GIT L1: Overview of GIT Flashcards
The GIT is an _______ muscular tube - about _____ m in an adult living human - called also digestive tract / gut / alimentary canal
open-ended; 4.5
Why does the mucus change in areas?
To stop infection..etc (different bacteria) due to the open-ended structures
What are the 6 major functions of the GIT (6 steps; 4 basic processes)?
- Ingestion
- Motility / propulsion
- Digestion
- Secretion
- Glands which secrete juices
- Absorption Get nutrients from
- Elimination (defecation)
What are the 4 layers of the GIT?
EXAM QUESTION
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
The GIT is _____ within open ended structure.
homogenous
What are 2 characteristics of mucosa?
- Has different layers
- Where secretion produced and absorption occur
What are 2 characteristics of submucosa?
- Maintain mucosa in a particular shape
- Bring blood from vessels and nutrients to the mucosa
What are 2 characteristics of muscularis externa?
- Muscles used to push food forward
- Help stomach to have a mechanical breakdown (digestion)
What is a characteristic of serosa?
Overs the whole tube
What are 4 functional types of epithelium?
- Protective
- Secretory
- Absorptive
- Absorptive/Protective
What are 4 examples of protective epithelium in the GIT wall?
- oral cavity
- pharynx
- oesophagus
- anal canal
What is an example of secretory epithelium in the GIT wall?
stomach
What is an example of absorptive epithelium in the GIT wall?
small intestine
What is an example of absorptive/protective epithelium in the GIT wall?
large intestine
What are 2 types of digestive motility?
- Peristalsis
- Segmentation
What is peristalsis?
EXAM QUESTION
Adjacent segments of the alimentary canal organs alternately contract and relax.
- Food is push FORWARD through the digestive tract (no digestion occurs)
- Very strong (hang upside down –> can still each against gravity)
What is segmentation?
EXAM QUESTION
Nonadjacent segments of the alimentary canal organs contract and relax.
- Food is moved FORWARD THAN BACKWARD
- MIX food with DIGESTIVE JUICES and help with ABSORPTION
What are 2 ways to regulate GIT functions?
EXAM QUESTION
- Involuntary
- Voluntary
What are long reflexes in the GIT triggered by? EXAM QUESTION
External stimuli (sight, smell, taste, thought of food) system needs to prepare food by producing gastric juices
What are short reflexes in the GIT triggered by? EXAM QUESTION
Internal stimuli (food inside month) –> chemoreceptors, osmoreceptors or mechanoreceptors
Pressure receptors activated when food is in the mouth