1. Chapter 5 Tissues

2. Introduction
Cells are arranged in tissues that provide specific functions for the body.
Cells of different tissues are structured differently, which leads to their differences in function.
The tissues of the human body include four major types.
Epithelial
Connective
Muscle
Nervous

4. Epithelial Function Location Characteristics
Protection, secretion, absorption, excretion
Sensory reception
Location
Covers your body surfaces, covers and lines internal organs, compose glands
Characteristics
Lack blood vessels, readily divide, cells are tightly packed
Anchored to a basement membrane
Replaced frequently

5. Epithelial
Epithelium- tissue that constitutes the outermost layer of the skin.
Carcinoma is a cancer originating from epithelium tissue.
About 90% of all cancers originate from epithelium tissue.

6. Types of Epithelium 1) Simple Squamous 2) Simple Cuboidal
3) Simple Columnar
4) Pseudostratified Columnar
5) Stratified Squamous
6) Stratified Cuboidal
7) Stratified Columnar
8) Transitional
9) Glandular

7. Simple Squamous Epithelium
Made up of a single layer of thin, flattened cells.
Suited for diffusion
Exchanges gases in the lungs
Lines:
Blood and lymph vessels
Body cavities
A basement membrane forms between epithelial and connective tissues

8. Simple Squamous Epithelium

9. Simple Cuboidal Epithelium
Consists of a single layer of cube-shaped cells with a centrally located nuclei.
It functions in secretion and absorption in the kidneys, and in secretion in glands.

11. Simple Columnar Epithelium
Cells are longer than they are wide
Single layer of cells
nuclei are located near the basement membrane
May be ciliated
It lines:
The uterus, stomach, and intestines
It also protects underlying tissues, secretes digestive fluids, absorbs nutrients

12. Simple Columnar Epithelium
Inner lining organs of the digestive system contain this type.
Goblet Cells:
Secrete Mucus
Embedded within the tissues
Unicellular gland.
Have microvilli
Increases the surface area for available for absorption.

14. Pseudostratified Columnar Epithelium
Appear Layered (but are not truly layered)
Varying positions of the nuclei
Cilia may be present
Also, Goblet Cells
Function to line and sweep debris from respiratory tubes.
Commonly found forming the inner lining of the respiratory passages.

16. Stratified Squamous Epithelium
Made up of layers of flattened cells
Designed to protect underlying layers.
Where is it found?
It makes up the outer layer of skin.
It lines the mouth, throat
Outer layers of cells undergo keratinization
Does not occur where tissues remain moist
throat

18. Stratified Cuboidal Epithelium
2-3 layers of Cuboidal Cells
Several layers of cells provides more protection than one single layer.
Lines:
Sweat glands
Salivary glands
Pancreas
Mammary glands

20. Stratified Columnar Epithelium
Several layers of cells- stratified
Where is it found?
Vas deferens
Parts of the male urethra
Parts of the pharynx

22. Transitional Epithelium
Designed to distend and return to its normal size
Lining of the urinary bladder
Provides distensibility
Keeps urine from diffusing back into the internal cavity

25. Glandular Epithelium
Produces and secretes substances into ducts or into body fluids
Exocrine- glands that secret products into ducts
Endocrine (ductless) - glands that secret products into body fluids and blood

26. Glandular Epithelium Gland classification = way product is secreted
Merocrine Glands
Release fluid products – exocytosis
Apocrine Glands
Lose portions of their cell bodies during secretion
Ex. Mammary glands
Holocrine Glands
Release entire cells
Ex. Sebaceous glands

28. Connective Function Location Characteristics
Bind, support, protect, fill spaces, store fat, produce blood cells, serves as framework, protect against infection, repairs tissue damage.
Has an abundant matrix (unlike epithelial)
Intercellular material
Has good blood supply (except cartilage)
Location
Widely distributed throughout the body
Characteristics
Mostly have good blood supply; cells are farther apart then epithelial cells with extracellular matrix between

29. 2 Major Types 1. Liquid or Vascular Connective Tissue
2. Solid Connective Tissue

30. Vascular Tissue Blood: Red blood cells (carry oxygen)
White blood cells (fight infection)
Platelets (cell fragments used for agglutination)
Plasma (fluid intracellular matrix)

31. Major Cell Types Fibroblast Cell Macrophages (wandering) Most common
Fixed, star-shaped cell
Large
Secretes Fibers
Macrophages (wandering)
Function
Scavenger cells
Defend against infection

32. Major Cell Types Mast Cells Large Located near blood vessels Release
Heparin (anticoagulant)
Histamine (promotes inflammation)

33. Connective Tissue Fibers
Collagenous Fibers
(white fibers)
Made of:
Collagen
Add Strength (for holding body parts together)
Elastic Fibers (yellow fibers)
Elastin
Stretchy
Add Flexibility to certain types of connective tissues

34. Connective Tissue Fibers
Reticular
Thin collagenous
Form supportive networks
Osteocytes (bone cells)
Arranged in concentric circles around the osteonic or Haversian Canals

35. Loose Connective (areolar) Tissue
Forms:
Delicate, thin membranes
Binds body parts together
Skin and underlying organs
The majority of the cells are fibroblasts that are separated by a gel-like intracellular material that contains collagenous and elastic fibers.

37. Adipose Tissue Loose connective tissue Where is it found? Stores fat
Beneath the skin
Around joints
Padding the kidneys, and internal organs
Abdominal membranes

38. Adipose Tissue

39. Dense Connective Tissue (Fibrous Connective Tissue)
Densly packed collagenous fibers
Very Strong!
Lacks a good blood supply
Where is it found?
Tendons and Ligaments

40. Cartilage Rigid connective tissue Enclosed within Perichondrium
Provides a supportive framework
Enclosed within Perichondrium
Lacks a vascular system
Healing takes longer
Chondrocytes- cartilage cells
Lie within the lacunae
Small chamber within a gel-like fluid matrix

41. Cartilage Hyaline Cartilage Where is it found? Function? Most common
White
Abundant fine collagen fibers
Where is it found?
Ends of bones
Function?
Supports respiratory passages
Trachea is composed of Hyaline Cartilage

42. Cartilage Elastic Cartilage Fibrocartilage Elastic Fibers
Forms Framework
Ex. External Ears & Parts of Larynx
Fibrocartilage
Collagenous Fibers
Tough- Tissue
Shock- absorbing
Ex. Intervertebral Disks of Backbone
Disks separate individual parts of backbone
Ex. Knees, Pelvic Girdle

43. Bone Most Rigid Connective Tissue Matrix Contains: Functions:
Deposits of Mineral Salts
Collagen
Functions:
Internally Supports the Body
Forms Muscle Attachments
Site for Blood Cell Formation
Osteocytes- Bone Cells
Found in Lacunae
Arranged in Osteons (concentric circles)
Around osteonic canals interconnected by canaliculi

44. Bone
Bone has a good blood supply, enabling rapid recovery after an injury.

45. Bone

46. Blood Composed of red and white cells Function: Suspended in plasma
Liquid matrix
Function:
Transport substances throughout body

47. Muscle Function Location Characteristics Movement
Attached to bones, in the walls of hollow internal organs, heart
Characteristics
Able to contract in response to specific stimuli

49. 3 Major Types of Muscle Tissue
1) Skeletal
2) Smooth
3) Cardiac

50. Skeletal Muscle Tissue
Attached to bone
Controlled voluntarily
Muscle Fibers
Long, striated, cylindrical, many nuclei
Major Characteristic
Ability to contract from nervous impulse
Least likely cell type to reprodue

51. Smooth Muscle Tissue Lacks Striations Uninucleate Spindle-shaped cells
Involuntary Muscle
Found in the walls of internal organs
Ex. Stomach, Digestive Tract, blood vessels, urinary bladder

53. Cardiac Muscle Tissue
1. Cardiac muscle tissue is found only in the heart and consists of branching fibers that are connected to each other with intercalated disks. This is the band that occurs where two cardiac muscle cells join.
2. This involuntary muscle has a single nucleus in each cell but appears striated.
3. When cardiac muscle cells are damaged by a heart attack, they are usually replaced by “connective tissue cells”

55. Nervous Tissues:
A. Nervous tissues are found in the brain, spinal cord, and nerves.
B. Neurons, or nerve cells, conduct nervous impulses while helper cells, or neuroglia, support and nourish the neurons.
C. Generally nervous tissue conducts nerve impulses from one neuron to another and it coordinates body activities.

56. Nervous Function Location Characteristics
Transmit impulses for coordination, regulation, integration, and sensory reception
Location
Brain, spinal cord, nerves
Characteristics
Cells connect to each other and to other body parts