Flashcards in ToB 4 Internal surfaces of the body Deck (79)
A mucous membrane
A serous membrane
What are the 3 main internal tubes which are lined with mucosae?
1) GI tract
2) Respiratory tract
3) Urinary tract
What does a normal mucosae consist of?
1) an epithelium lining the tube
2) a layer of connective tissue 'lamina propria'
In the GI tract, what does the mucosae consist of?
1) An epithelium lining the tube
2) A layer of connective tissue 'lamina propria'
3) A layer of smooth muscle 'muscularis mucosae'
Which of the mucosae and serosae line surfaces which are open to the exterior?
Describe a serous membrane:
Line body cavities which do not open to the exterior
Secrete a lubricating serum creating a friction-free environment
What does a serosae consist of?
A simple squamous epithelium which secretes a watery lubricating fluid
A thin layer of connective tissue (attaches epithelium to the tissues)
What is the name given to the inner membrane wall of a serosae?
What is a visceral wall?
It is the inner membrane of a serosae
What is the name given to the outer membrane wall of a serosae?
What is a parietal wall?
The outer membrane of a serosae
A fold of the peritoneum which attaches the posterior wall of the abdomen to the GI tract. Arteries and veins are included within it to supply the GI tract.
Name the 3 parts of the small intestine, in order:
Name the 4 layers of the gut wall:
3) Muscularis externae
In what layer of the gut wall can you find 'Peyer's patches'?
Within the lamina propria, in the mucosa
What type of epithelium is usually found throughout the gut wall?
Simple columnar epithelia
What is the gut wall mucosa made up of?
2) Lamina propria
3) Muscularis mucosae
In which layer of the gut wall are glands found?
What type of tissue is the submucosa?
In which layer of the gut wall can you find blood vessels?
In which layer of the gut wall are nerves contained?
What may the submucosa of the gut wall contain?
Describe the muscularis externae of the gut wall:
2 layers of muscle
encase the submucosa
inner circular layer
outer longitudinal layer
From which embryonic disk did the simple squamous epithelium of the serosa of the gut wall originate?
What causes connective tissue to often be a loose layer which can change shape?
Cells within connective tissue are not usually contiguous, because they produce so much extracellular material
The outer connective tissue of an organ/vessel/structure which is not encased by a serous membrane.
What organs/vessels/structures have an adventitia?
How could you describe the shape of the lumen of the oesophagus?
What type of epithelium is present in the oesophagus?
Non-keratinised stratified squamous
Why is the oesophagus the only part of the GI tract with an adventitia?
The rest of the GI tract is encased in the serous membrane 'peritoneum'
Describe the muscularis externae of the stomach:
3 layers of muscle
What are rugae?
Folds of gastric mucosa (form longitudinal ridges in an empty stomach)
What allows the rugae to change shape?
The submucosa is flexible due to the loose connective tissue
Describe plicae circulares:
Permanent crescent folds
of the villi to increase surface area
in the Jejunum of the small intestine
What type of epithelia is found in the jejunal mucosa?
Simple columnar epithelia
What type of epithelium is present in the large intestine?
Simple columnar epithelia
What are Peyer's patches?
Aggregations of lymphoid tissue
What 2 structures do the folds of Kerckring form (in the intestine)?
2) Crypts of Lieberkuhn
How is surface area increased in the intestines?
folds of Kerckring
villi and crypts of Lieberkuhn
Where are the goblet cells located in the intestines?
Within the crypts of Lieberkuhn
Where are the surface absorptive cells located in the intestines?
On the villi
What do surface epithelial cells in the large intestine absorb?
What is meant by the 'conducting portion of the respiratory tract'?
From the nasal cavity to the bronchioles
What is meant by the 'respiratory portion of the respiratory tract'?
From the respiratory bronchioles to the alveoli
Name the different parts of the respiratory tract:
What type of epithelia is makes up a serosae?
Simple squamous epithelia
What shape is the cartilage surrounding the trachea?
What type of cartilage surrounds the trachea?
What may happen to cartilage as part of the ageing process?
Turns to bone
What is the name of the muscle which seperates the trachea from the oesophagus?
Where is the trachealis muscle?
Between the trachea and the oesophagus
What type of membrane contains the trachealis muscle?
What is the first respiratory structure after the trachea that is not encased by cartilage?
What respiratory structures are encased by cartilage?
What keeps the bronchioles open (prevents from collapsing)?
Where does the epithelial cell transition occur in the repiratory tract? What does it transition from and to?
In the bronchi, as they decrease in size
From ciliated pseudostratified columnar, to ciliated simple cuboidal
What is the main function of the simple squamous epithelial cells which make up the alveolar and capillary walls?
Efficient gas exchange
What type of white blood cells line the alveolar surface, and why?
What type of alveolar cells are referred to as 'type I'?
What type of alveolar cells are referred to as 'type II'?
Why is it important for there to be cuboidal cells in the alveolar epithelium?
To secrete surfactant, for lubrication
What type of epithelial cells are present in the alveolar wall?
How long is the gas-exchange diffusion pathway from the alveoli into the red blood cells, approximately?
Why do macrophages line the alveolar surface?
To phagocytose microbes and dust
What happens to microbes and/or dust particles which get to the alveoli?
Phagocytosed by macrophages which line the alveolar surface
Alveoli are surrounded by a basketwork of what?
Capillaries and elastic fibres
What are the parts of the urinary tract?
Describe the shape of the ureter:
What type of epithelium lines the ureter?
Why is it important that the bladder epithelium is impermeable?
Urine is toxic, so must prevent reabsorption/leaks
What ensures that the bladder epithelium is impermeable?
Thick transitional epithelium
Intracellular tight junctions
Describe the shape of the urethral lumen:
Convoluted stellate lumen
What makes up the mucosa of the urethral wall?
What makes up the muscularis layer of the urethral wall?
What is the name of the outer membrane of the urethra?
Approximately how long is the male urethra?
Approximately how long is the female urethra?