GI tract Flashcards
What are the 2 types of gut epithelia
Stratified Squamous
Specialised simple columnar epithelia
3 salivary glands
Parotid
Submandibular
Su lingual
Role of saliva
[3]
Digestion
Lubrication
Protection
How does saliva help with digestion
Contains enzymes that breakdown food
How does saliva help with lubrication
Moistens food, easier to chew and swallow
How does saliva help with protection
Saliva has properties to help defend against harmful bacteria
How does saliva help with taste
Takes taste molecules to receptors on the tongue
2 main types of glands
Exocrine glands
Endocrine glands
Exocrine gland
Secrete products into ducts
Endocrine gland
Release their products
Role of glands
Regulation
Protection
Digestion
Lubrication
What are the 3 parts of the pharynx
Nasopharynx
Oropharnyx
Laryngopharynx
How does saliva help with ph regulation
Neutralise acids so no tooth decay
What is a gland
Specialised organ that produce and release substances
How do glands help with regulation
ENDOCRINE
Maintain homeostasis
How do glands help with protection
EXOCRINE
produce mucus and sweat to protect the body
How do glands help with lubrication
Keep skin and hair lubricated, prevent dryness
How do glands help with digestion
Release enzymes to breakdown food
Steps of swallowing
Oral preparation
Oral transit
Initiation of the swallow reflex
Soft palate elevation
Oral preparation
Food placed in mouth
Chew and mix with saliva
Forms bolus
Bolus
Rounded mass of food
Oral transit
Tongue pushes bolus back
Positioned for swallow
Initiation of swallow reflex
Bolus in oropharynx trigger swallow reflex
Automatic + involuntary
Soft plate elevation
Nasal passage closed off to stop food entering nasal cavity
Specialised cells in the stomach
Goblet cells
Parietal cells
Chief cells
D cells
G cells
What do Goblet cells secrete
Mucus
Protect stomach lining
What do parietal cells secrete
Gastric acid
What do chief cells secrete
Pepsinogen
What do D cells secrete
Somatostatin
What do G cells secret
Gastrin
