1. CYTOLOGY, GENETICS AND HISTOLOGY Flashcards
The characteristics of life. Different types of cells, organelles and tissues in the human body. DNA, RNA, gene structure, function and inheritance. Homeostasis, positive and negative feedback systems , movement of substances and protein synthesis.
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 each:
- 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 four of the characteristics of ‘Life’
Metabolism - sum of all chemical processes
Responsiveness - ability to respond to changes in env.
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 four characteristics of ‘Death’
Loss of heartbeat.
Absence of breathing.
Loss of brain function.
No vital force/life force/Qi.
Name four of the physiological variables that must be kept within narrow parameters to enable homeostasis in the body
- Core temperature (36.5 - 37.5 degrees C)
- Water and electrolyte balance
- pH of body fluids
- Blood glucose levels (4-7mmol/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 four body cavities
Cranial
Thoracic
Abdominal
Pelvic
Name four 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 one 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 three 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 (e.g. charged particles like hydrogen and larger molecules like glucose)
- Immunological identity: helps immune cells recognise our own cells
- Receptors: recognition sites for hormones etc.
Name two places in the body where tight cell junctions can be found
Stomach
Intestines
Bladder
Name five 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 in gametes?
23