Genetic & Congenital Disorders PDF

Genetic & Congenital Disorders Karyotype: The karyotype is a photographic representation of the chromosomes of a single cell, arranged in pairs and organized by size. It is used to look for abnormal numbers or structures of chromosomes. Allele: An allele is a version of a particular gene on a chro...

Genetic & Congenital Disorders Karyotype: The karyotype is a photographic representation of the chromosomes of a single cell, arranged in pairs and organized by size. It is used to look for abnormal numbers or structures of chromosomes. Allele: An allele is a version of a particular gene on a chromosome. Alleles represent certain traits. Humans have two alleles per trait, one inherited from each parent. Genotype: The genetic makeup of a person, represented by their specific set of alleles. For example, a brown-eyed person can have a B-B or B-b genotype. Phenotype: The observable expression of a genotype in terms of physical or biochemical traits. It is how the gene mix is manifested in the individual. Autosomes: Autosomes are the 22 pairs of chromosomes that are not sex chromosomes. They carry the bulk of the genetic material responsible for most inherited traits. Teratogen: A teratogen is any agent that can cause a birth defect or congenital disorder. Examples include infectious diseases, nutritional deficiencies, chemicals, alcohol consumption, illegal drugs, and toxins found at home and at work. Autosomal Dominant Disorders: These disorders are caused by a single mutant allele from an affected parent that is transmitted to an offspring regardless of sex. The affected parent has a 50% chance of transmitting the disorder to each offspring. Examples include: Marfan Syndrome Neurofibromatosis (NF) Huntington Disease Familial Hypercholesterolemia Ehlers-Danlos Syndrome Autosomal Recessive Disorders: These disorders are manifested only when both members of the gene pair are affected (homozygous). Both parents may be carriers of the defective gene but are unaffected themselves. Examples include: Cystic Fibrosis Phenylketonuria (PKU) Tay-Sachs Disease Sickle Cell Anemia Gaucher Disease Sex Chromosome Disorders: Disorders related to the X and Y chromosomes. Examples include: Turner Syndrome (45,X) Klinefelter Syndrome (47,XXY) Trisomy 21 (Down syndrome) Pathophysiology: Trisomy 21 is caused by an extra copy of chromosome 21, resulting from nondisjunction during cell division. Signs and Symptoms: Characteristic facial features (flat facial profile, small nose, epicanthal folds), intellectual disability (IQ typically between 25 and 50), congenital heart disease, esophageal and intestinal malformations, increased risk of leukemia, weak immune system, and susceptibility to infections. Adults may develop early-onset Alzheimer's disease. Cri du chat (cry of the cat) syndrome Pathophysiology: Caused by a deletion of the short arm of chromosome 5. Signs and Symptoms: High-pitched cat-like cry, microcephaly, mental retardation, moon-shaped face, and wide-set eyes. Huntington’s chorea Pathophysiology: Autosomal dominant disorder caused by a genetic defect on chromosome 4, leading to the formation of the Huntington protein. Signs and Symptoms: Onset typically in mid-30s to 40s, includes chorea (involuntary dancelike movements), severe chorea (uncontrollable flailing), parkinsonian features (muscle rigidity, postural instability), cognitive decline, dementia, depression, and suicidal ideation. Marfan’s syndrome Pathophysiology: Autosomal dominant disorder caused by mutations in the fibrillin-1 (FBN1) gene on chromosome 15, affecting connective tissue. Signs and Symptoms: Tall stature, elongated arms and fingers, kyphoscoliosis, hypermobility of joints, heart murmur, aortic dissection, visual problems, spontaneous pneumothorax. Von Recklinghausen’s disease (Neurofibromatosis type 1) Pathophysiology: Autosomal dominant disorder caused by mutations in the NF1 gene on chromosome 17. Signs and Symptoms: Café-au-lait spots, neurofibromas, optic and acoustic nerve tumors, scoliosis, bowed legs, macrocephaly, learning disabilities, increased risk of malignant tumors. Osteogenesis imperfecta Pathophysiology: Hereditary disorder affecting bone collagen. Signs and Symptoms: Brittle bones, multiple fractures, stunted growth, scoliosis, brain damage due to trauma during labor. Nonne-Milroy-Meige syndrome (Milroy’s disease) Pathophysiology: Hereditary disorder causing a congenital defect in lymphatic vessels. Signs and Symptoms: Lymphedema due to lymphatic vessel blockages, increase in interstitial fluid. Cystic fibrosis Pathophysiology: Autosomal recessive disorder caused by defects in the CFTR gene, affecting chloride channels. Signs and Symptoms: Thick mucus secretions in the respiratory and digestive systems, leading to respiratory infections, pancreatic insufficiency, and malnutrition. Tay-Sachs disease Pathophysiology: Autosomal recessive disorder caused by a mutation on chromosome 15, leading to deficiency of hexosaminidase A enzyme. Signs and Symptoms: Progressive weakness, muscle flaccidity, decreased responsiveness, motor and mental deterioration, seizures, cherry-red spot on the retina, leading to blindness and death by age 3-5 years. Gaucher’s disease Pathophysiology: Autosomal recessive disorder affecting lipid metabolism, leading to the buildup of glucocerebrosides in tissues. Signs and Symptoms: Hepatosplenomegaly, anemia, thrombocytopenia, bone pain, and neurological complications. Galactosemia Pathophysiology: Autosomal recessive disorder caused by the absence of the enzyme that converts galactose to glucose. Signs and Symptoms: Vomiting, diarrhea, jaundice, failure to thrive, and mental retardation. Alkaptonuria Pathophysiology: Autosomal recessive disorder resulting in the accumulation of homogentisic acid. Signs and Symptoms: Dark urine, ochronosis (darkening of connective tissues), arthritis. Phenylketonuria (PKU) Pathophysiology: Autosomal recessive disorder caused by a deficiency of the enzyme phenylalanine hydroxylase. Signs and Symptoms: Intellectual disability, microcephaly, delayed speech, musty odor, and seizures. Managed with a special diet. Klinefelter’s syndrome Pathophysiology: Presence of one or more extra X chromosomes in males (47,XXY). Signs and Symptoms: Tall stature, gynecomastia, small testes, reduced muscle mass, and infertility. Often detected at puberty. Turner’s syndrome Pathophysiology: Absence of all or part of one X chromosome in females (45,X). Signs and Symptoms: Short stature, webbed neck, broad chest, ovarian failure, cardiovascular issues, and infertility. Hemophilia A vs Hemophilia B Pathophysiology: X-linked recessive disorders. Hemophilia A is due to a deficiency of clotting factor VIII, and Hemophilia B (Christmas disease) is due to a deficiency of clotting factor IX. Signs and Symptoms: Prolonged bleeding, hemarthrosis (bleeding into joints), and easy bruising. Fabry’s disease Pathophysiology: X-linked recessive disorder causing glycolipid accumulation in tissues. Signs and Symptoms: Pain (especially in hands and feet), angiokeratomas, hypohidrosis, corneal opacity, renal failure, and increased risk of stroke and heart attack. Wilson’s disease Pathophysiology: Autosomal recessive disorder leading to copper accumulation in tissues. Signs and Symptoms: Liver disease, neurological symptoms (tremor, poor coordination, psychiatric symptoms), Kayser-Fleischer rings in the eyes. Milroy’s disease Pathophysiology: Hereditary lymphedema caused by congenital malformation of the lymphatic system. Signs and Symptoms: Chronic swelling of the lower limbs, commonly apparent at birth or in early infancy. How does the following conditions cause congenital disorders? Human Immunodeficiency Virus (HIV) HIV can be passed from mother to fetus through the placenta. It is an RNA virus that can lead to the development of Acquired Immunodeficiency Syndrome (AIDS) in the child. Signs and symptoms of HIV infection in the mother include night sweats, fever, and swollen lymph nodes. Acquired Immunodeficiency Syndrome (AIDS) AIDS results from the progression of HIV. If a mother has AIDS, the virus can be transmitted to the fetus, causing severe immunodeficiency and increasing susceptibility to infections and other health complications from birth. Syphilis Syphilis is a bacterial infection caused by Treponema pallidum, which can be transmitted from an infected mother to the fetus through the placenta. Children born with syphilis can have multiple malformations and are usually born blind. The infection has three stages, with the tertiary stage being the most severe, potentially affecting the aorta, nervous system, and causing large skin and organ lesions. Chlamydia Chlamydia is a bacterial infection caused by Chlamydia trachomatis. Mothers with chlamydia can pass the infection to their babies during birth, resulting in pneumonia and eye inflammation in the newborn. Many infected individuals, especially women, might be asymptomatic. Gonorrhea Gonorrhea is a bacterial infection caused by Neisseria gonorrhoeae. Babies born to mothers with gonorrhea can develop eye infections that can result in blindness. To prevent this, newborns' eyes are often treated with antibiotic drops shortly after birth. Chickenpox and German Measles (Rubella) Chickenpox is caused by the varicella-zoster virus. If a pregnant woman contracts chickenpox, it can cause encephalitis in the fetus. German measles (Rubella) is caused by the rubella virus. Infection during the first trimester of pregnancy can lead to congenital rubella syndrome, which can cause blindness, hearing loss, mental retardation, heart problems, premature delivery, and even fetal death. Fetal Alcohol Syndrome (FAS) FAS results from excessive alcohol consumption by the mother during pregnancy. Babies with FAS are typically born with low birth weights, facial and head malformations, and may suffer from mental retardation. They also experience withdrawal symptoms after birth, including shaking, vomiting, and irritability. Arnold-Chiari Deformity Pathophysiology: Congenital malformation of the medulla oblongata and cerebellum, which protrude inferiorly through the foramen magnum into the spinal canal. Signs and Symptoms: Associated with hydrocephalus, spina bifida, lesions, or infections due to cerebrospinal fluid accumulation. Hydrocephalus Pathophysiology: Accumulation of cerebrospinal fluid caused by congenital drainage defect or obstruction of the third or fourth ventricle of the brain. Signs and Symptoms: Malformation of the skull. Spina Bifida Pathophysiology: Caused by agenesis (absence) of the posterior vertebral arches. Forms: o Spina Bifida Occulta: No protrusion of the meninges or spinal cord. o Spina Bifida Cystica: Protrusion of the meninges (meningocele), spinal cord (myelocele), or both (meningomyelocele) in a cyst-like structure. Spina Bifida Occulta Pathophysiology: Agenesis of the vertebral posterior arches without protrusion of the meninges or spinal cord. Signs and Symptoms: Generally asymptomatic and often discovered incidentally. Spina Bifida Cystica Pathophysiology: Agenesis of the vertebral posterior arches with protrusion of the meninges, spinal cord, or both. Signs and Symptoms: Visible cyst-like structure on the back. Meningocele Pathophysiology: Protrusion of only the meninges through a defect in the spinal column. Signs and Symptoms: Cyst-like structure containing meninges but not the spinal cord. Myelocele Pathophysiology: Protrusion of only the spinal cord through a defect in the spinal column. Signs and Symptoms: Cyst-like structure containing the spinal cord. Meningomyelocele Pathophysiology: Protrusion of both the meninges and spinal cord through a defect in the spinal column. Signs and Symptoms: Cyst-like structure containing both meninges and spinal cord. Cerebral Palsy Pathophysiology: A variety of conditions causing brain damage, typically due to birth injury or oxygen deficiency during birth. Signs and Symptoms: Spastic gait, hemi- or paraplegia, slow spastic movements of the upper extremities. Hirschsprung’s Disease Pathophysiology: Congenital megacolon caused by the absence of normal bowel ganglion cells and nerve plexuses. Signs and Symptoms: Severely dilated colon, chronic constipation, impacted fecal matter, and diarrhea. Klippel-Feil Syndrome Pathophysiology: Congenital abnormality with multiple blocks or fusions of the cervical region. Signs and Symptoms: Short, wide neck, and central nervous system abnormalities. Sprengel’s Deformity Pathophysiology: Congenital elevation of the scapula. Signs and Symptoms: Elevated scapula. The Reproductive System Cryptorchidism Condition of undescended testicles where the testes remain high in the inguinal canal or abdominal cavity. Signs and Symptoms: Testes not descended into scrotal sacs by age 1. Testicular Torsion Twisting of the spermatic cord leading to obstruction of blood flow to the testicle. Signs and Symptoms: Sudden onset of severe unilateral scrotal pain, scrotal swelling, erythema, abdominal pain, nausea, and vomiting. Ovarian Torsion Twisting of the ovary, often due to an ovarian mass or cyst, leading to obstruction of blood flow. Signs and Symptoms: Unilateral sudden severe sharp abdominal pain radiating to the pelvis, groin, and thigh, nausea, and vomiting. Varicocele Dilatation of the veins within the scrotum. Signs and Symptoms: Scrotal pain, heaviness, swollen scrotum with varicose veins, often described as feeling like a bag of "worms." Rectocele Herniation of the rectum into the vaginal canal. Signs and Symptoms: Bulge in the vaginal canal. Enterocele Herniation of intestine within the area between the uterosacral ligaments posterior to the cervix. Signs and Symptoms: Protrusion of the small bowel. Benign Prostatic Hyperplasia (BPH) Excessive cell growth of the prostate gland. Signs and Symptoms: Frequency of urination, urgency, incomplete emptying of the bladder, hesitancy, decreased urine stream, susceptibility to urinary tract infections. Prostate Cancer Malignant tumor of the prostate gland. Signs and Symptoms: Urinary symptoms similar to BPH, hematuria, bone pain in advanced stages. Epididymitis Inflammation of the epididymis. Signs and Symptoms: Scrotal pain and swelling, fever, and urinary symptoms. Erectile Dysfunction (ED) Inability to achieve or maintain an erection sufficient for sexual intercourse. Signs and Symptoms: Persistent difficulty achieving or maintaining an erection, reduced sexual desire. Fibrocystic Breast Disease Benign condition characterized by fibrocystic changes in the breast tissue. Signs and Symptoms: Nodular, granular breast masses, breast tenderness, and cystic distension. Breast Cancer Malignant tumor of the breast tissue. Signs and Symptoms: Lump in the breast, changes in breast shape, dimpling of the skin, nipple discharge, breast pain. Pelvic Inflammatory Disease (PID) Infection of the female reproductive organs. Signs and Symptoms: Lower abdominal pain, fever, unusual vaginal discharge, pain during intercourse, irregular menstrual bleeding. Cervicitis Inflammation of the cervix. Signs and Symptoms: Purulent cervical discharge, intermenstrual or postcoital bleeding. Cervical Cancer Malignant tumor of the cervix. Signs and Symptoms: Abnormal vaginal bleeding, pelvic pain, pain during intercourse, watery or bloody vaginal discharge. Endometriosis Growth of endometrial tissue outside the uterus. Signs and Symptoms: Pelvic pain, dysmenorrhea, dyspareunia, infertility. Endometrial Carcinoma Malignant tumor of the endometrium. Signs and Symptoms: Postmenopausal bleeding, pelvic pain. Fibroid Tumor (Uterine Leiomyoma) Benign tumors of the myometrium. Signs and Symptoms: Abnormal vaginal bleeding, bladder compression, dysmenorrhea, back pain, infertility. Ovarian Cancer Malignant tumor of the ovary. Signs and Symptoms: Abdominal bloating, pelvic pain, urinary symptoms, and early satiety. Sexually Transmitted Diseases (STDs) Chlamydia: Often asymptomatic, but can cause urethritis, cervicitis, and pelvic inflammatory disease. Condyloma Acuminatum (Genital Warts): Caused by HPV, presenting as warts on genital areas. Gonorrhea: Urethritis, cervicitis, pelvic pain, and discharge. Syphilis: Painless sore (chancre), rash, systemic involvement in later stages. Herpes Simplex Type 1 and Type 2: Painful blisters and ulcers on the genital or oral areas. Trichomoniasis: Vaginal discharge, itching, and discomfort during urination. Bacterial Vaginosis: Vaginal discharge with a fishy odor, itching. Chlamydia Chlamydia is caused by the bacterium Chlamydia trachomatis. It is one of the most common STDs and can affect both men and women. Transmission: Spread through vaginal, anal, and oral sex. Signs and Symptoms: - Often asymptomatic, especially in women. - Women: Abnormal vaginal discharge, burning sensation during urination, lower abdominal pain, pain during intercourse, and bleeding between periods. - Men: Discharge from the penis, burning sensation during urination, pain and swelling in one or both testicles (less common). Complications: If left untreated, it can lead to pelvic inflammatory disease (PID) in women, causing damage to the fallopian tubes, infertility, and ectopic pregnancy. In men, it can cause epididymitis, which can lead to infertility. Condyloma Acuminatum (Genital Warts) Description: Caused by certain strains of the human papillomavirus (HPV), primarily types 6 and 11. Transmission: Spread through skin-to-skin contact during vaginal, anal, or oral sex. Signs and Symptoms: - Small, flesh-colored or gray swellings in the genital area. - Multiple warts close together that take on a cauliflower shape. - Itching or discomfort in the genital area. - Bleeding with intercourse. Complications: While genital warts are generally benign, certain high-risk HPV strains are associated with cancers, such as cervical, anal, and throat cancers. Gonorrhea Description: Caused by the bacterium Neisseria gonorrhoeae. It can infect the genitals, rectum, and throat. Transmission: Spread through vaginal, anal, and oral sex. Signs and Symptoms: - Women: Increased vaginal discharge, painful urination, vaginal bleeding between periods, and pelvic pain. - Men: White, yellow, or green discharge from the penis, painful urination, and painful or swollen testicles. Complications: In women, it can lead to PID, which can cause infertility and chronic pelvic pain. In men, it can cause epididymitis, which can lead to infertility. Disseminated gonococcal infection (DGI) can occur, causing arthritis, tenosynovitis, and dermatitis. Syphilis Description: Caused by the bacterium Treponema pallidum. It progresses through stages (primary, secondary, latent, and tertiary). Transmission: Spread through direct contact with a syphilis sore during vaginal, anal, or oral sex. Signs and Symptoms: - Primary Stage: Painless sore (chancre) at the site of infection, which heals on its own. - Secondary Stage: Skin rashes, mucous membrane lesions, fever, swollen lymph nodes, and sore throat. - Latent Stage: No symptoms but bacteria remain in the body. - Tertiary Stage: Severe medical problems affecting the heart, brain, and other organs. Complications: If untreated, it can cause serious damage to the heart, brain, and other organs, potentially leading to death. Herpes Simplex Type 1 (HSV-1) and Type 2 (HSV-2) Description: HSV-1 typically causes oral herpes (cold sores), while HSV-2 usually causes genital herpes. Transmission: Spread through direct contact with herpes sores, saliva, or genital secretions during vaginal, anal, or oral sex. Signs and Symptoms: - Painful blisters or ulcers at the site of infection. - Initial outbreak may be severe, with fever, body aches, and swollen lymph nodes. - Recurrent outbreaks are usually milder. Complications: Increases the risk of acquiring and transmitting HIV. Neonatal herpes can be severe and potentially fatal. Trichomoniasis Description: Caused by the protozoan parasite Trichomonas vaginalis. Transmission: Spread through vaginal sex. Signs and Symptoms: - Women: Itching, burning, redness or soreness of the genitals, discomfort during urination, and a thin discharge with an unusual smell that can be clear, white, yellowish, or greenish.  - Men: Itching or irritation inside the penis, burning after urination or ejaculation, and discharge from the penis. Complications: Increases the risk of getting or spreading other STDs, particularly HIV. Bacterial Vaginosis Description: Not always sexually transmitted but having new or multiple sex partners can increase the risk. It results from an imbalance in the natural bacteria in the vagina. Transmission: Not fully understood but associated with sexual activity. Signs and Symptoms: - Thin, white or gray vaginal discharge. - Strong fishy odor, especially after sex. - Vaginal itching. - Burning during urination. Complications: Increases the risk of acquiring STDs, complications during pregnancy, and pelvic inflammatory disease (PID). The Endocrine System Goiter Pathophysiology: Enlargement of the thyroid gland, often due to iodine deficiency. Signs and Symptoms: Swelling in the anterior cervical region, potential obstructive symptoms such as difficulty breathing or swallowing. Hypoparathyroidism Pathophysiology: Decreased secretion of parathyroid hormone. Signs and Symptoms: Muscular spasms, tetany, potential fatal outcomes if untreated. Addison’s Disease Pathophysiology: Hyposecretion of adrenal cortex hormones (corticosteroids, glucocorticoids, and aldosterone). Signs and Symptoms: Lethargy, nausea, vomiting, muscle weakness, weight loss, dehydration. Cushing’s Syndrome Pathophysiology: Hypersecretion of cortisol, often due to a pituitary or adrenal tumor or chronic use of steroid hormones. Signs and Symptoms: Redistribution of body fat, "buffalo hump," "moon face," obese abdomen with striae, thin extremities, hypertension, high blood glucose, increased urination, increased thirst. Diabetes Mellitus (Type 1 and Type 2) Type 1 Pathophysiology: Autoimmune destruction of pancreatic beta cells leading to no insulin production. Type 2 Pathophysiology: Insulin resistance with eventual loss of insulin production, often associated with obesity. Signs and Symptoms: High blood glucose, polyuria, polydipsia, polyphagia, weight loss (Type 1), potential ketoacidosis (Type 1), cardiovascular complications, neuropathy, and retinopathy (both types). Pituitary Dwarfism Pathophysiology: Hyposecretion of growth hormone during childhood. Signs and Symptoms: Short stature, facial bone abnormalities, delayed puberty. Gigantism Pathophysiology: Hypersecretion of growth hormone during childhood. Signs and Symptoms: Increased growth of bones, especially in the face, delayed puberty. Acromegaly Pathophysiology: Hypersecretion of growth hormone during adulthood. Signs and Symptoms: Enlarged hands, feet, and facial bones, thickened skin, organ enlargement, metabolic disturbances. Diabetes Insipidus Pathophysiology: Hyposecretion of antidiuretic hormone (ADH), leading to the kidneys' inability to reabsorb water. Signs and Symptoms: Excessive urination, increased thirst, muscle cramping, potential cardiac arrhythmias due to electrolyte imbalances. Cretinism Pathophysiology: Hyposecretion of thyroid hormones during fetal development. Signs and Symptoms: Mental retardation, short stature, abnormal bone growth. Myxedema Pathophysiology: Hypothyroidism in adults. Signs and Symptoms: Reduced metabolic rate, muscle weakness, dry hair and skin, lethargy. Graves’ Disease Pathophysiology: Hyperthyroidism due to autoimmune response. Signs and Symptoms: Increased metabolic rate, weight loss, nervousness, increased sweating, exophthalmos (bulging eyes). Functions of Hormones Antidiuretic Hormone (ADH): Stimulates water retention in kidneys, increasing blood volume. Oxytocin (OT): Stimulates uterine contractions during childbirth and milk ejection during breastfeeding. Growth Hormone (GH): Stimulates growth, cell reproduction, and cell regeneration. Thyroid-Stimulating Hormone (TSH): Stimulates the thyroid gland to produce thyroid hormones. Melanocyte-Stimulating Hormone (MSH): Stimulates melanin production in the skin. Adrenocorticotropic Hormone (ACTH): Stimulates the adrenal cortex to release cortisol. Follicle-Stimulating Hormone (FSH): Stimulates the growth of ovarian follicles in females and sperm production in males. Luteinizing Hormone (LH): Triggers ovulation and stimulates the production of estrogen and progesterone in females, and testosterone in males. Prolactin (PRL): Stimulates milk production in females and works with LH in males. Triiodothyronine (T3) and Thyroxine (T4): Regulate metabolism, growth, and development. Calcitonin: Lowers blood calcium levels by inhibiting bone resorption.  Parathyroid Hormone (PTH): Increases blood calcium levels by stimulating bone resorption. Melatonin: Regulates sleep-wake cycles and seasonal biological rhythms. Aldosterone (ALD): Regulates sodium and potassium levels, thus controlling blood pressure and fluid balance. Cortisol and Cortisone: Help the body respond to stress, have anti-inflammatory effects, and regulate metabolism. Epinephrine (Adrenaline): Increases heart rate, blood pressure, and blood glucose levels, preparing the body for a fight-or-flight response. Norepinephrine (Noradrenaline): Similar to epinephrine, helps manage stress and increases heart rate and blood pressure. Glucagon: Raises blood glucose levels by stimulating the liver to convert glycogen into glucose. Insulin: Lowers blood glucose levels by facilitating cellular uptake of glucose. Estrogen and Progesterone: Regulate female reproductive cycles and maintain pregnancy. Testosterone: Regulates male reproductive functions and secondary sexual characteristics. The Nervous System Trigeminal Neuralgia (Tic Douloureux) Pathophysiology: Caused by degenerative changes or compression/impingement of the trigeminal nerve (Cranial Nerve V). Signs and Symptoms: Deep, sharp, stabbing pain along the nerve distribution, which can be extremely severe. Bell’s Palsy Pathophysiology: Inflammation of Cranial Nerve XII, often due to trauma or infection caused by a virus or bacterium. Signs and Symptoms: Temporary paralysis of one side of the face, loss of muscle function for facial expressions, tearing of the eye, drooling, headaches. Alzheimer’s Disease Pathophysiology: Progressive degenerative disease of the cerebral cortex, involving loss of neurotransmitters and degeneration of neurons. Signs and Symptoms: Memory loss, dementia, disorientation, confusion, irritability, personality changes, speech deterioration. Amyotrophic Lateral Sclerosis (ALS) Pathophysiology: Progressive degenerative disease affecting motor neurons of cranial and spinal nerves, potentially linked to hereditary and environmental factors. Signs and Symptoms: Muscle spasms, cramps, fatigue, muscle weakness, slurred speech, difficulty chewing and swallowing, later stages include choking, paralysis, and breathing difficulty. Cerebral Palsy Pathophysiology: Nonprogressive disorder affecting motor function due to brain damage from infection, trauma, or toxic conditions during or before birth. Signs and Symptoms: Impaired motor functions like speech and walking, muscle spasms, spastic paralysis. Cerebrovascular Accident (CVA) Pathophysiology: Interruption of blood flow to the brain, causing ischemia and necrosis of brain tissue; can be ischemic (thrombosis or embolism) or hemorrhagic. Signs and Symptoms: Numbness, paralysis of one side of the face/body, slurred speech, aphasia, muscle weakness, mental confusion, visual impairments, coma, or death. Epilepsy Pathophysiology: Abnormal increase in electrical impulses in the brain causing seizures; can be due to brain injuries, tumors, infections, metabolic issues, or unknown causes. Signs and Symptoms: Nausea, visual disturbances, abnormal tastes and smells, loss of consciousness, muscle tremors, convulsions, loss of sensation. Encephalitis Pathophysiology: Inflammation of the brain, often due to viral infections. Signs and Symptoms: Fever, headache, lethargy, delirium, seizures, possible brain damage, coma, and death. Huntington’s Disease (Huntington’s Chorea) Pathophysiology: Progressive hereditary disorder causing degeneration of neurons in the brain, autosomal dominant defect on chromosome 4.  Signs and Symptoms: Muscle rigidity, mental changes, depression, dystonia, ataxia, choreic movements, difficulty swallowing, dementia. Parkinson’s Disease Pathophysiology: Degenerative disease affecting motor neurons, specifically the substantia nigra which fails to produce dopamine. Signs and Symptoms: Resting tremors, slow movements, slowed speech, lack of coordination and balance, shuffling gait, mask-like facial expression. Meningitis Pathophysiology: Inflammation of the meninges caused by viral or bacterial infection. Signs and Symptoms: Fever, headache, neck stiffness, confusion, vomiting, severe neurological issues if bacterial. Poliomyelitis Pathophysiology: Inflammation of the gray matter of the spinal cord due to poliovirus infection. Signs and Symptoms: Paralysis, muscle atrophy, respiratory failure, digestive and respiratory system infections, potentially fatal. Astigmatism Pathophysiology: Abnormal curvature of the lens causing irregular bending of light entering the eye. Signs and Symptoms: Blurred or distorted vision. Myopia Pathophysiology: Elongated eyeball shape causing difficulty seeing distant objects clearly. Signs and Symptoms: Nearsightedness. Hyperopia Pathophysiology: Shortened eyeball shape causing difficulty seeing close objects clearly. Signs and Symptoms: Farsightedness. Nyctalopia Pathophysiology: Night blindness due to retinol or vitamin A deficiency or retinal degeneration. Signs and Symptoms: Difficulty seeing in low light or darkness. Conjunctivitis Pathophysiology: Inflammation of the conjunctiva, usually due to bacterial or viral infection. Signs and Symptoms: Redness, itching, discharge, highly contagious. Strabismus Pathophysiology: Deviation of one or both eyes, caused by trauma or inherited factors. Signs and Symptoms: Misalignment of eyes, can be medial (convergent) or lateral (divergent). Glaucoma Pathophysiology: Increased intraocular pressure due to excessive buildup of aqueous humor, potentially leading to optic nerve damage. Signs and Symptoms: Visual field loss, potential blindness if untreated. Cataracts Pathophysiology: Cloudiness in vision caused by calcium buildup in the lens or cornea, often due to aging, trauma, or medication. Signs and Symptoms: Foggy or blurred vision. Tinnitus Pathophysiology: Ringing in the ears, caused by injury, infection, otosclerosis, or age- related auditory deterioration. Signs and Symptoms: Persistent ringing, buzzing, or other noise in the ears. Otitis Media vs. Otitis Interna Pathophysiology (Otitis Media): Middle ear infection, often following upper respiratory infections. Signs and Symptoms (Otitis Media): Ear pain, inflammation, fever, more common in children. Pathophysiology (Otitis Interna): Inner ear infection, also known as labyrinthitis. Signs and Symptoms (Otitis Interna): Dizziness (vertigo), nausea, inflammation. Meniere’s Disease Pathophysiology: Accumulation of endolymph in the inner ear, affecting males more commonly. Signs and Symptoms: Vertigo, tinnitus, nausea, progressive hearing loss. The Urinary System Hematuria Pathophysiology: Presence of blood in the urine. Signs and Symptoms: Blood in the urine, can be microscopic or visible. Acute Renal Failure Pathophysiology: Sudden loss of kidney function due to various causes like hypotension, trauma, dehydration, or infections. Signs and Symptoms: Decreased urine output, edema, back or abdominal pain, hypertension, and increased potassium levels. Chronic Renal Failure Pathophysiology: Gradual loss of kidney function over time, often due to hypertension, diabetes, or polycystic kidney disease. Signs and Symptoms: Often asymptomatic initially, later symptoms include fatigue, hypertension, and swelling. Glomerulonephritis Pathophysiology: Inflammation of the glomeruli, often due to immune response to infections like Streptococcus. Signs and Symptoms: Hematuria, hypertension, nausea, anemia, tiredness, seizures, and possibly coma. Polycystic Kidney Disease (PKD) Pathophysiology: Genetic disorder causing cyst formation in the kidneys. Signs and Symptoms: Hypertension, hematuria, anemia, back and abdominal pain, fatigue, and kidney stones. Pyelonephritis Pathophysiology: Bacterial infection of the kidney tissue. Signs and Symptoms: White blood cell casts in urine, back/flank/abdominal pain, fever, fatigue, blood and pus in urine. Urinary Tract Infection (UTI) Pathophysiology: Bacterial infection, more common in females due to shorter urethra. Signs and Symptoms: Increased urinary frequency, pain during urination, urine with blood or pus. Nephrotic Syndrome Pathophysiology: Increased glomerular permeability leading to protein loss in urine. Signs and Symptoms: Proteinuria, hypoalbuminemia, generalized edema, and hyperlipidemia. Proteinuria Pathophysiology: Presence of excess protein in urine, often due to kidney damage. Signs and Symptoms: Foamy urine, signs of underlying kidney condition. Hydronephrosis Pathophysiology: Dilation of the renal pelvis due to urine outflow obstruction. Signs and Symptoms: Pain, recurrent UTIs, hypertension. Hypoalbuminemia Pathophysiology: Low albumin levels due to urinary loss. Signs and Symptoms: Edema, ascites, muscle weakness, fatigue. Nephritic Syndrome Pathophysiology: Inflammatory damage to glomeruli causing hematuria and restricted filtration. Signs and Symptoms: Hematuria, oliguria, hypertension, azotemia. Oliguria Pathophysiology: Reduced urine output, often due to kidney failure. Signs and Symptoms: Less than 400 mL urine output per day, symptoms of underlying cause. Azotemia Pathophysiology: High levels of nitrogen-containing compounds in blood due to kidney dysfunction. Signs and Symptoms: Elevated BUN and creatinine levels, symptoms of kidney disease. Goodpasture’s Syndrome Pathophysiology: Autoimmune disorder attacking glomerular and pulmonary basement membranes. Signs and Symptoms: Hematuria, hemoptysis, glomerulonephritis. Cystitis Pathophysiology: Inflammation of the urinary bladder, often due to bacterial infection. Signs and Symptoms: Frequent urge to urinate, pain during urination, cloudy or bloody urine, fever, fatigue. Nocturia Pathophysiology: Frequent urination during the night. Signs and Symptoms: Waking up multiple times at night to urinate. Polyuria Pathophysiology: Excessive urine production. Signs and Symptoms: Producing abnormally large volumes of dilute urine. Uremia Pathophysiology: Accumulation of waste products in the blood due to kidney dysfunction. Signs and Symptoms: Fatigue, nausea, loss of appetite, confusion, fluid retention. Kidney Stones Pathophysiology: Crystallization of minerals in the urine forming hard deposits. Signs and Symptoms: Severe back or abdominal pain, nausea, fever, urgency to void, hematuria. Types: Calcium oxalate, calcium phosphate, uric acid, and struvite (ammonium magnesium phosphate) stones. 1. Calcium Oxalate Stones - Pathophysiology: These stones form when calcium combines with oxalate in the urine. They are the most common type of kidney stones. - Factors: Diets high in oxalate (found in certain fruits, vegetables, nuts, and chocolate), high doses of vitamin D, intestinal bypass surgery, and several metabolic disorders can increase the concentration of calcium or oxalate in urine. - Signs and Symptoms: Severe back or abdominal pain, nausea, fever, urgency to void, and hematuria (blood in the urine). 2. Calcium Phosphate Stones - Pathophysiology: Form in alkaline urine, where calcium binds with phosphate. - Factors: Can be associated with hyperparathyroidism and renal tubular acidosis. - Signs and Symptoms: Similar to calcium oxalate stones, including severe pain, nausea, fever, urgency to void, and hematuria. 3. Uric Acid Stones - Pathophysiology: These stones form in individuals who lose too much fluid or eat a high-protein diet, which increases the amount of acid in the urine. - Factors: Gout, dehydration, and high intake of animal proteins can contribute to their formation. - Signs and Symptoms: Severe pain, nausea, fever, urgency to void, and hematuria. 4. Struvite Stones (Magnesium Ammonium Phosphate) - Pathophysiology: Typically form in response to an infection. They can grow quickly and become quite large. - Factors: Commonly associated with urinary tract infections caused by bacteria that produce urease, such as Proteus and Klebsiella species. - Signs and Symptoms: Severe pain, recurrent urinary tract infections, fever, and hematuria. 5. Cystine Stones - Pathophysiology: These are rare and form in individuals with a hereditary disorder called cystinuria, which causes the kidneys to excrete too much of a specific amino acid. - Factors: Genetic predisposition due to cystinuria. - Signs and Symptoms: Severe pain, nausea, fever, urgency to void, and hematuria.