Lecture 3 notes Flashcards
The glands of the skin are
1) Merocrine (eccrine) gland
2) Holocrine gland
3) Apocrine gland
The merocrine (eccrine) gland
Most common; cell loses no structure (goblet cells, salivary glands, sweat glands)
The holocrine gland
Cell death occurs when it bursts; basal cells undergo mitosis to replace cells (sebaceous glands)
The apocrine gland
Base of cell remains intact while apical end pinches off with small amount of cytoplasm (mammory glands, prostate)
Two kinds of sweat glands
1) Merocrine
2) Apocrine
Describe merocrine glands
- Throughout the body, the highest numbers are on the soles of our feet and the palms of our hands
- watery sweat
- ducts empty onto free skin surface
Describe the apocrine sweat gland
- less numerous
- larger
- found only in axillae, groin, and areolae (nipples)
- ducts often empty into hair follicles
- possible pheromones
Sebaceous glands produce
An oily sebum that provides lubrication for hair, moisture for skin & inhibits bacterial growth
Ceruminous glands are
A modified sweat gland in the ear canal.
Mammory glands are
- Modified “apocrine” sweat gland
* Secretion is true apocrine
Nails grow from?
The nail root which lies under the eponychium (cuticle)
Functions of the skeleton are
- Support & lever action (for movement)
- Protect organs (skull, ribs)
- Blood cell production (RBC’s, WBC’s)
- Stores calcium (Ca++ needed by all cells especially muscle cells)
Bone is dynamic, it can
Grow, repair, thickens & undergoes atrophy
The sesamoid bone are
Small, round & flat bones that form within tendons, highly variable from individual to individual except for the patella
Flat bones have
Two parallel plates of compact bone with a thin layer of spongy bone sandwiched in between them
Mesenchyme is
Star shaped cells; they are stem cells that give rise to all connective tissue
Osteoprogenitor is
- From mesenchyme (usually in the endosteum)
- Can divide and differentiate into osteoblasts
- Differentiate during bone formation & after bone fracture
Fibroblast
- produce all connective tissue fibers
* collagen, reticular & elastic fibers
Chondoblast are
Cartilage forming cells
Chondrocytes are
Encased chondroblasts
Main points of osteoblasts
- Bone forming cells
- Secrete osteoid (organic bone matrix)
- Osteocyte (encased osteoblast)
- Mature bone cells occupying lacunae (maintains bone)
Main points of osteoclasts
- Bone destroying cells
- Giant, multinucleate (fused bone marrow stem cells)
- Contain lysosomes
- Secrete HCI
- Dissolve bone matrix (osteolysis)
- Frees Ca++ into blood
