Pathology Test 1

• What is chronic inflammation initiated by?


  it is initiated by monocytes and lymphocytes
• What is acute inflammation initiated by?


  it is initiated by Neutrophils

  it is immediate and is seen in response to infection or necrosis

  it is non-specific and protective
• 5 Cardinal Signs of inflammation

  rubor, tumor, calor, dolor, and functio laesa
• Systematic Effects of Inflammation


  pyrexia (fever)-body temp over 100.4 degrees F

  at high fevers (105-106) causes denaturing of proteins
• Pitting Edema


  leave impression of thumb on tissue
• Local Effect of Inflammation


  Capillary dilatation (caused by histamine release)

  Increased blood flow(hyperemia), in order to decease blood flow use of anti-histamines

  Increased warmth and redness (erythema)

  Blood plasma is mostly water

  Increased Capillary permeability, leading to extraversion (leaking out) of fluid, which in turn leads to swelling (edema)

  After 30% of fluid buildup then you can see it

  Attraction of neutrophils via chemotaxis (hurt tissue sends out chemical and neutrophils answer), they migrate to site of injury adn adhere to the endothelium of small blood vessels
• What does elevated WBC count mean?


  body is fighting something
• Where do infections occur?

  Outside of circulation/bloodstream

  Inside the issue spaces

  If inside blood stream infection is septic (way worse)
• White Blood Cell Types

  Neutrophils- 60%

  Lymphocytes- 30%

  Monocytes- 5%

  Eosinophils- 4%

  Basophils- 0-1%

  Saying: (Never Let My Engine Blow 60 30 5 4 0)
• Are there more or less White Blood Cells than Red Blood Cells?

  Less
• Postmortem autolysis

  decomposition

  Maceration: begins as the softening of tissue due to enzyme activity

  Embalming would happen before putrefaction

  Putrefaction: process of decay, first sign when sin on abdomen turns a greenish color

  Protein hydrolysis occurs as anaerobic bacteria form the digestive tract leak out and the bacteria consume and process the dead tissue releasing toxic gases such as putrescine and cadaverine, these gases give the noxious odor of dead flesh

  As gasses develop, and permeate the body, the body begins to swell

  As gasses escapes, body can begin to undergo the process of skeletonization (skin gets leathery and tissue and organs liquify out)
• Rigor Mortis


  Stiffening of joints and muscles after 4 hrs of death with peak contraction at 12-13 hours

  No O2 means no production of ATP so there is no uncoupling of the actin/myosin so muscles remain in locked position

  After 24-36 hrs contraction will disappear
• Tardieu Spots


  seen as petechial (pinpoint hemorrhaging) hemorrhages, typically in asphyxia cases
• Carbon Monoxide Poisoning


  when dead seen as bright red stains, happens everywhere
• Livor Mortis


  bluish-purple discoloration of the skin due to blood pooling (lividity) due to the pull of gravity in dependent parts of the body

  Since heart has ceased, blood collects in veins

  Once red blood cells have lysed, bruising (ecchymosis) is detected

  Visible after 2 hrs and stained is fixed after 12 hours
• Algor Mortis


  cooling of body to room temp (1.5 degrees per hour for first 12 hours)

  normal core temp is 100-101 degrees
• Palliative


  end of life care, helps patients be comfortable before death
• Somatic Death

  Death of an individual

  irreversible cessation of respiratory and circulatory function or irreversible cession of the entire brain which includes the brain stem

  Neurons are first to die within 3-7 mins

  4 Stages: algor mortis, livor mortis, rigor mortis, and postmortem autolysis
• Liquefactive


  Is seen in CNS, lungs and bacterial/fungal infection

  Tissue turns to liquid

  Results from rapid action of hydrolytic enzymes released by lysosomes

  Tissue digests itself
• Fibrinoid


  always refers to am autoimmune disorder like rheumatoid arthritic nodules of dead tissue

  Typically seen in rheumatoid arthritic nodules, nodules are firm, not tender, and located in the sub-Q layer of skin, can be seen in fingers, toes, elbows and knees
• Caseous

  Cheesy (think cottage cheese) as in tuberculosis in lung, gross descriptor not microscopic

  Present with a tannish/cheesy consistency that is friable (crumbly)

  Typically seen in lung tuberculosis

  Combination of coagulative and liquefactive
• Gangrenous


  can be wet, dry or gas

  Dry is known as coagulative (congeals) necrosis, presents as grey/black tissue, resembles mummified tissue and can progress to wet

  Wet is known as liquefactive (tissue turns to liquid) necrosis, presents as greenish/white pus and foul smelling

  Gas is caused by the saprophytic (lives on flesh) bacterium Clostridium perfringens, this anaerobe can be found in soil and can enter muscle through a puncture wound, exotoxins are released resulting in toxemia and sepsis.
• How to describe necrotic tissue?

  Gangrenous, caseous, fibrinoid, and liquefactive
• Necrosis


  Necro means death and sis means tissue

  typical tissue death is caused by ischemia (withholding of blood)

  Ischemia causes hypoxia
• Ultrasound


  Mapping echos produced by high-frequency sound waves transmitted into body, echos reflect change in tissue density to produce images
• Endoscopy


  examine interior of body using rigid or flexible tubular instruments equipped with lens and light source

  Perform surgery formerly done through large abdominal incisions (ie. bronchoscope, colonoscopy, cystoscope, laparoscope)
• NCV

  nerve conduction velocity study
• Electromyogram (EMG)


  Measures electrical activity of skeletal muscle during contraction and at rest
• Electroencephalogram (EEG)


  Measures electrical activity of brain, brain waves
• Electrocardiogram (ECG or EKG)


  measures serial changes in electrical activity of the heart in various phases if the cardiac cycle.

  Identify disturbances in heart rate, rhythm, and abnormal impulses

  Recognize heart muscle injury from ECG abnormalities
• Electrical Activity


  Measure electrical impulses associated with body functions and activities

  Include: ECG, EEG, EMG and NCV
• Cytology and Histology

  Include: pap smears and biopsies

  Papanicolaou(Pap)-smear: cells are removed from cervix using a brush, identifies abnormal cells in fluids or secretions, for recognizing early changes that may be associated with cervical and other cancers

  Biopsy: tissue samples obtained for histologic examination to determine abnormal structural and cellular patterns accompanying diseases (ie. for liver, kidney, and bone marrow)
• MRI vs CT

  MRI doesn't use ionization radiation, can detect abnormalities in tissues surrounded by bone, such as spinal cord, orbit or skull

  In CT bones interferes with scanning while in MRI they are low in water concentration so don't interfere
• What does a torn ACL look like with an MRI?


  it looks like a bomb went off
• T1-weighted vs T2-weighted MRI

  T1: want to see clear fluids, cerebral spinal fluid is black , fat is white, grey matter is dark grey, and white matter is light grey

  T2: more common, used for tissue, cerebral spinal fluid is white, fat is grey, grey matter is light grey, and white matter is dark grey
• How to remember that the olfactory cortex works with smell?

  there is a skunkus in my uncus
• What does the MRI for a normal brain look like?

  In the sagittal view the nose is on the left, notice ho clearly the fissure and folds over the surface of the brain can be seen and the distinction between the different neural elements that make up the brain
• Magnetic Resonance Imaging (MRI)

  Principle: computer-constructed images of body based on response of hydrogen protons in water molecules when placed in a strong magnetic field.

  Protons align in the direction of the magnetic field

  Protons are temporarily dislodged and wobble when radio-frequency waves are directed at them

  Protons emit a measurable signal that can be used to construct images

  Intensity of resonance depends on water content of tissues, strength and duration of radio-frequency pulse

  Gold standard to view soft tissue

  Uses: multiple sclerosis and ligamentous tears
• What does a CT of a chest look like?

  translucent structure are in black like the lungs and opaque structures are in white

  Heart appears in white in the center of scan with less dense lungs on either side, in the left lung there are indication of lung tumors bc there are white nodules.

  the the left of the vertebrae there is a perfect circle that is the descending aorta
• Computed Tomography (CT) Scan


  Principle: radiation detectors record amount of X-rays or ionizing radiation absorbed by body and feed data into a computer that reconstructs the data into an image.

  Radiopaque and radiolucent tissue appear white and dark as in conventional x-ray

  Individual organs sharply demarcated by planes of fat that appear dark because of their low density

  Delivers high dose of ionizing radiation than x-ray

  Can see the body in multiple planes

  Uses: screen for cancer in asymptomatic individuals and detect abnormalities in internal organs that cannot otherwise be identified by standard x-rays.