- Contains DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
- 1. The genetic info encoded in the nuclear DNA is transcribed into the nuclear RNA. The message is then transmitted by transfer RNA and messenger RNA into the cytoplasm to genetically produce specific proteins.
What surrounds the nucleus?
Cytoplasm contains numerous _________
The ratio of nucleus to the cytoplasm is higher in undifferentiated cells and is considered a marker for the identification of malignant cells.
Specialized cells such as kidney or liver cells
Small bodies with double membranes that contain maternal DNA.
energy for the cells
small granules composed of RNA and are associated with protein metabolism
Ribosomes attach to:
membranes forming RER (rough endoplasmic reticulum)
SER (smooth endoplasmic reticulum)
Associated with what?
Are seen in what?
- Meshwork of membranes with no ribosomes attached
- Associated with catabolic or breakdown processes
- Seen in liver cells
Golgi Apparatus are:
Clusters of tubules usually adjacent to the nucleus and secrete cell products
Golgi Aparatus are especially prominent in:
plasma cells where the immunoglobin is excreted
membrane bound digestive cytoplasmic organnesl that contain enzymes to break down various materials.
- A network of filaments and microtubules that support the cell, are associated with cell movement and intracellular transport. Also, form the spindle apparatus that allows cells to divide.
- A number of cytotoxic drugs derived from plants break down or prevent their normal functions. An example is Taxol and Vincristine, both powerful anti-cancer drugs.
Plasma membrane is composed of:
protein, lipids and carbohydrates in a complex bilayer that communicates both with the outside and the internal membranes of the cell.
Plasma membrane is maintained by:
- active processes and damage to the membrane results in cell death.
- The attack portion of the complement sequence can destroy the cell membrane
the communication of similar cells to each other. Example lymphocytes make cytokines that stimulate other lymphocytes to grow
a cell makes a substance which acts upon a specific cell to form a product
- A cell makes a product that acts upon many different kinds of cells
- Example thyroid hormone acts upon many different cells
Reversible Cell Injury
Short periods of lack of oxygen and exposure to certain toxins produce cytological and biochemical changes that do no produce death of a cell. We see cellular swelling (hydropic) change as well as mitochondrial swelling. The cell contains mostly K and the extra cellular fluid contains Na. There is active energy to maintain this relationship. Orthopedic surgeons can block blood flow to an extremity for over one hour and still cause no harm when the extremity becomes re-infused with blood.
marked by condensation of the chromatin
characterized by fragmentation into smaller particles, colloaqually called nuclear dust
involves dissolution of nuclear structure and lysis of chromatin by enzymes such as DNAase and RNAase
Irreversible Cell Injury
The cell dies, enzymes leak out and can be measured as in liver disease and heart ischemia. Nuclear changes can be visualized by looking at the nuclei. First, the chromatic condenses (pyknosis), Then the nucleus breaks apart (karyorrhexis) and then almost disappears (karyolysis).
Cellular sweeling as seen in Reversible Cell Injury
Causes of cell injury
- Toxic injury
- Microbial pathogens
- Immunologica and inflammatory reactions when carried to the extreme
- Genetic and metabolic abnormalities
- Lack of oxygen
- Can be caused by infection, substances that prevent oxygen from reaching tissue, such as CO and cyanide, lack of RBC among others.
- Some times when there is reoxygenation after cell injury free radicals are generated that produces tissue and cellular damage.
- Causes Cell injury
- Direct toxic effects on cells
- Some agents act directly such as radiation and heavy metals
- And others are toxic only after being metabolized by the organism.
- Causes of cell injury
- this includes bacteria, viruses and fungi as well as products produced by these organisms
Types of cell adaptations:
- Decrease in size of cell and tissue or organ.
- Some atrophy occurs with age.
- Some with disuse as in nerve and muscle injury,
- and some with disease processes
is an enlargement of a cell or organ, which can lead to the organ being bigger while hyperplasia is an increase in numbers of cells with an enlargement of an organ
change of one cell type to another, usually driven by inflammation
disordered growth with cells showing some features of Neoplasia
disordered growth with the ability to invade outside its Normal Boundaries and have cytological and biological features that we identify as cancer
The morphologic change in tissue caused by cell death
Necrosis divided into:
- 1. Coagulation – remnants of shadows of cells
- 2. Liquifactive necrosis – seen in brain tissue
- 3. Caseous necrosis – a chessy soft material seen in granuloma formation and often associated with TB
- 4. Fat necrosis – seen in pancreatitis where the pancreatic enzyme breaks down abdominal fat. Lipase can be measured in the blood
An active process activated by genetic control within a single cell. A highly regulated process. Can be a factor in tumor cells that lack the ability to destroy themselves and thus invade in areas they do not belong. Isoflavinoids are a class of compound found in fresh rapidly growing foods that are believed to cause apoptosis of prostate cancer cells. Bean sprouts are a good source of isoflavinoids.
Definition of Apoptosis
Programmed cell death that occurs normally in developing adult tissues but that can also be induced by various drugs and viruses