chemistry, cells and tissues by mary beth vogel, bsn, rn-c
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Chemistry, Cells and Tissues
By Mary Beth Vogel, BSN, RN-C
Useless facts:* All the chemicals in a human body combined are estimated to be
worth
less than $10
* The average human body contains enough: iron to make a 3 inch nail, sulfur to kill all fleas on an average dog, carbon to make 900 pencils, potassium to fire a toy cannon, fat to make 7 bars of soap, phosphorous to make 2,200 match heads, and water to fill a ten-gallon tank.
Chemistry Review…
4 kinds of atoms make up 96% of the human body: O2, C, H, N
Chemical Makeup of the Body 1. Water
2. Oxygen
3. Carbon Dioxide
4. Carbohydrates
5. Lipids
6. Proteins
7. Nucleic Acids: DNA and RNA
Major Types of Organic Compunds
CARBOHYDRATESMono, di, and polysaccharidesLIPIDSTriglycerides, chol., phospholipidsPROTEINFibers, enzymes, amino acidsNUCLEIC ACIDDNA, RNA
(FUNCTION)Source of energy
Stores energy, forms cell membranes
Forms structures, sends signals & reaxs
Genetic code for making proteins
8. Acids and Bases: H balanced by OH
pH scale: H+ and OH- ions balanced at 7
Basic: pH >7; low H/high OH
Acidic: pH <7; high H/low OH
Cells and Tissues
Diversity of Cells in the Human Body
Cell Functions Absorption
Metabolism
Release energy
Synthesize proteins
Excrete waste
Reproduce itself
Support functions specific to that cell
Cellular Fluids Dilute watery solutions found inside and outside cells
Contain O2, nutrients, proteins, ions
ICF: inside cells (cytosol)
ECF: outside cells (interstitial fluid)
Plasma: ECF in bld vess
Lymph: ECF in lymph vess
CSF: ECF @ brain, spinal cord
Components of Cytoplasm (“living matter” inside cells) H2O
Ions
Proteins
Nutrients
Lipids
Organelles
Plasma Membrane
Outer bi-layer
Selectively permeable
Phospholipids form this fluid framework of the plasma membrane
Contain receptors
Identifies cells as its own
Functions:
Physical isolation
Regulation of exchange w/ env
Sensitivity
Structural support
Cell Division
Mitosis: cell division: 1 cell forms 2 identical cells w/ same # chromosomes
Diploid/somatic cells undergo mitosis
Meiosis: cell division – ½ the # of chromosomes contributed by each
Haploid cells prod gametes
Mitotic rate
Mitotic rate: rate of cell div Generally: longer cell life expectancy = slower the
mitotic rate Stem cells undergo frequent mitosis
Changes in Cell Growth: Hypertrophy Atrophy
Mitosis and CA
Neoplasm Benign vs malignant Differentiation Hyperplasia Dysplasia Anaplasia
More on CA 2nd leading cause of death in US 1.5 million dx w/ CA in 2005 (ACS) Nearly 1/2 of all men and 1/3 of all women in the
US will develop CA at some point in their lives Skin CA (non-melanoma) is the most common form
of CA in US
Development of CA linked to 3 factors: aging, genetics, environment
Environmental exposures: tobacco, etoh, diet, lack of ex, sunlight, chemicals, hormones, infections
Less to do with exposure/env and more
to do with the increased
longevity?
Breast cancer cell
TX: surgery, radiation and/or chemotherapy are primary tx
Transport Mechanisms
Mvmnt of substances in/out of cell
Active vs Passive
1. Passive Transport
No additional energy required; down a press gradient
Types:
1. Diffusion (osmosis and dialysis)
2. Filtration
DiffusionVariations:
a. Osmosis: Diffusion of H2O (all cells)
B. Dialysis: Diffusion of solutes
Filtration: movement of water & solutes as result of hydrostatic pressure
2. Active transport
Uphill mvmt (move from lower concentration to higher)
Requires ATP (energy)
Several types:
Ion Pumps
Phagocytosis
Pinocystosis
ION PUMP
Active transport in the cell membranes Mvmvnt of ions against concentration gradient The “pump” is a prot complex Ion specific or can be coupled
Na pumps, Ca pumps, K pumps, Na/K pumps
Na-K Ion Pump
a. Phagocytosis: intake of solids
b. Pinocytosis: intake of fluids
Tissues
Group of cells w/ similar struc/funct
Differ from each other based on:
Size/shape of cells
Matrix
Function
Types Tissues
The four tissue types are: Epithelial Connective Muscular Nervous
1. Epithelial Tissue
Covers the body, lines
various structures
Protective
Cells packed tightly
Classified by
shape/arrangement
of cells
Location of Epi Tissues
Simple Squam: alveoli, capillaries Stratified Squam: skin, esophagus Simple cuboidal: glands, kidney Stratified cuboidal: rare; some ducts Simple columnar: lining of stomach/int , resp tract Stratified columnar: nasal cav, pharynx, urethra Stratified transitional: bladder lining Pseudostrat: trachea
2. Connective Tissue
Most abundant
Varied appearance/function
Each type has unique matrix
Types of Connective Tissue
a. Blood/lymph: liquid matrix b. Areolar: loose conn tiss c. Adipose: fat tissue d. Fibrous: bundles of collagen fibers e. Bone: cells in calcified matrix f. Cartilage: matrix is softer, flexible protein g. Hematopoietic: red marrow
3. Muscular Tissue Cardiac, Skeletal, Smooth
4. Nervous or Neural Tissue Located in nerves, brain and spinal cord
Neurons and Glial cells
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