Week 3 - Bowel Cancer + Shock

Question 1

Location of Baroreceptors

+ Function

Neurological Control

Answer 1

Carotid sinus - Efferent (CN IX)
Aortic Arch - Efferent (CN X)

Stretching of aortic baroreceptors causes increase in vagal nerve activity via projection to the NUCLEUS AMBIGUUS (in medulla). Also inhibits sympathetic activation. Leadin to decreased HR & BP.

Question 2

Low-pressure volume receptors in Atria

Types

Neurological Control

Answer 2

1. A receptors: activated by tension during atrial CONTRACTION.
2. B receptors activated by atria stretch during FILLING.

Question 3

Septic Shock

Pathophysiology

Answer 3

-

Gram (+) more common.

Question 4

Gastric Cancer

Answer 4

Intestinal
Pathogenesis: increased Wnt signalling (decreased APC, increased b-catenin).
H. pylori infection intiates.

Diffuse infiltrative type
Permeates stomach wall causes desmoplastic reaction (leather bottle).
Pathogenesis: Loss of E-cadherin (CDH1).

Wnt pathway:proliferation and differentiation of intestinal cells.

Question 5

Pancreatic Cancer

Answer 5

KRAS oncogene altered.
CDKN2A tumour suppressor inactivated.

Patho: ???
Trousseaus Sign of malignancy = migratory thrombophlebitis (arms typically).

Question 6

Colorectal Cancer

Answer 6

Wnt/b-catenin pathway

Question 7

Wnt Pathway

Answer 7

Role in embryonic development and adult tissue homeostasis.
- Proliferation - Apoptosis - Migration

B-Catenin is component of CADHERIN complex which is needed to activate Wnt pathway.