Cells are organized into what 4 cateories of tissue?
Epithelial, Connective, Muscle, and nervous
What is Histology?
Study of tissues and their arrangement in organs
What are Tissues comprised of?
Cells and Matrix
What is tissue matrix made up of?
Fibrous Proteins and Ground Substance (or ECF)
What is epithelial Tissue?
- Composed of layers of closely spaced cells
- Covers organ surface
- protects, secretes and absorbs
- Found in epidermis, lining of digestive tract, liver and glands
Describe Connective tissue
- Has more matrix than cell volume
- Specialized in support, bind and protect organs
- Found in tendons and ligaments, cartilage and bones, and fat and blood
Describe nervous tissue
Contains excitable cells specialized for rapid transmission of info
- found in brain, spinal cord, and nerves
Describe muscular tissue
- Composed of elongated excitable cells specialized for contraction and movement.
- Found in skeletal muscles, heart and walls of uterus, bladder, intestines, and other internal organs
The basement membrane of epithelium contains mostly ________?
Proteins
Which tissue type is most abundant and variable of the 4 tissue types?
Connective
What are the functions of connective tissue?
1) Binding organs
2) Support
3) Physical protection
4) immune protection
5) Movement
6) Storage
7) Heat production
8) Transport
What are the cells of fibrous connective tissue?
- Fibroblasts –> produce fibers and ground substance of matrix
- Macrophages
- Leukocytes (white blood cells)
What are the properties of blood?
1) Liquid connective tissue
2) Travels through tubular vessels
3) Transports cells and dissolved materials
What are the type of exocrine glands?
- Serous glands –> perspiration, milk and tears
- Mucous glands –> in respiratory and digestive tracts
- Mixed glands –> Salivary glands
- Apocrine glands –> Secretion of milk fat in mammary gland
- Merocrine Glands –> Tear glands and pancreas
- Holocrine glands –> oil-producing sebaceous glands of skin
What does the mucous membrane line?
Tracts of body open to exterior environment
- consists of epithelium, overlying areolar tissue, and thin layer of smooth muscle (sometimes)
What do serous membranes line?
Thoracic and abdominal cavities and covers external surfaces of organs.
- e.g. stomach and lungs
- pleura of lung, pericardium of heart and peritoneum of abdominal cavity
What are 2 types of tissue growth?
1) Hyperplasia –> Tissue growth through cell multiplication. Most embryonic and childhood growth
2) Hypertrophy –> Enlargement of preexisting cells, In skeletal muscles and adipose tissue
What is an example of Abnormal tissue growth?
Neoplasia –> development of a tumor of abnormal tissue. may be malign or malignant
What are 2 types of tissue repair?
1) Regeneration –> replacement of dead or damaged cells. replaced with same type of cell as before. Restores normal function to organ. (e.g. most skin injuries and liver)
2) Fibrosis –> Replacement of damaged tissue with scar tissue. Does not restore normal function (e.g. scaring of cardiac muscle from heart attack
What is Atrophy?
Shrinkage of tissue
- can result from lack of use of an organ or aging
What is Necrosis?
Pathological death of tissue
What are the different forms of necrosis?
- Infarction –> Sudden death of tissue when blood supply is cut off
- Gangrene –> From insufficient blood supply and often infection. Bed sore is a form of gangrene
What is Aptosis?
programmed cell death; the normal death of cells
