Tissues, Glands, & Membranes Flashcards
histology
the study of tissues
a group of cells similar in structure, arranged in a characteristic pattern, which perform a specific task
tissue
Which tissues have the most stem cells? The least?
Tissues subject to wear and tear, such as the skin and the lining of the digestive and respiratory tracts, have the most. These tissues can repair themselves relatively easily.
Other tissues, especially nervous tissue and muscle tissue, maintain few stem cells that divide infrequently, so these tissues repair themselves slowly, if at all. Brain tissue injured by a stroke or heart muscle tissue injured by a heart attack has limited regenerative ability.
Between these two extremes are organs, such as the liver, that maintain enough stem cells to replace the entire organ within months or years.
Stem cells
Young, actively dividing cells that differentiate into mature cells that make up different tissues
Name the four main groups of tissues
epithelial, muscle, nervous, connective
Name and describe the 3 different types of epithelial tissue
Squamous—flat and irregular
Cuboidal—square
Columnar—long and narrow
Describe the difference between exocrine and endocrine glands, and give examples of each.
Exocrine glands produce secretions that are carried out of the body, usually through ducts or tubes. Examples: glands in the stomach and intestine that secrete digestive juices, salivary glands, sweat and sebaceous (oil) glands of the skin, and lacrimal glands that produce tears.
Endocrine glands secrete hormones directly into surrounding tissue fluid (i.e. not through ducts). Secretions are usually absorbed into and then distributed by the bloodstream to target tissues. Examples: pituitary, thyroid, adrenal glands.
List five different types of connective tissue in order of increasing hardness.
1) Circulating connective tissue (fluid)
ex: blood, lymph
2) Loose connective tissue (like jelly):
ex: areolar, adipose
3) Dense connective tissue (like canvas, strong & fibrous)
4) Cartilage
5) Bone tissue (solid)
List the 3 kinds of epithelial membranes
1) serous membranes (a.k.a. serosa) line the walls of body cavities
2) mucous membranes line tubes and spaces open to the outside of the body
3) cutaneous membrane aka skin
List four types of connective tissue membranes
1) Synovial membranes
2) The meninges
3) Fascia (superficial and deep)
4) Ones that surround organs/bone/cartilage (fibrous pericardium, periosteum, perichondrium)
epithelial and connective tissues often form thin sheets of tissues called ____ that line and cover organs
membranes
Contrast simple vs. stratified epithelium
Epithelial cells may be in a single layer (simple) to allow for easy absorption (e.g. in the digestive tract) or in mutliple layers (stratified) to offer more protection to tissues subject to wear and tear.
transitional epithelium
Lines organs that expand (e.g. urinary bladder)
gland
an organ or cell specialized to produce a substance that is sent out to other parts of the body
Epithelial tissue produces the many secretions necessary for health. Name several examples.
mucus, digestive juice, sweat, hormones
Single-celled exocrine glands that are scattered among epithelial cells lining the respiratory and digestive passageways and secrete mucus
Goblet cells