230 likes | 255 Views
tissue, epithelial, connective, muscle, nervous, characteristics, cancer, regeneration, fibrosis
E N D
Bellwork • Define tissue. (Hint – look at your crossword or your notes from chapter 1!) • Tissue: A group of cells that work together for the same function.
Tissues 4 Main Tissue Types • 1 – Epithelial • 2 – Connective • 3 – Muscle • 4 – Nervous • Tissues differ from each other in size, shape, amount, kind of material, and function.
1 – Epithelial Tissue • Covers body and parts. • Packed tightly together • No blood vessels • Basement membrane anchors to tissue underneath • Regenerate easily
1 – Epithelial Tissue Shape • Squamous– Flat and scale like • Cuboidal– Cube shaped • Columnar– Higher than wide Arrangement • Simple– Single layer of same shaped cells • Stratified– Many layers of same shaped cells • Transitional– Several layers of different shaped cells
1 – Epithelial Tissue Simple Squamous • Single layer, flat, scale-like • Function – Absorption • Ex. Oxygen into blood from lungs (capillaries and alveoli) Stratified Squamous • Several layers of closely packed cells • Function – Protection from microorganisms • Ex. Skin and mucous membranes
1 – Epithelial Tissue Stratified Transitional • Found in areas needed to stretch • Usually ten or more layers (protection) when not stretched • When stretching occurs, epithelial sheet expands to form a few layers • Ex. Urinary bladder Simple Columnar • Contain “goblet cells” which produce mucous. • Specialize in absorption. • Ex. Inner surfaces of stomach, intestines, and parts of respiratory and reproductive tracts.
1 – Epithelial Tissue Pseudo-stratified • Appears to be two layered but actually is not (pseudo – false) • Absorption and secretion • Contain cilia • Ex. Trachea and windpipe Glandular • Act alone or in groups (glands). • Exocrine glands – Release products into ducts. (Ex. Liver) • Endocrine glands – Release hormones into bloodstream. (Ex. Thyroid)
Interesting Fact • Up to 90% of human cancers originate in epithelial cells.
Exit Ticket • Describe as many general characteristics about epithelial tissue as you can. (Hint – We had 5 in our notes)
2 – Connective Tissue • Most abundant type of tissue • Vary in blood supply • Extracellular matrix – non-living material surrounding living cells • Protein fibers and ground substance (mostly water)
2 – Connective Tissue A) Areolar • Thin delicate membranes • “Glue” that anchors internal organs. • Ex. Subcutaneous layer below skin B) Adipose • Space between cells so they may swell, nucleus pushed to one side • Specialized to store lipids, insulation • Reticular • Thin network of fibers • Provides support in organs which hold free blood cells (lymph nodes, spleen)
2 – Connective Tissue D) Bone (osseous tissue) • Matrix is hard and calcified. • Store Calcium and Phosphorus • Provide protection and support. • Dense • Make up tendons and ligaments
2 – Connective Tissue F) Blood • Liquid matrix • Function – Transportation and Protection • Ex. Red and White blood cells • Cartilage • 3 types: • Hyaline – fetal skeleton • Elastic – ears • Fibrocartilage – intervertebral discs
3 – Muscle Tissue • 3 Types • Skeletal (Striated) • Voluntary -can be willfully controlled. • Many nuclei • Individual cells appear threadlike. • Attached to bones - create movement.
B) Cardiac Only in heart Involuntary Striations and intercalated disks. Allows the heart to beat 3 – Muscle Tissue
C) Smooth (Visceral) Form walls of hollow organs (blood vessels, intestines) Involuntary Non- striated 3 – Muscle Tissue
4 – Nervous Tissue • Neurons and support cells • Send impulses to other areas of the body
Neurons contain 1 axon(carry impulses away from cell body) and 1 or more dendrites(carry impulses to cell body) Nerve Tissue
Tissue Discussion • Three patients in an ICU are examined by the doctor. One pt has brain damage from a stroke, another had a heart attack that severely damaged his heart muscle, and the third has a severely damaged liver (a gland) from a crushing injury in a car accident. All 3 pts have stabilized and will survive, but only one will have full functional recover through regeneration. Which one and why?
Tissue Discussion • Cancer-causing agents (carcinogens) usually act on dividing cells. Which of the four tissues would carcinogens most influence? Why?
Tissue Discussion • Joints such as the shoulder, elbow, and knee contain considerable amounts of cartilage and dense regular connective tissue. How does this explain that joint injuries are often slow to heal?
Tissue Repair • Regeneration • Replacement of destroyed tissue by the same kind of cells • Fibrosis • Repair by dense fibrous connective tissue (scar)