Download Connective Tissues

Tissues
Chapter 5
Epithelial tissue
Covers organs, forms the inner lining of
body cavities, lines hollow organs
Anchored to connective tissue by basement
membrane
Lacks blood vessels
Cells readily divide; injuries heal quickly
Simple squamous
epithelium
– Single layer of thin,
flattened cells
– Fit together like tiles
– Nuclei are broad and
thin
– Site of diffusion
– Line air sacs of lungs,
walls of capillaries
– Easily damaged
Simple cuboidal epithelium
– Single layer of cube shaped cells
– Centrally located spherical nuclei
– Covers ovaries, lines kidney tubules, ducts of
glands
– Functions in the kidneys in secretion and
absorption
– Functions in the glands in secretion of
glandular products
Simple columnar epithelium
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Elongated, thick
Nuclei located near the basement membrane
Lines uterus and most organs of digestive tract
Some have microvilli
Goblet cells scattered throughout
Pseudostratified columnar epithelium
– Appear layered
– Cell nuclei are at two or more levels in the row
of aligned cells
– Cilia
– Lines passages of the respiratory system
Stratified squamous epithelium
– Thick
– Cells divide in deeper layers, and newer cells push
older ones farther outward where they flatten
– Forms outer layer of the skin
– As skin cells age, they accumulate a protein called
keratin and then harden and die
– Prevents water loss and blocks substances from
entering
– (not keratinzed) Lining of mouth, throat, vaginal, and
anal canal
Stratified cuboidal epithelium
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Two or three layers
Form the lining of a lumen
Provides protection
Lines mammary glands, sweat glands, salivary
glands, pancreas, developing ovarian follicles
and seminiferous tubules
Stratified columnar epithelium
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Several layers
Superficial cells are elongated
Basal layers are cuboidal
Male urethra and vas deferens
Parts of the pharynx
Transitional epithelium
– Specialized to change in response to increased
tension
– Inner lining of urinary bladder, ureters, and part
of the urethra
Tissue Engineering
Video
Homework
Review Exercises p. 111 #1-5 (omit i.)
Write the questions and answers
Connective Tissues
Bind structures
Provide support and protection
Serve as frameworks
Fill spaces
Store fat
Produce blood cells
Protect against infections
Help repair tissue damage
Major cell types
– Fibroblasts
• Fixed
• Star-shaped
• Produce fibers by
secreting proteins into
the matrix of connective
tissues
• Scurvy (lack of vitamin
C) interrupts
fibroblasts’ ability to
produce collagen
– Macrophages
• Originate as white blood cells
• Carry on phagocytosis
– Mast cells
• Usually located near blood vessels
• Release heparin, which prevents blood clotting, and
histamine, which promotes inflammation
Connective tissue fibers
produced by fibroblasts
– Collagenous
• Great tensile strangth
• Compose ligaments and
tendons
• White fibers
– Elastic
• Composed of elastin
• Found in vocal cords
• Yellow fibers
– Reticular
• Very thin collagenous fiers
• Delicate support
Loose connective tissue (areolar)
– Composed of fibroblasts
– Binds the skin to the underlying organs
– Fills spaces between muscles
Adipose tissue (fat)
– Cushions joints and some organs, such as the
kidneys
– Insulates beneath the skin
– Stores energy in fat molecules
Dense connective tissue
– Consists of thick collagenous fibers and
network of elastic fibers
– Very strong
– Found in tendons, ligaments, white layer of
eyeball, and deeper skin layer
Cartilage
– Provides support and
protection
– Chondrocytes occupy
small chambers called
lacunae
– Three types
• Hyaline (nose)
• Elastic (ears)
• Fibrocartilage
(intervertebral disks)
Bone
– Hardness due to
mineral salts and
collagen
– Supports and protects
– Attachment for muscle
– Contains red marrow
(forms blood cells)
– Osteocytes
concentrically
clustered around
osteonic canal, form a
cylinder-shaped unit
called an osteon
Blood
– Transports
– RBCs, WBCs, platelets, plasma
Muscle Tissue
Contractile
muscle fibers lengthen
and shorten
Skeletal muscle
– Attached to bone
– Can control by conscious effort (voluntary)
– Alternating light and dark cross-markings
called striations
– Each cell has many nuclei
– Move the head, trunk, and limbs
Smooth muscle tissue
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Cells lack striations
Shorter than skeletal muscle tissue
Spindle-shaped
Single, centrally located nucleus
Makes up walls of hollow internal organs, such
as the stomach, intestines, urinary bladder,
uterus, and blood vessels
– involuntary
Cardiac muscle tissue
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Only in the heart
Striated cells are joined end to end
Cells touch each other an intercalated disk
Controlled involuntarily
Nervous Tissue
Found in the brain,
spinal cord, and
peripheral nerves
Sense changes in their
surroundings
Includes neurons
(nerve cells) and
neuroglial cells
Types of membranes
1. Serous
– Line body cavities that lack openings to the
outside
– inner lining of thorax and abdomen, cover
organs within cavity
– Simple squamous epithelium, loose connective
tissue
– Secrete serous fluid, a lubricant
2. Mucous
– Line cavities and tubes that open to the
outside of the body
– Oral and nasal cavities and the tubes of the
digestive, respiratory, urinary, and
reproductive systems
– Epithelium, loose connective tissue
– Secrete mucus
3. Synovial
– Inner linings of joint cavities between the
ends of bones
– Dense connective tissue, loose connective
tissue, adipose tissue
– Secrete synovial fluid, lubricant
4. Cutaneous
– skin
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