AANT316 Chapter 5: The Human Tissues

circular proteins: Connexions - allows ions to pass through

Function of cardiac and smooth muscle

Gap junction

Secretes hormones

Endocrine glands

Tissue is found on the surface

Water-repellent

Keratinized

Tissue lacks the surface layer of dead cells

found on tongue, esophagus, vagina

nonkeratinized

Covers body surfaces, cavities, linings, and forms glands

Epithelial tissue

Cell structures that lock adjacent cells together like spot welds to resist high mechanical stress

Desmosomes

Join cells tightly to neighboring cells to form a permeability barrier

Stomach and urinary bladder

J shaped

Tight junctions

Single layered

“fried egg” appearance, very thin cytoplasm

used for rapid transport of substances through membranes

Simple Squamous epithelium

Single layered

square/round cells, tightly fitted, centrally placed nuclei

used for absorption, secretion, and production + movement of respiratory mucus

located in the liver, glands, bronchioles

Simple cuboidal epithelium

Consists almost entirely of cells, barely any matrix

Outside surface of body, digestive, body cavities, heart & blood vessels

Apical surface & Basal surface

Epithelial tissue

Part of basement membrane that touches epithelium

Basal lamina

Part of basement membrane that touches connective tissue

Reticular lamina

cytoplasmic extensions of membrane

*increased surface area to maximize absorption/secretion

microvilli

Single layer

tall, narrow cells, vertically oriented

oval shaped nuclei, near base

used for absorption, secretion, movement

*goblet cells

found in stomach, intestines, uterus and uterine tubes

Simple columnar epithelium

uses brush-like motions to increase movement

ex: in throat, brushes mucus down

cilia

Single layer, looks multilayered (b/c of nuclei at several levels)

All cells reach basement membrane

Used for secretion (goblet cells) and propelling mucus (cilia)

found in respiratory tract, portions of male urethra

Pseudostratified Columnar Epithelium

Multiple layers

surface cells, keratin, basal cells

used to resist abrasion, retards water loss, resists penetration

found on soles and palms

Keratinized stratified squamous epithelium

Multiple layers

Resists abrasion and penetration

found on tongue, esophagus, anal canal, vagina

Nonkeratinized stratified squamous epithelium

2+ layers

surface cells

used for sweat secretions, ovarian hormones, sperm

found in sweat gland ducts, sperm producing duct of testis, egg producing follicles of ovaries

Stratified cuboidal Epithelium

AKA Urothelium

2-3 layers when stretched, 5-6 when relazed

some cells have 2 nuclei

Stretches to allow filling of urinary tract

Found in urinary tract — parts of kidney, bladder, urethra

Transitional epithelium

Highly vascular (except cartilage)

Most abundant tissue

Cells are not in direct contact w/ each other

Cells occupy less space than extracellular material

Connective tissue

Long, cylindrical fibers arranged parallel to one another

Multiple nuclei

Voluntary

Skeletal muscle

Myocytes/cardiocytes

Only one nucleus

Striated

Involuntary

Cardiac muscle

Myocytes
Relatively short

NOT striated