Cell Adaptation/injury/death: Class 1 Flashcards
Nucleus
-Function
- Brain of the cell
- Contains DNA
- Responsible for making ribosomes
Cell Membrane
-function
- Protects
- Transports
- Boundary system for the cell
Rough & Smooth Endoplasmic Reticulum (ER)
-function
- Where most protein synthesis occurs
- Synthesize lipids
- Smooth ER helps in detoxification of harmful substances
Ribosomes
-Function
- Make proteins that the cell and body need
Golgi Complex
-function
- UPS
2. Sorts and ships proteins made in the ER
Mitochondria
-function
- Packages the energy from food into ATP molecules
Vesicles
-function
- Stores and transports products produced by the cell
Cell injury can be caused by?
- Physical injury
- Toxic injury
- Infectious injury
- Hypoxic injury
- Deficiency injury
Ischemia
-cell sensitivity
- Skeletal muscle can tolerate 2-3 hrs of ischemia
2. Cardiac muscle can only tolerate 20 min of ischemia
Liver Cells
-Susceptible to what type of injury
- Chemical injury
Free Radicals
- Unpaired electron
- Highly unstable & reactive
- Will attempt to steal an electron from nearby molecule causing a chain reaction
Initiation of Free Radicals
- Absorption of extreme energy sources
- UV light & Radiation - Endogenous reactions when O2 is reduced to Water
- Cell growth and proliferation - Enzymatic Metabolism
- from external chemicals like Cigarette smoke and Alcohol
Samples of Free Radical Damage
- Lipid per-oxidation
- Attacking critical proteins
- DNA fragmenting
- Damaging mitochondria
Free Radicals
-Terminating them
- Antioxidant enzymes
- block synthesis of free radicals / inactivate them / Decompose - Endogenous
- Super Oxide Dismutase
- Catalase - Exogenous
- Vitamin A, “E”, C
Free Radicals
-Endogenous Termination
- Super Oxide Dismutase
2. Catalase
Free Radicals
-Exogenous termination
- Vitamin E
2. Vitamin A & C
Cell Alteration
- All forms of disease begin with alterations to cells
Altered Cells and tissues
-Result from…
- Adaptation
- Injury
- Neoplasia
- Aging
- Death
Cellular Adaptation
-Atrophy
- Reduction in the size of the cell
Cellular Adaptation
-Atrophy - Examples
- Disuse
- Nutritional Deprivation
- O2 Deprivation (Ischemia)
- Decreased Hormonal stimulation
- Aging
- Denervation pressure
Cellular Adaptation
-Hypertrophy
- Enlargement of Cell due to increased workload
Cellular Adaptation
-Hypertrophy - Examples
- Mechanical signals
- Stretch muscles causing enlargement - Trophic signals
- Send hormones causing enlargement
Cellular Adaptation
-Hyperplasia
- An increase in the number of cells caused by:
- increased workload
- hormonal stimulation
- decreased tissue
Cellular Adaptation
-Hyperplasia - Examples
- Hormonal
- Occurs mostly in estrogen-dependent organs (Uterus & breast) - Compensatory
- Liver cells (hepatocytes)
- Epidermal (callus)
Cellular Adaptation
-Metaplasia
- Replacement of one adult cell w/ another cell
Cellular Adaptation
-Metaplasia - Examples
- Barret’s Esophagus
- GERD
Cellular Adaptation
-Dysplasia
- Deranged cell growth of specific tissue results in abnormal size, shape, and appearance
- DOES NOT INDICATE CANCER & may not progress to cancer
- Often reversible
- Not considered true adaptive process but is related to hyperplasia and often called (ATYPICAL HYPERPLASIA)
Cellular Adaptation
-Dysplasia - Examples
- Cervical pre-cancer and Cancer R/T
- Human Papillomavirus (HPV)
Cells adapt in what 5 ways?
- Atrophy
- Hypertrophy
- Hyperplasia
- Metaplasia
- Dysplasia
Organisms
-Must be able to do what 3 things?
- Detect changes in their external & internal environments
- Interpret changes
- React or respond
If these are not done the cell with DIE
DETECT / INTERPRET / REACT
Necrosis
-Fat
- Caused by LIPASES (powerful enzymes)
- Affect in:
- Breast
- Pancreas
- Other Abdominal Structures
Necrosis
-Coagulative
- Causes gelatinous, transparent state of ALBUMIN to change to a firm, opaque state
- Affects:
- Heart, kidneys, & adrenal glands - Caused by:
- Severe ischemia or hypoxia
Necrosis
-Liquefactive
- Results from Ischemic injury to NEURONS & GLIAL CELLS in the BRAIN.
- Cells are digested by their own hydrolyses
- Tissue becomes soft, liquefies, and segregates from healthy tissue
- Forms cysts
Necrosis
-Caseous
- Results from TUBERCULOSIS pulmonary infection
- Tissue resemble clumped cheese (soft and granular
- Granulomatous inflammatory wall encloses areas of caseous necrosis
Necrosis
-Gangrene
- Results from severe hypoxic injury
- Occurs because of ARTERIOSCLEROSIS or blockage of major arteries PVD
- Wet Gangrene occurs when neutrophils invade the site, causing liquefactive necrosis (diabetic ulcer)
Wet Gangrene
- Develops when neutrophils invade the site, causing liquefactive necrosis (diabetic ulcer).
Necrosis
-Gaseous Gangrene
- Caused by infection of tissue by CLOSTRIDIUM species
- Produces
- hydrolytic enzymes & toxins that destroy connective tissue & cell membranes - Leads to gas bubbles to form in muscle cells
Apoptosis
- Programmed cell death
- Determines the size, patterning, and function of tissues
- Physiologic
- Pathologic
- Absence
Cell production and destruction
- You produce and destroy about 10 Billion cells per day
Re-perfusion Injury
- Results from oxidative stress (oxygen free radicals)
- Neutrophils adhesion to endothelium
- Treatment: blockage of inflammatory mediators
Hypoxia
- Most common cause of cellular injury
- Lack of sufficient oxygen
- Most common cause of hypoxia is ischemia (Reduced blood supply)
Hypoxia
-Results from
- Reduced amount of 02 in the air
- Loss of hemoglobin
- decreased efficacy of hemoglobin
- Decreased production of RBCs
- Diseases of the respiratory and cardiovascular systems
- Poisoning of oxidative enzymes w/in the cells
Mitosis
Process of dividing the duplicated DNA of the cell into two new nuclei
Mitosis
-Prophase
- DNA condenses, organizes and the classic chromosome structure appears
- Protein strands called microtubules are seen
- Nucleolus disappears
Mitosis
-Pro-metaphase
- Microtubules attach to the chromosomes
2. Begins when nuclear membrane is broken down
Mitosis
-Metaphase
- Chromosomes align
Mitosis
-Anaphase
- Chromosomes separate after metaphase
Mitosis
-Telophase
- Nuclear membranes reappear around the two sets of chromosomes
Cytokinesis
- Separation of the cytoplasm into 2 parts, a process that follows the division of the cell nucleus
Interphase
overview
- Most of the cells life is spent in interphase
- Interphase is made up of:
- G1, S, and G2
Interphase
-G1 (Gap 1)
- 1st growth phase of interphase
2. Cell grows to nearly its full size and performs many of its biochemical activities
Interphase
-S phase (Synthesis Phase)
- DNA in the nucleus is replicated
Interphase
-G2 (Gap 2)
- Cell finishes growing
Cellular Injury
-Occurs when?
- Cellular Injury occurs if the cell is unable to maintain homeostasis
Physical Injury
-Examples
- Trauma/Surgery
2. UV Radiation
Toxic Injury
-Examples
- External
- Inhale C02 - Internal
- byproducts of inflammatory response or another mechanism
Infectious Injury
-Examples
- Fungi
- Parasites
- Bacteria
- Viruses
Hypoxic Injury TEST
MOST COMMON INJURY
- Decreased Perfusion
- pt w/ an MI - Sickle Cell ANEMIA
- Ischemia
- Hypoxia
Cell Injury Can be?
- Reversible or Irreversible
Cell Injury
-Reversible
- Obstruction of blood flow
- Ischemia
- Decreased ATP production
- Na+ pump breaks down
- INcreased intracellular Sodium and Calcium
- Increased Extracellular Potassium - INcreased glycolysis and lactate w/ decreased pH
- leads to swelling of lysosomes // increased Ca influx
Vulnerable Cellular Systems to Injury
- Cell membrane integrity
- ATP generation/ Mitochondrial function
- Protein function / Enzyme function
- Genetic Integrity
Mechanisms of Cell Injury TEST
- Decreased O2
- decreased ATP production
- Increased ROS
- Decreased Mitochondrial function
- Increased intracellular Calcium
- Decreased Plasma Membrane Integrity
Initiation of Free Radicals
-Enzymatic Metabolism EX.
- External Chemicals
- Cigarette smoke
- Alcohol
Cellular Alteration and DIsease?
- All forms of disease begin with alterations to cells
Types of Adaptation
- Atrophy
- Hypertrophy
- Hyperplasia
- Metaplasia
- Dysplasia
Altered Cellular & Tissue biology Results from?
- Adaptation
- Injury
- Neoplasia
- Aging
- Death