaculatory ducts. The seminal vesicles are also located behind the bladder. Their secretions are about 60% of the total volume of the semen (= sperm and associated fluid) and contain mucus, amino acids, fructose as the main energy source for the sperm, and prostaglandins to stimulate female uterine contractions to move the semen up into the uterus. The seminal vesicles empty into the ejaculatory ducts. The ejaculatory ducts then empty into the urethra (which, in males, also empties the urinary bladder).

 

The initial segment of the urethra is surrounded by the prostate gland (note spelling!). The prostate is the largest of the accessory glands and puts its secretions directly into the urethra. These secretions are alkaline to buffer any residual urine, which tends to be acidic, and the acidity of the woman’s vagina. The prostate needs a lot of zinc to function properly, and insufficient dietary zinc (as well as other causes) can lead to enlargement which potentially can constrict the urethra to the point of interferring with urination. Mild cases of prostate hypertrophy can often be treated by adding supplemental zinc to the man’s diet, but severe cases require surgical removal of portions of the prostate. This surgery, if not done very carefully can lead to problems with urination or sexual performance.

 

The bulbourethral glands or Cowper’s glands are the third of the accessory structures. These are a small pair of glands along the urethra below the prostate. Their fluid is secreted just before emission of the semen, thus it is thought that this fluid may serve as a lubricant for inserting the penis into the vagina, but because the volume of these secretions is very small, people are not totally sure of this function.

 

The urethra goes through the penis. In humans, the penis contains three cylinders of spongy, erectile tissue. During arousal, these become filled with blood from the arteries that supply them and the pressure seals off the veins that drain these areas causing an erection, which is necessary for insertion of the penis into the woman’s vagina. In a number of other animals, the penis also has a bone, the baculum, which helps to stiffen it. The head of the penis, the glans penis, is very sensitive to stimulation. In humans, as in other mammals, the glans is covered by the foreskin or prepuce, which may have been removed by circumcision. Medically, circumcision is not a necessity, but rather a cultural “tradition”. Males who have not been circumcised need to keep the area between the glans and the prepuce clean so bacteria and/or yeasts don’t start to grow on accumulated secretions, etc. there. There is some evidence that uncircumcised males who do not keep the glans/prepuce area clean are slightly more prone to penile cancer.

 

Female Reproductive System

The female reproductive system is illustrated to the right. “Eggs” are produced in the ovaries, but remember from our discussion of meiosis, that these are not true eggs, yet, and will never complete meiosis and become such unless/until first fertilized by a sperm. Within the ovary, a follicle consists of one precursor egg cell surrounded by special cells to nourish and protect it. A human female typically has about 400,000 follicles/potential eggs, all formed before birth. Only several hundred of these “eggs” will actually ever be released during her reproductive years. Normally, in humans, after the onset of puberty, due to the stimulation of follicle-stimulating hormone (FSH) one “egg” per cycle matures and is released from its ovary. Ovulation is the release of a mature “egg” due to the stimulation of leutenizing hormone (LH), which then stimulates the remaining follicle cells to turn into a corpus luteum which then secretes progesterone to prepare the uterus for possible implantation. If an egg is not fertilized and does not implant, the corpus luteum disintegrates and when it stops producing progesterone, the lining of the uterus breaks down and is shed.

 

Each “egg” is released into the abdominal cavity near the opening of one of the oviducts or Fallopian tubes. Cilia in the oviduct set up currents that draw the egg in. If sperm are present in the oviduct (if the couple has recently had intercourse), the egg will be fertilized near the far end of the Fallopian tube, will quickly finish meiosis, and the embryo will start to divide and grow as it travels to the uterus. The trip down the Fallopian tube takes about a week as the cilia in the tube propel the unfertilized “egg” or the embryo down to the uterus. At this point, if she had intercourse near the time of ovulation, the woman has no idea whether an unfertilized “egg” or a new baby is travelling down that tube. During this time, progesterone secreted by the corpus luteum has been stimulating the endometrium, the lining of the uterus, to thicken in preparation for possible implantation, and when a growing embryo finally reaches the uterus, it will implant in this nutritious environment and begin to secrete its own hormones to maintain the endometrium. If the “egg” was not fertilized, it dies and disintegrates, and as the corpus luteum also disintegrates, its progesterone production falls, and the unneeded, built-up endometrium is shed.

 

The uterus has thick, muscular walls and is very small. In a nulliparous woman, the uterus is only about 7 cm long by 4 to 5 cm wide, but it can expand to hold a 4 kg baby. The lining of the uterus is called the endometrium, and has a rich capillary supply to bring food to any embryo that might implant there.

 

The bottom end of the uterus is called the cervix. The cervix secretes mucus, the consistency of which varies with the stages in her menstrual cycle. At ovulation, this cervical mucus is clear, runny, and conducive to sperm. Post-ovulation, the mucus gets thick and pasty to block sperm. Enough of this mucus is produced that it is possible for a woman to touch a finger to the opening of her vagina and obtain some of it. If she does this on a daily basis, she can use the information thus gained, along with daily temperature records, to tell where in her cycle she is. If a woman becomes pregnant, the cervical mucus forms a plug to seal off the uterus and protect the developing baby, and any medical procedure which involves removal of that plug carries the risk of introducing pathogens into the nearly-sterile uterine environment.

 

The vagina is a relatively-thin-walled chamber. It servs as a repository for sperm (it is where the penis is inserted), and also serves as the birth canal. Note that, unlike the male, the female has separate opening for the urinary tract and reproductive system. These openings are covered externally by two sets of skin folds. The thinner, inner folds are the labia minora and the thicker, outer ones are the labia majora. The labia minora contain erectile tissue like that in the penis, thus change shape when the woman is sexually aroused. The opening around the genital area is called the vestibule. There is a membrane called the hymen that partially covers the opening of the vagina. This is torn by the woman’s first sexual intercourse (or sometimes other causes like injury or some kinds of vigorous physical activity). In women, the openings of the vagina and urethra are susceptible to bacterial infections if fecal bacteria are wiped towards them. Thus, while parents who are toilet-training a toddler usually wipe her from back to front, thus “imprinting” that sensation as feeling “right” to her, it is important, rather, that that little girls be taught to wipe themselves from the front to the back to help prevent vaginal and bladder infections. Older girls and women who were taught the wrong way need to make a conscious effort to change their habits.

 

At the anterior end of the labia, under the pubic bone, is the clitoris, the female equivalent of the penis. This small structure contains erectile tissue and many nerve endings in a sensitive glans within a prepuce which totally encloses the glans. This is the most sensitive point for female sexual stimulation, so senstiive that vigorous, direct stimulation does not feel good. It is better for the man to gently stimulate near the clitoris rather than right on it. Some cultures do a procedure, similar to circumcision, as a puberty rite in teenage girls in which the prepuce is cut, exposing the extremely-sensitive clitoris. There are some interesting speculations on the cultural significance of this because the sensitivity of the exposed clitoris would probably make having sexual intercourse a much less pleasant experience for these women.

Reproductive System Diseases: Women
1)  Amenorrhea
2)  Cervical Erosion
3)  Cervicitis
4)  Oligomenorrhea
5)  Puerperal Fever

Reproductive System Diseases: Men
1)  Gynecomastia
2)  Hydrocele
3)  Priapism
4)  Prostate Disorders