Cells & Tissues Flashcards
Define ‘anatomy’
Study of the structures that form the body
Define ‘physiology’
How the parts of the body work
Define ‘pathology’
The study of abnormalities from normal function
Define ‘metabolism’
The sum of all the chemical processes in the body
Define ‘responsiveness’
The ability to respond to changes in the environment
List some of the characteristics of life
Metabolism Responsiveness Movement Reproduction Growth Differentiation Vital force / life force / Qi
List some of the characteristics of death
Loss of heartbeat
Absence of breathing
Loss of brain function
No life force / Qi
What is homeostasis?
The condition of equilibrium / balance in the body’s internal environment, maintained by its own regulatory processes
Which physiological variables must be kept within narrow parameters in order for the body to remain in homeostasis?
Core temperature (36.5 - 37.5) Water & electrolyte concentrations pH of body fluids Blood glucose levels Blood & tissue O2 & CO2 levels Blood pressure Flow of life force / Qi
What is a ‘normal’ core body temperature?
36.5 - 37.5 degrees
Body fluids are either ‘intracellular’ or ‘extracellular’. List some extracellular fluids.
Blood plasma
Synovial fluid
Lymph fluid
Interstitial fluid
List the 4 things that homeostatic control systems are made up of.
- DISRUPTORS (change homeostatic parameter)
- DETECTORS (receptors that detect the disruption - usually nerves)
- CONTROL CENTRE (determines limits within which parameters should be maintained. Evaluates input and generates output.
- EFFECTORS (structures that receive the output and generate the response)
What is a feedback system?
A group of receptors and effectors communicating with their control centre.
Define negative feedback
Where the output reverses the input.
Example: core body temperature is too high (input), so we begin to sweat (output) to cool down.
Define positive feedback
Where the output further strengthens the input / strengthens the change in one of the body’s controlled conditions.
Example: pressure from baby’s head on the cervix during childbirth makes labour contractions stronger, which increase the pressure from baby’s head (through the release of oxytocin)
In a negative feedback system, does the effector response increase or decrease the effect of the original stimulus?
Decreases it
List some of the physiological variables that are controlled by NEGATIVE feedback systems
Body temperature
Blood glucose
Blood pressure
List some of the physiological variables that are controlled by POSITIVE feedback systems
Childbirth Milk production Enzyme reactions Immunity Blood clotting
What are the smallest living units in the body?
Cells
What are tissues?
Groups of cells that work together to perform a function
What are organs?
Groups of tissues working together to perform a function(s)
What are systems?
Groups of organs that have a common / shared function
List the 12 systems of the human body
Skeletal system Muscular system Respiratory system Cardiovascular system Digestive system Endocrine system Lymphatic system Integumentary system Urinary system Reproductive system Nervous system Immune system
The body’s organs are primarily located within 4 cavities. List these cavities.
Cranial
Thoracic
Abdominal
Pelvic
What is the diaphragm and what 2 areas of the body does its presence differentiate?
The diaphragm is the main muscle of breathing.
Its presence differentiates the thoracic cavity (above it) from the abdominal cavity (below it).
What is the difference between cytology and histology?
Cytology is the study of cells.
Histology is the study of tissues.
Cells contain hereditary information. What is this in the form of, and how is it passed from cell to cell?
Cells contain hereditary information in the form of DNA. It is passed from cell to cell during cell division (mitosis or meiosis)
What do all cells in the body come from?
Pre-existing cells (stem cells) via cell division
In which body structure does all energy flow of life (metabolism and life force) occur?
Within cells
Describe ‘cell memory’
The ability of our cells to remember experiences which influence the Vital Force in our cells and body.
Traumatic experiences and even negative beliefs may be stored as a negative charge of energy in cells.
Vital force is free-flowing throughout the body in a healthy person, but it can become blocked, creating the possibility of disease.
List some things that can cause disruption of energy through cells / stagnation of energy.
Dietary choices
Lifestyle influences, i.e, smoking, not enough sleep
Drugs
Exposure to harmful substances, i.e, radiation
List 3 heavy metals that can accumulate in the body and cause damage to cells.
Mercury, aluminium, lead
Which metal has been linked to Alzheimers, brain neuron damage and breast cancer, and where is it found in everyday life?
Aluminium.
It can be found in kitchen foil, pans, anti-perspirants, baking soda, and it’s also a key ingredient in vaccines.
What does ‘cytotoxic’ mean?
Poisonous / toxic to cells
What is ‘oxidative damage / stress’?
Damage of a structure by a molecule containing oxygen.
What are free radicals?
Free radicals are unstable and highly reactive oxygen-containing molecules, which lack an electron in their atomic structure.
How do antioxidants reduce oxidative stress in the body?
By donating one of their electrons to the unstable free radicals that are causing the oxidative stress.
List some examples of antioxidants
Vitamin C, E and beta carotene (vitamin A precursor)
Quercetin, EFA’s.
Why is oxidative stress a problem in the body?
It can damage cell membranes, blood vessels and tissues.
It can influence and damage certain cell structures
It can cause genetic mutation (including cancer)
Cells are classified as being either P…….. or E………
fill in the blanks
Prokaryotic or Eukaryotic
Describe the differences between prokaryotic and eukaryotic cells
Prokaryotic cells have NO NUCLEUS and no membrane-bound organelles. They are smaller, divide via binary fission (rapid mitosis) and are generally bacteria. They have a cell wall.
Eukaryotic cells contain a nucleus and lots of membrane-bound organelles. They are bigger, divide via mitosis and are generally human/animal cells (although they also appear in plants/fungi). They do not have a cell wall, unless in plants/fungi.
What do ‘DNA’ and ‘RNA’ stand for?
Deoxyribonucleic Acid
Ribonucleic Acid
The cell membrane is a flexible, semi-permeable membrane which separates the cell’s internal and external environments. It is a bilayer.
Describe the arrangement / components of this bilayer.
The phospholipid bilayer of the cell membrane has 2 layers of:
- Hydrophobic (water hating) lipid tails on the inside
- Hydrophillic (water loving) phosphate heads on the outside
What is the purpose of the cell membrane?
- Transport and control of substances going in and out of cells
- Immunological identity
- Contains receptors for hormones, etc
What is an ion? Give some examples.
An ion is a molecule with an electrical charge.
e.g, Hydrogen, Potassium, Sodium
Where might you find transmembrane proteins and cholesterol?
In cell membranes.
When do autoimmune diseases occur?
When white blood cells target our own cell membrane proteins.
Define ‘hypoxia’
Hypoxia is a lack of oxygen
Which organs detect hypoxia?
Kidneys
What are atoms made up of?
Neutrons, protons and electrons
What creates vibrational energy?
Electrons moving rhythmically around the outside of their atoms
70% of the immune system is located where?
Within the digestive system
What is it that governs what type of cell a stem cell becomes?
Which genes are activated within the DNA of the stem cell.
What is a gene?
A sub-section of DNA
How long is the DNA in every cell?
About 6 feet long! This is why it is curled up and condensed inside the cell.
Where is the DNA / RNA found in a) a prokaryotic cell, and b) a eukaryotic cell?
Prokaryotic cell = in the cytoplasm (they don’t have nuclei)
Eukaryotic cell = in the nucleus
What are cell organelles?
Mini structures / organs within the cell
e.g, ribosomes produce proteins
Name the 2 types of cell division
Mitosis & Meiosis
What is cytosol?
Basic, watery fluid inside a cell
What is cytoplasm?
All cell contents EXCLUDING the nucleus.
Includes the cytosol and organelles.
Which cell structure controls what comes in and goes out of the cells?
Cell Membrane
How do ions / charged particles get in and out of cells?
Via transmembrane proteins (channel proteins)
What happens in autoimmune diseases?
Our white blood cells attack our own cell membrane proteins.
What are cell junctions?
Contact/communication points between the adjacent cell membranes of tightly packed cells.
List 2 types of cell junction and where they are found in the body
- Tight junctions (stomach, intestines, bladder)
2. Gap junctions (nerves)
Explain how tight junctions create a protective barrier
Tight junctions occur where transmembrane proteins in adjacent cells interlock / fuse together (at cell junctions) to create a tight seal. They completely seal off any passageways, creating a protective surface and preventing any leaking (i.e, in the intestines).
What is the name given to the GIT pathology caused by weak tight junctions in the intestinal cell wall?
Leaky gut
What is the difference between tight junctions and gap junctions?
Gap junctions have a small quantity of fluid between them. Tight junctions do not and are completely sealed.
List 4 key organelles found in body cells
Nucleus (and nucleolus) - the brain Mitochondria - the power plant Ribosomes - the protein factory Endoplasmic Reticulum (ER) - fat & protein factory Golgi Apparatus - the post office Lysosomes - the recycling plant Cytoskeleton - the cell scaffolding
Describe the appearance of the Endoplasmic Reticulum (ER)
The ER is a series of foldings, divided up into 2 parts:
The rough ER has lots of dots (ribosomes) on it
The smooth ER doesn’t have any ribosomes studded into it.
What do lysosomes do?
Help us recycle and break down old cell components