Clinical Pathologies 1

Changes in size, shape or organization of cells

Can be precancerous condition

Increased number of cells.

Not always pathological (high altitude = increase in RBC’s)

Enlarged cells

Physiological (hormonal) hypertrophy - occurs normally during puberty. Can occur in response to anabolic steroid abuse.

Increased functional demand - exercise increases muscle fiber size. (Hypertension increases left ventricular myocardial fiber size)

Decreased number of cells

Cells are smaller than normal

Many different sizes and shapes of cells.

Can also have nuclear pleomorphism.

Dedifferentiation of a cell type.

Existing cells don't actually dedifferentiate, but new, neoplastic cells are less differentiated than normal cells. In case of malignancies, degree of anaplasia determines degree of malignancy, i.e. less differentiated cells are typically indicative of a more malignant neoplasm.

Change from one cell type or tissue type to another as a result of physical or chemical stress to a tissue.

Simple epithelia can become stratified in response to physical stress

Chronic gastric reflux into lower esophagus causes the stratified squamous epithelium to become a gastric-like epithelium that secretes mucus (Barrett's epithelium). The mucus protects against acid and pepsin.

• Benign
• 1. Papilloma
• 2. Adenoma

• Malignant
• 1. Carcinoma - many types (i.e. adenocarcinoma)

• 1. Anaplasia
• 2. Mitotic activity (more activity = greater malignancy)
• 3. Invasion (ability to breach basal laminae)
• 4. Metastases (spread to distant sites)

Benign tumor arising from a surface epithelium

Benign tumor arising from a glandular epithelium

Malignant tumor (carcinoma) arising from glandular tissue

Metaplasia

Edema

• Best suited for bone
• (also picks up densities in tissues)

film is positioned closest to the object of interest

• Best for dense tissues and structures
• (excellent for bone!)

Spiral x-ray gives a series of axial plane images

Images viewed as if you are standing at the patient's feet

• Best for soft tissue details (i.e. brain)
• Provides little information on bones

Modality of choice for IV disc herniation

• Protons (H⁺) alligned by magnetic field
• (safe - no ionizing radiation)

Best used for studying tissue in real time

Uses sound waves (1-10 MHZ)

Excessive kyphosis

• postural change with aging and poor habit
• compression fracture of a thoracic vertebral body due to osteoporosis

Excessive lordosis

• poor postural habit
• muscle imbalances (weak abdominals)
• large abdomen (obesity)
• pregnancy

Lateral curvature of the spine coupled with rotation

Spinous processes point to concavity of abnormal curve (fryette's principle)

• Congenital (hemi vertebra)
• Abnormal muscle tone (polio, c. palsy)
• Idiopathic (infancy-early adolescence)

Two sides of vertebral arches, usually in lower vertebrae, fail to fuse during development resulting in an "open" vertebral canal

• Occulta - defect in bone only - asymptomatic
• Cystica - Defect in bone/meninges - neurolgical involvement

L4/5 IV Disc

Ligamentum Flavum

Posterior longitudinal ligament

Ligamentum flavum

Interspinous ligament

Supraspinous ligament

Facet joint capsules

Intervertebral discs

Anterior longitudinal ligament

Anterior body musculature

Lumbarization = 6 lumbar & 4 sacral vertebra

Sacralization = 4 lumbar & 6 sacral vertebra

Spondylolisthesis is the forward displacement of one vertebrae relative to the one below

Bilateral fracture of pars interarticularis

(L5/S1 most common)

Spondylolisthesis is the forward displacement of one vertebrae relative to the one below

• Bilateral fracture of pedicle

Spondylolysis - Fracture

Spondylolisthesis - Slippage

Restricts blood flow to the brain

Lesion of dorsal scapular nerve

Autoimmune!

• Antibodies bind to proteins associated w/ hemidesmosomes
• They detach from basement membrane

Causes blisters

Absence of dynein - cilia are immobile

• Frequent resp. infections
• Males are infertile

Genetic disturbance in collagen synthesis

• 1) defect in procollagen peptidase - forms defective collagen fibrils
• 2) defect in enzyme lysyl hydroxylase (lysine->hydroxylysine)

Joint dislocation / hyperelastic skin / pseudotumor over elbow

• Autosomal dominant defect in fibrillin gene (fibrillin 1)
• Forms abnormal elastic tissue
• CV abnormalities / dissecting aneurysm of aorta / arachnodactyly

• Overproduction of ghrelin

• VENULE SIDE:
• high hydrostatic pressure (congestive heart failure)
• low colloid osmotic pressure (starvation)

Erosion of the articular (hyaline) cartilage

(two layers on the distal end of the femur: fibrocartilge / hyalin cartilage)

Cortisone, hydrocortisone - inhibits cartilage histogenesis, growth and matrix production

Thyroxine, Testosterone, Somatotrophin - stimulate cartilage histogenesis

Vitamin C deficiency - enzyme cofactor for collagen synthesis

Hyaline matrix production stops. Distorts cartilage columns in epiphyseal plates

Poor bone growth / fracture repair

Bones loss (lose organic matrix and mineral components; ratio = normal)

There are 3 vitamin K dependant calcium binding proteins produced by osteoblast that are necessary for the mineralization of bone

• Maintains bone density in both sexes
• inhibits bone resorption

(testes and adrenals produce estrogen)

After menopause

During periods of disuse (immobilization)

Red Bone Marrow (sternum and iliac crest)

Impaired mineralization of bone matrix (soft bones)

Due to vitamin D deficiency which causes deficient calcium & phosphorus absorption in the gut.

In children/growing bone vitamin D deficiency leads to Rickets

“Brittle Bone Disease”

Genetic disorder of type I collagen characterized by repeated fractures after minor trauma, thin skin, weak tendons, and in certain subtypes blue sclerae

Deficiency of growth hormone (somatotropin) during the developing years leads to failure of bone growth.

Excess growth hormone during the developing years (prior to the closure epiphyseal plate) leads to an abnormal increase in the length of bones

Excess growth hormone in adulthood leads to thickening of the bones since the growth (epiphyseal) plates have already closed.

Absense of dystrophin (x-linked)

• Focal fat replacement of muscle fibers
• Hypertrophic myofibers
• Increased endomysial fibrosis
• (causes pseudohypertrophy seen in calves of patients)

Dystrophin – a cytoskeletal protein located beneath the sarcolema and plays a role in linking to laminin (ECM protein)

• Antibodies made to ACh receptor (autoimmune)
• prevents ACh from binding to receptors on post-synaptic membranes

• Progressive weakness: remits with rest / worse with exercise
• Drooping eyelids / weakness of eye muscles

"Lou Gehrig’s Disease"

• Denervation atrophy
• Most common motor neuron disease

Necrosis of cardiac muscle cells due to prolonged ischemia

Repaired by fibrous connective tissue (function in heart is lost)

• Assess damage by measuring serum enzymes
• (serum cardiac specific troponin)

Increased size of lymphoid tissue

Increase number and size of lymphocytes and other cellular pools

Primary infection

May cause bowel obstruction in children

Follicular hyperplasia

• Caused by chronic infection and inflammation
• (RA, toxoplasmosis, early HIV)

Reaction / activation of T-cells

• Normal structure of B-cell region may disappear
• Caused by viral infection / drug reaction

Distention and proliferation of sinusoids (non-specific)

Frequent in cases of malignancy in regional lymph nodes

AC Dislocation = tear the acromioclavicular ligament.

AC Separation = dislocation + tear of coracoclavicular ligaments

Axillary N.

Posterior Circumflex Humeral A.

Typically involves supraspinatus m.

Difficulty abducting / flexing the arm