Biology B3- epithelial tissues Flashcards
what is a tissue?
tissues are a collection of similar cells that perform a specific function.
what are the 4 main types of tissues in animals ?
Epithelial tissue, connective tissue, muscle tissue and nervous tissue
what is the meaning of epithelial tissue ?
Epithelial tissue is sheets of cells that cover exterior surfaces of the body, lines , internal cavities and passageways and form certain glands
what is the meaning of connective tissue ?
connective tissue binds the cells and organs together and functions in the protection , support and integration of all parts of the body.
what is the meaning of muscle tissue ?
muscle tissue is the excitable responding to stimulation and contracting to provide movement and occur as three main types.
what are the 3 major types of muscle tissue ?
- skeletal muscle
- smooth muscle
- cardiac muscle in the heart
what is the meaning of nervous tissue ?
nervous tissue is the excitable allowing progation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body.
what is epithelial tissue ?
epithelial tissue is the skin tissue that covers the body.
what do epithelial cells also cover ?
epithelial cells cover the inside too , organs of the digestive system are lined with epithelial cells also body cavities such as the inside of the chest and abdominal cavities.
what are the names of the different types of epithelial tissues ?
Columnar epithelial cells
Cuboidal epithelial cells
simple squamous epithelial cells
stratified squamous epithelial cells
transitional cells
Pseudostratified columnar epithelial cells
Alveolar epithelium
what is each individual alveolus surrounded by ?
Each individual alveolus is surrounded by simple squamous epithelium
what is simple squamous epithelium ?
simple squamous epithelium is a thin and leaky epithelium , which functions in the exchange of materials by diffusion .
This type of epithelium tissue lines blood vessels and the air sacs of the lungs , where diffusion of nutrients and gases is critical.
what is an example of squamous epithelial tissue ?
Alveoli
what does simple squamous epithelium make up ?
simple squamous epithelium makes up the walls of the alveoli
what are alveoli ?
Alveoli are the sites where oxygen and carbon are exchanged
where does oxygen from the air diffuse from in the alveoli ?
Oxygen from air diffuses into the blood in the capillaries around the alveoli
what is carbon dioxide in alveoli and where does it diffuse ?
Carbon dioxide is a waste product from blood diffuses into air into capillaries around the alveoli
what are the adaptations of the alveoli ?
- Network of blood capillaries.
- Large surface area.
- Moist surface of alveoli
- Concentration gradient
- Distance between alveoli and blood capillaries
- Wall of alveoli and blood capillaries.
why is there a network of blood capillaries in the alveoli ?
There is a network of blood capillaries in the alveoli for transport of gases to and form the alveoli.
why is there a large surface area in the alveoli ?
Large surface area allows increased rate of diffusion
why is there a moist surface alveoli ?
The moist surface alveoli allows gases to dissolve before diffusion occurs.
why is there a concentration gradient in alveoli ?
Concentration gradient allows an increased rate of diffusion
why is there a distance between alveoli and blood capillaries ?
Short distance increases rate of diffusion.
why is there a wall of alveoli and blood capillaries ?
One cell thick means faster diffusion
describe the pathway taken by an oxygen molecule from an alveolus to the blood ?
It is across the alveolar epithelium . Endothelium and epithelium of capillary.
Explain how one feature of an alveolus allows efficient gas exchange to occur ?
The alveolar epithelium is one cell thick and creates a short diffusion pathway , which reduces the diffusion distance.
what is ciliate columnar epithelium ?
Ciliate columnar epithelium forms a mucous membrane that lines portions of the respiratory tract of many vertebrates . The beating cilia move the film of mucus along the surface
what do the single layers of cell line in the ciliated columnar epithelium tissue ?
Single layer of cells lining the trachea
what does cilia cover in ciliated columnar epithelium tissue ?
Cilia cover free surfaces of cells.
what does the ciliated columnar epithelium contain ?
Epithelium contains goblet cells
what do the goblet cdells secrete in the ciliate columnar epithelium ?
goblet cells secrete mucus
what do the cilia produced in the ciliated columnar epithelium ?
Cilia produce rapid wave like motions.
what do cilia do in the ciliate columnar epithelium ?
Cilia move mucus and trapped foreign bodies such as pathogens up and out of the respiratory system.
where are endothelial cell located ?
endothelial cells are located within the internal of the body such as the interior of blood vessels
where are the epithelial cells located ?
Epithelial cells are usually described as covering the outside of the body such as the outer layer of the skin.
what is the outer layer of the skin called ?
Epidermis
where is endothelium present ?
Endothelium is present in all blood vessels.
what is the meaning of endothelium ?
Endothelium is a special type of squamous epithelium that lines the blood vessels
what is the inner layer of arteries and veins ?
The inner layer of arteries and veins is the endothelium.
what is the structure of capillaries in epithelial tissues ?
Capillaries are smaller in diameter than the cells they supply , allowing close and intimate contact with those cells.
The endothelium support on a membrane is one cell thick allowing easy exchange across the capillary.
Gaps between endothelial cells increase the rate of exchange with the tissues and allows phagocytes to migrate .
Very low blood pressure at the capillary produces low velocity of blood flow , therefore lots of time to exchange to happen.
.
where are most cancers from ?
Most cancers are cancers of the epithelial cells.
what are the names of the cancers in epithelial cell ?
They are called carcinomas.
what percentage do carcinomas make up all cancers ?
85 %
what can different types of epithelial cells develop into ?
They develop into different types of cancer.
