Cytology

Question 1

What is cytology?

Answer 1

The study of cells.

Question 2

Describe the cell:

Answer 2

• 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

Question 3

What is interstitial fluid?

Answer 3

• A salt-water solution derived from the blood which cells bath in
• exchanges between cells and blood is through this fluid

Question 4

Describe the cell membrane:

Answer 4

• 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.

Question 5

What are receptors?

Answer 5

• 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

Question 6

Describe cytoplasm

Answer 6

• 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”

Question 7

What is protoplasm?

Answer 7

The protoplasm consists of the nucleus, cytoplasm and plasma membrane

Question 8

Describe endoplasmic reticulum (ER)

Hint: little network within cytoplasm

Answer 8

• 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

Question 9

Describe ribosomes

Hint: protein granule

Answer 9

• 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.

Question 10

Mitochondria:
Hint: powerhouse that produces ATP (energy)

Answer 10

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

Question 11

Lysosomes

Hint: breakdown bodies/ cell demolition sites

Answer 11

• 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

Question 12

Golgi Apparatus

Transports the proteins out of the cell

Answer 12

• 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

Question 13

Centrioles

Rod shaped

Answer 13

• 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.

Question 14

Nucleus

Hint: dense protoplasm found in the centre of the cell

Answer 14

• 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

1. The nuclear envelope
2. Nucleoli
3. Chromatin

If a cell rejects or loses its nucleus, it will die

Question 15

Chromosomes

Thread shaped bodies contained in the nucleus

Answer 15

• 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

Question 16

Genes

Blue print for protein structure

Answer 16

• 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.

Question 17

Metabolism

Answer 17

• 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:

1. Anabolism
2. Catabolism

These are carried out simultaneously and continually within the cells

Question 18

The two phases of metabolism

Answer 18

1. 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
2. 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

Question 19

Cell growth and reproduction

Answer 19

• 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

Question 20

Tissue

Answer 20

• 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:

1. Connective tissue
2. Muscular tissue
3. Epithelial tissue
4. Nerve tissue

Question 21

Discuss the 4 types of tissue

Answer 21

1. Connective tissue: holds together other body parts (bone fascia)
2. Muscular tissue: contracts and moves the parts of the body
3. Epithelial tissue: protective coverings (skin, mucous membranes)
4. Nerve tissue: Carrie’s message from the brain and coordinates all body functions. Made of neutrons (brain, spinal cord, nerve controls)

Question 22

What are organs?

Answer 22

Group of tissues designed to perform specific functions

Examples of important body organs:
Brain, eyes, heart, kidneys, lungs, liver, skin, stomach, etc.

Question 23

What is an organ system?

Answer 23

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.

Question 24

What are the 3 major regions of a cell?

Answer 24

1. Nucleus
2. Plasma membrane
3. 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.

Question 25

Describe mitosis

Answer 25

When the nucleus divides, each daughter cell ends up with the same genetic information as the original/ mother cell.

• Two small structures near the nucleus called centrioles move to each side during mitosis to help divide the cell.

Explained further: A process of asexual reproduction in which the cell divides in two, producing a replica with an equal number of chromosomes in each, resulting diploid cell( 2 cells)

Question 26

Cell growth and reproduction

Answer 26

• a cell can reproduce to replace old damaged cells
• provided the body is healthy, cells will grow and reproduce healthy cells
• if the body is unhealthy cells may die and produce diseased cells

Question 27

Describe meiosis

Answer 27

A type of cellular reproduction in which the number of chromosomes are reduced by half through the separation of chromosomes which produces two haploid cells(4 cells)

They have to go through the process twice in order to have correct chromosomal information.

Ex egg & sperm

Question 28

What does mitosis serve? Or what is the purpose?

Answer 28

• development of an individual (baby growing)
• growth of the tissues and organs after birth
• replacement of the cells that die
• repair damaged tissues

Question 29

4 stages of Mitosis PMAT

Answer 29

Interphase - not really a part of cell division, but it is the resting stage between cell division.

PROPHASE
METAPHASE
ANAPHASE
TELOPHASE

PROPHASE: centrioles begin to move to opposite side of the nucleus, chromosomes double into pairs and become chromatids, nuclear membrane disappears, spindle fibres begin to form and attach to centrioles.

METAPHASE: chromatids align in the middle of spindle fibres, the chromatids split evenly and move apart on the spindle fibres

ANAPHASE: chromatids repel each other and move to opposite ends of the spindle fibres, the cell constricts in the middle, anaphase is over when chromosomes movement ends

TELOPHASE: chromosomes lengthen into fine networks, spindle fibres disappear, 2 nuclei are formed, and a nuclear membrane around each nucleus is formed, the cell pinches further inward and divides into two daughter cells, each cell is genetically equal, both cells then enter a new interphase!

Question 30

What is Homeostasis?

Answer 30

• the body’s ability to maintain relatively stable internal conditions even though the outside world is continuously changing.
• a dynamic state of equilibrium
• the body is in homeostasis when it’s needs are being met and it is functioning smoothly or optimally