Chapter 4 Epithelial Tissues Flashcards
1
Q
Groups of cells that are similar in structure and perform a common or related function.
A
Tissues
2
Q
What are the four basic types of tissues?
A
- Epithelial
- Connective
- Nervous
- Muscle
3
Q
True or false: most organs contain all four tissue types.
A
True
4
Q
What type of anatomy does histology compliment? Together they provide the structural basis for understanding organ physiology.
A
Gross anatomy
5
Q
The study of tissues is called …?
A
Histology
6
Q
The primary function of epithelial tissue is to …?
A
Cover
7
Q
The primary function of connective tissue is to …?
A
Support
8
Q
The primary function of muscle tissue is to …?
A
Produce movement
9
Q
The primary function of nervous tissue is to …?
A
Control
10
Q
Muscle tissue: Contracts to cause movement. Includes:
A
- Muscles attached to bone (Skeletal)
- Muscles of the heart (Cardiac)
- Muscles of walls of hollow organs (Smooth)
11
Q
Allows us to study tissue structure.
A
Microscopy
12
Q
When tissue is fixed for microscopy.
A
Preserved
13
Q
How is tissue cut for preparation for microscopy?
A
It must be sliced thin enough to transmit light or electrons.
14
Q
Although some apical surfaces are smooth and slick, most have ____, fingerlike extensions of the plasma membrane.
A
microvilli
15
Q
What do microvilli do?
A
Tremendously increase the exposed surface area.
16
Q
In epithelia that absorb or secrete (export) substances (those lining the intestine or kidney tubules, for instance), the microvilli are often so dense that the cell apices have a fuzzy appearance called a ___ ___.
A
brush border
17
Q
Covering and lining epithelia is found…?
A
On external and internal surfaces
18
Q
Glandular epithelia is found…?
A
in secretory tissue of glands
19
Q
In its role as an interface tissue, epithelium accomplishes many functions, including:
A
1) protection
2) absorption
3) filtration
4) excretion
5) secretion
6) sensory reception
20
Q
What are epithelial tissue’s five distinguishing characteristics?
A
1) polarity
2) specialized contacts
3) supported by connective tissues
4) being avascular but innervated
5) having the ability to regenerate
21
Q
The basal lamina acts as a ___ ___ that determines which molecules diffusing from the underlying connective tissue are allowed to enter the epithelium.
A
selective filter
22
Q
Epithelium which fashions the glands of the body
A
Glandular epithelium
23
Q
The basal lamina is a noncellular ___ ___ consisting largely of ____ secreted by the epithelial cells, plus some fine collagen fibers
A
adhesive sheet, glycoproteins
24
Q
Noncellular basal lamina is made up of
A
Glycoproteins and collagen fibers which lies adjacent to basal surface.
25
Name the three functions of noncellular basal lamina.
- Adhesive sheet
- Selective filter
- Scaffolding for cell migration in wound repair.
26
Where can microvilli be found in the body?
Brush border of intestinal lining
27
Where can cilia be found in the body?
Lining of trachea
28
The basal lamina and the reticular lamina form the ___ ___, which reinforces the epithelial sheet, helps it resist stretching and tearing, and defines the epithelial boundary
basement membrane
29
Some epithelia, such as that lining the trachea (windpipe), have ___ ___ (tiny hairlike projections) that propel substances along their free surface.
motile cilia
30
Name all characteristics of noncellular basal lamina:
- Made up of glycoprotein and collagen fibers which lie adjacent to basal surface
- Adhesive sheet
- Selective filter
- Scaffolding for cell migration in wound repair
31
Covering and lining epithelial tissues fit closely together forming ___ ___.
continuous sheets
32
___ ___ bind adjacent cells to form continuous sheets.
Specialized contacts
33
What are specialized contacts?
They are lateral contacts which include:
Tight junctions
Desmosomes
34
All epithelial sheets rest upon and are supported by ___ ___.
connective tissue
35
What is the function of tight junctions?
They help keep proteins in the apical region of the plasma membrane from diffusing into the basal region, which maintains epithelial polarity.
36
Epithelial cells fit closely together to form continuous sheets except for ___ ___.
glandular epithelium
37
What makes up the connective tissue which supports epithelial tissue?
- Reticular lamina
| - Basement membrane
38
Where is the reticular lamina located?
Lies deep (below) to basal lamina
39
What is the reticular lamina made of?
A network of collagen fibers
40
What is the basement membrane made of?
Basal lamina + reticular lamina
41
What are the three functions of the basement membrane?
- Reinforces epithelial sheet
- Resists stretching and tearing
- Defines epithelial boundary
42
Homeostatic imbalance: an important characteristic of cancerous epithelial cells is their failure to respect the ___ ___ ___, which they penetrate to invade tissues beneath.
basement membrane boundary
43
Just deep to the basal lamina is the ___ ___, a layer of extracellular material containing a fine network of collagen protein fibers that "belongs to" the underlying connective tissue.
reticular lamina
44
Containing no blood vessels.
Avascular
45
Supplied by nerve fibers.
Innervated
46
Some epithelia are exposed to ___ causing their surface cells to rub off, or are damaged by ___ ___ ___.
friction, hostile environmental substances
47
If and when the apical-basal polarity and lateral contacts are destroyed, epithelial cells begin to reproduce themselves rapidly. As long as epithelial cells receive ___ ___, they can replace lost cells by ___ ___.
adequate nutrition, cell division
48
Epithelial tissues are named in the way they are classified: by cell ___, special features if present, and cell ___.
Cell layering
| Cell Shape
49
What are the types of epithelial tissue cell layering?
Simple
Stratified
Pseudostratified
50
What are the types of epithelial cell shapes?
Squamous
Cuboidal
Columnar
51
Cell layer that has is false layering; appears stratified but all cells touch the basement membrane
Pseudostratified
52
Does the shape of the nucleus conform to its cell shape? If so, list the differing shapes of each type of cell shape
Yes.
Simple cells: nucleus is a flattened disc
Cuboidal cells: nucleus is spherical
Columnar cells: nucleus is elongated from top to bottom and is usually found closer to the cell base
53
In stratified epithelia, cell shapes differ in its many layers. To avoid ambiguity, stratified epithelia are named according to the shape of the cells in what layer?
The apical layer
54
Cell shape that appears flattened (observed from one side)
Sqaumous
55
Cell shape that appears "cube-shaped"; equal in height and width.
Cuboidal
56
Cell shape that appears "column-shaped", taller than it is wide.
Columnar
57
Simple epithelia characteristics:
- Absorption
- Secretion
- Filtration
- Very thin
58
Because they consist of a single layer and are usually very thin, ____ is not one of simple epithelia's specialties.
Protection
59
What kind of epithelium is found where filtration or the exchange of substances by rapid diffusion is a priority?
Simple squamous epithelium
60
Two simple squamous epithelia in the body have special names that reflect their location. What are they?
Endothelium
| Mesothelium
61
Where can simple squamous epithelium be found?
- Kidney glomeruli
- air sacs of lungs
- lining of heart
- blood vessels
- lymphatic vessels
- lining of ventral body cavity (serosae)
62
Mesothelium can be found ...?
The epithelium of serous membranes in the ventral body cavity
63
Endothelium can be found ...?
The linings of:
- lymphatic vessels
- Blood vessels
- heart
64
Epithelium which consists of a single layer cells as tall as they are wide
Simple cuboidal epithelium
65
What are the major functions of simple cuboidal epithelium?
Secretion and absorption
66
Where can simple cuboidal epithelium be found?
- Kidney tubules
- Ducts and secretory portions of small glands
- Ovary surface
67
Epithelium which consists of a single layer of tall, closely packed cells.
Simple columnar epithelium
68
What are the functions of simple columnar epithelium?
- Absorption
- Secretion of mucous, enzymes, and other substances
- Ciliated type propels mucous (or reproductive cells) by ciliary action
69
Simple columnar epithelium bearing cilia propels mucous or reproductive cells by ...?
ciliary action
70
Epithelial tissue has a high regenerative capacity; regeneration is stimulated by loss of ____ ____ and ___ ___.
apical-basal polarity, lateral contacts
71
Epithelium which have cells that vary in height; cell nuclei located at different levels and appears stratified, but is not. Secretion and absorption.
Pseudostratified columnar epithelium
72
What is the function of pseudostratified columnar epithelium?
- secrete substances, particularly mucus
| - propulsion of mucus by ciliary action
73
Where is pseudostratified columnar epithelium located?
- non-ciliated type in males sperm-carrying ducts and ducts of large glands
- ciliated variety lines the trachea, most of the upper respiratory tract
74
Epithelial tissue which is made up of two or more cell layers, regenerate from below, more durable than simple epithelia, protection is a major role.
Stratified epithelium
75
How does stratified epithelial tissue regenerate?
Regenerates from below; basal cells divide, cells migrate to surface
76
What is the most widespread type of stratified epithelia?
Stratified squamous epithelium
77
Stratified squamous epithelium's free surface is squamous, but it's deeper layers are ___ or ___
cuboidal, columnar
78
What areas are stratified squamous epithelium most likely to be located in general?
In areas of high wear and tear
79
Stratified squamous epithelium that are ___ from the basal layer (and therefore nutrients) are less ___.
farthest, viable
80
What type of epithelium has a thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers.
Stratified squamous epithelium
81
What is stratified squamous epithelium's function?
Protects underlying tissues in areas subjected to abrasion
82
Where is stratified squamous epithelium located?
Nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina
Keratinized variety forms the epidermis of the skin, a dry membrane
83
What is the only type of pseudostratified epithelium found in the body?
Columnar
84
Resembles both stratified squamous and stratified cuboidal or columnar; basal cells cuboidal or columnar; surface cells dime shaped or squamouslike depending on degree of organ stretch
Transitional epithelium
85
What is the function of transitional epithelium?
Stretches readily, permits stored urine to distend urinary organ.
86
Where is transitional epithelium located?
Lines ureters, bladder, and part of the urethra.
87
One or more cells that make and secrete an aqueous fluid called a secretion.
Gland
88
How are glands classified?
Classified by:
- site of product release-endocrine or exocrine
- relative number of cells forming the gland i.e. Unicellular (goblet cells) or multicellular
89
Ductless glands secrete (by exocytosis) hormones that travel through lymph or blood to their specific target organs; target organs respond in some characteristic way
Endocrine glands
90
Secretions released onto body surfaces (skin) or into body cavities
Exocrine glands
91
Which gland is more numerous?
Exocrine glands
92
Which gland secretes products into ducts? Examples include mucus, sweat, oil, and salivary glands
Exocrine glands
93
Unicellular exocrine glands: the only important unicellular glands are ___ ___ and ___ ___.
mucous cells, goblet cells
94
Where are unicellular exocrine glands found?
They are found in epithelial linings of intestinal and respiratory tracts
95
Only unicellular exocrine glands produce ___?
mucin
96
What is mucin?
Dissolves in water to form mucus; slimy protective, lubricating coating
97
Multicellular exocrine glands are composed of a __ and a ___ ___.
Duct, secretory unit
98
Multicellular exocrine glands are usually surrounded by ___ ___ ___.
supportive connective tissue
99
The supportive connective tissue which usually surrounds multicellular exocrine glands supplies ...?
blood and nerve fibers
100
The supportive connective tissue which usually surrounds multicellular exocrine glands extends
into and divides gland into lobes
101
What are the structural classifications of multicellular glands?
- Simple glands (unbranched duct) or compound glands (branched duct)
- cells tubular, alveolar, or tubularalveolal
102
What are the types of secretions that multicellular glands are classified by?
Merocrine
Holocrine
Apocrine
103
What are merocrine glands?
Make up most multicellular glands; secrete products by exocytosis as produced
104
What are holocrine glands?
Accumulate products within, then rupture
105
What are apocrine glands?
Accumulates products within, but only apex ruptures - controversy if it even exists in humans
106
Which glands are ductless glands (secretions not released into a duct)?
Endocrine gland
107
Secrete (by ___ ) hormones that travel through lymph or blood to their specific target organs. Target organs respond in some characteristic way
exocytosis
108
Exocrine glands more numerous than endocrine glands, secretes products __ ducts. Examples include mucous, sweat, oil, and salivary glands
into
109
Unicellular glands are found in epithelial linings of ..?
intestinal and respiratory tracts
110
Unicellular glands all produce ___:
mucin
111
Multicellular exocrine glands are composed of a duct and a __ __.
secretory unit
112
Multicellular exocrine glands are Usually surrounded by supportive connective tissue which
- Supplies blood and nerve fibers
| - Extends into and divides gland into lobes
