famf module 2: epithelial tissue
TRANSCRIPT
S
Tissue
Epithelial Tissue
S Characteristics:
- Covers body surfaces (inside and out)
- Main glandular tissue
- Basement membrane
- Rapid reproduction (healing)
- Tightly packed together
Epithelial Tissue
S Simple vs Stratified
S Squamous
S Cuboidal
S Columnar
Simple Squamous
S Function: Diffusion and Filtration
S Location: Lungs, Walls of capillaries
Simple Cuboidal
S Function: Secretion and Absorption
S Location: Kidney tubules and ducts, covering ovaries
Simple Columnar
S Function: Secretion and Absorption
S Location: Digestive tract and uterus
* Contains goblet cells (secrete mucus)
Stratified Squamous
S Function: Protection
S Location: Skin and Mouth
It takes approx 27 days for human skin to shed
and be replaced. Where does it all go?
How come tattoos don’t just wash off?
Some
cuts are
too deep
and
require
stitches.
Pseudostratified Columanr
S Single layer- uneven nuclei
S Can have goblet cells and cilia
S Location: lines air passages and tubes of
reproductive system
Transitional Epithelium
S Stretches
S Blocks Diffusion
S Found in the bladder
Review
Lab 2.1
S End of day 1 epithelial lecture
Glandular Epithelium
S Cells are specialized to produce and secrete
substances.
S These cells make up glands
S Exocrine glands- sweat, saliva
S Endocrine glands- hormones
3 Types of Exocrine Glands
S Merocrine Glands- secrete without losing cellular material
via exocytosis
S Apocrine Glands- have cytoplasm in their secretions
(pinch off a portion)
S Holocrine Glands- secretions contain disintegrated cells
(whole cells are ejected and then rupture)
-See fig 2.8 on page 43-
Endocrine Glands
S Have no ducts
S Secrete hormones into blood
via exocytosis
Connective Tissue
S Throughout body
S Connects other structures
S Usually has a good blood supply
S Provides support, protection, framework, etc
S Cells are relatively far apart (compared to epithelial cells)
S Extracellular Matrix
Connective Tissue Proper
S Loose connective tissue
- fibroblasts, connects skin to muscle, light duty binding, holds things together.
S Dense irregular connective tissue
- Collagen fibers are going all different directions (improved strength). Skin is dense irregular.
S Dense regular connective tissue
- Collagen fibers all go the same direction, tensile strength, tendons and ligaments
Connective Tissue Proper
S Adipose Tissue- Fat
- This is loose connective + fat cells
- Energy storage and insulation
- Insulates organs too!
- Too much or too little is dangerous
Cartilage
S Firmer than connective tissue proper
- The matrix is too firm for the cell to live directly inside it.
Cells live in a small, hollowed-out space called the
lacuna.
S No blood supply
S Chondrocytes- Mature cartilage cells
Hyaline Cartilage
S Firm and resilient
S Bridge of nose
S Covers ends of joints
S Connects ribs to sternum
Fibrocartilage
S Lots of collagen fibers
S Strong binding
S Resilient support
S Found in backbone
Elastic Cartilage
S Not much collagen
(elastic)
S Rubber-band like
S Flexible support
S Tip of nose
S Outer ear
Bone & Blood
Membranes
S Epithelial tissue + connective tissue = membranes
S Mucous Membranes (mouth, stomach, digestive tract,
resp tract, urine and reproductive tracts) – all open to
outside of body (protection)
S Synovial Membranes- lubrication in moving joints
S Serous Membranes- prevent friction between organs
Tissue Repair
S Stromal Cells- provide structure & support for
parenchymal cells (infrastructure)
S Parenchymal Cells- Cells that provide actual function of
tissue (do work)
Cell Regeneration
S Labile Cells- regular and quick mitosis
S Stable Cells- don’t regularly undergo mitosis, but are able
to if needed
S Permanent Cells- cannot undergo mitosis