01_Cytology, Basic Genetics and Histology Flashcards
What are the characteristics of life?
- Metabolism
- Responsiveness
- Movement
- Reproduction
- Growth
- Differentiation
- Vital Force / Life Force / Qi
What are the characteristics of death?
- Loss of heartbeat
- Absence of breathing
- Loss of brain function
- No Vital Force / Life Force / Qi
Define homeostasis.
Condition of equilibrium in the body’s internal environment maintained by regulatory processes.
What physiological variables must be kept within narrow parameters for homeostasis?
- Core temperature (36.5-37.5°C)
- Water and electrolyte concentrations
- pH of body fluids
- Blood glucose levels
- Blood and tissue O2 / CO2 levels
- Blood pressure
- Flow of Life Force
What is the role of disruptors in homeostatic control?
Change homeostatic parameter.
What is the function of detectors in homeostatic control?
Receptors that detect disruption (often nerves).
What is the control center’s role in homeostasis?
Determines limits within which parameters should be maintained, evaluates input, and generates output.
What are effectors in the context of homeostasis?
Structures that receive output from the control center.
What is a negative feedback system?
The output reverses the input and accounts for most body variables.
What is a positive feedback system?
Tends to strengthen or reinforce change in one of the body’s controlled conditions.
List the 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
What are the four main body cavities?
- Cranial
- Thoracic
- Abdominal
- Pelvic
What does the cell theory state?
- All known living things are made up of cells and Vital Force
- The cell is the structural and functional unit of all living things
- All cells come from pre-existing cells by cell division
- All energy flow of life occurs within cells
What is cell memory?
The ability of cells to remember experiences influencing the Vital Force in our cells and body.
What causes disease according to the text?
A disruption of body physiology due to interconnected cells and energy flow.
What heavy metals are known to cause cell damage?
- Aluminium
- Mercury
- Lead
What is oxidative stress?
Damage caused by free radicals, often due to toxins, stress, and poor diet.
What are prokaryotic cells?
Cells that contain no nucleus and no membrane-bound internal structures.
What are eukaryotic cells?
Cells that contain a nucleus and membrane-bound organelles.
Fill in the blank: Human cells do NOT have a _______.
cell wall
What is the structure of the cell membrane?
A flexible, semi-permeable phospholipid bilayer.
What is the function of transmembrane proteins?
- Transport of substances in/out of cells
- Immunological identity
- Receptors for hormones
What are tight junctions?
Contact points that prevent leaking between adjacent cells, found in the stomach, intestines, and bladder.
What are gap junctions?
Small fluid-filled tunnels between neighbouring cells.
List key organelles found in body cells.
- Nucleus
- Mitochondria
- Ribosomes
- Endoplasmic reticulum
- Golgi apparatus
- Lysosomes
- Cytoskeleton
What is the function of the nucleus?
Contains genetic information in the form of DNA and controls all cell functions.
What happens to red blood cells during development?
They lose their nucleus to maximize space for oxygen transport.
The nucleus controls cell functions and contains RNA and DNA.
What is the function of the nucleus in a cell?
The nucleus controls all cell functions and contains a nucleolus that produces RNA.
The nucleus is often referred to as the brain of the cell.
Define DNA.
DNA (deoxyribonucleic acid) is a self-replicating material that carries genetic information in living organisms.
DNA is the main constituent of chromosomes.
What is the role of RNA?
RNA (ribonucleic acid) is essential for protein synthesis.
What does the nuclear membrane do?
It separates the nucleus from the cytoplasm and contains nuclear pores for substance movement.
The nuclear membrane is continuous with the rough endoplasmic reticulum.
What is the cytoskeleton?
A network of protein filaments that assist in cell movement, support, shape, and division.
List three functions of the cytoskeleton.
- Generate cell movement
- Provide physical support and shape
- Assist in cell division
What are mitochondria known as?
The cell powerhouses because they generate ATP (adenosine triphosphate).
What is ATP?
ATP (adenosine triphosphate) is the energy currency of body cells.
How do mitochondria produce ATP?
Through a process called aerobic respiration using oxygen and nutrients like glucose.
What distinguishes free ribosomes from bound ribosomes?
Free ribosomes are mobile in the cytoplasm, while bound ribosomes are attached to the rough endoplasmic reticulum.
What is the primary function of ribosomes?
They act as the sites of protein synthesis.
What is the difference between rough ER and smooth ER?
Rough ER has ribosomes on its surface and synthesizes proteins, while smooth ER has no ribosomes and synthesizes lipids and steroid hormones.
What does the Golgi apparatus do?
It modifies, sorts, packages, and transports proteins received from the rough ER.
What are lysosomes?
Vesicles that perform a key role in cell digestion and recycling of worn-out organelles.
Define chromosomes.
Thread-like structures carrying genetic information in the form of genes, found in the nucleus of most living cells.
How many chromosomes does a human somatic cell contain?
46 chromosomes (or 23 pairs).
What are genes?
Sub-sections of DNA that act as instructions to make proteins.
What is protein synthesis?
The process by which cells use the DNA code to produce specific proteins.
What are the two phases of protein synthesis?
- Transcription
- Translation
What is a mutation?
A change in the genetic information (DNA sequence).
What are the four nucleotide bases found in DNA?
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
What is the process of mitosis?
The reproduction of somatic cells to create two identical daughter cells.
How often do red blood cells replace themselves?
Every 90-120 days.
What is meiosis?
The process through which gametes (sex cells) are formed.
How many chromosomes do gametes have?
23 chromosomes (haploid).
What is fertilization?
The fusion of a male and female gamete leading to the formation of a zygote.
What is passive transport?
Movement of substances from high to low concentration without energy.
List the three types of passive transport.
- Diffusion
- Osmosis
- Facilitated diffusion
What is active transport?
Movement of substances from low to high concentration requiring energy (ATP).
What are the main examples of active transport?
- Pumps
- Endocytosis
- Exocytosis
What are the four types of tissue?
- Epithelial tissue
- Connective tissue
- Muscular tissue
- Nervous tissue
What is epithelial tissue?
Covering or lining tissue consisting of closely-packed cells.
What are the four main types of tissue in the body?
- Epithelial tissue
- Connective tissue
- Muscular tissue
- Nervous tissue
Define epithelial tissue.
Covering / lining tissue consisting of closely-packed cells arranged in continuous sheets.
What are the two types of epithelial tissue?
- Covering epithelium
- Glandular epithelium
What is the primary function of epithelial tissue?
Provides a selective barrier for protection and secretion of substances.
Where is epithelial tissue located?
- Blood vessels
- Heart
- Lungs
- Reproductive organs
- Urinary tract
- Gastrointestinal tract
- Skin
- Eyes
What is a gland?
A single cell or groups of epithelial cells that produce secretions.
What are exocrine glands?
Glands that secrete their products into ducts, including saliva, milk, sebum, sweat, enzymes.
What are endocrine glands?
Glands that secrete hormones into interstitial fluid, which then diffuse into blood.
Define connective tissue.
The most diverse and abundant kind of tissue in the body, providing supportive functions.
What are the two basic elements of connective tissues?
- Extracellular matrix
- Cells
What is the extracellular matrix?
Formed of ground substance and protein fibres, it helps determine the functionality of the tissue.
What are the main types of protein fibres in connective tissue?
- Collagen fibres
- Elastic fibres
What is the role of fibroblasts in connective tissue?
They produce collagen and elastic fibres and are active in repair and healing.
What are the functions of connective tissue?
- Structural framework
- Transport nutrients and wastes
- Protection for vital organs
- Support and interconnection
- Insulation
- Energy store
- Production of blood and lymphatic cells
- Defence and repair
What are the four types of membranes in the body?
- Cutaneous membrane
- Mucous membrane
- Serous membrane
- Synovial membrane
What is the function of mucous membranes?
They line hollow organs that open to a surface of the body and secrete mucus.
Where do mucous membranes line in the body?
- Digestive tract
- Respiratory tract
- Genito-urinary tract
What do goblet cells produce?
Mucus
What is the function of serous membranes?
They line body cavities that do not open to the exterior and reduce friction between organs.
Name the three serous membranes in the body.
- Pericardium
- Pleura
- Peritoneum
What is the purpose of synovial membranes?
They line cavities of freely movable joints and secrete synovial fluid.
What does synovial fluid do?
Lubricates and nourishes moveable joint cavities.
Fill in the blank: The _______ is a serous membrane surrounding the heart.
[Pericardium]
True or False: Connective tissue cells are closely packed together.
False
