1. Chapter 5
Tissues

2. Introduction Cells are specialized for particular functions
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Introduction
Cells are specialized for particular functions
Where have we heard this before??
Form Follows Function!!
(See? What we learned before IS important!)
Tissues – group of cells with similar structure and function
Histology – study of tissue

3. Tissue Four major types Epithelial – protection/secretion/absorption
Connective – support and structure
Muscle – movement (internal and external)
Nervous – communication and control

4. Epithelial Tissue General characteristics:
Anchored to connective tissue underneath by a basement membrane
Avascular – no blood vessels within it
Nutrients and wastes are exchanged with the blood stream via diffusion
Divide easily and often!
Continually replacing damaged cells
Tightly packed
Creates barriers

5. Free Surface vs. Basement Membrane

6. Classification Combination of two things: Shape of cells
Number of cell layers

7. Classification Shape Squamous - flattened Cuboidal - cube-shaped
Columnar - column-like

8. Classification Number of cell layers Simple Stratified One layer
Found in areas of transport
Stratified
More than one layer
Found in areas of high abrasion

9. Simple Squamous Epithelium
Made of a single layer of thin/flattened cells
Nuclei are broad and thin
Functions: diffusion, filtration, osmosis, and covering surfaces
Locations: air sacs, capillary walls, blood vessels, body cavities
Broad and thin nuclie
Easily damaged

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11. Simple Cuboidal Epithelium
Made of a single layer of cube-shaped cells
Nuclei are spherical and found in the middle of the cell
Functions: secretion (from glands) and absorption
Locations: covering the ovaries, lining kidney tubules, lining of glands

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13. Simple Columnar Epithelium
Made of a single layer of “tall” cells
Nuclei are often at the bottom of the cell near the basement membrane
Cell may be ciliated
Functions: protects underlying tissues, secretes digestive fluids, and absorbs nutrients
Locations: lines the uterus, stomach, and intestines

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15. Pseudostratified Columnar Epithelium
Appear layered… but are not. (“Pseudo” = Fake/False)
All cells touch the basement membrane
Made of a single layer of “tall” cells
Nuclei are found at different levels
Functions: line and sweep debris from the respiratory tubes
Locations: passageways of the respiratory system

17. Stratified Squamous Epithelium
Made of layers of flattened cells
Thick!
Functions: protect tissue underneath
Locations: outer layer of skin, lines the mouth, throat, vagina, and anal canal
Cell division happens deep – more superficial cells are squished as more cells are created underneath
“Squamous” label is based on surface cell appearance

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19. Stratified Cuboidal Epithelium
Made of 2-3 layers of cuboidal cells
Provides greater protections than just one layer
Functions – protection, secretion, absorption
Locations – lines larger ducts of the mammary glands, sweat glands, salivary glands, and pancreas

21. Stratified Columnar Epithelium
Made of several layer of “tall” cells
Functions: protection and secretion
Locations: male urethra and parts of the pharynx

23. Connective Tissue General Characteristics
Bind, support, protect, fill spaces, store fat, produce blood cells, protect against infection, and repair tissue damage
Have an abundant extracellular matrix
Have a good blood supply (except cartilage)
Can be very rigid or very flexible

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25. Loose Connective Tissue
Made of mainly fibroblasts, a gel matrix, collagenous, and elastic fibers
Functions – attaches skin to deep organs, fills spaces between muscles, under most epithelial layers (blood vessels nourish epithelial cells)
Location – beneath skin and epithelial tissue, between muscles and organs

27. Adipose Tissue Made of adipocytes Adipo – fat Cytes - cells
Functions – store fat (energy), insulation, cushion joints and organs
Locations – beneath the skin, around the kidney, surface of the heart, behind the eyeballs

29. Bone
Made of mineral salt, collagen fibers, and osteocytes (bone cells)
Function – internal support, protection, attachment site for muscles, location of blood cell formation
Location – Entire skeletal system

31. Blood
Made of red and white blood cells (RBCs and WBCs) in a liquid matrix called plasma
Function – maintain a stable environment (homeostasis!), transport substances throughout the body
Location – blood vessels and heart

33. Dense Connective Tissue
Made of densely packed collagen fibers
Very strong but not a good blood supply
Can withstand pulling
Slow to heal
Function – binds organs (bone and muscle)
Location – tendons and ligaments

35. Cartilage
Rigid connective tissue that provides a supportive framework for various structures
Lacks a blood supply
Slow to heal

36. Hyaline Cartilage Most common Made of fine collagen fibers, white
Function – support, protect, provide framework
Location – nose, end of bones in joints
Between ages 30-70, a nose may lengthen and widen by as much as half an inch, and the ears may lengthen by a quarter of a ince due to the fact that cartilage is one of the few tissues that continues to grow as we age.

38. Elastic Cartilage Made of dense network of elastic fibers
More flexible
Functions – supports, protects, provides flexible framework
Location – framework for external ear, parts of the larynx

40. Fibrocartilage Made of many collagenous fibers
Function – support, shock absorption
Location – intervertebral disks, knees, pelvic girdle

42. Muscle Tissue General Characteristics
Composed of elongated cells (fibers) that can contract

43. Skeletal Muscle
Made of skeletal muscle cells (muscle fibers) that are long, cylindrical, have many nuclei, and have striations (alternating light and dark fibers)
Functions – voluntary movement of skeletal parts
Locations – Any muscle that is attached to a bone

45. Smooth Muscle
Lacks striations, only has one nucleus, and contracts involuntarily
Functions - Involuntary movements of internal organs
Locations – walls of internal organs, digestive tract, blood vessels, and bladder

47. Cardiac Muscle
Is striated, has one nucleus, cells are connected by intercalated disks
Functions – Involuntary heart movements
Location - heart

49. Nervous Tissue
General Characteristics: sense certain types of changes in surroundings and respond by transmitting nerve impulses to other nerve cells, muscle, or glands

50. Nervous Tissue
Made of neurons (nerve cells) and neuroglial cells (supporting cells)
Function – sensory reception, conduction of nerve impulses
Location – brain, spinal cord, nerves