Histology Flashcards
What is ‘histology’?
The study of tissues
What is a ‘tissue’?
A group of specialised cells that have a similar/shared function
List the 4 types of tissue
Epithelial tissue (covers and lines) Connective tissue (blood, bone, cartilage) Muscular tissue (contracts) Nervous tissue (sends nerve impulses)
Which type of tissue is the most abundant tissue in the body? List some examples.
Connective tissue is the most abundant.
Examples are blood, cartilage and bone
Describe epithelial tissue and give some examples.
Epithelial tissue is the main tissue that lines and covers parts of the body. Glands are also made up of epithelial tissue.
Epithelial cells are packed tightly together, in either single or multiple layers.
Examples are the skin covering, and the lining of the digestive tract, lungs, heart, blood vessels.
There are 2 types of epithelial tissue, list them.
- Covering epithelium
2. Glandular epithelium
What is a gland?
A gland is a single cell, or group of epithelial cells that produce secretions.
What are the 2 types of gland and what is the difference between them?
- Exocrine glands - secrete their substances (i.e, saliva, milk, sweat, sebum, enzymes) into ducts
- Endocrine glands - secrete hormones into the blood.
What 2 basic elements are connective tissues made up of?
- Extracellular matrix
2. Cells
The extracellular matrix in connective tissue is comprised of 2 things. What are they?
Ground substance and protein fibres.
Name the 2 types of protein fibres in connective tissue.
Collagen and elastic fibres
What is ‘ground substance’ and where is it found?
Ground substance is found in the extracellular matrix in connective tissue. It contains water, hyaluronic acid and chondroitin sulphate, and helps determine the functionality of that particular connective tissue (ie, fluid, semi fluid or calcified).
Which are bigger - collagen or elastic fibres?
Collagen fibres are bigger
What is the name of the cells that produce the protein fibres in connective tissue?
Fibroblasts
What is the scaffolding in bone?
Strong collagen fibres form the scaffolding in bone, on to which minerals are deposited.
There are 3 types of cells in connective tissue. What are they?
- Fibroblasts
- Adipocytes (fat storage cells)
- White blood cells
Which are the largest and most numerous cells in connective tissue?
Fibroblasts
Which connective tissue cells are most active in repair and healing (including formation of scar tissue)?
Fibroblasts
List 3 types of white blood cells that can be found in connective tissue.
Macrophages - engulf foreign cells
Lymphocytes - produce antibodies
Mast cells - release inflammatory chemicals
List some functions of connective tissue.
- Structural framework (bone, cartilage)
- Transport of nutrients (blood)
- Protection of vital organs (bone, cartilage, adipose)
- Support & interconnection (ligaments, tendons)
- Insulation (adipose tissue)
- Energy storage
- Blood & lymphatic cell production (bone marrow)
- Defence & repair (blood, lymph)
What are membranes and what is their function in the body?
Membranes are flat sheets that cover or line areas of the body. The combine epithelial and connective tissue.
List the 4 main types of membranes in the body.
- Cutaneous membrane (the skin)
- Mucous membrane
- Serous membrane
- Synovial membrane
Mucous membranes line hollow organs that open to a surface of the body. True or false?
True
Mucous membranes can be found lining the entire digestive, respiratory and genitourinary tracts. True or false?
True
What is the stomach pH level in a healthy individual?
2 - 3 pH
What type of cells are located within the epithelial layer of mucous membranes, and produce and secrete mucous?
Goblet cells
List 2 functions of mucous.
- Mucous protects membrane linings from damage, injury and drying out (ie in the stomach).
- Mucous traps foreign particles (ie, in the respiratory tract)
Mucous has a pH of 7.
What do goblet cells do?
Produce and secrete mucous
Where are serous membranes found in the body?
Serous membranes line body cavities that do NOT open to the exterior.
How many layers do serous membranes have? Name them.
Serous membranes have 2 layers:
- Visceral (inner) layer, surrounds organs
- Parietal (outer) layer, lines a cavity
What is found between the visceral and parietal layers of serous membranes?
Serous fluid (a watery secretion)
What is the purpose of serous fluid and where is it found?
Serous fluid is found between the parietal and visceral layers of serous membranes. Its purpose is to enable organs to glide freely within a cavity, without friction.
Name the serous membrane that surrounds the lungs.
The pleura.
How many serous membranes are there in the body? Name them.
There are 3 serous membranes:
- Pericardium
- Pleura
- Peritoneum
What is the pericardium and where is it found?
The pericardium is the serous membrane that surrounds the heart. It is found in the chest cavity.
What is the pleura and where is it found?
The pleura is the serous membrane that surrounds the lungs. It lines the thoracic cavity.
What is the peritoneum and where is it found?
The peritoneum is the serous membrane that surrounds the abdominal organs (and some pelvic organs). It is found in the abdominal cavity.
Where are synovial membranes found in the body?
Synovial membranes line the cavities of the freely moving joints in the body.
What type of cell secretes synovial fluid and where are they found?
Synoviocytes secrete synovial fluid.
They are found in synovial membranes.
What is the purpose of synovial fluid?
To lubricate and nourish the moveable joint cavities.
