Chapter 5: tissues Flashcards
1
Q
tissue
A
- a group of similar cells that perform a common function
- organs can contain 2, 3, or 4 different types of tissue
- tissue is the connective fabric that holds the body together
- provides the body with its shape
- gives the body the ability to move
2
Q
initial organization of cells
A
- ectoderm (outer layer)
- mesoderm (middle layer)
- endoderm (inner layer)
3
Q
ectoderm
A
- outer layer
- gives rise to epidermis and nervous system
4
Q
mesoderm
A
- middle layer
- gives rise to connective and muscle tissue
5
Q
endoderm
A
- inner layer
- produces mucous membrane of respiratory track, thyroid gland, secretory parts of pancreas
6
Q
differentiation
A
- cells become increasingly distinct from the cells of other layers
- eventually each layer gives rise to a different type of tissue
7
Q
epithelial tissue
A
- covers body surface
- lines cavities and organs
- forms glands
- is exposed to environment on the top
adheres to connective tissue on the bottom - too thin to contain blood vessels
- depends on the connective tissue underneath to supply oxygen and nutrients
8
Q
stem cells
A
- undifferentiated cells
- can differentiate into more than 200 kinds of specialized cells
- can help replace worn-out cells, repair damaged tissue, and help grow organs in a developing chid
- embryonic stem cells occur in the early embryo
9
Q
cell shapes in epithelial tissue
A
- squamous
- cuboidal
- columnar
10
Q
cell layers
A
simple - every cell touches the basement membrane
stratified- cells stack; some do not touch the basement membrane
11
Q
squamous cells
A
- flat and plate-like
- “scaly”
12
Q
cuboidal cells
A
- cube-shaped
- contain more cytoplasm than squamous cells
13
Q
columnar cells
A
tall and cylindrical; column-shaped
14
Q
gland
A
a collection of epithelial cells that secrete a particular substance
15
Q
exocrine glands
A
- secrete products into ducts
- ducts empty onto skin surfaces or inside a body cavity
- example: sweat glands secrete sweat onto the skin’s surface
16
Q
endocrine glands
A
- “ductless” glands
- secrete hormones directly into the blood
- example: adrenal glands secrete epinephrine & norepinephrine into the bloodstream
17
Q
simple squamous epithelium
A
- single layer of flat, “scaly” cells
- allows for easy diffusion or filtration because of thinness
- found in alveoli and lining of blood & lymphatic vessels
18
Q
simple cuboidal epithelium
A
- single layer of cube-like cells
- secretes and absorbs
- found in ducts and tubules of many organs (like kidneys)
19
Q
simple columnar epithelium
A
- single layer of columnar cells
- participates in absorption
- secretes mucus by goblet cells
- lines the intestines
20
Q
pseudostratified columnar epithelium
A
- single layer of irregularly shaped columnar cells
- cells with nuclei at different levels make it appear stratified
- provides protection
- secretes mucus
- lines trachea, large bronchi, and nasal mucosa
21
Q
stratified squamous epithelium
A
- contains multiple cell layers
- stronger than simple epithelia
- most widespread epithelium in the body
- found in epidermis of the skin, esophagus, and vagina
22
Q
glandular epithelium
A
23
Q
goblet cells
A
24
Q
connective tissue
A
- most widespread and diverse tissue
- connect the body together, and to support, bind, and protect organs
25
Q
extracellular matrix
A
- key component of connective tissue
- framework in which cells are embedded
- contains various kinds and amounts of protein fibers and fluid
- this variation in composition is what gives tissue its
characteristics
- this variation in composition is what gives tissue its
- fibers may be collagenous, reticular, or fibrous
