Cytology - Basic Genetics - Histology

Study of the structure.

How the parts of the body work.

Study of abnormalities from normal function.

[Patho] - disease

• 1. Metabolism
• 2. Responsiveness
• 3. Movement
• 4. Reproduction (formation of new cells)
• 5. Growth
• 6. Differentiation (cells reaching to specialised state)
• 7. Vital Force/Chi

• 1. Loss of heartbeat.
• 2. Absence of breathing.
• 3. Loss of brain function.
• 4. No Vital Force/Chi.

• The condition of balance in the body’s internal environment.
• It is dynamic and ever-changing whilst always remaining within narrow limits.

• 1. Core temperature (36.5-37.5c).
• 2. Water & Electrolyte* concentrations, *charged elements.
• 3. pH of body fluids.
• 4. Blood Glucose levels.
• 5. Blood & Tissue (Oxygen & Carbon Dioxide) Levels.
• 6. Blood Pressure.
• 7. Flow of LifeForce.

Cytoplasm is an intracellular fluid.

Interstitial and Synovial are both extracellular fluids.

• [Inter] - between
• [Stitial] - positioned

Interstitial fluid is a fluid composition that is in between the cells. It changes as substances move back and forth between it and blood plasma.

Homeostatis is constantly being disturbed by external and internal environments. Control Systems maintain Balance/equilibrium.

• 1. Disruptor(input)
• 2. Detectors(receptors)
• 3. Control Centre
• 4. Effector(output)

Feedback systems are groups of receptors and effectors communicating with their control centre.

A Negative Feedback System is when the Effector(output) reverses the Disruptor(input). The effector response decreases the effect of the original stimulus, maintaining/restoring homeostasis.

E.g. change of body temperature.

The Output(effector) amplifies the Input(disruptor). So the stimulus increases the response as long as the stimulus is continued.

E.g. child birth/milk production.

• Chemical Level (Atoms & Molecules)
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• Cells (each specialised to carry specific function)
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• Tissues (groups of cells with similar structures)
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• Organs (made of different number of tissue working together with a specific function)
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• Systems (consist of a number of organs and tissues to contribute to one or more survival needs of the body)
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• Vital Force/Chi (life energy throughout the body)
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• Human Being/Organism

• 1. Skeletal
• 2. Muscular
• 3. Respiratory
• 4. Cardiovascular
• 5. Digestive
• 6. Endocrine
• 7. Integumentary (skin,hair,nails)
• 8. Urinary
• 9. Reproductive
• 10. Nervous System
• 11. Immune System
• 12. Vital Force

• 1. Cranial
• 2. Thoracic
• 3. Abdominal
• 4. Pelvic

• Cytology is the study of plant and animal cells.
• All known living things are made up of cells and vital Force.
• All cells come from pre-existing cells by division.

• Disruption of body physiology can cause disease.
• Cells are interconnected making up organs and systems. When this is disrupted, diseases manifest in these organs.

• 1. Toxins from foods.
• 2. Environment or drugs.

Lead accumulates slowly in the body and affects red blood cells, nervous system and kidneys.

• 1. Prokaryotes
• 2. Eukaryotes

• Prokaryote cells are cells mainly for bacteria.
• They have no nucleus.
• They have a cell wall.
• They are unicellular.
• Contain no organelles.

• These are human and animal cells, fungi, plant and worms.
• Many organelles inside cell.
• Membrane bound nucleus.
• Cell wall only present in plants.

• 1. Plasma Membane - membrane surrounding cell)
• 2. Cytosine - basic watery fluid/intracellular fluid.
• 3. Organelles - small structures within the cell with specialised functions.
• 4. Cytoplasm - cell content excluding the nucleus.

The Plasma Membrane is flexible and semi-permeable and separates the cells external and internal environment.

• Structurally the Plasma Membrane has a phospholipid bilayer.
• The phosphate heads are hydrophilic (water-loving).
• The lipid tails are hydrophobic (water-hating).

This regulates what goes in and out depending what the cell needs.

[Trans] - across 

• 1. For movement of Ions.
• 2. Carriers - allow/transport larger substances across membrane.
• 3. Immunological identity - help identify foreign cells.
• 4. Receptors - recognition sites for hormones.

• 1. Nucleus
• 2. Mitochondria
• 3. Ribosomes
• 4. Endoplasmic Reticulum (ER)
• 5. Golgi Apparatus
• 6. Vesicles & Vacuoles
• 7. Lysosomes
• 8. Centrioles
• 9. Microtubules

• 1. All somatic cells have a nucleus except red blood cells. 
• 2. This is the "hub" for each cell. 
• 3. Some cells have multiple nuclei.

A Nucleolus is within the nucleus and it is made up or Protein, DNA & RNA.

The Nucleolus produces RNA.

• DNA - Deoxyribonucleic Acid is a self replicating material present in all living organisms. 
• It is the main constituent of chromosomes and the carrier of genetic information.

RNA - Ribonucleic Acid is made of of Nucleotides, essential for genetics and Protein Synthesis.

Chromosomes are thread-like structures of nucleic acid and protein found in the nucleus of most living cells, carrying genetic information in the form of Genes.

46

• Nucleotides (building blocks of DNA).
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• DNA forms a Double Helix. 
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• These coil round proteins called Histones. 
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• DNA is organised into dense fibres called Chromatin. 
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• Just before cellular division, Chromatin condenses even further and is subdivided into 46 individual Chromosomes.

XX

XY

Genes are portions of DNA that hold genetic information.

• Build and maintain cells.
• Pass genetic traits to offspring.

• Cytoskeletons are a network of protein filaments that extend through the cytosol. 
• These are formed by Microtubules & Microfilaments. 
• Microfilaments help to generate movement & provide support. 
• Microtubules are organised in the Centrosome. 
• The centrosome is located near the nucleus and this regulates cell division.

• Mitochondria generate ATP. ATP is the current of energy in body cells. 
• They also have an inner membrane which has a series of folds called cristae which produce enormous surface areas for reactions.

• Ribosomes are the sight of protein synthesis. 
• They have a high content of RNA.

• 1. Mobile ribosomes are found in the cytoplasm and make protein inside the cell. 
• 2. Stationary ribosomes are bound to Rough Endoplasmic Reticulum(RER) and make protein for outside the cell.

• 1. For specific organelles.
• 2. Insertion into plasma membrane.
• 3. Export from cell.

A network of membranes in the form of flattened sacs. 

• Endoplasmic = within plasma
• Reticulum = network (in Latin) 

• Continuous with the nuclear membrane. 
• Studded with ribosomes. 
• To synthesise and transport proteins.

• 1. Contains unique enzymes. 
• 2. Contains no ribosomes. 
• 3. Synthesises lipids and steroid hormones.

Golgi Apparatus a.k.a "The Cell Post Office" are flattened membranous sacs called cisternae.

• 1. They modify, package and transport proteins received from the Endoplasmic Reticulum (ER).
• 2. Transport vesicles from RER move towards the Golgi and release proteins into it's lumen. 3. Enzymes modify the proteins and then bud off in transport vesicles. 

• Vesicles = small sac or cyst containing fluid or gas. 
• Lumen = inside space of tubular structure. 

• Lysosomes are special types of membrane enclosed vesicles that perform a key role in cell digestions. 
• Lisosomes are the "recycling plant" of the cell.
• They remove and recycle cell structures. 

• Lyso = loosen
• Somes (from the Greek word soma) = body 

[Cyto] = cell  [Toxic] = harmful 

Cytotoxic.

Toxins can produce harmful effects by producing highly reactive molecules which contain oxygen. These then causes oxidative damage. 

• Mitosis is a type of cell division which creates 2 identical Diploid cells from original mother cell. 
• Only 1 division takes place and there are 46 Chromosomes in the daughter cells. 

These cells are used for growth and repair.

• 1. Skin Cells - continuous Mitosis takes place.
• 2. Nerve Cells - no Mitosis soon after birth.
• 3. Liver Cells - do not undergo continuous Mitosis unless repairing minor damage.

• Meiosis is a type of cell division which creates 4 non-identical Haploid cells from original mother cell. 
• 2 divisions take place and there are 23 Chromosomes in the daughter cells. 

These cells are used for making eggs/sperm and reproduction. 

Haploid Cells = Gametes (sex cells) 

• Fertilisation works when there is a fusion of male and female gametes.
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• A Zygote cell is a diploid cell resulting from the fusion of two haploid gametes (sex cells). 
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• The zygote then undergoes mitosis and develops into the embryo and finally a foetus.

• A mutation is a change in the genetic information (change in DNA sequence). 
• Causes for Mutation: 
• 1. Chance (spontaneous mutations). 
• 2. Induced by mutagenic agents e.g. X-Ray.

• 1. Substitution.
• 2. Deletion. 
• 3. Insertion. 
• 4. Inversion.

• Cells use the DNA code in the nucleus as a template for the synthesis in proteins.
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• Transcription - a copy of one gene from the DNA segment is made into MRNA (messengerRNA). This then travels out of the nucleus to a ribosome where translation occurs. 
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• Translation - the ribosome reads the code and synthesises a chain of amino acids to form the required protein.

• 1. Steepness of gradient. 
• 2. Temperature (Higher temp. increases speed of body processes e.g. exercise).
• 3. Mass.
• 4. Surface Area.

Passive transport moves down the concentration grade (from a high to low  concentration of molecules) and doesn't require any energy to do so.

• 1. Isotonic - same amount of water as blood.
• 2. [Hypo]Tonic - less solubles, more water.
• 3. [Hyper] Tonic - more solubles e.g. sodium, less water. 

• Hypo - low
• Hyper - high 

• 1. Simple Diffusion - movement of small substances e.g. gases. 
• 2. Facilitated Diffusion - movement of larger substances like glucose with the aid of protein career molecules imbedded in the plasma membrane. 
• 3. Osmosis - movement of water (soluble) when balance cannot be achieved by simple diffusion(molecules too big).

Active transport moves up the concentration grade (from low to high) which means it requires ATP (energy) to transport the molecules.

• 1. Sodium Potassium Pump - specific "lock/key" carier sisters for molecules like sodium & potassium.
• 2. Endocytosis - fusing of substances to be able to pass through the membrane. Phagocytosis - "cell-eating" large particles. Pinocytosis - "cell-drinking" small particles. 
• 3. Exocytosis - removal of waste material.

The study of the microscopic structure of tissue.

Cell Junctions are contact/communication points between the adjacent plasma membranes.

• 1. Tight Junctions - the function is to form a seal to prevent molecules passing through. Found in stomach, intestines etc. Prevents contents of these organs leaking into blood/other tissues. 
• 2. Gap Junctions - small fluid filled tunnels between neighbouring cells e.g. muscle/nerves.

• 1. Epithelial - cover & protect body. 
• 2. Connective - provide support.
• 3. Muscular - movement. 
• 4. Nervous - control & communication.

• Consists of: closely packed cells arranged in continuous sheets. 
• We find them in: blood vessels, heart, lungs, skins, eyes. etc.

• 1. Columnar Cells (column-like) - much higher than wide. 
• 2. Cuboidal Cells (cube-like) - look like squares.
• 3. Squamous Cells (flattened, scale-like) - flat and not very tall. 

These different cells can be arranged to form different structures. 

Glands are single or groups of epithelial cells that produce secretions. 

• [Exo]crine glands secrete their products into ducts e.g. saliva, sebum. 
• [Endo]crine glands enter interstitial fluid and then diffuse into blood. Secretes hormones into blood. 

• Exo - exit
• Endo - enter 

• 1. Extracellular Matrix - medium of how cells are suspended to give structural support to surrounding cells.
• 2. Widely spaced cells.

• Made of ground substances and Fibres. 
• Contains many substances including water & Hyaluronic Acid & Chondroitin Sulphate.

• 1. Fibroblasts (makes fibres) - secretes protein fibres to make collagen, elastin & matrix. 
• 2. Adipocytes - store triglycerides(fat). 
• 3. Leukocytes(white blood cells) 

• 1. Macrophages - they initiate defence mechanisms. 
• 2. Plasma Cells - synthesise and secrete micro bodies for defence. 
• 3. Mast Cells - produce & release heparin, histamine (inflammation).

• 1. Structural
• 2. Transport
• 3. Protection
• 4. Support & Interconnection
• 5. Insulate
• 6. Store Energy
• 7. Produce Blood & Lymphatic Cells
• 8. Defense & Repair

Membranes are flat sheets of pliable tissue that cover or line parts of the body.

• 1. Synovial
• Made up of connective tissue & elastic fibres. 

• 2. Cutaneous -skin. 
• 3. Mucous
• 4. Serous 
• Made up of epithelial & connective tissue. 

• The mucus membrane lines entire digestive, respiratory and genitourinary tracts. 
• The mucus membrane secretes enzymes needed for digestion.

• 1. Protects - lining of membrane from mechanical & chemical injury. 
• 2. Traps - foreign particles in the respiratory.

Serous membrane is a smooth tissue membrane consisting of two layers of which secrete serous fluid. This is to reduce friction between membranes. 

• The double layer of loose areolar(small area) connective tissue are: 
• 1. Parietal Layers line a cavity. - outer 
• 2. Visceral Layers surround organs - inner.

• 1. Pleura - lining the thoracic cavity.
• 2. Pericardium - lining the pericardial cavity & surrounding heart. 
• 3. Peritoneum - lining the abdominal cavity & surrounding abdominal organs.

Synovial membranes are connective tissue which lines cavities of freely movable joints.

Synovial membranes secrete clear, sticky, oily synovial fluid which lubricates and nourishes the moveable joint.