Overview of the Alimentary Tract Flashcards
What is a carnivore?
- high energy content
- muscle, blood, adipose tissue
- easily digested
- short, simple digestive tract
What is a herbivore?
- energy from plant material in form of carbohydrates which cannot be broken down by enzymes produced by animal itself
- large microbe containing chambers in the digestive tract
What is an omnivore?
- plant and animal origin - large species variation
Alimentary system or gastrointestinal system consists of what?
- headgut
- foregut
- midgut (small intestine)
- mid/hindgut (large intestine)
What components and glandular organs are associated with the headgut?
- mouth
- pharynx
- oesophagus
- salivary glands
what components and glandular organs are associated with the foregut?
- stomach
- liver
- gall bladder
- pancreas
What are the components of the midgut (small intestine)?
- duodenum
- jejunum
- ilium
What are the components of the midgut/hindgut?
- caecum - mid
- ascending colon - mid
- transverse colon - mid/hind
- descending colon - hind
- rectum - hind
What are the 4 major functions of the alimentary system?
- motility
- secretion
- digestion
- absorption
What is motility?
- the movements of the alimentary system that mid and circulate its contents and propels these along its length
What is secretion?
- associated glands secrete water and other substances into the tract
What is digestion?
- large ingested molecules are chemically degraded to produce smaller molecules that cab be absorbed across the wall of the tract
What is absorption?
- nutrient molecules absorbed by the GIT and enter the bloodstream
What are the 4 layers of the gastrointestinal tract?
- mucosa
- submucosa
- muscularis externa
- serosa (adventitia)
What’s contained within the mucosa?
- muscularis mucosa
- lamina propria
- epithelium
What’s contained within the muscularis externa?
- circular muscle
- longitudinal muscle
What are the other components of the GI tract layers?
- lumen
- villus
- lymph node
- submucosal plexus
- myenteric plexus
- glands in the submucosa
What is prehension?
- act of grasping
what is mastication?
- process by which food is crushed and ground down by the teeth
Describe the structure of the oesophagus
- lined by stratified squamous epithelia
- longitudinally arranged smooth muscle of the muscularis mucosae varies in amount from anterior to posterior
- muscularis externa is entirely skeletal muscle in ruminant with transmission in smooth muscle at different points in other species
- mucous or mixed glands present in the submucosa again species variation
Give 4 examples of salivary glands:
- parotid
- mandibular
- sublingual
- zygomatic
What components make up the simple stomach? (dog and cat)
- cardiac region
- fundus
- body
- pyloric region
= glandular mucosa
What is a composite simple stomach?
- stomach of the horse and pig
- possesses a small area of non-glandular mucosa as well as glandular mucosa
What is the composite complex stomach?
- found in ruminants
- 4 chambers
1. rumen
2. reticulum
= non glandular mucosa
3. omasum
4. abomasum = glandular mucosa