Chapter 4: Tissues Flashcards
1
Q
What are the 4 basic types of tissues?
A
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
2
Q
What are the two forms of Epi. tissue?
A
- Covering and lining epithelium
2. Glandular epithelium
3
Q
Functions of epithelium
A
- Protection of the underlying tissues
- Secretion (release of molecules from cells)
- Absorption (bringing small molecules into cells)
- Diffusion (movement of molecules down their conc. gradient)
- Filtration (passage of small molecules thr. a sieve-like men.)
- Sensory reception
4
Q
Special Characteristics of Epithelia (6)
A
- Cellularity
- Specialized contacts
- Polarity
- Support by connective tissue
- Avascular but innervated
- Regeneration
5
Q
Classification of Epithelia: by # of layers and shape of the cells
A
of layers:
- Simple epithelia
- Stratified epithelia
Shape of the cells
- Squamous cells: flat cells w/ flat disc-shaped nuclei
- Cuboidal cells: cube-shaped cells w/ spherical, centrally located nuclei
- Columnar cells: nuclei are located near the basal surface and are commonly oval in shape, elongated from top to bottom
6
Q
Simple Squamous Epithelium
- Function
- Location
A
- Function:
- - Allows passage of materials by diffusion and filtration in sites where protection is not important
- - Produces lubricating fluid in serosae - Locations:
- - Kidney glomeruli
- - Air sacs of lungs
- - Lining of heart
- - Blood vessels & Lymphatic vessels
- - Lining of ventral body cavity (serosae)
7
Q
Simple Cuboidal Epithelium
A
- Function:
- - Secretion and absorption - Location:
- - Kidney tubules
- - Ducts and Secretory portions of small glands
- - Ovary surface
8
Q
Simple Columnar Epithelium
A
- Function:
- - Absorption (Active transport)
- - Secretion of mucus, enzymes and other substances
- - Ciliated type propels mucus (or reproductive cells) by ciliary action - Location:
- - Nonciliated type lines most of the digestive tract (stomach to anal canal), gallbladder & excretory ducts of some glands
- - Ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus
9
Q
Pseudostratified Columnar Epi
A
- Function:
- - Secretion, particularly of mucus
- - Propulsion of mucus by ciliary action - Location
- - Nonciliated type in male’s sperm-carrying ducts and ducts of large glands
- - Ciliated variety lines the trachea, most of the upper respiratory tract
Note:
- Cells vary in height; all of which rest on the basement mem., but only the tall cells reach the apical surface of the epithelium
- Cell nuclei lie at several different levels
10
Q
Stratified Squamous Epithelium
A
- Basal cells are cuboidal or columnar and metabolically active – active in mitosis and produce the cells of the more superficial layers
Surface cells are full of keratin and dead - Function
– Protects underlying tissues in areas subjected to abrasion - Location
– Nonkeratinized type forms the moist lining of the esophagus, mouth and vagina
– Keratinized variety forms the epidermis of the skin, a dry mem.
11
Q
Stratified cuboidal epithelium
A
- Generally 2 layers of cube like cells
- Function: protection
- Location:
- - Largest ducts of sweat glands, mammary glands and salivary glands
12
Q
Stratified Columnar Epithelium
A
- Several cell layers
- - Basal cells usually cuboidal
- - Superficial cells elongated and columnar - Function:
- - Protection
- - Secretion - Location (rare in the body)
- - Small amounts in male urethra and in large ducts of some glands
13
Q
Transitional epithelium
A
- Resembles both stratified squamous and stratified cuboidal
- - Basal cells cuboidal or columnar
- - Surface cells dome shaped or squamous-like, depending on degree of organ stretch - Function:
- - Stretches readily and permits dissension of urinary organ by contained urine - Location:
- - Lines the ureters, bladder and part of the urethra
14
Q
Classification of glands
A
- Endocrine glands
2. Exocrine glands
