PATH 3610 - Unit 1 (Cell Death)

Lesion

structural change; cut, pimple, bruise, etc.

Pathogenesis

how a lesion developsU

Ulcer

open sore on internal/external surface of the body

Degeneration

type of injury, cells are not yet dead, can lead to cell death, reversible

Cell Death

type of injury, process of death, irreversible

Stimulus

good outcome (ex. running release endorphins), causes adaptation and is reversible

Injury

bad outcome, causes degeneration or death, can be reversible or irreversible

Stimulus vs. Injury

depends on duration, severity, and physiological state

Hypertrophy

an adaptation to stimulus, cells get bigger and is possible in ALL cells; skeletal muscle, heart, organs with no stem cells

Hyperplasia

an adaptation to stimulus, cells proliferate, can be labile or stable cells (only with active stem cells); skin, bone marrow

Permanent Cells

cells that only undergo hypertrophy, already fully differentiated (no stem cells); neurons, cardiac myocyte, skeletal myocyte

Stable Cells

have inactive stem cells, can divide when injured; liver, kidney, major organs, fibrous tissue

Labile Cells

cells with active stem cells; skin, stomach lining, intestine, bone marrow

Cytotoxic Chemotherapy

cancer treatment, targets labile cells which is why it causes hair loss (epithelial labile cells), bone marrow changes, GI issues

Regeneration

type of healing, when the body replaces lost cells, the body chooses this first always

Growth Factors

factors that send cells into the cell cycle, can be positive or negative

Embryonic Stem Cells

pluripotent (immature), can produce any cell in the body (often found in bone marrow)

Adult Stem Cells

when they divide, they can only produce cells in that area, can be reverted back to embryonic stem cells

Necrosis

process of death

Accidental Cell Death

traumatic death; animal hit by car, burn, cut, etc.

Regulated Cell Death

anything other than accidental cell death, including programmed cell death, cell death pathways (found in every cell)

Oncotic Necrosis

Type 3, hydropic cell death, cell swelling

Coagulative Necrosis (Gangrene)

cell stays the same (dead cells look the same as alive ones)

Apoptotic Cell Death

Type 1, cell shrinks, taken up by neighbouring cells/macrophages

Efferocytosis

macrophages carry and remove dead cells from the body

Macroscopic Descriptor

what we can see without a microscope

Histological Descriptor

what we can see under a microscope

Liquifactant Necrosis

cell death with pus, abscess

Caseous Necrosis

cell death that is crumbly, pasty, cheese like

Fatty Change

cell swelling, fat filled instead of water, common in the liver

Autophagic Cell Death

cells digest themselves from the inside out, type II of cell death

Cornification

process of making cornified cells of the epidermis (upper layer falls off)

Intrinsic Cellular Aging

• theory that telomeres shorten → can only replicate DNA a certain amount of times

• nematodes - have clock genes, and die at a set time

Extrinsic Cellular Aging

exposure to free radicals causes aging (RONS like ODFR and nitric oxide)

ODFR

oxygen derived free radical

Antioxidant

counteracts free radicals (vitamin A, E, C)

BMR and Aging

higher BMR → higher free radical formation → increased aging