Question

a. Selecting two body systems, demonstrate through the production of annotated diagrams and a short explanation for the understanding of the structure and function of these systems in maintaining human health. 300 words please.

b. Explain the effect of cystic fibrosis on the body.

c. Explain the effect of Huntingdon’s Disease on the body

Answer 1

QA) Digestive system:-

The function of the digestive system is digestion and absorption. Digestion is the breakdown of ingested food into small molecules, which are then absorbed into the body. The digestive system is divided into two major parts-

The digestive tract (alimentary canal) is a continuous tube having two openingsthey are- mouth and the anus. It includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Food passing through the internal cavity, or lumen, of the digestive tract do not enter the body till it is absorbed by the walls of the digestive tract and passes into blood or lymphatic vessels and circulatory system.

ii) Accessory organs are teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

process of digestion -

It includes - Ingestion- it is the process of taking food.next stage is propulsion or the movement of food along the digestive tract, propulsion is done by peristaltic movement, this is a series of alternating contractions and relaxations of smooth muscle lining the walls of the digestive organs which forces food to move forward.

Secretion of digestive enzymes and other substances liquefies, adjusts the pH of, and chemically breaks down the food.

Mechanical digestion is a process of physically breaking down food into smaller pieces. This process begins by the chewing of food and continues upto muscular churning of the stomach. Additional churning takes place in the small intestine by muscular constriction of the intestinal wall. This process, called segmentation, it is similar to peristalsis, Chemical digestion is the process of chemically breaking down food into simpler molecules. The process is carried out by enzymes in the stomach and small intestines.

Absorption is the movement of molecules (by passive diffusion or active transport) from the digestive tract to nearby blood and lymphatic vessels. Absorption is the entrance of the digested food or nutrients into the body.last stage is defecation , it is the process of eliminating undigested food material to outside by the anus.

QB) Effect of Cystic Fibrosis:-

Cystic fibrosis is an inherited disorder that is  autosomal recessive caused by the presence of mutations in both copies of the gene of parents for( cystic fibrosis transmembrane conductance regulator (CFTR) protein). this causes severe damage to the lungs, digestive system and other organs of the body.

Cystic fibrosis affects the cells producing mucus, sweat and digestive juices. These secreted fluids are usually thin and slippery. But in people with cystic fibrosis, the defective CFTR gene makes the secretions sticky and thick. Instead of acting as a lubricant, the secretions blocks the tubes, ducts and passageways, specially in lungs and pancreas.

Cystic fibrosis signs and symptoms vary, depending on the severity of the disease. Even in the same person, symptoms may worsen or improve with passage of time. Some people may not experience symptoms until adolescence or adulthood.

People with cystic fibrosis have a higher than normal level of salt in their sweat. other symptoms of cystic fibrosis is seen in respiratory and digestive system. Adults with cystic fibrosis usually have recurring bouts of inflamed pancreas (pancreatitis), infertility and recurring pneumonia.

Effect on Respiratory system-

The thick and sticky mucus associated with cystic fibrosis blocks the tubes which carry air in and out of the lungs. There is a continious cough remains producing a thick mucus (or sputum), there is a continious whistling sound, breathlessness, patient is not tolerant to exercise, there will be repeated lung infection, having a stuffy nose.

Coughing up blood (hemoptysis). With passage of time cystic fibrosis may cause thinning of the airway walls. As a result,the patient particularly teenagers and adults may cough blood.

Pneumothorax. - It occurs mostly in older people , in this condition, air gets collected in the space which separates the lungs from the chest wall. due to this condotiion there will be pain in chest and there will be breathlessness.

Respiratory failure. With passage of time, cystic fibrosis damage lung tissue so badly, that they no longer works as a result it becomes life threatening.

Complications associated wth digestive system:-

Effect on digestive system:-

The thick mucus can block the tubes which carry digestive enzymes from pancreas to small intestine. Without these digestive enzymes, intestines will not be able to completely absorb the nutrients in the food taken as a result there will be foul-smelling, greasy stools, person will not gain weight, there may be intestinal blockage specially in new borns, also there remains severe constipation, due to constipation when frequent strain is put rectum or end oof large intestine may come out of anus.

Diabetes. The pancreas produces insulin, cystic fibrosis increases the risk of diabetes.

Blocked bile duct. The tube that carries bile from liver and gallbladder to small intestine may get blocked and inflamed, leading to liver problems and sometimes gallstones.

Effect on reproductive system :-

All men with cystic fibrosis are infertile because the tube which connects the testes and prostate gland (vas deferens) is either blocked with mucus or is absent.

Women with cystic fibrosis are less fertile than other women,.

Other complications due to cystic fibrosis:-

Thinning of the bones (osteoporosis). People with cystic fibrosis are at higher risk of developing thinning of bone or osteoporosis.

Electrolyte imbalances and dehydration. As people with cystic fibrosis have saltier sweat, the balance of minerals in their blood gets disturbed leading to increased heart rate, fatigue, weakness and low blood pressure.

Children are required to inherit one copy of the gene from each parent to have this disease. If they inherit only one copy, disease will not develop but, they will be the carriers of cystic fibrosis.

QC) Effect of Huntington's disease :-

Huntington's disease is an inherited disease (autosomal dominant condition, a defect in a single parent's gene can cause this disease) which affects the brain and nervous system.The defective gene is inherited from the parents. This faulty gene is carried on chromosome 4. The gene is responsible for making a protein called Huntingtin, it is a major protein which helps in nerve cell function.When the gene of this protein becomes becomes defective, it leads to damage and death of some of the neurons ( or brain cells) in a particular part of the brain that is in the basal ganglia and cortex. Tthis damage leads to the symptoms of Huntington's Disease. There is also a chemical called dopamine is produced in the brain which creates problem in the movement. It is a slowly progressive condition interfereing with the movements of the body, can also affect the awareness, thinking and judgement and also leads to changes in behaviour

The movement problem is called dystonia. This gradually replace chorea. Dystonia means having spasm in muscles, usually the muscles of the shoulder, neck, arms and leg, leading to twisting movements, repetitive movements, or abnormal postures. Gradually in the affected persons limbs become stiff or rigid and movements slow down. This slow movement is called bradykinesia.

Swallowing problem is seen, as it affects the muscles which control swallowing and the muscles around the mouth. Choking may occur as well as difficulty in eating leading to become underweight.

Also it is seen problem in speech , speech becomes slow.Eye movements also get affected, causes problem in looking from side to side or up and down.Depression is common in HD, and there is also sucidal tendency remains in HD.