Category Archives: Second semester

ADAPTATION

INTRODUCTION

—Cellular adaptation refers to changes(structure, function, or behavior ) made by a cell in response to adverse environmental changes which improves its chance of survival in a specific environment.

—The adaptation may be physiological (normal) or pathological (abnormal).

—Adaptations develop as the result of genetic variations that are capable of being passed from one generation to the next.

Variations that prove advantageous will tend to spread throughout the population.

Types of cellular adaptations

There are five types of adaptation –

—Atrophy – Atrophy is a decrease in cell size.

—Hypertrophy – Hypertrophy is an increase in cell size.

—Hyperplasia – Hyperplasia is an increase in the number of cells.

—Dysplasia – Dysplasia refers to abnormal changes in cellular shape, size, and/or organization.

—Metaplasia – Metaplasia occurs when a differentiated cell of a certain type is replaced by another cell type, which may be less differentiated.

ACIDOSIS & ALKALOSIS

INTRODUCTION

—Acidosis and alkalosis describe the abnormal conditions that result from imbalance in the pH of the blood caused by an excess of acid or alkali.

—This imbalance is typically caused by some underlying conditions or disease.

—Normal blood pH must be maintained within a narrow range of 7.35-7.45 to ensure the proper functioning of metabolic processes and the delivery of the right amount of oxygen to tissues.

—Acidosis refers to an excess of acid in the blood that causes the pH to fall below 7.35 and the alkalosis refers to an excess of base in the blood that causes the pH to rise above 7.45. many conditions and diseases can interfere with pH control in the body and cause a person’s blood pH to fall outside of healthy limits.

—Normal body functions and metabolism generate large quantities of acids that must be neutralized and/or eliminated to maintain blood ph balance.

—Most of the acid is carbonic acid, which is created from carbon dioxide and water.

—Lesser quantities of lactic acid, ketoacids and other organic acids are also produced.

The lungs and kidneys are the major organs involved in regulating blood pH.

—The lungs flush acid out of the body by exhaling carbon dioxide. Raising and lowering the respiratory rate alters the amount of carbon dioxide that is breathed out and this can affect blood pH within minutes.

—The kidneys excrete acids in the urine and they regulate the concentration of bicarbonate in blood. Acid base changes due to increase or decreases in carbonate concentration occur more slowly than changes in carbon dioxide taking hours or days.

—Both of these processes are always at work and they keep the blood pH in healthy people tightly controlled.

—Buffering systems that resist changes in pH also contribute to the regulation of acid and base concentrations.

—The main buffers in blood are haemoglobin, plasma proteins, bicarbonate and phosphates.

—The absolute quantities of acids or bases are less important than the balance between the two and its effect on blood pH.

ACIDOSIS

It occurs when blood pH falls below 7.35. It can be due to-

—Increased acid production within the body.

—Consumption of substances that are metabolizes to acids

—Decreased acid excretion

—Increased excretion of base

ALKALOSIS

It occurs when blood pH rises above 7.45. It can be due to-

—Electrolyte disturbances caused by for example prolonged vomiting or severe dehydration

—Administration or consumption of base

—Hyperventilation (with increased excretion of acid in form of carbon dioxide)

—Any disease or condition that affects the lungs, kidneys, metabolism or breathing has the potential to cause acidosis or alkalosis.

Terms frequently used in Pathophysiology

BASIC TERMINOLOGIES

Absorption – Absorption is defined as process of movement of unchanged drug from the site of administration to systemic circulation.

Affinity – The ability to combine with the receptor.

Agonist – A n agent capable of interacting with the receptor which stimulates it and produces a response.

Akinesia – Akenesia is loss of normal motor function, resulting in impaired muscle movement.

Allergic rhinitis – Allergic rhinitis is an inflammation of the nasal passages, usually associated with watery nasal discharge and itching of the nose and eyes.

Alzheimer’s disease – Alzheimer’s disease is a brain disorder which gradually destroys the ability to reason, remember, imagine and learn. It is different from the mild forgetness normally observed in older people.

Amyloidosis – Amyloidosis referes to the variety of conditions in which amyloid proteins are abnormally deposited in organs and/or tissues.

Analgesia – The ability to feel pain while still conscious.

Angina pectoris – Anginas pectoris is the result of myocardial ischemia caused by an imbalance between myocardial blood supply and oxygen demand.

Ankylosing spondylitis – Previously it was known by the name Bechterew’s disease or Bech terew syndrome or arie strumpell disease, now it is called as Ankylosing spondylitis. It is a form of spondyloarthritis, chronic, imflammatory arthritis and autoimmune disease. It mainly affects joints in the spine and the sacroilium in the pelvis, and can cause eventual fusion of the spine.

Antagonism – Antagonism occurs when one drug opposes the action of the other on the same physiological system, thus diminishing or completely abolishng the effect of the other.

Antagonist – It is an agent which binds to the receptor but is unable to stimulate it. It prevents the agonist action on the receptor by making the receptor unavailable. It is also called blocker of receptors and has structural similarilty to the agonist by which it is identified by the receptor.

Anxiety – It refers to fear, headache and pressure.

Apnoea – Apnoea is the term for suspension of external breathing.

Arthritis – Derived from greek words arthro meaning joint and itis meaning inflammation. Arthritis is a group of conditions involving damage to the joints of the body.

Asthma – Asthma is a predisposition to chronic inflammation of the lungs in which the airways (bronchi) are reversibly narrowed.

Ataxias – Ataxias is a neurological sign and symptom consisting of gross lack of coordination of muscle movements.

Benign fasciculation syndrome – Benign fasciculation syndrome is a neurological disorder characterized by fasciculation (twitching) of various voluntary muscles in the body.

Bioavailability – The term bioavailability is defined as the rate and extent (amount) of basorption of unchanged drug from its dosage form.

Bioassay – Biological standardization or bioassay of drugs is defined as the assessment of the activity of a preparation by measuring its effect  on living animals and tissues.

Bradycardia – A slow heart rate, usually defined as less than 60 beats/minute.

Bronchitis – Bronchitis is inflammation of the mucous membranes of the bronchi, the airways that carry airflow from the trachea into the lungs.

Bronchoscopy – Bronchoscopy is the technique of visualizing the inside of the airways for diagnostic and therapeutic purposes.

Bursitis – Bursitis is the inflammation of one or more bursae (small sacs) of the synovial fluid in the body.

Cardiac arrhythmias – These conditions make the heart pump lass effectively, so that not enough blood reaches the brain and other vital organs.

Cerebral hemorrhage – A cerebral hemorrhage (or intracerebral hemorrhage, ICH), is a subtype of intracranial hemorrhage that occurs within the brain tissue itself.

Chronic obstructive pulmonary disease – Chronic obstructive pulmonary disease (COPD) refers to chronic bronchitis and emphysema, a pair of two commonly co-existing diseases of the lungs in which the airways become narrowed.

Clearance – Clearance is defined as the hypothetical volume of body fluids containing drug from which the drug is removed or cleared completely in a specific peroid of time. It is expressed in ml/min and is a constant for any given plasma drug concentration.

Congestive heart failure – Congestive heart failure (CHF) or heart failure is a condition in which the heart can’t pump enough blood to the body’s other organs.

Constipation – Constipation, costiveness or irregularity is a condition of the digestive system in which a person or animal experiences hard faeces that are difficult to expel.

Cycloplegia – Cycloplegia is paralysis of the ciliary muscle of the eye, resulting in a loss of accomodation.

Diarrhea – Diarrhea is a condition of having three or more loose or liquid bowel movements per day.

Dizziness – Dizziness refers to an impairment in spatial perception and stability. It is considered imprecise. It can be used to mean vertigo, presyncope, disequilibrium or for a non-specific feeling such as giddiness or foolishness.

Drowsiness – Drowsiness refers to feeling abnormally sleepy during the day. People who are drowsy may fall asleep in in appropriate situations or at inappropriate times.

Dyspepsia – Dyspepsia is also known as upset stomach or indigestion, meaning hard or difficult digestion, is a medical condition characterized by chronic or recurrent pain in the upper abdomen, upper abdominal fullness and feeling full earlier than expected when eating.

Dysuria – Painful or difficult urination. This includes burning sensation.

Edema – Edema means swelling caused by fluid in your body’s tissues.

Efficacy or intrinsic activity – The ability to produce a response.

Emphysema – Emphysema is a long term, progressive disease of the lung that primarily causes shortness of breath.

Esophagoscopy – Examination of the esophagus using a thin, lighted instrument.

Euphoria – Euphoria is medically recognized as a mental/emotional state defined as a sense of great (usually exaggerated) elation and wellbeing.

Excretion – Excretion is defined as the process whereby the drugs and/or their metabolites are irrversibly transferred from the internal or external environment.

Fibrositis – It is inflammatory hyperplasia of white fibrous connective tissue, especially surrounding the muscles and causing pain and stiffness.

Flushing – Skin blushing or flushing is a sudden reddening of the face, neck or upper chest.

Glaucoma – Glaucoma is a disease in which the optic nerve is damaged, leading to progressive, irreversible loss of vision.

Glomerular filtration – Glomerular filtration is a non-selective, unidirectional process whereby most compounds, ionized are filtered except those that are bound to plasma proteins or blood cells and thus behave as macromolecules.

Gout – Gout is one of the most painful forms of arthritis. It occurs when too much uric acid builds up in the body.

Half life – Half life describes the time necessary for the plasma concentration of drug (reflecting the amount of drug in the body) to decline to half of its existing value.

Hallucinations – Hallucinations are defined as perceptions in a concious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid, substantial and located in external objective space.

Hyperthyroidism – Hyperthyroidism is a condition in which an overactive thyroid gland is producing an excessive amount of thyroid hormones that circulate in the blood.

Hypothyroidism – Hypothyroidism is the disease state in humans and in vertebrates caused by insufficient production of thyroid hormone by the thyroid gland.

Hypersensitivity reactions – Hypersensitivity refers to undesirable (damaging, discomfort-producing and sometimes fatal) reactions produced by normal immune system.

Hypertension – Hypertension is increase in blood preesure above normal i.e. 120/80 mmHg.

Hypotension – Hypotension is decrease in blood preesure below normal i.e. 120/80 mmHg.

Hypertrophic obstructive cardiomyopathy – Hypertrophic cardiomyopathy is a disease of the myocardium (the muscles of the heart) in which a portion of the myocardium is hypertrophied (thickened) without any obvoius cause.

Hyperuricemia – Hyperuricemia is a level of uric acid in the blood that is abnormally high.

Hypnosis – It is a process of calm down and inducing sleep.

Insomnia – Insomnia is a symptomwhich can accompany several sleep, medical and psychiatric disorders, characterized by persistent difficulty falling asleep and/or staying asleep despite the opportunity.

Lacrimation – The production, secretion and shedding of tears.

Laryngoscopy – Laryngoscopy is an examination a doctor users to look at the back of the throat, including the voice box (larynx) and vocal cords.

Metabolism – Metabolism of drugs is defined as the conversion from one chemical form to another. The term is used synonymously with biotransformation.

Migraine – Migraine is a type of severe or sometimes even disabling headache.

Miosis – Miosis is constriction of the pupil of the eye.

Motion sickness – Motion sickness or kinetosis also known as travel sickness, is a condition in which a disagreement exists between visually perceived movement and the vestibular system’s sense of movement.

Mydriasis – Mydriasis is an excessive dilation of the pupil due to disease, trauma or the use of drugs.

Myocardial infraction – Myocardial infraction or acute myocardial infraction commonly known as heart attack, is the interruption of blood supply to part of the heart, causing some heart cells to die.

Myasthenia gravis – Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body.

Myositis – Myositis is inflammation of skeletal uscles, which are also called the voluntary muscles.

Nausea and vomiting – Nausea and vomiting are symptoms of an underlying disease and not a specific illness. Nausea is the sensation that the stomach wants to empty itself, while vomiting (emesis) or throwing up, is the act of forcible emptying of the stomach.

Nephropathy – Nephropathy refers to damage to or disease of the kidney. An older term for this is nephrosis.

Parkinson’s disease – Parkinson’s dosease is an age related deterioration of certain nerve systems which affects our movement, balance and muscle control.

Pharmacodynamics – Pharmacodynamics concerns te actions, interactions and the mechanism of action of drugs.

Pharmacokinetics – Pharmacokinetics is defined as the study of time course of drug absorption, distribution, metabolism and excretion and their relationship with its therapeutic and tixic effects of the drugs.

Pheochromocytoma – A pheochromocytoma is a neuroendocrine tumour of the medulla of the adrenal glands (originating in the chromaffin cells), which is due to excess secretions of catecholamines.

Photophobia – Photophobia is a symptom of excessive sensitivity to light.

Placebo – In medical research, placebos depend on use of controlled and measured deception. Common placebos are inert tablets, sham surgery and other procedures based on false information. In one comon placebo procedure, a patient is given an inert pill, yold that it may improve his/her condition, but not told that it is inert. Such an intervention may cause the patient to believe the treatment will change his/her condition, and this belief may produce a subjective perception of a therapeutic effect, causing the patient to feel their condition has improved. This phenomenon is called the placebo effect.

Prodrug – A prodrug is a pharmacological substance (drug), that is administered in an inactive (or significantly less active) form. An inactive precursor of a drug, converted into its active form in the body by normal metabolism.

Prophylaxis – A measure taken for the prevention of a disease or condition.

Pruritis – Pruritis pamphlet pruritis is an itch or a sensation that makes a person want to scratch. Pruritis can cause discomfort and be frustrating.

Pulmonary embolism – Pulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream (embolism).

Rashes – A rash is a change of the skin which affects its color, appearance or texture.

Receptors – The component of the cell or organism which interacts with the drug and initiates a chain of responses leading to the observed effects of the drug .

Renal clearance – It can be defined as the volume of blood or plasma which is completely cleared of the unchanged drug by the kidney per unit time.

Reye’s syndrome – Reye’s syndrome is a potentially fatal disease that causes numerous detrimental effects to many organs especially the brain and the liver as well as causing hypoglycemia.

Sialogogue – A sialogogue is a drug that increases the flow of saliva. Sialogogues can be used in the treatment of xerostomia (dry mouth).

Shock – Shock is a serious, life-threatening medical condition characterized by a decrease in tissue perfusion to a point at which it is inadequate to meet cellular metabolic needs.

Synergism – When the therapeutic effects of the two drug combination are greater than the individual drug is known as synergism.

Steatorrhea – Steatorrhea is the presence of excess fat in faeces. Stool may also float due to excess lipid, have an oily appearance and oroduce foul smell.

Tachycardia – A rapid heart rate, usually defined as greater than 100 beats per minute.

Thyrotoxicosis – Thyrotoxicosis or hyperthyroidism is the clinical syndrome caused by an excess of circulating free thyroxine and free triiodothyronine or both.

Tinnitus – Tinnitus is a ringing, swishing or other type of noise that seems to originate in the ear or head.

Tremor – A tremor is an involuntary, somewhat rhythmic, muscle movement involving oscillations of one or more body parts.

Urticaria – Urticaria are a kind of skin rash notable for dark red, raised, itchy bumps.

Vasoconstriction – Narrowing of the blood vessels resulting from contracting of the muscular wall of the vessels.

Vasodilation – Widening of blood vessels resulting from relaxation of the muscular wall of the vessels.

Xerostomia – Xerostomia is the medical term from the subjective complaint of dry mouth due to a lack of saliva.