Wk 1: Human Biology Flashcards
The study of the effects of ionizing radiation on biologic tissue:
Radiobiology
What is the primary goal of Radiobiology?
To research the effects of radiation on humans & to make it safe in diagnostic and therapeutic use
What are considered “early effects” in Radiobiology?
Local tissue damage (skin, gonads), Hematologic depression, Gastrointestinal Syndrome and Central Nervous System Syndrome
What are considered “late effects” in Radiobiology?
Leukemia, Eye Damage and Certain Cancers (bone, thyroid, breast and lung)
What concept is termed: as dose increases an increase in severity (radiation injuries) will occur?
Deterministic Effect
When do Deterministic Effects occur?
Within days after high radiation exposure
What concept is termed” effects that occur from an exposure that appears later (years)?
Stochastic Effect
What is the % make up of a human cell?
80% Water
15% Protein
2% Lipids (Fats)
1% each of Carbohydrates (sugars/starches), Nucleic Acid, and Other
What molecules are considered life supporting and contain carbon?
Organic Molecules
What is the rarest organic molecule?
DNA (it is considered radiosensitive)
Who are the two individuals that developed Cell Theory?
Theodore Shwann (1st & 2nd principles) Rudolf Virchow (3rd prinicple)
What are the three principles of Cell Theory?
#1 All organisms are made of 1 or more cells #2 Cells are the basic building blocks of life #3 All cells come from existing cells
Who are the two individuals that showed that plants and animals contains cells as their basic functional units?
Schlieiden and Schwann
Who accurately described a living cell based on his microscopic observations?
Anton van Leeuwenhoek (1673)
What regulates cellular activity and contains the master chemical; which has all the information necessary for a cell to function?
DNA (Deoxyribonucleic Acid)
What are chromosomes?
Tiny rod-shaped bodies that are composed of DNA
How many chromosomes are in the normal human body?
There are 46 chromosomes (23 pairs)
What are the basic units of heredity?
Genes
What are the two types of cells found in the human body?
Genetic & Somatic Cells
What are Genetic Cells in males & females?
The genetic cell in females are called oogonium
The genetic cell in males are called spermatogonium
What are Somatic Cells?
Somatic Cells are all other cells found in the human body
What are the three different names of “immature” cells?
Stem cells, Precursor cells and Undifferentiated cells
What is a cell membrane? Define its function.
The cell membrane is a structure encasing and surrounding the cell; it protects cellular contents from their outside environment and controls the passage of water and other materials into and out of the cell
What is cytoplasm? Define its function.
The cytoplasm is the protoplasm that exists outside the cells’ nucleus; it makes up the majority of the cell and eliminating waste products
List the five important details about water in human biology.
Constitute 80% - 85% of protoplasm, Most abundant molecule and most simplest, The most important inorganic substances are water and mineral salts (electrolytes), Water aids in sustaining life, and Maintains body temperature
List the five important details about protein in human biology.
Constitute about 15% of cell content, Essential for growth and the construction of new body tissue, Principle component is amino acid, Provide structure and support, Functions as enzymes, hormones and antibodies
List the six important details about lipids in human biology.
Constitute 2% of cell content, Also referred to as fats or fatlike substances, Organic macromolecule, Contains glycerol and fatty acids, Present in all tissues in the body, Stores fat under the skin and serves as a thermal insulator
List the six important details about Carbohydrates in human biology.
Make up about 1% of cell content, Provide fuel for cell metabolism, Also called: saccharides. Monosaccharides and disaccharides are all sugars, Glucose is the ultimate molecule that fuels the body, Important structural parts of cell walls and intercellular materials, Most abundantly in the liver and in muscle tissue
List the four important details about Nucleic Acids in human biology.
Compose about 1% of the cell, Two principal nucleic acids DNA and RNA, DNA located principally in the nucleus of the cell, RNA located principally in the cytoplasm
What is Endoplasmic Reticulum?
Enables the cell to communicate with the extracellular environment and transfer food from one part of the cell to another
What are called the “engines” of cells?
Mitochondria, they a bean-like shaped structures, macromolecules are digested here to produce energy for the cell
What is the site of protein synthesis which are found in cytoplasm?
Ribosomes, they are small dot-like structures, essential to normal cellular function
What contains enzymes capable of digesting cellular fragments and helps control intracellular contaminants?
Lysosomes, they are small pea-like sacs
What is the “Atomic Composition” of the body?
60% Hydrogen
- 7% Oxygen
- 7% Carbon
- 4% Nitrogen
- 2% Calcium
- 1% Phosphorus
- 1% Sulfur
- 8% Trace Elements
Radiobiology is:
The study of the effects of ionizing radiation on biologic tissue (yellow box in textbook)
Macromolecules are:
Very large molecules that sometimes consist of hundreds of thousands of atoms (yellow box in textbook)
What is the most abundant molecule in the human body?
Water
What does Metabolism consist of?
Anabolism & Catabolism
What is Anabolism?
The process of synthesizing smaller molecules into a larger macromolecule
What is Catabolism?
The process that creates energy for a cell by breaking down molecular nutrients that are brought to and diffused through the cell membrane
What are Enzymes?
Molecules that are necessary in small quantities to allow a biochemical reaction to continue even though they do not directly enter into the reaction
What are Hormones?
Molecules that exercise regulatory control over some body function, such a growth and development; they are produced and secreted by the endocrine glands (pituitary, adrenal, thyroid, parathyroid, pancreas & gonads)
What are Antibodies?
They are the primary defense mechanism of the body against infection and disease
What is the chief function of carbohydrates?
The chief function of carbohydrates in the body is to provide fuel for cell metabolism (yellow box in textbook)
What is the radio-sensitive target molecule?
DNA (yellow box in textbook)
What are the only two possible base bondings in DNA?
Adenine-thymine and Cytosine-guanine (yellow box in textbook)
What is Cell Proliferation?
The act of a single cell or group of cells to reproduce and multiply in number (yellow box in textbook)
What is Mitosis?
The process of somatic cell division wherein a parent cell divides to form two daughter cells identical to the parent cell
What are the four subphases of Mitosis?
Prophase, Metaphase, Anaphase, Telophase
What is Prophase?
Phase in cell division during which the nucleus and the chromosomes enlarge and the DNA begins to take structural form (1st subphase)
What is Metaphase?
Phase of cell division during which the chromosomes are divisible (2nd subphase)
What is Anaphase?
Phase during which chromatids repel one another and migrate along the mitotic spindle to opposite sides of the cell (3rd subphase)
What is Telophase?
Phase during which the disappearance of structural chromosomes into a mass of DNA and the closing off of the nuclear membrane into two nuclei (4th subphase)
Which subphase of Mitosis is Radiation-induced chromosome damage analyzed?
Metaphase (2nd subphase)
What is Meiosis?
The process of germ cell division that reduces the chromosomes in each daughter cell to half the number of chromosomes in the parent cell
The Process whereby genetic cells undergo reduction division (yellow box in textbook)
What cells are more sensitive to radiation that mature cells?
Stem Cells
What cells have HIGH radiosensitivity?
Lymphocytes, Spermatogonia, Erythroblasts
What cells have INTERMEDIATE radiosensitivity?
Intestinal crypt cells, Endothelial cells, Osetoblasts, Spermatids
What cells have LOW radiosensitivity?
Fibroblasts, Muscle cells, Nerve cells
What is an overall integrated organization of tissue and organs called?
Organ System
What are the principle organ system of the body?
Nervous, Digestive, Endocrine, and Reproductive
What are the effects of fetal irradiation:
Childhood Malignancy, Congenital Malformation, Diminished Growth & Development, Neonatal Death
Who described the molecular structure of DNA in 1953?
Watson and Crick
Approximately what percentage of the body is water?
80%
When somatic cells divide and proliferate, they undergo a process known as:
Mitosis
What are the sites of protein synthesis that are essential to normal function?
Ribosomes
What contains enzymes capable of digesting cell fragments?
Lysosomes
The production of large molecules from small is called:
Anabolism
Which of the following are present in the tissues of the body and are the structural components of cell membranes?
Lipids
During which of the following subphases of the meiosis does each chromosome split at the centromere, so that two chromatids are connected by a fiber to the poles of the nucleus?
Anaphase
Which of the following is the concept of the relative constancy of the internal environment of the human body?
Homeostasis
