Chapter 4 Tissue

Question 1

What are the functions of tissues

Answer 1

• Provide physical protection
• Control permeability
• Provide Sensation
• Storage
• Movement
• Secretion
• Conduct Impulses

Question 2

What are the four primary types of tissues?

Answer 2

• Epithelial
• Connective
• Muscle
• Nervous

Question 3

What is Epithelial (epithelium - plural) tissue? And what are the two types?

Answer 3

• It covers the surface of the body or lines body cavities.
• Covering and lining
  and
• Glandular

Question 4

What is polarity of epithelial tissue?

Answer 4

The apical surface is exposed to a cavity or the outside environment
The basal surface (at the opposite pole) is attached to underlying connective tissue.

Question 5

What function do microvilli have?

Answer 5

increased surface area for absorption and secretion

Question 6

What do cilia do?

Answer 6

They move substances along the surface of a tissue.

Question 7

What are the two primary cell junctions in epithelial tissue?

Answer 7

Desmosomes - keep cells from tearing apart.

Tight junctions - these are impermeable

Question 8

What is the basal lamina?

Answer 8

A non-cellular adhesive sheet made of glycoproteins and collagen fibers. The lamina is secreted by epithelial cells and is a selective filter for diffusion.

Question 9

What is a basement membrane?

Answer 9

It reinforces epithelial sheets to resist tearing.
It’s located between epithelial and connective tissue.
It’s made up of basal lamina and reticular lamina.

Question 10

What is reticular lamina?

Answer 10

extracellular material containing a fine network of collagen protein that belong to the underlying connective tissue.

Question 11

How does epithelial tissue receive nutrients?

Answer 11

Through diffusion.

It is avascular but innervated.

Question 12

What are the two primary and three secondary categories of epithelial tissue categorization?

Answer 12

1 - Simple - single cell layer - found where absorption, secretion, and filtration occur
2- Stratified - two or more layers stacked found in high abrasion areas

• squamous - flattened and scale-like
• cuboidal - boxlike, fat as wide
• columnar - tall and column shaped
  x - psuedostratified - all the cells rest on the basement membrane. Not all of them make it to the apical surface. Nuclei rest at different heights giving the appearance of stratification.

Question 13

What is a gland?

Answer 13

They consist of one or more cells that make a particular product (a secretion). It’s water based and usually contains protein.

Question 14

What is an endocrine gland?

Answer 14

Ductless glands which produce hormones (chemical messengers) secreted by exocytosis.

Question 15

What is an exocrine gland?

Answer 15

These secrete their products directly on to the surface of skin or into body cavities via exocytosis.

Unicellular exocrine glands produce mucin, which disolves in water to produce mucous.

Question 16

Major functions of connective tissue are?

Answer 16

1 - binding and supporting
2 - protecting
3 - insulating
4 - storing and reserve fuel
5 - transporting substances

Question 17

Common features of connective tissue?

Answer 17

1 - an extracellular matrix

2 - Common origin - mesenchyne

Question 18

What are the ground substances of connective tissue?

Answer 18

Interstitial fluid - for diffusion of nutrients
Cell adhesion proteins - glue allow C.T. to attach to ECM
Proteoglycans - protein core with polysaccharide attachments (called glycosaminoglycans)

Question 19

What are connective tissues…types and composition?

Answer 19

They are proteins that provide support
Collagen fibers - secreted into extracellular space where spontaneous assembly results in crosss-linked fibrils.
Elastic Fibers - lon, thin, elastic fibers from branching networks. Contain elastin.
Reticular fibers - fine network found in the basement membrane of epithelial tissue and places where connective tissue is next to other tissues.

Question 20

C.T. cell types?

Answer 20

Fibroblasts - fibrocytes in connective tissue proper
Chondroblasts - in cartilage become chondrocytes
Osteoblasts - in bone are osteocytes.
Blood is an exception to all of this - it is not located in its tissue and does not make the fluid matrix.

Question 21

Other C.T. types?

Answer 21

Adipocytes - fat cells
White blood cells
Mast cells - detect microorganisms and initiate inflammatory responses.
Macrophages - devourers of foreign materials. dispose of dead tissue

Question 22

What are the functions of areolar tissue?

Answer 22

• Support and Bind other tissue
• Hold body fluids (this is the job of ground substance)
• Defend against infection (white blood cells and macrophages)
• Store nutrients as fat in adipocytes

Question 23

Some Adipose facts…

Answer 23

• adipocytes account for 90% of tissue mass
• adipocytes are among the largest in the body
• typically accumulates in subcutaneous tissue
• it insulates and shock absorbs

Question 24

Reticular connective tissue roles and locations…?

Answer 24

supports many free blood cells in lymph nodes, spleen and bone marrow.
it forms stroma (bed or mattress) an internal framework

Question 25

What is another name for dense connective tissue?

Answer 25

fibrous

Question 26

What are the features of dense regular C.T.?

Answer 26

packed bundles of collagen fibers in the same direction parallel to pull.
mainly fibroblasts
poorly vascularized
found in tendons, ligaments, aponeuroses

Question 27

What are features of dense irregular C.T.?

Answer 27

bundles are very thick and irregular in order to account for tension in all directions
found in sheets in body
found in skin as the dermis, forms fibrous joint capsules and fibrous covering that suround organs (kidney’s, bones, cartilages, muscles, and nerves)

Question 28

What are features of elastic C.T.?

Answer 28

allows tissue to recoil
maintains pulsatile flow ob blood through arteries
recoil of lungs

Question 29

What are the features of cartilage?

Answer 29

Cartilage is avascular and nutrients are received via diffusion
Chondroblasts dominate growing cartilage.
Chondrocytes occupy lacunae in mature cartilage.
There are three types.

Question 30

What are the three types of cartilage?

Answer 30

Hyaline - covers the ends of long bones as articular cartilage, providing springy pads for compression absorption
supports the tip of the nose
connects the ribs to sternum
supports most repiratory system passages (e.g. trachea)
makes up embryonic skeleton

Elastic - nearly identical to hyaline but with more elastic fibers.

Fibrocartilage - rows of chondrocytes alternate with dense rows of thick collagen fibers. Found in spine and knee because it resists compression so well.

Question 31

What are features of bone?

Answer 31

storages of fat and blood synthesis.
bone matirx similar to cartilage but harder and rigid (this is due to added calcium salts).
Osteoblasts produce the organic part of the matrix and then calcium salts are added between the fibers.

Question 32

What are the features of blood?

Answer 32

Classified as connective because it develops from mesenchyne and develops cells.
Most are erythrocytes (red blood cells).
Transports, nutrients, wastes, repiratory gases, and many other substances.

Question 33

Features of muscle tissue include…?

Answer 33

myofilaments - comprised of actin and myosin.
Three types
1-skeletal peripherally located nuclei and obvious bands or striation indicating precise myofilament alignment

2-cardiac only found in heart walls and uninucleate with nucleus located centrally
3-smooth is named because it has no visible striations. spindle shaped and contain one centrally located nucleus main in hollow organs other than heart

Question 34

What are the three stages of skin repair?

Answer 34

1 - inflammation sets the stage
2 - Organization restores the blood supply
3- regeneration and fibrosis effect permanent repair