1. Ch. 3b
tissues

2. There are four tissue types in the body
Tissues
There are four tissue types in the body
Epithelial tissue
Connective tissue
Muscle tissue
Nerve tissue

3. Characteristics of Epithelial Tissue
Cells have: Polarity— apical (unattached/ free) and basal (attached) surfaces
Apical surfaces: May bear microvilli /cilia
Basal surface: Supported by a basement membrane

4. Characteristics of Epithelial Tissue
Composed of closely packed cells
Cells held together by tight junctions and desmosomes
Avascular
High rate of regeneration

5. Apical surface Basal surface Simple Apical surface Basal surface
Stratified
Figure 4.2a

6. Classification of Epithelia
Ask two questions:
How many layers?
1 = simple epithelium
>1 = stratified epithelium

7. Classification of Epithelia
What type of cell?
Squamous
Cuboidal
Columnar
(If stratified, name according to top layer of cells)

8. Disc- like nucleus Round, central nucleus Round to oval nucleus
Squamous
Round, central nucleus
Cuboidal
Round to oval nucleus
Columnar
(b) Classification based on cell shape.

9. Single layer of flat cells
(a) Simple squamous epithelium
Description:
Single layer of flat cells
Function:
Diffusion/Filtration
Location:
Air sacs of lungs
Lining of ventral body cavity
Figure 4.3a

10. (b) Simple Cuboidal epithelium
Description: Single layer
of cubelike cells
Function: Secretion/
absorption.
Location: Glands and
ducts

11. Description: Single layer of tall cells May have goblet cells
(c) Simple Columnar epithelium
Description: Single layer of tall cells
May have goblet cells
Function: Absorption and secretion
Location: Lines most of digestive tract

12. (d) Pseudostratified Ciliated Columnar epithelium
Description: Single layer of cells of differing heights on same basement membrane;
May have goblet cells
Function: Secretion, propulsion of mucus by
ciliary action.
Location: upper respiratory tract.
Trachea

13. (e) Stratified squamous epithelium
Description: Thick, surface cells squamous
Two types:
Non-Keratinized: alive
Keratinized: surface cells dead & full of keratin
Function: Protection in areas subjected to abrasion.
Location: Non-keratinized: Lines cavities which open to exterior
Keratinized: forms epidermis

14. (f) Transitional epithelium
Description: Basal cells cuboidal/columnar
Surface cells dome shaped or squamous (depends on degree of stretch)
Function: Stretches readily
Location: Lines hollow urinary organs
Figure 4.3f

15. Glandular Epithelia
Gland: consists of one/more cells that make and secrete a product (secretion)
Two major types:
Endocrine glands- ductless glands that secrete hormones into the blood stream
Exocrine glands-have ducts that lead to a surface and secrete product onto surface/lumen leading to surface

16. Connective Tissue
Most abundant and widely distributed tissue type
Flow Chart:

17. Characteristics of Connective Tissue
Connective tissues have:
Varying degrees of vascularity
Cells separated by nonliving extracellular matrix (ground substance and fibers)

18. Extracellular Matrix Ground substance Fibers Components:
Interstitial fluid, Adhesion proteins (“glue”),
Large polysaccharides
Fibers
Collagen
Strongest, most abundant type; Provides tensile strength; form thick cables
Elastic
Long, thin, fibers; allow for stretch
Reticular
Short, fine, branched fibers that form an internal network (mesh) that is supportive to other cells

19. Cells of Connective Tissue
“blasts” = Mitotically active and secretory cells
“cytes” = Mature cells
Fibroblasts in connective tissue proper
Chondroblasts and chondrocytes in cartilage
Osteoblasts and osteocytes in bone
Hematopoietic stem cells in bone marrow

20. (j) Others: Osseous tissue
Description: Hard, calcified
matrix; osteocytes in lacunae;
Central
canal
Function: Support, protection, attachment site for muscles.
Lacunae
Location: Bones
Lamella
Figure 4.8j

21. Connective Tissue: Cartilage
Three types of cartilage:
Hyaline cartilage
Elastic cartilage
Fibrocartilage

22. (g) Cartilage: Hyaline
Description: most abundant of cartilage types;less hard and more flexible than bone;
Chondrocytes in lacunae.
Function: Supports,cushions, resists compressive stress.
Location: Forms most of embryonic skeleton; articular cartilage; cartilages of nose, trachea, larynx.
Chondrocyte
in lacuna
Matrix
Costal
cartilages

23. (h) Cartilage: Elastic
Function: Also allows
great flexibility.
Chondrocyte
in lacuna
Location: Ear, epiglottis.
Matrix

24. (i) Cartilage: Fibrocartilage
Location: Intervertebral discs
Chondrocytes
in lacunae
Intervertebral
discs
Collagen
fiber

25. (d) Connective tissue proper: Dense regular connective tissue
Description: Parallel collagen fibers
Collagen
fibers
Function: Withstands tensile
stress when pulling force is applied in one direction.
Location: Tendons, most
ligaments
Nuclei of
fibroblasts
Shoulder
joint
Ligament
Tendon

26. (e) Connective tissue proper: Dense irregular connective tissue
Description: Irregularly arranged collagen fibers
Nuclei of
fibroblasts
Function: Withstands
tension exerted in many
directions
Location: Fibrous capsules
of organs ,joints; dermis of
skin
Collagen
fibers
Fibrous
joint
capsule

27. (a) Connective tissue proper: Areolar connective tissue
Description: Most widely distributed variety of CT
Soft, pliable, like cobwebs
Elastic
fibers
Function: Wraps and cushions
organs
Collagen
fibers
Location: Under epithelia of body,
universal packaging material
Fibroblast
nuclei
Epithelium
Lamina
propria

28. (b) Connective tissue proper: Adipose connective tissue
Description: Closely packed adipocytes
Function: Reserve fuel
insulation; supports & protects organs.
Nucleus of
fat cell
Location: Hypodermis; around kidneys and eyeballs; in abdomen; breasts.
Adipose
tissue
Vacuole
containing
fat droplet
Mammary
glands

29. (c) Connective tissue proper: Reticular connective tissue
Description: Network of reticular fibers
Function: Fibers form a
soft internal skeleton that supports other cells
Location: Lymphoid organs (lymph nodes, bone marrow, and spleen).
White blood
cell
(lymphocyte)
Reticular
fibers
Spleen

30. (k) Others: blood Description: Red and white
blood cells in a fluid matrix
(plasma).
Plasma
Function: Transport of
respiratory gases, nutrients,
wastes, and other substances.
Neutrophil
Location: Contained within
blood vessels.
Red blood
cells
Lymphocyte

31. Muscle Tissue

32. (a) Skeletal muscle Description: Long, cylindrical,
multinucleate cells; obvious
striations.
Striations
Function: Voluntary movement
Nuclei
Location: Skeletal muscles
attached to bones or
occasionally to skin.
Part of
muscle
fiber (cell)
Photomicrograph: (approx. 460x).

33. (b) Cardiac muscle Description: Branching,
striated, Have intercalated discs.
Striations
Intercalated
discs
Function: Propel blood into
circulation; involuntary control.
Location: Walls of the heart.
Nucleus
Photomicrograph: (500X);

34. (c) Smooth muscle Description: Spindle-shaped
Cells; no striations; cells form sheets.
Smooth
muscle
cell
Function: Propels substances
or objects; involuntary control.
Location: Mostly in walls
of hollow organs.
Nuclei
Photomicrograph: Sheet of smooth muscle (200x).

35. Nervous Tissue

36. Nervous tissue
Description: Neurons w/ cell processes that extend from the cell body; Contains supporting cells
Nuclei of
supporting
cells
Neuron processes
Cell body
Axon
Dendrites
Cell body
of a neuron
Function: Transmit electrical
signals from sensory receptors
to effectors.
Neuron
processes
Location: Brain, spinal
cord, and nerves.

37. Steps in Wound Repair Inflammation
Increased blood flow with healing components & clotting factors to damaged area (redness, swelling, pain, heat) due to the release of inflammatory chemicals
Clot forms and exposed portion forms scab
Organization and restored blood supply
Granulation tissue forms=new capillaries and phagocytes and fibroblasts
Regeneration and fibrosis
Surface ET regenerates, scab detaches, underlying scar tissue

38. Scab
Epidermis
Blood clot in incised wound
Migrating white blood cell
Inflammatory chemicals
Artery

39. Regenerating epithelium
Area of granulation tissue ingrowth
Fibroblast
Macrophage

40. Regenerated epithelium
Fibrosed area