Organisation of Cells into Tissues and Organs Flashcards
What are the 3 major salivary glands?
Parotid, submandibular and sublingual glands. There are many smaller glands scattered in the oral mucosa.
What is the unusual feature of salivary glands?
The striated ducts.
What is the difference between ducts in most glands and striated ducts?
The duct only conveys the secretory product, but the striated ducts actually modify the saliva that is passing through them by pumping salt out of the fluid so that our saliva is hypotonic to blood.
State the 4 major layers of the digestive tract.
Mucosa - 3 parts - a. epithelium: sits on a basal lamina b. Lamina Propria: loose connective tissue c. Muscularis Mucosae: thin layer of smooth muscle.
Submucosa - loose connective tissue.
Muscularis Externa - two thick layers of smooth muscle, an inner
circular layer and an outer longitudinal layer.
Serosa or Adventitia - outer layer of connective tissue that either suspends the digestive tract or attaches to other organs.
What is protective mucosa made from? Give examples as well.
non- keratinized stratified squamous epithelium. Oral cavity, pharynx, oesophagus, anal canal.
What is secretory mucosa made from? Give examples as well.
Simple columnar epithelium with extensive tubular glands. Stomach.
What is absorptive mucosa made from? Give examples as well.
simple columnar epithelium with villi & tubular glands. Small intestine.
What is protective & absorptive mucosa made from? Give examples as well.
Simple columnar epithelium with tubular glands. Large intestine.
What is the nervous system in the digestive tract called?
Enteric nervous system. It has the same number of neurons as the spinal cord.
Where does the ENS receive input from?
The autonomic nervous system, but is capable of coordinating gut motility locally.
What is the name of the groups where most neurons live called?
Ganglia.
Where do most neurons in groups live?
Between the two muscle layers that make up the muscularis externa.
What do the goblet cells of the epithelium together with the submucosal glands (SM) in the trachea produce?
A viscous fluid that coats the surface of the airway, trapping particles that are then propelled out of the airway by the cilia.
What is the difference between bronchi and bronchioles?
Bronchi are large diameter airways and have hyaline cartilage in their wall. Bronchioles are smaller airways, have no cartilage and smooth muscle predominates in their wall.
The columnar cells of the epithelium tend to get shorter the further down the respiratory tree you go. Does gas exchange occur in these epithelia?
No.
