Chapter 1 & 13 NOTES PDF

**Chapter 1** **[General Concepts]** - Must understand cellular processes to understand disease. - Pathophysiology: the study of the disorder or breakdown of the human body's function. - Disease occurs when there is a disruption in homeostasis or deviation from normal. **[Homeosta...

**Chapter 1** **[General Concepts]** - Must understand cellular processes to understand disease. - Pathophysiology: the study of the disorder or breakdown of the human body's function. - Disease occurs when there is a disruption in homeostasis or deviation from normal. **[Homeostasis]** - Dynamic process -- not stagnant, constantly changing - The relative consistency of the body's internal processes - Give and take system - Equilibrium is necessary for all cells - Self-regulating - Compensatory - Negative feedback---most common (e.g., glucose regulation) - Positive feedback (e.g., contractions of labor) - May use many means to correct one imbalance \- A negative feedback example is the regulation of blood sugar levels in the body, where rising blood sugar triggers insulin release to lower it, while a positive feedback example is the process of childbirth contractions, where increasing contractions stimulate further contractions until delivery occurs More examples: Negative Feedback: - **Body temperature regulation:** When body temperature rises, the body starts sweating to cool down.  - **Blood pressure control:** When blood pressure increases, the body triggers mechanisms to lower it.  - **Hormone regulation:** When a hormone level gets too high, the body produces less of that hormone.  - **Workplace feedback:** \"I noticed your recent reports were missing key details, could you focus on including all necessary information next time?\"  Positive Feedback: amplifies changes! - - - - Key takeaway: Negative feedback loops aim to maintain stability by counteracting a change, while positive feedback loops amplify a change, often leading to a rapid outcome **[Factors That Determine baseline normal for patients]** - Age - Gender - Genetic and ethnic background - Geographic area - Time of day - Environment: altitude, temp, etc. - Remember, findings are only relevant to the individual's "normal." **[Pathophysiology]** - Etiology: cause or reason for the event - May include agents, age, gender, health, nutritional status, genetics, etc. - Idiopathic: unknown (Example: idiopathic hypertension.) - Iatrogenic: unintended effect of a medical treatment OR relating to illness caused by medical examination or treatment. - - - - - - - - - Pathogenesis: development and evolution of a disease - Clinical manifestations - Includes S/S of the disease, stages of the disease, acute vs. chronic - Epidemiology - patterns of diseases in a group of people Question time! - In order to understand pathophysiology, we need a solid working knowledge of which of the following? - A. The patients history - B. Where the patient lives - C. Epidemiology of the patient's region - **D. Normal and diseased states** - E. All of the above **[Cellular Function]** - What do those little things do? Why is that important? **[Cellular Attributes]** - Ability to exchange material with their environment - Ability to obtain energy from organic nutrients (glucose\* MAIN STAPLE. and oxygen are key) - Ability to manufacture complex molecules - Ability to replicate themselves (mitosis) -- EXAMPLE: SKIN CELLS The **[Parts of The Cell- What is in there?]** The **[Parts of The Cell- What is in there?]** **Functional Cell Components** **Three major components of eukaryotic cells** - Nucleus - Control center - Genetic code - Cytoplasm - Contains water, electrolytes, suspended protein, neutral fats, and glycogen (glycogen is the stored form of glucose) - Contains the organelles - Cell membrane - Semipermeable -- phospholipid bilayer - Contains protein receptors Notes: Oxygen, Fats, can pass through, DNA CONTAINS ALL THE codes for all the proteins in the body.  - Selective permeability **[Functional Cell Components: Organelles]** - Ribosomes - Site for protein synthesis : for muscle, hair or skin - Endoplasmic reticulum (ER) - Ribosomes usually attached here - Can also produce other substances in the cell such as fats and enzymes -- primarly used to store ribosomes and it's a structure for them to be on. - Golgi apparatus (THINK OF UPS- package and send out) - Packages substances that are to be excreted from cell - Lysosomes - Break down cell products and foreign bodies to be used again - Peroxisomes - Break down toxins in the cell - Mitochondria - Power plants - Aerobic metabolism---ATP - Microtubules (filtration) - Cilia and flagella (move sperms) - Hair-like processes - Aid in movement - Membrane receptors - Open and close ion channels allowing substances to pass through - OR they send second messengers into cells **Question time!** The cells semipermeable membrane allows it to maintain a proper shape. - **True** or false? - **True.** - The cell membrane, also known as the **plasma membrane**, is **semipermeable**, meaning it allows certain substances to pass through while blocking others. This selective permeability helps maintain the internal environment of the cell, which is crucial for maintaining the cell\'s shape and function. By regulating the movement of ions, water, nutrients, and waste products, the membrane contributes to the cell\'s homeostasis, which is key to preserving the proper shape and internal balance. Youtube Chapter 1 part 2 https://www.youtube.com/watch?v=wFIOi1RQ0Qs **[Cellular transportation]**\ who is invited and who is not? **[Cellular Transportation\ Solution definition = a solvent with a solute dissolve in it. Solvent is major liquid (water) and solute is a substance that is dissolved in the solvent that create a solution. ]** - Passive - Diffusion -- movement of solutes from high to low concentration - Osmosis -- movement of water (or another solvent) to high solute concentration (such as isotonic solutions) - Facilitated diffusion -- molecules move from low to high concentration with a carrier molecule - Active transport (uses ATP-energy) - Sodium Potassium pump (helps re-establish proper ion concentrations in and out of cells.) = Sodium Potassium pump uses energy to balance sodium and potassium\*\* - Endocytosis (such as phagocytosis) = Suck things in - Exocytosis = excretion 9781284121131\_CH01\_FIG05.jpg  9781284121131\_CH01\_FIG08.jpg= USES ENERGRY!\* Sodium Potassium Pump Active and uses energy! Its going to pump sodium out of the cell and potassium into the cell.!!! And has to go through protein channel. Establishes the proper intra and extracellular solutions! Resting cell -- you will have sodium on the outside Na+ Potassium in a resting cell it will be inside K+  Question time! - Active transport includes which of the following? - A. Diffusion - B. Osmosis - C. Sodium potassium pump - D. Endocytosis - **E. Two of the above** Active transport includes: **C. Sodium-potassium pump**\ **D. Endocytosis** These processes require energy (usually ATP) to move substances against their concentration gradient. Diffusion and osmosis, on the other hand, are passive processes and do not require energy. So, the correct answer would be: **[Cell Cycle = cells replicate through mitosis. Cell needs 23 pairs of chromosomes, 46 total. ]** - Cell proliferation - Cells divide and reproduce - Mitosis (cells replicate 46) - Meiosis (division of sperm and oocytes to half the chromosome number 23) 9781284121131\_CH01\_FIG09.jpg Cell Cycle\ (2 of 2) - Cell differentiation = divides - Fertilized cells become more specialized as they mature to organs - Begins after fertilization - Generalized to specific (cells to layers to organs) Question Time! - The main difference between mitosis and meiosis is that cells have 46 pairs of chromosomes after mitosis and 23 pairs of chromosomes after meiosis. - True or false? - The statement is incorrect because after mitosis, the resulting daughter cells have the same number of chromosomes as the original cell (46 chromosomes in humans, which is 23 pairs), not 46 pairs. - - In meiosis, however, the chromosome number is halved, and the resulting daughter cells have 23 chromosomes (not 23 pairs). These are haploid cells, which will combine during fertilization to restore the diploid number (46 chromosomes or 23 pairs in humans). - **[Cell Changes]** **[Atrophy]** Decrease workload ( or disease state) -\> decreased size of organelles -\> decrease energy use -\> drecrease functionality in disease state Example: cast on leg, leg is smaller, decrease of workload. If you exercise it can get back to normal. **[Hypertrophy = Increase of the size of the cell itself (don't replicate)]** Increase workload ( or disease state) -\> Increased size of organelles -\> Increase contractitlity -\> decrease functionality in disease state Example: when the heart undergoes abnormality, the heart has to work harder, because the heart is already flabby and stretched out so it pumps harder. **[Hyperplasia = increase in the number of cells (will replicate)]** Increase workload Physiological state -\> Increase tissue size due to the increased number of cells -\> increased functionality -- 2 types of compensatory & hormonal Example: Keep rubbing your fingers on something and it with continual growing until you stop. **[Metaplasia = replacement of normal cells with abnormal cells]** Pathological -\> Normal cells -\> ARE REPLACED BY abnormal cells = such as cigarettes smoking. Example: barettes esophagus, cigerettes smoking.. **[Dysplasia= normal cells to abnormal shape and size ]** Pathological -\> Normal cells \> MUTATION TO ABNORMAL -\> Abnormal shape & size - \> Epithelial tissue  Question time! - When cilia are lost in the respiratory tract, this is an example of what type of cell change? - A. metaplasia - B. Dysplasia - C. hyperplasia - D. hypertrophy The correct answer is **A. metaplasia**. - Metaplasia refers to the reversible replacement of one differentiated cell type with another. In the case of the respiratory tract, the loss of cilia and the possible replacement of ciliated epithelial cells with squamous epithelial cells is a classic example of metaplasia. This often occurs in response to chronic irritation, such as smoking, which causes the ciliated columnar cells to transform into squamous cells, which are more resistant to injury but less effective at clearing debris. Youtube Chapter 1 Part 3 **[Cell injury]** - Most diseases start with cell injury. - Can be reversible to a point. - In normal states, it is balanced with cell renewal. **[Physiological Cell Death = normal breakdown of cells]** **Apoptosis-\> "Programmed suicide"** Normal process of cell replacement & development replacement & development *Balance between death and regeneration* **[Causes of Cell Injury]** - Physical agents - Mechanical forces - Extreme temperature - Electrical - Radiation - Ionizing - Ultraviolet - Non-ionizing - Chemical - Poisonings - Drugs - Biological agents - Nutritional imbalances **[Mechanisms of Injury = loss of blood supply to an area]** - Ischemia leading to potential Necrosis or cell death (Decrease of nutrients, oxygen and blood supply) - Example: stroke, blot clot. - Free radicals causing all sorts of cell damage (charge particles that can get into tissue) we can use antioxidants to fight off free radicals. If not it can cause cell damage. **[Necrotic Cell Death]** Coagulative = (Interruption in the blood flow) \> Firm & opaque (KIDNEYS AND HEART) Liquefactive -\> Walled-off liquid goo (Brain) Caseous -\> "Cased"-off cheese globules (Lungs with Tuberculosis) Fatty -\> Opaque, chalky, soapy (Fat) **[Gangrene:]** Caused by severe hypoxic injury Progressed coagulative necrosis and bacterial invasion Dry -\> Coagulative Wet -\> Liquid Gas -\> Releases gas into tissue, Caused by Clostridium bacterium **[Let's practice! Necrosis and gangrene]**  \_= liquefactive necrosis in the brain 9781284121131\_CH01\_FIG13.jpg =Casueous necrosis  =coagulative cerebellum 9781284121131\_CH01\_FIG14.jpg=Fat necrosis  =wet gangrene 9781284121131\_CH01\_FIG18.jpg =GAS gangrene  = dry gangrene **[Cancer]**: The progression (or not) to cancer from normal cells **Alterations in Cell Growth and Replication** - Neoplasia = "new growth" - Lacks normal controls and regulation - Can originate in one organ - Prostate most common in men - Breast most common in women - Lung leading cause of death in men and women - Can also spread from another site **[Carcinogenesis]** - Cancer development - Steps in carcinogenesis 1. Initiation: introduction of the agent (whatever caused it) 2. Promotion: initiation of uncontrolled growth (grow into bloodstream or tissue) 3. Progression: permanent malignant changes - Heredity -- what we gain via parents - **Oncogenes** -- genes that get turned on in cancerous cells. They begin as **proto-oncogenes** which direct normal cell growth and differentiation. Cancer causing agents convert them to oncogenes which cause abnormal cell growth and differentiation - Carcinogens -- environmental changes that lead to cancerous cells **[Benign vs. Malignant Cancer]** - **Benign** - Slow, progressive, localized, well defined, resembles host (more differentiated), grows by expansion, does not usually cause death - **Problems with benign growth is pressure and are encapsulated.** - **Malignant** - Rapid growing, spreads (metastasis), fatal, highly undifferentiated - Please note! More differentiated in cancer means the cells are closer in structure to the original tissue.... undifferentiated means unlike the original tissue - TO KNOW: Malignant is rapid growing, invasive, it spreads, it can take into surround tissues, it can move into surrounding organs, it moves into the blood stream into distal and different areas 9781284121131\_CH01\_FIG20A.jpg **[Question time!]** Malignant cells tend to look like the original tissue. TRUE OR **FLASE**? FALSE Malignant cells (cancer cells) tend to look **less like the original tissue** compared to normal cells. This lack of resemblance is known as **anaplasia**. Malignant cells often exhibit irregular shapes, larger nuclei, and a loss of differentiation, meaning they do not maintain the structure or function of the tissue from which they originated. This is in contrast to **benign cells**, which usually maintain a more normal appearance.  **CHAPTER 1 PART 4** **[Clinical Manifestations]** **C**hange in bowel or bladder habits **A** sore that doesn't heal **U**nusual bleeding or discharge **T**hickening or lump in the breast or elsewhere **I**ndigestion or difficulty swallowing **O**bvious change in a wart or mole **N**agging cough or hoarseness **[Complications]** - Anemia -- low O2 - Cachexia - wasting - Fatigue - Infection - Leukopenia -- decreased wbc - Thrombocytopenia -- decreased platelets - Pain **[Classification = go according to size, nodal involment and if its. spread ]** - Staging: TNM (tumor node metastasis); based on spread of the disease - Grading: according to histology - I, II, III, and IV: as it increases, the tumor is more invasive and prone to spreading via blood vessels and/or lymph vessels and surround tissues **[Classification - tumor]**\ - Primary tumor (T) - TX: Main tumor cannot be measured. - T0: Main tumor cannot be found. - T1, T2, T3, T4: Refers to the size and/or extent of the main tumor. The higher the number after the T, the larger the tumor or the more it has grown into nearby tissues. **[Classification -- Nodes]** - Regional lymph nodes (N) - NX: Cancer in nearby lymph nodes cannot be measured. - N0: There is no cancer in nearby lymph nodes. - N1, N2, N3: Refers to the number and location of lymph nodes that contain cancer. The higher the number after the N, the more lymph nodes that contain cancer. **[Classification -- Metastasis (whether it spread or not)]** - Distant metastasis (M) - MX: Metastasis cannot be measured. - M0: Cancer has not spread to other parts of the body. - M1: Cancer has spread to other parts of the body. 9781284121131\_CH01\_FIG23.jpg This picture is in the colon  **[Treatment]** - Three goals - Curative - Palliative - Prophylactic- "if you are in doubt send them out" -- go CHECK OUT your symptoms. - Surgery - Radiation - Chemotherapy - Hormone and antihormone therapy - immunotherapy **[Question time!]** - Stage IV Cancer most likely: - A. Is encapsulated - B. Has no node involvement - **C. Has spread beyond the initial area of cancer** - D. To cause no symptoms in a patient **C. Has spread beyond the initial area of cancer** Stage IV cancer is classified as **advanced or metastatic**, meaning that the cancer has spread to distant parts of the body beyond the original site. It is the most severe stage of cancer. Here's why the other options are incorrect: - **A. Is encapsulated**: Encapsulation is more characteristic of benign tumors, not malignant ones. In Stage IV cancer, the tumor has typically spread, so encapsulation is unlikely. - **B. Has no node involvement**: Stage IV cancer typically involves distant metastasis, and it may also involve lymph nodes, but the defining feature is the spread beyond the initial area. - **D. To cause no symptoms in a patient**: Stage IV cancer often causes symptoms due to the spread of cancer to other organs, so it\'s less likely to be asymptomatic. **[Genetics]**  **Mitosis**: This is the process by which a somatic (body) cell divides, resulting in two identical daughter cells, each with the same number of chromosomes as the original cell. The chromosomes replicate during **interphase**, condense during **prophase**, align during **metaphase**, separate during **anaphase**, and finally, the cell divides during **telophase** and **cytokinesis**.  **Meiosis**: This is a type of cell division that occurs in **gametes** (sperm and egg cells). It reduces the chromosome number by half, resulting in four non-identical daughter cells, each with 23 chromosomes. This is important for sexual reproduction because it ensures that the offspring have the correct number of chromosomes when the sperm and egg unite. **Chromosomes = located in nucleus, long strands of DNA** - Contains genetic information - 23 pairs -- 46 chromosomes in 23 pairs.!  Humans typically have **46 chromosomes** arranged in **23 pairs**. One set of 23 chromosomes comes from the mother, and the other set comes from the father. -  **Gametes (egg and sperm cells)** have half the number of chromosomes, so they contain **23 chromosomes**. When fertilization occurs, the chromosomes from the egg and sperm combine to form a complete set of 46 chromosomes. - Sex chromosome (22 pairs autosomes XX and 1 pair sex chromosomes XY) - Karyotype: chromosome count - Phenotype: observable characteristics from genes, (height, weight etc,) - Patterns of inheritance in gene pairing. Expressed as alleles or the variations of genes (eye color) - Homozygous: Identical pairs of genes - Heterozygous: Different pairs of genes - Dominant: will show as an observable characteristic (Expressed) - Recessive: will be 'trumped' by the dominant if there, but will show if paired with another recessive **[Genetic and Congenital Disorders]** - Caused by a mutation - 800 disorders - Characterized by the patterns of transmission - Practiced in Punnett square - Dominant will show if present - Recessive will show if homozygous **[Autosomal Dominant Disorders]** - Transmitted from an affected parent to offspring regardless of gender - Examples: Marfan syndrome and neurofibromatosis **[Autosomal Dominant Disorders]** - \*Marfan syndrome - Disorder of connective tissue - Mutation on chromosome 15 - Affects eyes, skeleton, and cardiovascular system - Aortic defects - Lens displacement - Increased height with long spiderlike fingers - Funnel chest - Scoliosis - Valve defects such as regurgitation - \*Neurofibromatosis - Neurogenic tumors - Two forms - Type 1: defect on chromosome 17; subcutaneous lesions, café-au-lait spots (at least 6 at birth), freckles, scoliosis, erosive bone defects, and nervous system tumors - Type 2: defect on chromosome 22; tumors of the acoustic nerve and may be on other cranial and spinal nerves as well. - Treatment - Palliative removal of tumors **[Autosomal Recessive Disorders]** - Rare - Affects both genders - One out of four will be affected - Two out of four will be carriers - Onset early - Usually presents as a deficient enzyme - Examples: PKU and Tay-Sachs **[Autosomal Recessive Disorders: PKU = low diet of phenylalanine]** - Mutation on chromosome 12 leads to an error in converting phenylalanine to tyrosine (both are amino acids that create proteins) - Appears normal at birth then fails to meet milestones - Progressive neurological decline - If untreated, can lead to severe intellectual disability. Early testing and need a diet low in phenylalanine **[Autosomal Recessive Disorders: Tay-Sachs 17:30]**\ (1 of 2) - \*Progressive disorder due to mutation (chromosome 15) of hexosaminidase (enzyme) A Necessary to break down certain lipids - Lipids accumulate, destroying and demyelinating (FAT) nerve cells - \*Nerve cell destruction of leads to a progressive mental and motor, sensory decrease /deterioration - Most are of Jewish decent - Three forms: infantile, juvenile, adult (rare) - Appears normal at birth, then the infant begins to miss milestones - Progresses to seizures, muscular rigidity, and blindness - Usually fatal by 5 years of age - Diagnosis: history, physical examination, and low serum and amniotic hexosaminidase A levels - No cure- - Genetic counseling suggested **[X-Linked Disorders]** - Sex-linked disorders are almost always X linked. - Example: Fragile X syndrome - **Fragile X syndrome** - Associated with the X chromosome - Manifestations: long face with large mandible, large ears, large testicles, mental retardation, learning disabilities, speech delays, connective tissue disorders, behavioral issues, and autism spectrum disorder - Diagnosis: history, physical examination, genetic testing - Treatment: supportive **[Multifactorial Inheritance Disorders]**\ (1 of 2) - Result from an interaction between environmental and genetic factors - Less predictable - Extremely common - May be expressed at birth or later - Examples: cleft lip/palate, clubfoot, congenital dislocation of hips, congenital heart defects, pyloric stenosis, urinary tract malformations, diabetes mellitus, hypertension, cancer, and psychiatric disorders - Cleft lip and palate - Improper formation of soft tissues of mouth and lips - Unilateral or bilateral deformities lead to feeding and nutritional issues - Maternal smoking, diabetes, and seizure medication use (first trimester) are important risk factors - Diagnosis: prenatal ultrasound - Treatment: surgery, speech therapy **[Chromosomal Disorders]** - May be related to abnormality in chromosomal number and/or duplication that occurs in meiosis - More than 60 syndromes **[Trisomy 21 (Down's Syndrome)]**\ (1 of 2) - Risk increases with maternal age - Manifestations: small square head, upward slant of eyes, small low-set ears, fat pad on back of the neck, open mouth with protruding tongue, simian crease, varying degrees of mental retardation, and behavioral issues - Also associated with congenital heart defects, ocular issues, leukemia, respiratory complications, gastrointestinal complications, hypothyroidism. - 50% of patients with Down's syndrome develop Alzheimer\'s disease by age 50. - Diagnosis: parental screening including amniocentesis, hormone levels, 4D ultrasound. 4d ultrasound can also look at spina bifida = when there's a nonunion of the posterior aspect of the vertebral body. - Treatment: symptomatic and supportive. **[Monosomy X]** = NO MENTAL RETARDATION\ (Turner's Syndrome) = happens in females - Deletion of all or part of an X---occurs spontaneously - Specific gene(s) associated: not known - No Y chromosome, so female - Manifestations: gonadal streaks instead of ovaries, (infertility) short stature, increased weight, neck webbing, small lower jaw, drooping eyelids, small fingernails, and widely spaced nipples, No mental retardation present Trisomy X = happens in males\ (Klinefelter's Syndrome) - One or more extra X chromosomes with the presence of the Y - Male appearance - Often undetected - Manifestations: gynecomastia, small testes and penis, tall stature, increased weight, and sparse body hair - Also associated with learning disabilities, behavioral problems, sexual dysfunction, pulmonary disease, varicose veins, osteoporosis, and breast cancer - Treatment: testosterone Let's practice! 9781284121131\_CH01\_FIG26.jpg = Fragile X  = Marfan syndrome 9781284121131\_CH01\_FIG25.jpg =Nuerofibrocytosis type 1 = Turner syndrome 9781284121131\_CH01\_FIG30.jpg = (Klinefelter's Syndrome)  Down syndrome 9781284121131\_CH01\_FIG27.jpg Cleft palate **[Chapter 13- Integumentary Function]** **[Integumentary System]** - Functions - Protects the body from pathogen invasions - Regulates temperature - Senses environmental changes - Maintains water balance - Includes skin, nails, hair, mucous membranes, and glands **[Skin]** - Layers - Hypodermis: inner fat - Dermis: middle connective tissue, glands (sweat and oil glands), blood vessels and nerves - Epidermis: outer squamous epithelium - Melanin: pigment that protects  9781284121131\_CH13\_FIG02.jpg **[Integumentary Conditions- Alterations primarily result in impaired skin integrity and possibly infections. 9:00]** **[Vascular birthmarks]** - Hemangiomas (you can get them in the liver too) - Most are benign - Port-wine stains - Discolorations that look like wine was spilled on the skin. - beigns **[Pigmented Birthmarks]** - Cluster of pigment cells - Moles (watch for changes!) - Café au lait spots - Very common and are color of coffee with milk. - One spot alone is not usually a concern, but several spots larger than a quarter can be neurofibromatosis. - Mongolian spots - Flat, bluish-gray patches, often found on the lower back or buttocks **Let's practice!**  Hemangioma 9781284121131\_CH13\_FIG07.jpgMongolian spot port wine stain 9781284121131\_CH13\_FIG06.jpg Café au lait spot **[Inflammatory integumentary disorders]** **[2 types of Dermatitis]** - Contact dermatitis: Acute inflammatory reaction triggered by direct exposure to an irritant or allergen-producing substance - Causes inflammation and response similar to a burn - Redness, swelling and pain , can be blistered too - Atopic dermatitis: Also called eczema, Chronic inflammatory condition triggered by an allergen or immune system dysfunction - Usually face, scalp, hands or feet. Knees and elbows may be in older patients - Red to brown skin patches with cracked scaly skin **[Urticaria]** - Hives : open blood vessels to bring blood to surface of skin - Allergen or stress cause histamine to be released - Example: If you have a bad allergic reaction where you release histamine on a systemic level and it opens all your blood vessels youll have a decrease in systemic blood pressure because blood moves out to the surface of skin., which can cause people to black out because it doesn't pump enough blood **[Psoriasis = cells proliferate, build up, get scaly and produce too much every 3-4 days]** - Common chronic inflammatory condition that affects skin cell life cycle. - Cellular proliferation is significantly increased, causing cells to build up too rapidly on the skin's surface. - Specific cause is unknown. May be environmental, alcohol, genetic or one thought is: autoimmune where t cells attack skin and substances are released which increase keratinocyte (top skin cells) production - Normally takes weeks for cell turn over, but occurs over 3--4 days with psoriasis. - May also have arthritis---psoriatic arthritis.  Note: will test on what is the definition of TERMS not so much pictures Let's practice 9781284121131\_CH13\_FIG12.jpg contact dermatitis  psoriorsi9781284121131\_CH13\_FIG14.jpg = urticaria = Atopic dermatitis **[Infectious integumentary disorders]** - Skin infections are common. - Organisms gain access through breach in skin or mucous membrane. - This triggers inflammatory responses. - Can occur in any skin layer or structure. - Severity varies. - Resolves with treatment. **[Bacterial Infections]** - Can be caused by any of the normal flora bacteria such as *Staphylococcus* and *Streptococcus* - Folliculitis - Involving the hair follicles - Characterized by tender, swollen areas that form around hair follicles, often on the neck, breasts, buttocks, and face - Furuncles (boils) - Begin in the hair follicles and then spread into the surrounding dermis and Starts as a firm, red, painful nodule that develops into a large, painful mass, which frequently drains large amounts of purulent exudate. - Carbuncles refer to clusters of furuncles. - Impetigo - Common and highly contagious. - Can occur without an apparent skin breach, but typically arises from a break in the skin. - Lesions usually begin as small vesicles that enlarge and rupture, forming the characteristic honey-colored crust. - Can spread throughout the body through self-transfer of the exudate. - Typically caused by staphylococci, which produce a toxin that attacks collagen and promotes spread. - Cellulitis - Occurs deep in the dermis and subcutaneous tissue - Usually results from a direct invasion of pathogens through a break in the skin, especially those breaches where contamination is likely, or spreads from an existing skin infection - Appears as a swollen, warm, tender area of erythema - Systemic manifestations: indicators of infection (e.g., fever, leukocytosis, malaise, and arthralgia) - Complications: necrotizing fasciitis, septicemia, and septic shock - Necrotizing fasciitis - Rare, serious infection, but rates are rising. - Can aggressively destroy skin, fat, muscle, and other tissue. - Typically results from a highly virulent strain of gram-positive, group A, beta-hemolytic *Streptococcus* that invades through a minor cut or scrape. - The bacteria release harmful toxins that directly destroy the tissue, disrupt blood flow, and break down the tissue. - Necrotizing fasciitis - The first sign may be a small, reddish, painful area that quickly evolves into a painful bronze- or purple-colored patch. - The center of the lesion may become black and necrotic. - Exudate is often present. - The wound may grow in less than an hour. - Systemic manifestations: fever, tachycardia, hypotension, and confusion. - Complications: gangrene and shock. **[Viral Infections]** - Herpes simplex type 1 - Typically affects the lips, mouth, and face. - Usually begins in childhood. - Can involve the eyes, leading to conjunctivitis. - Transmitted by contact with infected saliva. - The primary infection may be asymptomatic. - After the primary infection, the virus remains dormant in the sensory nerve ganglion to the trigeminal nerve until it is reactivated. - Herpes zoster (shingles) - Caused by the varicella-zoster virus. - Appears in adulthood years after a primary infection of varicella in childhood. - The virus lies dormant on a cranial nerve or a spinal nerve dermatome (stretch of skin thT Innovate) until it is activated years later. - The virus affects this nerve only, giving the condition its typical unilateral manifestations. - Verrucae - Warts caused by a number of human papillomaviruses. - Can develop at any age and often resolve spontaneously. - Transmitted through direct skin contact between people or within the same person. - The human papillomavirus replicates in the skin cells, causing irregular thickening. Cauliflower appearance. Let's practice! 9781284121131\_CH13\_FIG19.jpgnectrotizing fascitis  HP9781284121131\_CH13\_FIG20.jpg Herpes zoster cellulitis 9781284121131\_CH13\_FIG17.jpg impetigo **[Parasitic infections]** - Tinea - Causes several types of superficial fungal infections. - Typically manifests as a circular, erythematous rash accompanied by pruritus and burning. - Tinea capitis: involving the scalp. - Tinea pedis: athletes foot - Scabies - Result of a mite infestation. - Female mites burrow into the epidermis, laying eggs over a period of several weeks through a series of tracts. - Burrowing and fecal matter left by the mites triggers the inflammatory process, leading to erythema and pruritus. - Pediculosis - Lice infestation: small, brown insects that feed off human blood and cannot survive long without host.  lice9781284121131\_CH13\_FIG22.jpg tinea scabies Question time! - Parasitic infections: - A. Can be due to fungi on the body - B. Need a virus to be present - C. Cause no pruritis in scabies - D. Can never be cured **[https://www.youtube.com/watch?v=KkI1Ly44quo]** **[Wounds]** 9781284121131\_CH13\_FIG26CD.jpg  **[Burns]** - First-degree burns: affect only the epidermis and cause pain, erythema, and edema - Second-degree burns: affect the epidermis and dermis and cause pain, erythema, edema, and blistering - Third-degree burns: extend into deeper tissues and cause white or blackened, charred skin that may be numb - Complications: Infections and loss of fluids 9781284121131\_CH13\_FIG27A.jpg **[Let's Practice!]**  **[Skin cancer]** - Abnormal growth of skin cells. - Most frequently occurring cancer in the United States. - Most prevalent in males, Caucasians, those with fair complexion, and those with a family history. - UV exposure, natural or artificial, is the most significant risk factor. - Most skin cancers occur on areas that have the most sun exposure. - Three types - Basal cell carcinoma - Most common - Develops from abnormal growth of the cells in the lowest layer of the epidermis - Rarely metastasizes - Squamous cell carcinoma - Involves changes in the squamous cells - Three types - Melanoma - Develops in the melanocytes - Least common type but the most serious - Often metastasizes to other areas - Varies widely in appearance. - Can be small, shiny, waxy, scaly, rough, firm, red, crusty, bleeding, and so on. - Basal cell is shiny - Squamous cell is scaly - Melanoma color change or shape change - Any suspicious skin lesion should be examined by a healthcare professional. - Suspicious features: - Asymmetry - Border irregularity - Color variations - Diameter larger than 6 mm - Any skin growth that bleeds or will not heal - Any skin growth that changes in appearance over time - Early detection is crucial to positive outcomes. - Diagnosis: history, physical examination, and biopsy. - Prevention: limiting or avoiding exposure to UV light. - Treatment: excisional surgery, laser therapy, Mohs' surgery (the skin growth is removed layer by layer, examining each layer under the microscope, until no abnormal cells remain), chemotherapy etc 9781284121131\_CH13\_FIG30.jpg  Question Time! Which of the following are good ways to detect skin cancer? - A. Checking for Asymmetry and Border irregularity - B. Looking for Color variations or changes in appearance - C. Watching or testing Moles with a Diameter larger than 6 mm - D. Checking Any skin growth that bleeds or will not heal - E. All of the above **[Rules of nine]** The rule of nines is a method for estimating the size of a burn by dividing the body\'s surface area into percentages. It\'s also known as the Wallace Rule of Nines How it works  - The head and neck are each 9% of the body\'s surface area - Each arm and hand are each 9% of the body\'s surface area - The chest and stomach are each 9% of the body\'s surface area - The upper and lower back are each 9% of the body\'s surface area - Each leg and foot are each 18% of the body\'s surface area - The genital area is 1% of the body\'s surface area Why it\'s important  - The rule of nines helps medical professionals assess the total body surface area (TBSA) of a burn patient. - This information helps determine how much fluid resuscitation a patient needs. - It also helps determine a patient\'s eventual outcomes. A diagram of a human body AI-generated content may be incorrect. **[Punnett square]** A Punnett square is a diagram that predicts the possible outcomes of a genetic cross between two organisms. It\'s a visual representation of Mendelian inheritance, which is a fundamental concept in genetics.  How it works 1. List the genotype of the female parent at the top of the square  1. List the genotype of the male parent down the left side of the square  1. Combine the alleles from each parent in the boxes inside the square  What it shows - **Genotypes**: The genetic makeup of an organism, which is represented by a combination of alleles  - **Phenotypes**: The physical makeup of an organism, which is the characteristics that can be seen  - **Probabilities**: The likelihood of an offspring having a particular genotype or phenotype  When it\'s used - To predict the outcomes of breeding plants, animals, or humans  - To determine the probability of an offspring having a particular trait   **[Barrett\'s esophagus]** Barrett\'s esophagus is a condition that occurs when the lining of the esophagus changes from normal tissue to tissue that resembles the lining of the intestine. It\'s a complication of gastroesophageal reflux disease (GERD), which is when stomach acid flows back into the esophagus.  Causes - **GERD**: Stomach acid can irritate the esophagus over time, leading to Barrett\'s esophagus.  - **Obesity**: High levels of belly fat may increase the risk.  - **Smoking**: Smoking can increase stomach acid production and weaken the lower esophageal sphincter (LES).  - **Family history**: Inherited genes may be a risk factor.  - **Age**: The average age of diagnosis is 55 years old.  Symptoms heartburn, nausea, regurgitation, and pain.  Treatment  - Lifestyle changes like dieting, exercising, and avoiding tobacco - Endoscopic surveillance to check for dysplasia Risk of cancer - Barrett\'s esophagus can increase the risk of developing esophageal cancer.  - The risk depends on the extent of dysplasia in the esop