Cytology Flashcards
(30 cards)
What is cytology?
The study of cells.
Describe the cell:
- Basic unit of all living things
- tiny living building blocks that are responsible for carrying on all life processes
- our body consists of trillions of cells which vary in shape, size and purpose
- cells are about 60% water
- have the ability to grow and reproduce
- have the ability to respond and adapt to changes in the environment
- cells contain food elements such as proteins, fats, carbs, mineral salts and water
- cells bodies are constantly bathed in a salt-water solution called interstitial fluid which is derived from the blood
- all exchanges between the cells and blood is through this fluid
What is interstitial fluid?
- A salt-water solution derived from the blood which cells bath in
- exchanges between cells and blood is through this fluid
Describe the cell membrane:
- the outer wall of the cell which protects the cell structure
- permits soluble substances to enter and leave the cell
- works like a lock and key mechanism
- composed of a double layer of fat surrounded by two layers of protein
- it is flexible and allows for growth
- it serves as a semi permeable passageway for oxygen, carbon dioxide, and water to pass in the either direction
- on the cell membrane are special structures called receptor sites.
What are receptors?
- receptors are the communication system between different cells, tissues, organs, and parts of the body.
- receptors receive messages from hormones and other chemical messengers made by other cells
Describe cytoplasm
- cytoplasm is granular fluid which acts as a support for all of the structures within the cell
- cytoplasm is part of the protoplasm (living substance of a cell)
- cytoplasm consists of organelles except the nucleus
- the site with the most activity, like a “factory area”
What is protoplasm?
The protoplasm consists of the nucleus, cytoplasm and plasma membrane
Describe endoplasmic reticulum (ER)
Hint: little network within cytoplasm
- a network within the cytoplasm
- consists of clear tubular structures which serve as passageways for cellular material
- allows for substances and organelles to move around
- has two appearances: rough and smooth
- the inner surface of ER is lined with ribosomes (also called rough ER)
- Rough ER produces the phospholipids and proteins that are either packaged or secreted from the cell
- smooth ER does not have any ribosomes
Describe ribosomes
Hint: protein granule
- ribosomes are small granules of protein located along the inner surface of the endoplasmic reticulum.
- they read coded genetic messages (RNA) and assemble amino acids into proteins
- they contain a large amount of proteins called RNA (ribo nucleic acid)
- ribosomes are actual sites of protein synthesis in the cell
- ribosomes can float freely in the cytoplasm or attach to the ER or the nuclear membrane.
Mitochondria:
Hint: powerhouse that produces ATP (energy)
The mitochondria helps break down nutrients like proteins, fats and carbs and turns them into energy.
- “power house” of the cell
- takes complex substances and breaks them down
- breaks down glucids (sugar) and lipids (fats) and releases them into the cell
- the broken down sugar and fats release energy for the cell
- much of the energy escapes as heat but some is captured and form ATP molecules (adenosine triphosphate)
- ATP provides energy for all cellular work
- every cell needs a constant supply of ATP to perform its activities
Lysosomes
Hint: breakdown bodies/ cell demolition sites
- inner-cellular digestion
- the cells garbage disposal system
- digest waste material and food within the cell
- breaks down large complex food into smaller foods so the mitochondria can process them into energy
- digest worn out cell structures and foreign substances
Golgi Apparatus
Transports the proteins out of the cell
- a stack of membranous sacs with tiny vesicles
- receives protein from the endoplasmic reticulum and sends it to the cell membrane for export
- closely located to the nucleus and is the “traffic director”
- serves to collect and transfer proteins out of the cell
Centrioles
Rod shaped
- located close to the nucleus and consists of two tubular structures
- function: to intervene in the cycle of cell reproduction (mitosis)
- during cell division, the centrioles direct the formation of the mitotic spindle.
Nucleus
Hint: dense protoplasm found in the centre of the cell
- controls and regulates the metabolic activities of a cell
- dictates cell division
- contains all of the cells hereditary and genetic material (chromosomes, genes, DNA)
- important part of reproduction and metabolism
- genetic control centre
- directs protein
3 distinct regions
- The nuclear envelope
- Nucleoli
- Chromatin
If a cell rejects or loses its nucleus, it will die
Chromosomes
Thread shaped bodies contained in the nucleus
- humans have 23 pairs of chromosomes
- they house thousands of genes and DNA (deoxyribonucleic acid)
- DNA is responsible for behavioural patterns of the body and genetic makeup
- DNA also serves as the master blueprint for protein synthesis
Genes
Blue print for protein structure
- A gene is a DNA segment that carries the information for building one protein/ polypeptide chain
- proteins are key substances for all aspects of life
- basic unit of heredity
- each chromosome has up to 1250 genes which are responsible for physical traits such as body structure, hair and eye colour, etc.
Metabolism
- a complex chemical action where the body’s cells are nourished and supplied with the energy needed to function (growth, weight)
- it is the correct exchange of nutrients and waste through the cell wall
The metabolism has 2 phases:
- Anabolism
- Catabolism
These are carried out simultaneously and continually within the cells
The two phases of metabolism
- ANABOLISM:
- is constructive metabolism - the process of building up larger molecules from smaller ones
- during this process, the body stores water, food, and oxygen for when it’s needed for cell growth and repair
- takes a simple substance and builds it up to a more complex form - CATABOLISM
- is the phase of metabolism in which complex compounds are broken down into small ones
- this process releases energy that is stored by special molecules to be used in muscle contraction, body secretions, or heat production
Cell growth and reproduction
- cells can reproduce to replace old damaged cells
- mitosis: is the process when one cell reproduces two identical daughter cells
If the body is healthy, cells will grow and reproduce healthy cells
If the body is unhealthy, cells may die or produce diseased cells
Tissue
- a collection of similar cells that perform a particular function
- each tissue has a specific function and can be recognized by its characteristic appearance
- body tissue is composed of 60-90% water and other substances
The body consists of 4 types of tissue:
- Connective tissue
- Muscular tissue
- Epithelial tissue
- Nerve tissue
Discuss the 4 types of tissue
- Connective tissue: holds together other body parts (bone fascia)
- Muscular tissue: contracts and moves the parts of the body
- Epithelial tissue: protective coverings (skin, mucous membranes)
- Nerve tissue: Carrie’s message from the brain and coordinates all body functions. Made of neutrons (brain, spinal cord, nerve controls)
What are organs?
Group of tissues designed to perform specific functions
Examples of important body organs:
Brain, eyes, heart, kidneys, lungs, liver, skin, stomach, etc.
What is an organ system?
A group of organs that cooperate to accomplish a common purpose
Each organ has its own job to do and working together to perform actions.
11 organ systems in the body.
Example: digestive system includes the esophagus, stomach and small intestine all need to work together to keep food moving through the digestive system.
What are the 3 major regions of a cell?
- Nucleus
- Plasma membrane
- Cytoplasm
Nucleus: control centre that directs cell activity. Contains genetic material which carries instruction for synthesis of proteins.
Plasma membrane: limits and encloses the cytoplasm. Acts as a selective barrier for substances to move in & out of the cell. Composed of a double layer of fat surrounded by 2 layers of protein.
Cytoplasm: where most cellular activity occurs “factory area”. It is fluid substance and specialized organelles, each with a specific function.
