The structure and main function of epidermis, vascular endothelium, enterocytes and hepatocytes Flashcards
LO 2 Outline the structure and main function of epidermis, vascular endothelium, enterocytes and hepatocytes
How may layers does the EPIDERMIS have?
Multiple
STRATIFIED EPITHELIUM
What is the term used to describe the cornification of the top layers of the EPITHELIUM?
Keratinisation
What is the top layer of the EPIDERMIS known as?
STRATUM CORNEUM
In the epidermis what is the basement bordered with ?
DERMIS
What is the VASCULAR ENDOTHELIUM?
Epithelium that lines the insides of vessels in vascular and lymphatic lining epithelium
What comprises the TUNIA INTIMA of the VASCULAR ENDOTHELIUM?
- Simple squamous epithelial cells and the basement membrane plus smooth muscle form the TUNICA INTIMA
- ENDOTHELIAL cells are in direct contact with the blood
How do nutrients etc. pass through the ENDOTHELIUM?
PERMEABILITY between the squamous endothelial cells can be regulated.
Re: ENDOTHELIAL CELLS what is a FENESTRATION?
A pore to allow the passage of nutrients and for the vessel to be permeable
Re: ENDOTHELIAL CELLS what does SINUSOIDAL mean?
Large gaps to allow the passage of nutrients
What is TRANSCYTOSIS?
The process of ENDO- and EXO-CYSTOSING products through the ENDOTHELIAL CELL
What is an ENTEROCYTE?
SIMPLE COLUMNAR EPITHELIUM that lines the ILEUM and COLON
Where can both VILLI and CRYPTS (formed by ENTEROCYTES) be found?
Both ILEUM and COLON
Where can VILLI (formed by ENTEROCYTES) be found?
ILEUM only
Are the VILLI absorptive OR secretory?
ABSORPTIVE
Are the CRYPTS absorptive or secretory?
SECRETORY
What kind of cells are ENTEROCYTES?
EPITHELIAL
How are ENTEROCYTES joined?
By SELECTIVELY PERMEABLE TIGHT JUNCTIONS
The ENTEROCYTES have ___________
that form the brush border
SHORT CILIA
Immature enterocytes start in the __________ and mature as they move up the _________, becoming more _________. Until they slough off into the _________.
- CRYPT
- VILLI
- MATURE
- LUMEN
Enterocytes absorb
Water and electrolyes
Carbs
Proteins
Fat
What percentage of the liver is HEPATOCYTES?
80%
What is the HEPATIC PORTAL VEIN?
A vessel that delivers blood to the liver from the GI tract
Name the feature of hepatocytes that increased absorption?
MICROVILLI
What are SINUSOIDS?
Blood vessels within LIVER LOBULES
What are LIVER LOBULES?
Groups of hepatocytes formed into hexagonal shapes
What type of blood do SINUSOIDS receive?
Both venous and arterial.
Venous to bring nutrients for storage and metabolism and also arterial to fuel the hepatocytes.
