Tissue: Fabric of Life

Read & Review Chapter 4

Body Tissues

Histology- study of biology of tissuestissues are cells organized for a specific

function

Development of Tissues Primary Germ Layers

the process of forming 3 germ layers is called gastrulation

the process of the germ layers differentiating into tissues is called histogenesis

Tissue development

Endoderm – innermost layer ex. Lining of digestive and

respiratory organs, thyroid Mesoderm - middle layer

ex. muscle, skeleton, blood, skin, connective tissue, excretory and reproductive organs

Ectoderm – outermost layer ex. skin, nervous, epidermis

tissue

Tissues

Groups of cells that are similar in structure and function

Four primary tissue types

1. Epithelial

2. Connective

3. Muscle

4. Nervous

CoveringSupportMovementControl

II. Epithelial TissuesA. 2 Main Types1. Membranous epithelium- lining/ covering2. Glandular epithelium- secreting

Epithelial: Functions

1. Protection- ex. skin2. Sensory- ex. skin, nose, eye, ear3. Secretion- ex. hormones, digestive

juices, sweat4. Absorption- ex. small intestine, lungs5. Excretion- ex. urine, sweat

C. Characteristics

1. limited extracellular space (matrix); cells appear tightly packed

2. apical surface (free surface exposed to the body exterior or the cavity of an internal organ) & basement membrane (bottom surface connected to connective tissue)

Characteristics-(Continued)

3. avascular- no blood vessels; uses diffusion instead

4. innervated- contains nerve fibers

5. origin is ectodermal, mesodermal, endodermal

6. high regeneration capacity

D. Classification of membranous epithelial

1. Cell Shapesa. Squamous- flat, roundb. Cuboidal- cubedc. Columnar- narrow cylinderd. Pseudostratified- one layer of odd-shaped columnar cells; appears appears to be more than one to be more than one layerlayer

Layers of Cells

Layers of Cells

a. Simple- single layer

b. Stratified- more than one layer

3. Cell Shapes & Layers of Cellsa. simple squamous-

ex. alveoli in lungs

b. simple cuboidal-

ex. glands, kidney

c. simple columnar-

ex. golbet cells, cilia,

microvilli

Simple Squamous Epithelium

Absorption Secretion Filtration

Simple Cuboidal Epithelium Glands, ducts Walls of the kidney

tubules Surface of the

ovaries

Simple Columnar Epithelium

Goblet cells secrete mucus that aids in the function of respiratory system

Pseudostratified columnar ex. goblet cells, respiratory

All the cells rest on the basement membrane

Since some of the cells are shorter then others, the nuclei appear at different heights

Stratified Squamous (keratinized and non-keratinized)

Stratified Squamous Epithelium: Most common stratified epithelium in the body

Squamous at the free edge and columnar or cuboidal at the basement membrane

Sites of abuse or friction: esophagus, mouth and outer portion of the skin, the outer surface of skin is keratinized (surface cells contain keratin, a tough protective protein)

Keratinized vs. Nonkeratinized

Stratified Cuboidal Stratified Cuboidal

and Columnar Epithelium usually just two cell layers

Fairly rare in the body; mainly ducts of large glands Sweat glands Mammary glands

Transitional Epithelium

highly modified stratified squamous: urinary bladder, ureters, urethra.

All these organs are part of the urinary system and are subject to considerable stretching

Section 2 vocab: common suffixes

-ac, -al, -ary, -ic, -tic, -ous: pertaining to/related to

-ad: derived from -algia: pain -cele: hernia -centesis: puncturing -ectomy: cutting out -iasis: a process or its results -itis: inflammation -ium: diminuitive, small -ize: to make into -lysis: break down -oid: resembling, like

-oma: tumor/cancer -osis: denotes states or

condition -ous: possessing, full of -plasty: molding, forming -rrhea: flow -sect: to cut, divide -sia, -sis, -tion, -y:

action/condition -stomy: make an artificial

opening -tomy: to cut

Three Week Schedule9/8- Gladular Epithelial tissue; Scope Work9/9- Quiz (Epithelial tissue); Connective Tissue & Muscle tissue9/10- Scope Work (Sub day)9/11- Nervous Tissue; Scope Work9/12- Vocab quiz (2); Microscope work (no lecture)

9/15- Integumentary Notes, Scope work9/16- Integ. Notes, Tissues Review, Scope work9/17- Tissue Practicum Quiz, Tissue Packet Due9/18- Finish Integ Notes; Lab activity 9/19- Vocab Quiz (3), Disease & Disorder Lecture (End 1st 6 wks)

9/22- Review for Test 9/23- Tissue/IntegumentaryTest9/24- Bones/Skeletal Lecture9/25- Bones Discussion and Identification9/26- Vocab Quiz (5), Bones Lab

Glandular Epithelium

Gland: one or more cells that make and secrete a product

Secretion: protein molecule in aqueous fluid [some secrete a lipid or steroid rich secretion]

Classification of glandular epithelial tissue

1. Cell Number

a. Unicellular glands- single cells

ex. goblet cells- mucus

b. multicellular glands- clusters of cells;

ex. mammary ducts- milk

Classification of glandular epithelial tissue

2. Discharge methoda. Exocrine glands – secrete into duct

ex. saliva, sebaceous, mammary, sweat

b. Endocrine glands - ductless; secrete hormones into bloodstreamex. pituitary gland, thyroid, ovary, testes, adrenal,

pancreas

Glandular Epithelium

Endocrine: ( internal secreting) ductless; all hormone

secretions directly into the blood or lymphatics (secrete by the process of exocytosis)

thyroid; adrenals; pituitary

Multicellular Exocrine Glands

Two basic parts:DuctSecretory unit

that consists of secretory cells called acini

Modes of secretion Merocrine glands-

exocytosis (pancreas, salivary

glands, sweat glands) Holocrine Glands-

rupture (Sebaceous oil glands

of the skin)

Epithelial tissue overviewEpithelial

Simple Stratified Pseudostratified

Squamous Cubodial Columnar ciliated nonciliatedtransitional

cubodial

columnar

squamous

keratinized

nonkeratinized

ciliated

nonciliated