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Flashcards in ToB 4 Internal surfaces of the body Deck (79)
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1
Q

Define mucosae:

A

A mucous membrane

2
Q

Define serosae:

A

A serous membrane

3
Q

What are the 3 main internal tubes which are lined with mucosae?

A

1) GI tract
2) Respiratory tract
3) Urinary tract

4
Q

What does a normal mucosae consist of?

A

1) an epithelium lining the tube

2) a layer of connective tissue ‘lamina propria’

5
Q

In the GI tract, what does the mucosae consist of?

A

1) An epithelium lining the tube
2) A layer of connective tissue ‘lamina propria’
3) A layer of smooth muscle ‘muscularis mucosae’

6
Q

Which of the mucosae and serosae line surfaces which are open to the exterior?

A

The mucosae

7
Q

Describe a serous membrane:

A

Thin
2-part membrane
Line body cavities which do not open to the exterior
Secrete a lubricating serum creating a friction-free environment

8
Q

What does a serosae consist of?

A

A simple squamous epithelium which secretes a watery lubricating fluid
A thin layer of connective tissue (attaches epithelium to the tissues)

9
Q

What is the name given to the inner membrane wall of a serosae?

A

Visceral wall

10
Q

What is a visceral wall?

A

It is the inner membrane of a serosae

11
Q

What is the name given to the outer membrane wall of a serosae?

A

Parietal wall

12
Q

What is a parietal wall?

A

The outer membrane of a serosae

13
Q

Define mesentery:

A

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.

14
Q

Name the 3 parts of the small intestine, in order:

A

1) Duodenum
2) Jejunum
3) Ileum

15
Q

Name the 4 layers of the gut wall:

A

1) Mucosa
2) Submucosa
3) Muscularis externae
4) Serosa

16
Q

In what layer of the gut wall can you find ‘Peyer’s patches’?

A

Within the lamina propria, in the mucosa

17
Q

What type of epithelium is usually found throughout the gut wall?

A

Simple columnar epithelia

18
Q

What is the gut wall mucosa made up of?

A

1) Epithelium
2) Lamina propria
3) Muscularis mucosae

19
Q

In which layer of the gut wall are glands found?

A

Submucosa

20
Q

What type of tissue is the submucosa?

A

Connective tissue

21
Q

In which layer of the gut wall can you find blood vessels?

A

Submucosa

22
Q

In which layer of the gut wall are nerves contained?

A

Submucosa

23
Q

What may the submucosa of the gut wall contain?

A

Glands
Arteries
Veins
Nerves

24
Q

Describe the muscularis externae of the gut wall:

A
2 layers of muscle 
encase the submucosa
inner circular layer
outer longitudinal layer
generates peristalsis
25
Q

From which embryonic disk did the simple squamous epithelium of the serosa of the gut wall originate?

A

Mesoderm

26
Q

What causes connective tissue to often be a loose layer which can change shape?

A

Cells within connective tissue are not usually contiguous, because they produce so much extracellular material

27
Q

Define adventitia:

A

The outer connective tissue of an organ/vessel/structure which is not encased by a serous membrane.

28
Q

What organs/vessels/structures have an adventitia?

A
Oesophagus
Ureter
Blood vessels
Renal pelvis
Ductus deferens
Seminal glands
29
Q

How could you describe the shape of the lumen of the oesophagus?

A

Convoluted tube

30
Q

What type of epithelium is present in the oesophagus?

A

Non-keratinised stratified squamous

31
Q

Why is the oesophagus the only part of the GI tract with an adventitia?

A

The rest of the GI tract is encased in the serous membrane ‘peritoneum’

32
Q

Describe the muscularis externae of the stomach:

A

3 layers of muscle
oblique
circular
longitudinal

33
Q

What are rugae?

A

Folds of gastric mucosa (form longitudinal ridges in an empty stomach)

34
Q

What allows the rugae to change shape?

A

The submucosa is flexible due to the loose connective tissue

35
Q

Describe plicae circulares:

A

Permanent crescent folds
of the villi to increase surface area
in the Jejunum of the small intestine

36
Q

What type of epithelia is found in the jejunal mucosa?

A

Simple columnar epithelia

37
Q

What type of epithelium is present in the large intestine?

A

Simple columnar epithelia

38
Q

What are Peyer’s patches?

A

Aggregations of lymphoid tissue

39
Q

What 2 structures do the folds of Kerckring form (in the intestine)?

A

1) Villi

2) Crypts of Lieberkuhn

40
Q

How is surface area increased in the intestines?

A

folds of Kerckring
villi and crypts of Lieberkuhn
microvilli

41
Q

Where are the goblet cells located in the intestines?

A

Within the crypts of Lieberkuhn

42
Q

Where are the surface absorptive cells located in the intestines?

A

On the villi

43
Q

What do surface epithelial cells in the large intestine absorb?

A

Water

Electrolytes

44
Q

What is meant by the ‘conducting portion of the respiratory tract’?

A

From the nasal cavity to the bronchioles

45
Q

What is meant by the ‘respiratory portion of the respiratory tract’?

A

From the respiratory bronchioles to the alveoli

46
Q

Name the different parts of the respiratory tract:

A
Nasal cavity
Nasopharynx
Oropharynx
Larynx
Trachea
Bronchi
Bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli
47
Q

What type of epithelia is makes up a serosae?

A

Simple squamous epithelia

48
Q

What shape is the cartilage surrounding the trachea?

A

C-shaped

49
Q

What type of cartilage surrounds the trachea?

A

Hyaline cartilage

50
Q

What may happen to cartilage as part of the ageing process?

A

Turns to bone

51
Q

What is the name of the muscle which seperates the trachea from the oesophagus?

A

Trachealis muscle

52
Q

Where is the trachealis muscle?

A

Between the trachea and the oesophagus

53
Q

What type of membrane contains the trachealis muscle?

A

Fibroelastic membrane

54
Q

What is the first respiratory structure after the trachea that is not encased by cartilage?

A

Bronchioles

55
Q

What respiratory structures are encased by cartilage?

A

Trachea

Bronchi

56
Q

What keeps the bronchioles open (prevents from collapsing)?

A

Surrounding alveoli

57
Q

Where does the epithelial cell transition occur in the repiratory tract? What does it transition from and to?

A

In the bronchi, as they decrease in size

From ciliated pseudostratified columnar, to ciliated simple cuboidal

58
Q

What is the main function of the simple squamous epithelial cells which make up the alveolar and capillary walls?

A

Efficient gas exchange

59
Q

What type of white blood cells line the alveolar surface, and why?

A

Macrophages

60
Q

What type of alveolar cells are referred to as ‘type I’?

A

Squamous

61
Q

What type of alveolar cells are referred to as ‘type II’?

A

Cuboidal

62
Q

Why is it important for there to be cuboidal cells in the alveolar epithelium?

A

To secrete surfactant, for lubrication

63
Q

What type of epithelial cells are present in the alveolar wall?

A

Simple squamous

Simple cuboidal

64
Q

How long is the gas-exchange diffusion pathway from the alveoli into the red blood cells, approximately?

A

200 nm

65
Q

Why do macrophages line the alveolar surface?

A

To phagocytose microbes and dust

66
Q

What happens to microbes and/or dust particles which get to the alveoli?

A

Phagocytosed by macrophages which line the alveolar surface

67
Q

Alveoli are surrounded by a basketwork of what?

A

Capillaries and elastic fibres

68
Q

What are the parts of the urinary tract?

A

Kidney
Ureter
Bladder
Urethra

69
Q

Describe the shape of the ureter:

A

Convoluted tube

70
Q

What type of epithelium lines the ureter?

A

Transitional epithelia

71
Q

Why is it important that the bladder epithelium is impermeable?

A

Urine is toxic, so must prevent reabsorption/leaks

72
Q

What ensures that the bladder epithelium is impermeable?

A

Thick transitional epithelium

Intracellular tight junctions

73
Q

Describe the shape of the urethral lumen:

A

Convoluted stellate lumen

74
Q

What makes up the mucosa of the urethral wall?

A

Transitional epithelium

Lamina propria

75
Q

What makes up the muscularis layer of the urethral wall?

A

Inner longitudinal

Outer circular

76
Q

What is the name of the outer membrane of the urethra?

A

Adventitia

77
Q

Approximately how long is the male urethra?

A

20 cm

78
Q

Approximately how long is the female urethra?

A

3-4 cm

79
Q

What type of epithelium is present in the penile urethra?

A

Stratified columnar epithelium