histology (skin) - part 2

sweat glands(eccrine)

Sweat gland

Myoepithelial cell

Sweat duct

Secretory cell

ECCRINE AND APOCRINE GANDS

Skin Glands

Structures of skin: hair follicle Invagination of

epidermis Hair contains keratin

and melanin Dermal papilla

Connective tissue invagination into bulb, has capillary network

Matrix Germinative layer

adjacent to dermal papilla

Also contains melanocytes

Sebaceous gland Secretion empties into

hair follicle Arrector pili muscle

Smooth muscle, inserts on hair follicle and base of epidermisbulb

(dermal papilla)

THE HAIR

The hair is formed of

Shaft: medulla, cortex and cuticle The hair follicle is formed of : Inner root sheath formed of: Cuticle ,Huxleys layer,Henles layer Outer root sheath: identical with

Malpighian Layer of epidermis Connective tissue sheath

Structures of skin: hair follicle

Dermal papilla

Arrector pili muscle

Sebaceous gland

Thick skin vs thin skin

Thick skin Palms and soles Thicker epidermis Hairless ,more sweat glands

Thin skin Everywhere else Thinner epidermis Hair, sebaceous And sweat glands

FINGER PRINTS

THE PANCREAS

The Pancreas

Exocrine part Stroma : thin C.T capsule

&trabeculae. Parencaima : pancreatic

acini ,lined with Pyramidal cells with apical

acidophilic zymogen granules and basal basophilic striation.

Secrete digestive enzymes via duct system starting by intercalated ducts.

Pancreatic acinus

PancreasIntercalated ducts &Centroacinar cells

Endocrine Pancreas

ISLETS OF LANGERHANS

Non capsolated anastomosing cords of cells separated by blood sinusoids

Alpha-cells 15-20um, prepheral Secrete glucacone 20 % stain pink with Gomori Beta –cells 10-15um, central in

position 60-75%, Stain blue with Gomori stain Secrete insulin

Delta cells 2% Secrete somatostatine which

supresses A,B cells and growth hormone

secretion PP cells 2% secrete pancreatic

polypeptide which is involved in protein and carbohydrate metabolism.

Ganglion cells Involved in nervous control of

islet functions.

http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Liver/Images/pan20he.jpg

Islets- glucagon

Islet- insulin

Islet-somatostatin

Cells of islets of langerhans

Immunohistochemical stain

β

δ

α

Islet of langerhans

Pancreas

Pancreas

DO YOU KNOW? ? Quiz

2. Where are the stem cells of the epidermis located?

A.

B.

C.

D.

E.

2. What is the name of the layers labeled (A) &(B) and (C)?

A.

B.

C.

D.

E.

3 .The structure at the pointer: A. is involved

in touch sensation

B. contains unmyelinated nerve endings

C. both A and B D. is involved in

vibratory sensation

E. none of the above

Thank youThank you