11/13/08 (notes from lecture on 11/23 added in red)

Cell Membrane

• Physical isolation
• Regulation of exchange with the environment – control entry of ions and nutrients as well as exit of wastes
• Sensitivity
• Structural support
• Sometimes called the phospholipids bilayer as t is made up of two phospholipids layers, the hydrophilic on the outside and the hydrophobic on the inside
• Isolates the cytoplasm from the surrounding extracellular fluid

Membrane proteins may function in a number of ways

• Receptors
• Channels
• Carriers
• Enzymes
• Anchors
• Identifiers

Membrane transport

• Some are impermeable, selectively permeable, freely permeable

Carrier mediated transport –

• Passive – move ions or molecules w/o any energy expended by the cell
  • Diffusion– net movement of molecules from an area high concentration t an area of lower concentration – eventually become uniformly distributed
    • Osmosis, special type of diffusion. Diffusion of water across a membrane. Occurs across selectively permeable membranes that are freely permeable by water but not to solutes. Water flows across the membrane towards the solution that has the higher concentration of solutes because that is where the concentration of water is lower.
    • Osmotic pressure indication of the force of water into that solution
    • Types of solutions
      • Isotonic – equal, does not cause net movement of water in or out of the cell
      • Hypotonic – lower solution – water flows into the cell, causing it to swell and burst (lyse)
      • Hypertonic – higher solution -cells will lose water by osmosis to the fluid causing the cell to crenate (shrivel)p
  • Filtration – hydrostatic pressure forces water across a membrane. If solute molecules are small enough they will be carried along with the water. (e.g., blood pressure in circulatory system– pushes water and dissolved nutrients through walls of small blood vessels into the tissues of the body.
  • Facilitated diffusion – passive transported across the cell membrane by carrier proteins. First the molecule binds to a receptor site and then the shape of the protein changes and moves the molecule to the inside of the cell where it is released. Only works as long as there are free carrier proteins, once they are all used …..
• Active process – requires the cell to expend energy (ATP)
  • Active transport – Uses ATP energy and is not dependant on concentration. Can import or export material regardless of their concentration.
    • Ion pumps – many move specific anion or cation in one direction. If it can move n both directions it is called an exchange pump. Major function of exchange pumps is to maintain cell homeostasis. Sodium-potassium exchange pump may use 40% of ATP produced by a resting cell.
• Vesicular Transport – materials
  move in or out of a cell in vesicles, small sacs that form at or fuse with the cell membrane – requires ATP
  • Endocytosis – packaging of extracellular material for import into the cell
    • Receptor mediated cytosis
    • Pinocytosis – cell drinks
    • Phagocytosis – cell eats
  • Exocytosis – out of cell, hormone, mucus, waste

The Cytoplasm (material inside a cell)

• Cystol – intracellular fluid, may also include insoluble materials called inclusions such as glycogen and lipid
• Oranganelles
• Cytoskeleton – strength and support, enable movement of cellular structures
  • microtubules
  • Microfilaments
    • Thin – protein actin
    • Thick – protein myosin (in muscle cells produce powerful contractions)
• Cilia – move materials over the cell surface (eg, throat, nose etc. move dirt particles out of body)
• (centrioles are necessary for cells to divide , RBC don’t have and cannot divide)
• Microvilli
• Ribosomes – manufacture proteins using info provided by the DNA. Free and fixed. Fixed are attached to the rER. Proteins made by fixed ribosomes enter the rER and are packaged for export
• Proteasomes- remove and recycle abnormal proteins
• Endoplasmic Reticulum - synthesis, storage, transport, detox.
  • Smooth or SER is site where lipids and carbs are produced.
  • Rough or RER has attached ribosomes and exports proteins out via the Golgi Apparatus
• Golgi apparatus – 5 or 6 flattened discs. Modifies and packages secretions like hormones , renewal and mod of the cell membrane, packaging of special enzymes for use in the cystol
  • Lysosomes contain digestive enzymes- perform cleanup and recycling within the cell, also function in defense against disease. Under a diseased state, may deteriorate and digest and destroy the cell itself (autolysis)
  • Secretory vesicles
  • Membrane renewal vesicles
• Peroxisomes – smaller than lysosomes and carry different enzymes. Not made in the Golgi, arise from growth and division of existing Peroxisomes. They absorb and break down fatty acids and other organic compounds. The generate hydrogen peroxide, a potentially dangerous free radical

Mitochondria – provide energy for the cell, ATP, vary based on energy demands. RBCs have no mitochondria {Red Blood Cells – to run a full blood analysis you would need a Hematology Analyzer}.

• Consume oxygen during energy production (aerobic metabolism) Glucose + O2 = Co2 and H2o2 , produces 38 units of ATP waste is lactic acid – if no O2 (anaerobic conditions) then produces only 2 units of ATP
• Generate CO2 & ATP

ATP – Adenosine triphosphate -Energy molecule for the cell

Nucleus usually largest part of a cell. A single nucleus stores all the information necessary to control over 400k proteins in the body. Nucleus determines both structure and function of a cell. Most cells have one, some have more. Skeletal muscles have many, RBC have none.

• Nuclear envelope, double membrane surrounds nucleus and separates from cystol
• Nuclear pores facilitate communication between the cystol and nucleus
• Nucleoli (nucleolus) synthesize ribosomal RNA (rRNA)
• Chromatin – break up before mitosis to form separate chromosomes.
  

Mitosis

• Interphase
  
• Prophase
  
• Metaphase
  
• Anaphase
  
• Telophase
  
• Separation
  

Protein synthesis

• Transcription – takes place in the nucleus, forms mRNA
• Translation – takes place in the cytoplasm

DNA

• Reproduction –mitosis
  
• Establish what the cell does – kind of proteins that the cell will make
  

RNA

• rRNA – ribosomal
  
• mRNA –messenger (single strand – formation of is called transcripton)
  

tRNA – transport – picks up amino acids

11/12/08

Internal Environment =Can be measured by analyzing extracellular fluid, interstitial fluid

Disease process –( number of days )

• Inflammation – process of the body to get rid of disease
  • Humoral – cytological, antibodies
  • Fluid component – results in swelling – extra fluid accumulates in interstitial spaces to bring RBC, oxygen, nutrients, etc to injury site to help heal the damage)Red, warm, etc. (Anaphylaxis, is an abnormal fluid response)
• Repair Process
  
  • Regeneration – cell has ability to recreate/regenerate itself (Epithelial, connective, bone, etc) (scar tissue, contains large elements of organized collagen fibers – created if body cannot regenerate the damage cells – cannot conduct electrical impulses, cannot contract)
  • Repair –

Hyperplasia , (or “hypergenesis”) is a general term referring to the proliferation of cells within an organ or tissue beyond that which is ordinarily seen

Neoplasm (tumors) – is the abnormal proliferation of cells, resulting in a structure known as a neoplasm. The growth of this clone of cells exceeds, and is uncoordinated with, that of the normal tissues around it. It usually causes a lump or tumor. Neoplasms may be benign, pre-malignant or malignant. Cancer = a malignant neoplasm, keeps growing as mutated cells

(muscle and nervous tissue (neurons) do not reproduce (Neuroglial and glial cells – have a support function and do reproduce)

Hypertrophy is the increase of the size of an organ or in a select area of the tissue. Adds protein filaments to the muscle. (Cardiac hypertrophy – bad- affects rhythms, chambers decrease in size – leads to heart failure.)
Cardiomegaly

• Stem cells
• Neutrophils
• Lymphocytes
• (White blood cells – 6 types)

11/9/08

• Tissues- Groups of similar cells that do the same thing
• Organ- Groups of different tissues working together
• System- Groups of organs working together
• Organism- All systems

Cellular structure

• Outside, cell membrane
• Cytoplasm, liquid inside cells
• Cytoskeleton, maintains structure of cells

Organelles:

• Mitochondrion – Provides energy for cells, burns glucose “cellular power plants” because they generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy.
  
• Endoplasmic Reticulum (ER) – transport system of cells
  
• Ribosomes Make proteins for cells – deposit in ER
  
• Golgi body
  
• Lysomes – digest and recycle

Nucleus – Center of cell

• Contains 23 pairs of chromosomes, info about cell makeup
• DNA
• Nucleolus where RNA is transcribed

Energy Storage

Mitochondria – take glucose and combine with O2 – also called cellular respiration, need o2 in order to release glucose. CO2 is released as a waste product from cellular respiration

Proteins: made up of amino acids (20 types) and make up much of cellular (and body) structure

• Ribosomes- convert intake proteins to human proteins
• DNA – blueprint – including how to make the right proteins for that individual
• Gene- Small section of DNA molecule with information for one specific function
• RNA- makes copes of genes and sends instructions out to ribosomes

Cellular Reproduction

Zygote – Fertilized egg, half of chromosomes from mother and half from father, keeps reproducing to create the whole person. Keeps splitting but not diluting total number of chromosomes using process called mitosis –(the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell.)

11/3/08

Study of;
Structure, eg
· Cells
· Tissues
· Organ systems

Relationship of structure. Eg heart in mediastnum in pericardium, ect

Anatomy –Identification & Labeling and naming (Structure)

Physiology-study of function – dynamic, actions, set of processes, involves knowledge of anatomy, understand the flow (Function)

Signs and symptoms are a reflection of abnormalities in a&p

Pathophysiology – study of organism in the presence of disease

Homeostasis – bodies ability to maintain a balance

Fluid in intra an extra cellular spaces

Body is 60% water 40% various solid substances

Internal environment (the 60%)
Intracellular fluid – within the cells (cytoplasm) 45%
Extracellular –
· spaces between cells = interstitial fluid 10.5%

· rest in blood vessels 4.5%

stressors = cause something abnormal to take place in the cells disrupting homeostasis and causing disease

Compensation – returns body to homeostasis (may use other systems)

(Normal body PH is 7.35 to 7. 45 )

Negative feedback –once process is complete inhibits further action (eg thermostat, when heat rises, sends neg feedback to shut furnace)

Cells – building blocks, fundamental unit of life – smallest unit of life. Each cell maintains homeostasis, chemical manufacturing plants

Properties of Life;

1) Metabolism is the set of chemical reactions that occur in living organisms in order to maintain life
a) Anabolism –synthesis – smaller to larger.
b) Catabolism – break down substances, specifically sugars.

2) Grow and reproduce
3) Excretion
4) Respond to stimulus
5) Ability to move

(Inflammatory response – body’s way of bringing nutrients to an injured or ill site)

Lymphocytes – immune protection– B memory cells, seek out other cells ……. T Cells…….