SCI 225 Pathophysiology Midterm Study Guide Fall 2022 PDF

 Terms associated with genetic disease - Heterozygous – Having inherited different alleles - Homozygous – Having inherited two identical alleles - Genotype – Genetic composition of an individual organism - Phenotype – Outward appearance due to both genotype and environ...

 Terms associated with genetic disease - Heterozygous – Having inherited different alleles - Homozygous – Having inherited two identical alleles - Genotype – Genetic composition of an individual organism - Phenotype – Outward appearance due to both genotype and environment - Allele – One of two or more alternative forms of a gene that arise by mutation  Chromosome Disorders: - Klinefelter syndrome  XXY  Boys are born with an extra X chromosome  1 in 1,000 male births  Have a male appearance but usually sterile  50% develop gynecomastia - Down syndrome  Trisomy 21  1 in 800-1000 live births  Virtually all males are sterile; some females can reproduce  Distinctive facial features - Turner syndrome  One X chromosome is missing or partially missing  Found only in females  1 in 2000-2500 live female births - cri du chat syndrome  Piece of chromosome 5 in missing  “Cry of the cat”  describes characteristic cry of the affected child  1 in 20,000-50,000 newborns  Genetic Diseases: - Huntington disease  Autosomal dominant neurologic disorder (~ 1 in 10,000 people)  Delayed age of onset (40yo 104 F (40 C)  Meningitis - Inflammation of the brain or spinal cord - Infectious meningitis may be caused by  Bacteria  Viruses  Fungi  Parasites  Toxins - Infection may be acute, subacute, or chronic - Symptoms  Severe throbbing headache  Severe photophobia  Nuchal rigidity (neck stiffness)  Positive Kernig + Brudzinski signs  Kernig sign - Straightening the knee with the hip and knee in a flex position produces pain in the back and neck regions  Brudzinki sign - Passive flexion of the neck produces neck pain and increased rigidity  Encephalitis - Acute inflammation of the brain - Usually of viral origin - Most common forms are caused by  Bites of mosquitos, ticks, or flies  Herpes simplex 1 - May arise from  Complication of system viral diseases  After recovery from viral infections  Follow vaccination with a live attenuated virus vaccine  Typhus  Trichinosis  Malaria  Schistosomiasis (tropical virus)  Multiple sclerosis - Chronic immune-mediated inflammatory disease - Involves demyelination, scarring and loss of axons - Etiology is unknown. Onset usually between 20-40 - Risk Factors (inconclusive)   Environmental factors  Smoking  Vitamin D deficiency  Obesity  Infection o Epstein-Barr virus infection  Genetic factors  Subdural hematoma - Bleeding between the dura mater and the arachnoid membrane - Caused by tearing of veins - Most common cause of traumatic intracranial mass lesions - Forceful impact  Vehicular accidents or falls  Especially in old people and alcoholics  Epidural hematoma - Extradural - Bleeding between the dura mater and the skull - Represents 1-2% of major head injuries and occurs in all age groups  Most common in 20-40 yo - Vehicular accidents, minor falls, sporting accidents - Temporal fossa is most common site  Spondylolisthesis - Osseous defect of the pars interarticularis - Allows a vertebra to slide anteriorly in relation to the vertebra below - Commonly occurs at L5-S1 - Graded from 1-4 based on percentage of slip that occurs  Grade 1-2  Symptoms of pain the lower back and buttocks  Muscle spasms in the lower back and legs  Tightened hamstrings  Management o Exercise o Rest o Back bracing  Grade 3-4  Usually requires surgical intervention  Cauda equina syndrome - Compression of nerve roots below L1 - Caused by fracture and dislocation of spine or large posterocentral intervertebral disk herniation - Symptoms  Lower extremity motor deficits  Variable sensorimotor dysfunction   Variable reflex dysfunction  Variable bladder, bowel, and sexual dysfunction  Herniated nucleus pulposus - No intrinsic innervation (supply of nerves) - When herniated thru prolapsed disk  irritates spinal nerve and causes pain referred to segmental area  Spinal stenosis - Narrowing of the spinal canal - Causes pressure on the spinal nerves or cord - Can be congenital or acquired (more common) - Associated with trauma or arthritis - Categorized by affected area of the spine  Cervical  Thoracic  Lumbar - Acquired conditions include  Bulging disk  Facet hypertrophy  Thick, ossified posterior longitudinal ligament - Symptoms  Related to affected area of the spine  Pain  Numbness  Tingling in neck/extremities  Weakness  Difficulty walking - Surgical decompression is recommended for those w/ chronic symptoms  Cerebral vascular accident (stroke) - Causes  Blocked artery (ischemic)  Leaking or bursting of a blood vessel (hemorrhagic) - Risk Factors  Poorly controlled or uncontrolled arterial hypertension  Smoking (increases risk by 2-4 times)  Insulin resistance and diabetes mellitus  A-fib  Polycythemia (excess red blood cells)  Thrombocytopenia (excess platelets)  High total cholesterol or low high-density lipoprotein (HDL) cholesterol  Congestive heart disease/peripheral vascular disease  Hyperhomocysteinemia   Sickle cell disease  Postmenopausal hormone therapy  High sodium intake >2300 mg; Low potassium intake