Chapter 4: Tissues

Question 1

4 Types of Tissues
What is the study of Tissues?

Answer 1

Connective (10-15)
Epithelial (6)
Muscle (3)
Nervous (2)
Histology is study of tissues.

Question 2

Cell Junctions

Answer 2

Tight Junctions- ziplock closure (tight seal between 2 cells that prevents molecules from slipping between cells, Epitheleal cells have a lot)

Gap junctions- shoe lace holes, sharing molecules quickly, allow materials to get one cells to neighboring cells without having to cross cell membrane. EX: Muscle & Nerve impulses)

Question 3

Exocrine vs. Endocrine Glands

Answer 3

Exocrine glands- cells that secrete through ducts to surface of gland (inside or outside the body). EX: sweat, ear wax, saliva or digestive enzymes)
Endocrine glands- secrete hormones into the bloodstream to maintain homeostasis.

Question 4

3 Major types of Connective Tissue

Answer 4

1) -blasts- (immature) producing matrix (osteoblasts make bone & chondroblasts make cartilage)
2) -clasts -dissolve matrix (EX: lump around broken bone is a healed area that osteoclasts break down to restore bone to size)
3) -cytes (mature)- cell that is dormant & can reactive when needed

Question 5

Composition of Connective Tissue Matrix

Answer 5

Fibers in the ground substance is what changes the characteristics.
EX: few fibers= areolar & tightly packed tough fibers= fibrocast
ACTUAL CELLS LOOK EXTREMELY SIMILAR

Question 6

3 Connective Properties (Material)

Answer 6

1) Collagen (majority, 25% of protein in body), toughest, rope-like (thick) protein
2) Elastic (lungs)- thin fibers able to stretch & return to shape
3) Reticular (spleen, lymph nodes)- thin fibers, woven from fine random tough collagen that give organs their shape

Question 7

Connective Ground

Answer 7

Area around cells composed of fibers and gel like materal