Click this link for some pictures of histology slides: 

http://www.kumc.edu/instruction/medicine/anatomy/histoweb/

 

 

Histology Lab Study Guide

 

I.  Introduction to Tissue

 

            A.  Tissues are groups of cells that are similar in structure & function

 

            B.  The study of tissues is histology

 

            C.  There are four basic tissue types

                        1.  Epithelial (covering)

                        2.  Connective (support)

                        3.  Nervous (control)

                        4.  Muscular (movement)

 

            D.  The basic tissue types are further divided into specific tissue types

 

II. Epithelium: an epithelium is a sheet of cells that covers a body surface or

lines a cavity

 

            A. Characteristics: covers surfaces
                        1. composed of closely packed cells with little extracellular material

                        between them
                        2. exhibits polarity: has free surface (apical), attached surface

                        (basal)
                        3. supported by underlying connective tissue: basal and reticular

                        lamina form basement membrane
                        4. innervated but avascular
                        5. can divide rapidly, regenerates


B. Functions
            1. physical protection: abrasion, dehydration, destruction
            2. control permeability: affected by hormones, physical stress
            3. provide sensations: smell, taste, sight, hearing, equilibrium,

            touch
            4. produces specialized secretions: glands, goblet cells
            5. moves fluids across the surface of, or through the cell


    C. Classification of epithelia

1.  Simple squamous epithelium

            Function:  allows diffusion and filtration, secretions

Slides:  arteries & veins (lining), lung section (alveoli), simple

squamous epithelium

                        2.  Simple cuboidal epithelium

Function:  allows secretion and absorption

                                    Slides:  kidney section (tubules), simple cuboidal epithelium

                        3.  Simple columnar epithelium

                                    Function:  secretion (mucus), may have cilia

                                    Slides:  Stomach, ileum, colon, omentum

                        4.  Pseudostratified columnar epithelium

                                    Function:  Secretion of mucus & propulsion of mucus by

                                                ciliary action

                                    Slides:  primate trachea, pseudostratified columnar

                                                epithelium

                        5.  Stratified squamous epithelium

Function:  protects tissues in areas of high abrasion; surface

            is squamous-shaped & the underlying cells are

            cuboidal or columnar in shape

                                    Slides:  esophagus, skin corpuscle human, scalp human

                        6.  Stratified cuboidal epithelium

                                    Function:  found mostly in the ducts of some larger glands
                                    Slides:  Sweat gland human skin

                        7.  Stratified columnar epithelium

                                    Function:  Protection, secretion

Slides:  None, unfortunately.  This tissue is found in small

            amounts in pharynx, male urethra, & lining some large

            glandular ducts

                        8.  Transitional epithelium

                                    Function:  tolerates stretching

                                    Slides:  Primate ureter, urinary bladder, transition epithelium

                                                human

 

III. Connective tissue:


            A. Function: fills spaces, fluids, defense
                        1. bind and support, ex) tendons, ligaments, bones
                        2. protect, ex) skeletal
                        3. storage, insulate, ex) fat
                        4. transportation of substances within the body, ex)blood


            B. Characteristics:
                        1. vascularity varies from avascular to highly vascularized
                        2. Connective tissue is composed mainly of nonliving extracellular

                        matrix that separates the cells of the tissue

 

C.  Structural elements of connective tissue
           1. ground substance: the unstructured material that fills the space

            between the cells and contains the fibers (what makes up the

            matrix)

2. fibers: provide support
            a. collagen: rope-like fibers of protein, extremely short           

b. elastic:  branched, wavy; contain elastin.  ex) skin, lungs
           c. reticular: tough, flexible, interwoven fibers that form

networks

3.  Each major class of connective tissue has a fundamental cell

type that exists in immature and mature forms
            a. blast: builder cell, undifferentiated
            b. cyte: after matrix cemented around blast cell
            c. clast: may break down damaged tissue

 

D.  Types of Connective Tissue

                        1.  Mesenchyme

                                    Function:  forms during the early weeks of embryonic life

                                                from the mesoderm layers and eventually

                                                differentiates into all other connective tissue

                                    Slides:  None, unfortunately.

                        2.  Connective tissue proper:  Cells are fibroblasts

                                    a.  Loose connective tissue

                                                1)  Areolar

                                                Function: binds body parts together while

                                                            allowing them to move freely over one

                                                            another; fills open spaces, cushions,

                                                            supports, storage

                                                            Slides:  Areolar tissue spread, areolar

                                                                        connective tissue

2)  Adipose

                                                Function:  nutrient storage (energy), protection,

                                                            and insulation

                                                            Slides:  Adipose tissue

                                                3)  Reticular:  only has reticular fibers
                                                            Function:  forms stroma (internal framework) of

                                                                        liver, spleen, lymph nodes, bone marrow

                                                            Slides:  Liver, lymph nodes, bone marrow

                                    b.  Dense connective tissue

                                                1)  Dense regular

                                                            Function:  closely packed bundles of collagen

                                                                        fibers running in the same direction; 

                                                                        makes up tendons, aponeuroses, &

                                                                        ligaments

                                                            Slides:  Ligamentum nuchae (dense regular

                                                                        elastic)

                                                2)  Dense irregular

                                                            Function:  thick bundles of collagen fibers

                                                                        arranged in an irregular fashion

                                                            Slides:  skin corpuscle human, scalp human

                                                                        (*look at the dermis*)

                        3.  cartilage: cells (chondrocytes) in spaces (lacunae), avascular,

                        no nerves, rapid growth, high in water for resilience

                                    1)  Hyaline ("glass") cartilage:  the most abundant cartilage

                                                Function:  Provides firm support with some flexibility

                                                Slides:  Hyaline cartilage, primate trachea (*look deep

                                                            to the pseudostratified columnar epithelium)

                                    2)  Elastic cartilage

                                                Function:  Maintains shape of a structure while

                                                            allowing great flexibility

                                                Slides:  Elastic tissue

                                    3)  Fibrocartilage:  composed of collagen

Function:  strong support & the ability to withstand

            heavy pressure are required such as

            intervertebral discs, knees, pubic symphysis

Slides:  Fibro cartilage, collagenous tissue

                        4.  Bone (osseous tissue):  osteocytes (bone cells in lacunae)

            Function:  Supports & protects body structures due to its

                        hardness which is determined by Ca salts deposited

                        around collagen in the extracellular matrix

            Slides:  Bone dry ground human (l.s. & c.s.)

5.  Blood:  blood cells and plasma proteins surrounded by blood

plasma

            Function:  body's transport system

            Slides:  human blood smear

 

IV.  Muscle tissue:  muscles are called fibers because they are elongated

 

            A.  Functions:  contractile, produces movement and heat

 

B.  Characteristics:  well-vascularized, highly cellular

 

C.  Structural elements:  myofilaments: actin and myosin

 

            D.  3 types of muscular tissue

                        1. skeletal: striated, voluntary, multiple nuclei
                        2. cardiac: striated, involuntary, heart, branching, intercalated discs

                        between cells, 1 nucleus

3.  smooth: non-striated, involuntary, walls of visceral organs,

spindle shaped, 1 nucleus           

 

V.  Nervous Tissue: the main component of the nervous system

A.  Functions:  Fast-acting regulation & control of body functions. ex)

brain, spinal cord, nerves

 

B.  Nervous tissue is composed of two types of cells…

1) neurons: generate and conduct nerve impulses

a)  nerve cell body & neuron processes

2) neuroglia: support, nourish, insulate, and provide limited repair of

axons.  Nonconductive cells