1. BIOLOGICAL
SCIENCES
By:
MARIA KRISIA
FAE DELOS
REYES DE ASIS,
BSN-RN

2. 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

3. 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

5. 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

7. 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

8. 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

9. 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

10. TISSUE LEVEL OF
ORGANIZATION
3. Plasma cells – small cells that
develop from immune cells called Blymphocytes. 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.

11. 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.

12. 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

14. 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

17. TISSUE LEVEL OF
ORGANIZATION
MATURE CONNECTIVE TISSUE
LOOSE CONNECTIVE TISSUE
- Loosely intertwined between cells
1. 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

19. 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

21. 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

23. TISSUE LEVEL OF
ORGANIZATION
DENSE CONNECTIVE TISSUE
- More numerous thicker and denser
fibers, but fewer cells
1. 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

26. 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

28. 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

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

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

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

33. QUESTION:
3. What is the primary
function of glandular
epithelium?

34. 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.

35. QUESTION:
5. These are also
called fat cells or
adipose cells.

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

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

38. QUESTION:
8. What are the
substances secreted by
endocrine glands?

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

40. QUESTION:
10. Connective tissues
which are loosely
intertwined between
cells.

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

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

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

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

45. QUESTION:
15. These are cells
that secrete
antibodies.