1. Exocrine Glands
Exocrine glands – “externally secreting” - secrete their products onto body surfaces (skin) or into body cavities
Examples include mucous, sweat, oil, & salivary glands
Almost all exocrine glands are multicellular.
Are more numerous than endocrine glands
Are classified according to duct type & structure of their secretory units

2. Functions of Connective Tissue
1- Binding & support
2 - Protection
3 - Insulation
4 - Transportation

3. Characteristics of Connective Tissue
Characteristics of connective tissues
1 – All connective tissues arise from mesenchyme –(an embryonic tissue) so they all have a common tissue of origin
2 – Connective tissue has varying degrees of vascularity (amounts of blood vessels running through them)
ex: cartilage has few blood vessels, bone has more
3 - Nonliving extracellular matrix, consisting of ground substance and fibers

4. Characteristics of Connective Tissue
3 – Connective tissue is composed mostly of nonliving extracellular matrix, consisting of ground substance & fibers which separates, often widely, the living cells of the tissue.
(Other primary tissues are mostly composed of cells)

5. Types of Connective Tissue Proper
1 – Loose Connective Tissue
1) Areolar connective tissue - gel-like matrix with all three connective tissue fibers (collagen, elastic, & reticular)
serves to bind body parts together while allowing them to move freely over one another
wraps small blood vessels & nerves, surrounds glands, & cushions organs
is widely distributed throughout body

6. Connective Tissue Proper: Loose
Figure 4.9a

7. Connective Tissue Proper: Loose
2) Adipose connective tissue – (fat) richly vasculatized tissue that is similar to areolar connective tissue with closely packed adipocytes
Functions:
1- reserves food stores
2- insulates against heat loss
3- supports
4 - protects

8. Connective Tissue Proper: Loose
Found under skin, around kidneys, within abdomen, & in breasts
Local fat deposits serve nutrient needs of highly active organs

9. Connective Tissue Proper: Loose
Figure 4.9b

10. Connective Tissue Proper: Loose
3) Reticular connective tissue – loose ground substance with reticular fibers
Reticular cells lie in a fiber network
Forms a soft internal skeleton, or stroma, that supports other cell types
Found in lymph nodes, bone marrow, & spleen

11. Connective Tissue Proper: Loose
Figure 4.9c

12. Types of Dense Connective Tissue
2 - Dense Connective Tissue - all have fibers
Also called fibrous connective tissues
1) Dense Regular connective tissue - contain closely packed bundles of parallel collagen fibers (running in same direction) with a few elastic fibers
Makes up tendons & ligaments

13. Connective Tissue Proper: Dense Regular
Figure 4.9d

14. Types of Dense Connective Tissue
2) Dense Irregular Connective Tissue – contains thick bundles of collagen fibers arranged in an irregular way with some elastic fibers
can withstand tension in many directions providing structural strength
is found in dermis & submucosa of digestive tract

15. Connective Tissue Proper: Dense Irregular
Figure 4.9e

16. Types of Cartilage Types of Cartilage
1- Hyaline Cartilage – (gristle) most abundant cartilage in body
Matrix has network of collagen fibers
Functions: 1) supports 2) reinforces 3) cushions & 4) resists compression
**provides firm support with some pliability
Found in embryonic skeleton, end of long bones, nose, trachea, & larynx

17. Types of Dense Connective Tissue
2 - Dense Connective Tissue - all have fibers
Also called fibrous connective tissues
1) Dense Regular connective tissue - contain closely packed bundles of parallel collagen fibers (running in same direction) with a few elastic fibers
Makes up tendons & ligaments

18. Connective Tissue Proper: Dense Regular
Figure 4.9d

19. Types of Dense Connective Tissue
2) Dense Irregular Connective Tissue – contains thick bundles of collagen fibers arranged in an irregular way with some elastic fibers
can withstand tension in many directions providing structural strength
is found in dermis & submucosa of digestive tract

20. Connective Tissue Proper: Dense Irregular
Figure 4.9e

21. Types of Cartilage Types of Cartilage
1- Hyaline Cartilage – (gristle) most abundant cartilage in body
Matrix has network of collagen fibers
Functions: 1) supports 2) reinforces 3) cushions & 4) resists compression
**provides firm support with some pliability
Found in embryonic skeleton, end of long bones, nose, trachea, & larynx

22. Connective Tissue: Hyaline Cartilage
Figure 4.9f

23. Types of Cartilage
2- Elastic Cartilage – nearly identical to hyaline cartilage but with more elastic fibers
Maintains shape & structure while allowing flexibility
Supports external ear (pinna) & epiglottis

24. Connective Tissue: Elastic Cartilage
Figure 4.9g

25. Types of Cartilage
2- Fibrocartilage – structuaral intermediate between hyaline cartilage & regular connective tissues & has matrix similar to hyaline cartilage but less firm with thick collagen fibers
found where strong support & the ability to withstand heavy pressure are required such as the intervertebral discs & in discs of knee joint
provides tensile strength & absorbs compression shock

26. Connective Tissue: Fibrocartilage Cartilage
Figure 4.9h

27. Connective Tissue: Bone (Osseous Tissue)
Bone - hard, calcified matrix with collagen fibers
also called osseous tissue
Osteocytes (mature bone cells)are found in small spaces called lacunae & are well vascularized with blood vessels
has exceptional ability to support & protect body structures due to its hardness, which is determined by collagen fibers & calcium salts found in extracellular matrix

28. Connective Tissue: Bone (Osseous Tissue)
Figure 4.9i

29. Connective Tissue: Blood
Blood – consists of red & white blood cells & plasma proteins in a fluid matrix (plasma)
contained within blood vessels
f unctions in the transport of respiratory gases, nutrients, & wastes
is classified as a connective tissue because it developed from mesenchyme

30. Connective Tissue: Blood
Figure 4.9j

31. Nervous Tissue Nervous Tissue – main componenet of nervous system
Neurons – highly specialized branched nerve cells with long cellular processes that generate & conduct nerve impulses
dendrites – respond to stimuli
axons – carry impulses away from nerve cell body
support cells
transmits electrical signals from sensory receptors to effectors
Found in the brain, spinal cord, and peripheral nerves

32. Nervous Tissue
Support cells – nonconducting cells that support, insulate, & protect delicate neurons
Neurons are found in brain, spinal cord, & peripheral nerves

33. Nervous Tissue
Figure 4.10

34. Types of Muscle Tissue
Muscle Tissue – highly cellular, well-vascularized
responsible for most types of body movement
1- Skeletal Muscle - attaches to bones of skeleton
Forms flesh of body & cause voluntary movement
Skeletal muscle cells (called muscle fibers) are long, cylindrical, multinucleate cells with striations

35. Muscle Tissue: Skeletal
Figure 4.11a

36. Types of Muscle Tissue
2- Cardiac Muscle - branching, striated, uninucleate cells interlocking at intercalated discs
responsible for involuntary movement of heart
3- Smooth Muscle – has no striations
propels substances along internal passageways (i.e., peristalsis)
found in walls of hollow organs
is involuntary muscle

37. Nervous Tissue
Support cells – nonconducting cells that support, insulate, & protect delicate neurons
Neurons are found in brain, spinal cord, & peripheral nerves

38. Nervous Tissue
Figure 4.10

39. Types of Muscle Tissue
Muscle Tissue – highly cellular, well-vascularized
responsible for most types of body movement
1- Skeletal Muscle - attaches to bones of skeleton
Forms flesh of body & cause voluntary movement
Skeletal muscle cells (called muscle fibers) are long, cylindrical, multinucleate cells with striations

40. Muscle Tissue: Skeletal
Figure 4.11a

41. Types of Muscle Tissue
2- Cardiac Muscle - branching, striated, uninucleate cells interlocking at intercalated discs
responsible for involuntary movement of heart
3- Smooth Muscle – has no striations
propels substances along internal passageways (i.e., peristalsis)
found in walls of hollow organs
is involuntary muscle

42. Muscle Tissue: Cardiac
Figure 4.11b

43. Muscle Tissue: Smooth
Figure 4.11c

44. Coverings & Lining Membranes
Some of the body’s membranes incorporate more than 1 type of tissue.
1 – Cutaneous Membrane - cutis = skin
Consists of stratified squamous epithelium firmly attached to a thick layer of dense irregular connective tissue (dermis)

45. Coverings & Lining Membranes
2- Mucous Membrane– also called mucosae
line body cavities such as those of hollow organs of digestive, respiratory, & urogenital tracts that open to exterior & contain either stratified squamous or simple columnar epithelia

46. Coverings & Lining Membranes
3 – Serous Membrane – moist membranes found in closed ventral body cavities
consists of stratified squamous epithelium resting on a thin layer of loose connective (areolar) tissue
Are named by where they are located
Pleura = lungs
Pericardium = covering of heart
Peritoneums = coverings in abdominopelvic cavity

47. Tissue Repair Steps of Tissue Repair –
1- Inflammation – caused by tissue trauma & is characterized by dilation of blood vessels, increase in vessel permeability, redness, heat, swelling, & pain
Blood clot forms

48. Tissue Repair 2 – Organization restored the blood supply.
Blood clot is replaced with granulation tissue
3 – Regeneration & Fibrosis
If wound is small & damaged tissue can divide, the tissue will regenerate & cover the fibrous tissue
When wound is extensive or damaged tissue cannot divide, it is repaired only by fibrous connective (scar) tissue.

49. Developmental Aspects
3 primary germ layers for early during embryonic development & becomes specialized into the 4 types of tissues.
Ectoderm – top layer - nervous tissue comes from ectoderm
Mesoderm – middle layer – muscle & connective tissue come from mesoderm
Endoderm – inside layer – organs
Epithelium arises from all 3 primary germ layers