4. GIT tract- species comparison intro Flashcards
what is the digestive system?
organs groups as alimentary canal and accessory organs
Where does the alimentary canal run from and to and what are the segments?
Tube from lips to anus
- mouth
- pharynx
- oesophagus
- stomach
- small intestine
- large intestine
Name the 3 serous membrane cavities
- thoracic cavity
- abdominal cavity
- body wall enclosing these cavities
what facia lines the thoracic cavity?
endothoracic fascia
what fascia lines the abdominal cavity?
transversalis fascia
what does the body wall enclosing the cavities consist of?
- skin
- double layer fascia ( deep and superficial)
- muscles
- inner fascia
what type of serous membrane lines the abdominal cavity?
peritoneum
what epithelium makes up the serous membrane?
simple squamous epithelium
what is the epithelium of the serous membrane supported by to the underlying fascia?
connective tissue
What type of serous membrane lines the wall of the cavity?
parietal serosa
What type of serous membrane lines the organs?
visceral serosa
What is connecting serosa?
The ends of the serous membrane where it may bunch together slightly at the edges of organs
What does the serous membrane produce?
serous fluid (peitoneal fluid)
What is the function of serous membranes?
To stop adhesions among organs - smooth, moist so they don’t get stuck and can have free movement
What are the 3 types of peritoneum?
Viceral
Parietal
Connective
What is connecting peritoneum?
Double layered serosa connecting 2 peritoneum
What does the connecting peritoneum mostly connect?
Visceral and parietal peritoneum
What is connecting peritoneum also called depending on the area it is in?
mesentery
ligament
omenta
fold
What is the peritoneal cavity?
The cavity containing the organs in the abdomen
What is mesentery (connecting peritoneum)?
Connecting peritoneum between intestinal and reproductive tracts to the abdominal wall
What is ligament (connecting peritoneum)?
Connecting peritoneum between visceral and parietal peritoneum or between 2 visceral peritoneum
What is fold (connecting peritoneum)?
Connecting peritoneum between 2 visceral peritoneum
What is omenta (omentum) (connecting peritoneum)?
Connecting peritoneum between the stomach and abdominal organs or abdominal wall
What is the alimentary tract
Digestive tract from larynx/oesophagus to anus
Name the 4 layers of the alimentary tract
Tunica mucosa
Tunica submucosa
Tunica muscularis
Tunica serosa/adventitia
What/where is the tunica mucosa?
Next to the lumen, protected by a layer of mucous
What is the tunica submucosa?
dense connective tissue that may contain submucosal glands
e.g. blood, lymph vessels and Meissner’s plexus (ANS)
What is the tunica muscularis?
Smooth or skeletal muscle.
Inner layers orientated circularly, outer layers orientated longitudinally
Nerve plexus: myenteric (Auerbach’s) plexus (ANS)
What is the tunica serosa/adventitia?
Loose connective tissue. Special name for serosa: pleura, peritoneum etc
What is a plexus?
A network of nerves
What are the 3 layers within the tunica mucosa layer of the alimentary tract?
Laminae epithelialis mucosa
Lamina propria mucosa
Lamina muscularis mucosae
Describe the laminae epithelialis mucosa layer of the tunica mucosa
Surface epithelium resting on a basal membrane
Describe the lamina propria mucosa layer of the tunica mucosa
Layer of connective tissue (collagen, elastic and reticular fibres) immediately beneath the epithelium. There are mucosal glands, blood vessels and lymphoid structures
Describe the lamina muscularis mucosae layer of the tunica mucosa
Thin layers of smooth muscle, but not always present.
What is the difference between the tunica serosa/adventitia?
If organ is surrounded by other tissues, called tunica adventitia
If organ is suspended in the body cavity, called tunica serosa
What is tunica serosa covered with?
Simple squamous epithelium which is called mesothelium
Name the 3 regions of the oesophagus
Cervical
Thoracic
Abdominal
List the 4 layers of the oesophagus
Mucosa
Submucosa
Muscularis
Adventitia/serosa
is it tunica adventiva or serosa in the:
- cervical oesophageal region
- thoracic oesophageal region?
adventivia in cervical
serosa in thorax
what cells line the oesophagus?
stratified squamous epithelium
where does the oesophagus start and end?
pharanx to stomach
species differences of tunica muscularis of the oesohphagus?
- ruminants and dogs it i entirely skeletal muscle
- humans and chickens it is entirely smooth muscle
- hore and cat, distal third is smooth muscle, rest is skeletal
