Lecture 1 - Cytology, genetics and histology Flashcards
Define ‘homeostasis’.
Homeostasis is the dynamic and ever-changing condition of equilibrium (balance) in the body’s internal environment maintained by the body’s own regulatory processes. It is a fundamental principle of physiology.
Differentiate the following terms by defining them:
- Anatomy
- Physiology
- Pathology
- Anatomy is the study of structures that form the body.
- Physiology is how the parts of the body work.
- Pathology is the study of abnormalities from normal function.
Name 4 characteristics of ‘life’.
- Metabolism - sum of all chemical processes
- Responsiveness - ability to changes in environment
- Movement - cells, organs and whole organism
- Reproduction - formation of new cells / organism
- Growth - increase in size / number
- Differentiation - development to specialised state
- Vital Force/ Qi - energy of life
Name 4 characteristics of ‘Death’.
- Loss of heartbeat
- Absence of breathing
- Loss of brain function
- No vital force / life force / Qi
Name 4 of the physiological variables that must be kept within narrow parameters to enable homeostasis in the body.
- Core temperature (36.5 - 37.5 degress C)
- Water and electrolyte balance
- pH of body fluids
- Blood glucose levels (4-7 mmol/L)
- Blood and tissue oxygen / CO2 levels
- Blood pressure
- Flow of life force
Blood plasma, synovial fluid, lymph fluid and interstitial fluid are all examples of _________ fluids.
Extracellular
Name the 4 body cavities.
- Cranial
- Thoracic
- Abdominal
- Pelvic
Name 4 things that can cause oxidative damage in the body.
- Stress
- Smoking
- Toxins
- Diet high in refined foods and sugar
Define a negative feedback system and give 1 example
A negative feedback system is one where the output (from the effectors) reverses the input (detected by the receptors).
Examples are increasing or decreasing body temperature, blood glucose, blood pressure).
A positive feedback system strengthens / enhances change in one of the body’s controlled conditions, and is much rarer than negative feedback systems. Give 3 examples of positive feedback systems.
- Blood clotting
- Childbirth
- Milk production
- Enzyme reactions
- Immunity
What are free radicals and how can they be countered in the body?
Free radicals are unstable and highly reactive molecules. They lack an electron in their atomic structure, which can be donated by antioxidants such as Vitamin A, C, E, beta-carotene (Vitamin A precursor), quercetin and lycopene.
What are the main differences between prokaryotic and eukaryotic cells?
Prokaryotic cells contain no nucleus and no membrane bound internal structures, while eukaryotic cells have both.
True or false:
Only prokaryotic cells have cell walls.
False:
Plants and fungi are eukaryotes and their cells have cell walls.
Differentiate between ‘cytosol’ and ‘cytoplasm’ by defining them.
Cytosol is the basic watery fluid inside a cell.
Cytoplasm is the cell content excluding the nucleus (cytosol + organelles)
The cell membrane is a __________, semi-_____________ membrane that separates the cell’s ___________ and internal environment.
- Flexible
- Permeable
- External
Briefly describe the structure of the cell membrane
The cell membrane is a phospholipid bilayer, these being arranged with the hydrophilic phosphate heads towards the outsides and the hydrophobic lipid tails on the inside.
Cell membranes are embedded with _________ proteins and controls substance ___________ in and out of cells.
Transmembrane
Movement
What are the functions of transmembrane proteins?
- Transport of substances in/out of cells (eg/ charges particles like hydrogen and larger molecules like glucose
- Immunological identity: helps immune cells recognise our own cells
- Receptors: recognition sites for hormones etc.
Name 2 places in the body where tight cell junctions can be found
- Stomach
- Intestines
- Bladder
Name 5 of the key organelles found in body cells
- Nucleus (with nucleolus)
- Mitochondria
- Ribosomes
- Endoplasmic reticulum
- Golgi apparatus
- Lysosomes
- Cytoskeleton
All body cells have a nucleus with the exception of _____________.
Red blood cells
The nucleus is a spherical structure that contains the body’s ___________ information in the form of _________. It controls all cell functions, hence known as the _________ of the cell. It contains a ___________, which produces RNA.
Genetic
DNA
Brain
Nucleolus
What organelle is continuous with the nuclear membrane?
Rough endoplasmic reticulum
DNA forms a double ______ which coils around proteins called ___________.
Helix
Histones
How many chromosomes are there in somatic cells?
23 pairs (46)
How many chromosomes are there is gametes?
23