BIOLOGICAL SCIENCES

By:

MARIA KRISIA FAE DELOS REYES DE ASIS, BSN-RN

TISSUE LEVEL OF ORGANIZATION

GLANDULAR EPITHELIUM-Function: SECRETION-Often lie in clusters deep to the covering and lining epithelium-A gland may consist of a single cell or a group of cells that secrete substances into ducts, onto a surface, or into the blood

TISSUE LEVEL OF ORGANIZATION

> Endocrine Glands-Diffuse substances directly into the bloodstream without flowing through a duct-Secretions are called hormones, which regulate chemical reactions in the body

TISSUE LEVEL OF ORGANIZATION

> Exocrine Glands-Secrete their substances into ducts that empty onto a surface such as skin or lumen-Examples of substances: sweat, oil, earwax, saliva, enzymes

TISSUE LEVEL OF ORGANIZATION

CONNECTIVE TISSUE-ranges in consistency from the gel-like softness of areolar connective tissue to the hardness of bone-Blood is also a connective tissue-Connective tissue (CT) forms an extensive compartment in the body and can be considered as the "glue" that holds the body together

TISSUE LEVEL OF ORGANIZATION

Types of Connective Tissue:

1. Fibroblasts – are large, flat cells with branching processes. They are usually the most numerous. They migrate through the connective tissue, secreting the fibers and ground substance of the extracellular matrix

TISSUE LEVEL OF ORGANIZATION

2. Macrophages – are capable of engulfing bacteria and cellular debris by phagocytosis

Fixed macrophages- reside in specific tissues

Wandering macrophages- can move throughout the

tissues where inflammation and infection are located

TISSUE LEVEL OF ORGANIZATION

3. Plasma cells – small cells that develop from immune cells called B-lymphocytes. They secrete antibodies.

4. Mast cells – abundant alongside the blood vessels that supply connective tissue. They produce histamine, a chemical that influences inflammatory response. They can also engulf bacteria.

TISSUE LEVEL OF ORGANIZATION

5. Adipocytes – also called fat cells or adipose cells. They store triglycerides as a reserve source of energy

6. White blood cells – they migrate from blood into the connective tissue during infection or allergic reactions.

TISSUE LEVEL OF ORGANIZATION

EMBRYONIC CONNECTIVE TISSUE

Mesenchyme- composed of irregularly

shaped cells, a semifluid ground substance, and delicate reticular fibers.

- Function: forms all other types of connective tissue

- present in the embryo

TISSUE LEVEL OF ORGANIZATION

Mucous connective tissue- found mainly in the

umbilical cord of the fetus- Function: supports the 2

arteries and 1 vein in the umbilical cord

- also called Wharton’s jelly

TISSUE LEVEL OF ORGANIZATION

MATURE CONNECTIVE TISSUELOOSE CONNECTIVE TISSUE- Loosely intertwined between cells1. Areolar- Most widely distributed- All types of fibers (collagen,

elastic, reticular) are arranged randomly throughout the tissue

- Combined with adipose tissue, they form the SUBCUTANEOUS LAYER of the skin

TISSUE LEVEL OF ORGANIZATION

2. Adipose- Contain adipocytes- Good insulator that reduces heat

loss through the skin- Protection for various organ- Energy reserve White Adipose Tissue- usually found in adults Brown Adipose Tissue- Has very rich blood supply

TISSUE LEVEL OF ORGANIZATION

3. Reticular- Forms the stroma (supporting

tissue) of the liver, spleen, and lymph nodes

- Helps bind together smooth muscle cells

- Also removes worn out cells and bacteria

TISSUE LEVEL OF ORGANIZATION

DENSE CONNECTIVE TISSUE- More numerous thicker and denser fibers, but fewer cells1. Dense Regular- Bundles of collagen are regularly

arranged in parallel patterns to provide great strength to tissues

- Fibroblasts appear in rows between the fibers

- Tissues are silvery white and tough. Ex. Tendons, ligaments

TISSUE LEVEL OF ORGANIZATION

2. Dense Irregular- Contains collagen fibers that are

packed more tightly together and irregularly arranged

- Found in parts of the body where pulling forces are exerted in various directions

- Ex. Dermis of the skin, pericardium of the heart

TISSUE LEVEL OF ORGANIZATION

3. Elastic- Contains branching elastic fibers

that gives the tissue a yellow color

- Fibroblasts are present between the fibers

- Very strong and recoils to original shape after being stretched

- Ex. Lungs, arteries

Please bring out any piece of paper and prepare for a quiz..

GOOD LUCK!

QUESTION:

1. This type of connective tissue is found mainly on the umbilical cord

QUESTION:

2. How many arteries are found in the umbilical cord?

QUESTION:

3. What is the primary function of glandular epithelium?

QUESTION:

4. It may consist of a single cell or a group of cells that secrete substances into ducts, onto a surface, or into the blood.

QUESTION:

5. These are also called fat cells or adipose cells.

QUESTION:

6. Connective tissues which have bundles of collagen are regularly arranged in parallel patterns to provide great strength to tissues.

QUESTION:

7. Connective tissues which is very strong and recoils to original shape after being stretched.

QUESTION:

8. What are the substances secreted by endocrine glands?

QUESTION:

9. Combined with adipose tissue, they form the SUBCUTANEOUS LAYER of the skin.

QUESTION:

10. Connective tissues which are loosely intertwined between cells.

QUESTION:

11. This is a good insulator that reduces heat loss through the skin.

QUESTION:

12. Connective tissues which form all other types of connective tissue

QUESTION:

13. These are macrophages that can move throughout the tissues where inflammation and infection are located

QUESTION:

14. These are usually the most numerous type of connective tissue.

QUESTION:

15. These are cells that secrete antibodies.