TISSUES CHAPTER 5
TISSUES ARE GROUPS OF CELLS THAT HAVE A SIMILAR
EMBRYOLOGICAL ORIGIN. THEY ARE SPECIALIZED FOR A PARTICULAR FUNCTION.
HISTOLOGY IS THE SCIENCE THAT DEALS WITH THE STUDY OF TISSUES.
AS YOU STUDY THE DIAGRAMS OF DIFFERENT TYPES OF TISSUES IN YOUR BOOK, BE SURE TO LOOK AT THE STRUCTURE OF THE CELLS (DO THEY HAVE CILIA, SPECIAL GOBLET CELLS, ETC.) & ASK YOURSELF HOW THE STRUCTURE OF THE CELL DETERMINES ITS FUNCTION.
IF YOU CAN FIGURE OUT THE FUNCTION, YOU CAN USUALLY EASILY DETERMINE WHERE YOU MIGHT FIND THAT PARTICULAR TISSUE.
DEPENDING ON THEIR FUNCTION & STRUCTURE, THE TISSUES OF MAN ARE CLASSIFIED INTO FOUR TYPES:
I. EPITHELIAL
TISSUE
A. Covers _____________________
B. Lines _______________________
C. Forms ______________________
D. Epithelial
tissue forms a continuous layer (sheet) over the
body surface & most of the body's inner cavities.
E. A basement
membrane anchors it to connective tissue.
F. Epithelial tissue contains
______________________________________________________
very little _____________________________________________________
G. Epithelial tissue is __________________________________
continuously.
H. If it is external, it PROTECTS from infection, injury, drying; also can have a sensory function.
I. If it is internal, it is specialized for absorption or secretion.
II. THREE TYPES OF EPITHELIAL TISSUE: TISSUE: SQUAMOUS, CUBOIDAL, COLUMNAR
They may have hairlike extensions called CILIA or cellular extensions called MICROVILLI
A. Simple squamous epithelium Fig. 5.1 ________________________________________________
1. Where? Lines _____________________________ , __________________________
2. Function? Adapted for ________________ , __________________ , _________________
B. Simple cuboidal epithelium Fig. 5.2 ____________________________________________
1. Where? Lines _________________________________ ,
covers _________________
2. Function? Adapted for
_________________________ ; production & releases of a fluid like mucus or enzymes
and absorption (intake of fluid)
C. Simple columnar epithelium Fig. 5.3 ____________________________________________
1. Where? : In _________________ & uterus; specialized cells contain microvilli
2. What is the function of the goblet cells in the intestines?
3. What is the purpose o the microvilli?
D. Pseudostratified
columnar ciliated epithelium Fig 5.5 ____________________________
1. Where? In _____________________________ (note that smokers don't have the cilia), uterine tubes, paranasal sinuses.
2. Function?_____________________________, _______________________________________
trap dust, toxins.
3. What do the cilia do in the respiratory tract? In the uterine
tubes? In the sinuses?
E. Stratified squamous epithelium Fig. 5.6.___________________________________________
1. Where? A keratinized (waterproof protein) variety forms
_______________________________ a non keratinized variety lines _______________________ , esophagus, vagina, and anal canal
F. Cuboidal & columnar cells Fig. 5.7
These cells may also be stratified and serve in protection.You will not be held responsible for recognizing these two stratified types on the practical.
G. Transitional epithelium Fig. 5.9 several layers of cells that allow _____________________________ of an organ
1. Where? Walls of organs of the urinary tract, esp.
_________________
2. Function? Permits distension
H. Glandular epithelium � made of cells that secrete substances
1. Exocrine glands � secrete __________________ or directly onto a _________________ sweat,
oil & digestive juice
2. Endocrine glands � ductless; produce hormones that enter tissue fluid or blood
3. Arrangement of exocrine glands � Fig. 5.10
a. Unicellular � a ________________________ cell
b. Multicellular - _______________________________
1.) Simple � unbranched duct that may be tubular or alveolar (sac like)
2.) Compound � branched ducts that may be tubular or alveolar
Note Fig. 5.10 for the different arrangements
4. Composition of secretions Fig. 5.11
a. Merocrine � releases fluid by ______________________________
example: sweat glands
b. Apocrine � release part of cell content (note � this def. is different
from book)
example: mammary glands
c. Holocrine � release entire cell
example: sebaceous glands in skin
See table in book for comparisons
II. CONNECTIVE TISSUES
A. Characteristics:most abundant tissue in the body by weight; connects, supports, protects, forms a
framework, fills spaces; stores fat, produces blood cells, provides protection against infection, & helps repair damaged tissues. Cells are far apart, separated by a MATRIX
(noncellular material). This matrix may contain white fibers (containing collagen that gives flexibility and strength)&/or yellow fibers (elastin that gives structures such as the outer ear
their elastic properties).
B. Major cell types Fig. 5.13, 5.14, 5.15
1. Fibroblasts: produce ____________________& ________________________ fibers
2. Macrophages: ________________________________
3. Mast cells: release __________________& _____________________________
C. Types of fibers in connective tissue Fig. 5.16
1. Collagenous fibers: contain _____________________ & are very strong
2. Elastic fibers: made of microfibrils embedded in elastic --- can give
3. Reticular fibers: very fine collagenous fibers
D. LOOSE CONNECTIVE TISSUE:
Aerolar connective tissue, adipose tissue, reticular connective
1. Aerolar Fig. 5.18 looks "airy"
Where? Found in subcutaneous layer and mucous
membranes; around blood vessels, nerves and organs
Function? Gives ___________________ ,
________________________ , ________________
2. Adipose Fig 5.19 large, rounded, balloon like
Where? In subcutaneous layer, around organs, in
yellow marrow of long bones
Function? _____________________________ , energy
reserve, supports, protects, generates heat in newborns
3. Reticular connective tissue Fig. 5.20
Where? In ________________________ &
_________________________
Function? Fine interlacing reticular fibers and reticular cells hold organ together
E. DENSE CONNECTIVE TISSUE: Dense regular connective tissue, dense
irregular connective tissue, elastic tissue
1. Tendons/ligaments: Fig. 5.21
Where? Tendons � at ends of ___________________
;ligaments � at ______________________
Function? Tendons � hold muscle to bone;
ligaments �
hold bone to bone
F. CARTILAGE
has jellylike matrix (solid, but flexible) with collagenous & elastic
fibers and chondrocytes; has no blood vessels or nerves, thus takes a long time
to heal. (looks like jello with walnuts under scope).
There are three types of cartilage: hyaline, elastic and fibrocartilage
1. Hyaline cartilage Fig. 5.23 most common type; very fine collagenous fibers; matrix
looks like milk-glass;
Where? Nose, at ends of
__________________________________ & ribs, in supporting rings of trachea;
in fetus
2. Elastic cartilage Fig. 5.24 more elastic fibers than hyaline cartilage; more
flexible
Where? Framework of outer _________________________
3. Fibrocartilage Fig. 5.25 matrix with strong collagenous fiber
Where? In pads between vertebrae in backbone and wedges in knee joint
Function? Withstand tension and pressure
IV. Bone, blood, muscular tissue and nervous tissue will be covered in detail as we study each of these systems. Look at slides of these in lab an be able to recognize blood, bone, the three types of muscle tissue and nervous tissue. When you study the tissues, use a chicken wing or a chicken drumstick. Start with
the skin and think about what that tissue looks like at the cellular level. When you lift up the skin,
notice the thin membrane (aerolar connective tissue) that connects skin to muscle.Think about the types of fibers and cells in this tissue. Next, look at the tendons that hold muscle to bone and think of the fibers in this tissue. Examine the ligaments that hold bone to bone and think of the types of fibers found there. As you look at the nerves, the blood vessels and the bone, try to visualize the cells and fibers found in these
tissues. Look at the ends of the bones and examine the cartilage. Think of the cells and the matrix in the cartilage.
Helpful Activities to do after you finish reading this chapter
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