BIO-210L Lab 2

Epithelial Tissue

Tightly packed cells that cover and line body surfaces

Apical surface

Towards top/exposed area

Basal surface

Towards bottom/unexposed area

Simple Squamous Epithelium Structure

Simple flat layer

Simple Squamous Epithelium Location

Mesothelia lining ventral body cavities, endothelia lining heart and blood vessels, kidney tubules, inner lining of cornea, alveoli of lungs

Simple Squamous Epithelium Functions

Reduces friction, controls vessel permeability, performs absorption and secretion

Stratified Squamous Epithelium Structure

Many layers squished irregularly

Stratified Squamous Epithelium Locations

Surface of skin(keratinized), lining of mouth, throat, esophagus, rectum, anus, and vagina(nonkeratinized)

Stratified Squamous Epithelium Functions

Physical protection against abrasion, pathogens, and chemical attack

Types of Stratified Squamous Epithelium

Keratinized stratified squamous epithelium and Non-keratinized stratified squamous epithelium

Simple Cuboidal Epithelium Structure

Single layer cube shape

Simple Cuboidal Epithelium Locations

Glands, ducts, portions of kidney tubules, thyroid gland

Simple cuboidal epithelium function

Limited protection, secretion, absorption

Stratified Cuboidal Epithelium Structure

Many layers cube shaped

Stratified Cuboidal Epithelium Location

Lining of some ducts

Stratified Cuboidal Epithelium Functions

Protection, secretion, absorbtion

Simple Columnar Epithelium structure

Single layer, column shaped

Simple Columnar Epithelium location

Lining of stomach, intestine, gallbladder, uterine tubes, collecting ducts of kidneys

Simple Columnar Epithelium functions

Protection, secretion, absorption

Stratified Columnar Epithelium Structure

Many layers column shaped

Stratified Columnar Epithelium Locations

Small areas of pharynx, epiglottis, anus, mammary glands, salivary gland ducts, and urethra

Stratified Columnar Epithelium function

Protection

Pseudostratified Ciliated Columnar Epithelium Structure

Cilliated (hairs at top)

Goblet cells structure

Goblet-shaped

Goblet cell function

Secrete mucus

Transitional Epithelium Locations

Urinary bladder, renal pelvis, ureters

Transitional Epithelium Functions

Permits expansion and recoil after stretching

Endocrine Glands

Into blood (hormones)

Exocrine Glands

Out through ducts (sweat, saliva)

Merocrine Glands

Released by vesicles (fluid filled sac)

Apocrine Glands

Part of cell pinches off

Holocrine Glands

Whole cell breaks down

Types of exocrine glands

Sweat glands, salivary glands, mammary glands, liver

Cell Junction

Specialized areas of the plasma membrane that attach a cell to another cell or to extracellular materials

Gap junctions

Hollow proteins that allow for the free diffusion of ions and small molecules between two cells

Desmosomes

Durable intercellular connection

Tight Junctions

Formed by cell membranes interlocking

Mesenchyme

First connective tissue to appear in an embryo

Mesenchyme/embryonic connective tissue develops into

Connective and skeletal tissues including blood and lymph

Types of Connective Tissue

Dense, Blood, Loose, Bone, Cartilage

Types of dense connective tissue (collagenous tissues)

Regular, irregular, elastic

Types of loose connective tissue

Loose areolar, adipose, reticular

Types of bone connective tissue

Compact/cortical, spongy/trabecular

Types of Cartilage connective tissue

Hyaline, elastic, fibrocartilage

Dense Regular Function

Allow force of a contracting muscle to pull on bone

Dense Regular Examples

Tendons and ligaments

Dense Irregular Structure

College fibers with no consistent arrangement

Dense Irregular Function

Strengthen and support areas subject to stresses in many directions

Dense irregular examples

Deep layer of skin, periosteum, perichondrium, organ capsules that surround internal organs like kidney and spleen

Dense Regular Structure

Collagen fibers are arranged parallel and tightly packed

Elastic Tissue Structure

Elastic fibers (like rubber bands) dominate

Elastic tissue function

Stabilized position of vertebrae, permits expansion and contraction of organs such as blood vessels

Elastic tissue location

Between vertebrae of spinal column, blood vessel walls

Loose connective tissue Areolar structure

Elastic and collagen fibers with lots of space between fibers and cells

Loose connective tissue Areolar function

Binds tissue together

Loose connective tissue Areolar location

All basement membranes, superficial layer of dermis of skin

Loose connective tissue Adipose structure

Adipocytes most of volume filled with lipids and triglcycerides (marshmallows)

Loose connective tissue Adipose function

Padding and cushion, energy storage, insulates

Loose connective tissue Adipose location

Hypodermis, buttocks

Loose connective tissue Reticular structure

Recticular fibers form stroma (Cherry blossom)

Loose connective tissue Reticular function

Provides supporting framework

Loose connective tissue Reticular locations

Liver, kidney, spleen

Types of fluid connective tissue (blood and lymph)

Red blood cells, white blood cells, platelets

Types of white blood cells

Monocytes, lymphocytes, phasocytes

Red blood cell/erythrocytes function

Transport of oxygen

White blood cells/leukocytes function

Defend body from disease and infection

Platlete function

Blood clotting

Types of bone cells

Compact, spongy, osteoblast, osteoclast, osteocytes, lacunae

Osteon

Cylindrical, structural unit of compact bone

Lamellae

Circular layers of bone matrix that make up osteon

Osteocytes

Bone cells

Lacunae

Surrounds osteocytes

Haversian canal

Down one osteon

Volkman’s canal

Across multiple osteons

Spongy bone

Found where bones are not heavily stressed + center of long flat bones. Red bone marrow found between the trabeculae of spongy bone.

Hyaline Cartilage function

Stiff but flexible support, reduces friction

Hyaline Cartilage examples

Connects ribs to sternum, nasal

Elastic cartilage examples

Auricle of ear, epiglottis

Elastic cartilage function

Provides support without damage and returns to original shape

Fibrocartilage function

Resists compression and shock

Fibrocartilage examples

Intervertebral disc, meniscus