HISTOLOGY

Question 1

4 LAYERS of the GI TRACT:

Answer 1

innermost:
- MUCOSA
- SUBMUCOSA
- MUSCULARIS
- ADVENTITIA

Question 2

MUCOSA LAYER consists of

Answer 2

lining EPITHELIUM forming GLANDS and LAMINA PROPRIA (connective tissue between glands)
sitting on MUSCULARIS MUCOSAE (SMOOTH MUSCLE)

specialised for absorption and secretion

Question 3

GI TRACT EPITHELIUM type

Answer 3

SIMPLE COLUMNAR Epithelium

Question 4

EPITHELIUM type in the MOUTH

Answer 4

STRATIFIED SQUAMOUS Epithelium

Question 5

SUBMUCOSA layer

Answer 5

THICK layer of LOOSE CONNECTIVE TISSUE

• contains BLOOD VESSELS, LYMPHATIC VESSELS, NERVES

& submucosal plexus (ENS)

Question 6

MUSCULARIS PROPRIA

Answer 6

THICK LAYER of SMOOTH MUSCLE (for movements)

arranged in 2 layers:
INNER CIRCULAR layer,
OUTER LONGITUDINAL layer

• MYENTERIC PLEXUS (ENS) between circular and longitudinal layer

Question 7

OUTER LAYER of GI TRACT is..

Answer 7

EITHER ADVENTITIA or SEROSA

Serosa - SIGNLE layer epithelial cells (mesothelium) and underlying connective tissue

Adventitia - outer layer when it is abutting (touching or leaning on) another organ or the posterior abdominal wall - Adipose tissue