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2.3.5. Gastrointestinal System > Purpose of the Gut > Flashcards

Flashcards in Purpose of the Gut Deck (44)
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1
Q

What type of surface is the GI tract?

A

External = epithelial lined

2
Q

What other connections are made to the gut?

A

Salivary glands, liver, gallbladder, pancreas (exocrine)

3
Q

Why do we need water in the gut lumen?

A

For chemical reactions to occur

4
Q

What is the purpose of sphincters?

A

Divide sections to have functional areas (upper oesophageal sphincter, lower oesophageal, pyloric sphincter, ilieo-secal sphincter, anal sphincter)

5
Q

What is the enteric nervous system?

A

Or the intrinsic nervous system = main divisions of the nervous system and consists of a mesh-like system of neurones that governs the function of the GI tract

6
Q

What is the longest part of the gut?

A

SI = Jejunum, ileum – where most of the absorption takes place

7
Q

What is the overall purpose of the gut?

A

Get food to – monosaccharides, small peptides, AA, FA, glycerol

Absorb water, vits, minerals

Expel waste produces that were not absorbed/not needed

8
Q

What areas of the GI allow for mechanical disruption of food?

A

Mouth/teeth

Stomach = contractions liquify food to chyme

9
Q

What enables the stomach to expand?

A

Rugae – temporary folds

10
Q

What is the function of the colon?

A

Temp storage facility

11
Q

Briefly outline the chemical digestion of the GI tract

A

Saliva = amylase, lipase

Stomach = acid, pepsin

Duodenum/jejunum = bile, exocrine pancreas

12
Q

What is the function of the brush border of the SI?

A

Increase surface area

13
Q

Briefly outline how the GI tract prevents entry of pathogens?

A

Saliva, HCL, liver (kupffer cells), peyers patches (lymphoid follicles, mucosa)

14
Q

Outline the types of movement in the GI tract

A

Peristalsis = successive waves of involuntary contraction of longitudinal muscles

Segmentation = contractions of circular muscles

Haustral shunting = One haustrum distends as it fills with chyme, which stimulates muscles to contract, pushing the contents to the next haustrum

Mass movement = forcible peristaltic movements of short duration, 3-4 times a day

15
Q

What features aid absorption in the gut?

A

Length

Folds

Villi/microvilli

16
Q

What are the broad functions of the mouth?

A

Physical breakdown

Digestive enzymes released

Infection control

17
Q

What is the broad function of the stomach?

A

Storage

Produce chyme

Infection control

Secrete intrinsic factor (vit B12)

18
Q

What is the function of the UOS vs the LOS?

A

UOS = prevents air from entering the GI tract (weaker)

LOS = helps prevent reflux into oesophagus

19
Q

What is the broad function of the duodenum?

A

Neutralisation/osmotic stabilisation of chyme

Pancreatic secretions

Bile is added

20
Q

What are the broad functions of the jejunum/ileum?

A

final digestion

Nutrient absorption

Water/electrolyte absorption

Bile recirculation

B12 absorption

21
Q

What drives water absorption in the large bowel?

A

Presence of aquaporins

22
Q

What are the broad functions of the large bowel?

A

Final water/electrolyte absorption

23
Q

Where is the largest amount of water absorbed in the GI tract?

A

SI

24
Q

What is the peritoneal cavity?

A

Potential space between the parietal peritoneum and visceral peritoneum

25
Q

What is the parietal peritoneum?

A

Surround the abdominal wall

26
Q

What is the visceral peritoneum?

A

Surround the internal organs

27
Q

What is the greater omentum?

A

Large apron-like fold of visceral peritoneum that hands down from the stomach, passes in front of the SI and doubles back to ascend to the transverse colon before reaching the posterior abdominal wall

28
Q

What is the difference between the abdominal cavity and the peritoneal cavity?

A

P = cavity within the abdominal cavity - space between the parietal and visceral peritoneum, see-through

A = space bounded by the abdominal walls, diaphragm and pelvis

29
Q

What is in the peritoneal cavity?

A

Nothing, apart from a small amount of fluid it secrets for lubrication

However it is a potential space

30
Q

What are retro-peritoneal viscera?

A

Lie behind the peritoneal viscera with only there anterior surface in contact with the peritoneal but not enveloped

E.g. Kidneys

31
Q

What is intra-peritoneal?

A

Inside the peritoneum

32
Q

What is the mesentery?

A

Fold of peritoneum which attaches the stomach, SI, pancreas, spleen to the posterior abdominal wall, that allows a conduit of venous drainage, blood supply

33
Q

What are the muscles of the abdominal wall?

A

External oblique abdominal muscle.

Internal oblique abdominal muscle.

Rectus abdominis.

Transverse abdominal muscle.

Pyramidalis muscle.

34
Q

What does the transverse colon divide?

A

Divides the peritoneum into the supracolic and infracolic regions

35
Q

What forms the rectus sheath?

A

Aponeuroses of the transverse abdominal and the external and internal oblique muscles

36
Q

What are the paracolic gutters?

A

Space between the colon and the abdo wall

37
Q

What is the pouch of douglus (recto-uterine)?

A

Extension of the peritoneal cavity between the rectum and back wall of the uterus

Only females

Deepest point in the peritoneal cavity

38
Q

What is the vesico-uterine pouch?

A

Shallower pouch formed by peritoneum over the uterus and bladder

In females

39
Q

What is the recto-vesicle pouch?

A

In men

Lies between the urinary bladder and the rectum

40
Q

What are the quadrants of the abdo?

A

Lines = zifisternum to pubis (midline) + one side to another through the naval

Quadrants = RU, RL, LU, LL

41
Q

What are the 9 regions of the abdo?

A

Lines = Midclavicular line each side, subcostal line (under costal cartilage), transtubecular line through iliac tubercles

Right/left hypocondrial (below anterior ribs) (top corners)

Right/left lumbar area (ouside middle)

Right/left inguinal regions (iliac fossa) (bottom corners)

Midline zones = Epigastric, umbilical, suprapubic

42
Q

What are the layers of the anterolateal abdo wall?

A

Skin

Superficial fasica

Investing facia

Abdo muscles = external oblique, internal oblique, transverse abdominis, rectus abdominis

Endoabdominal fascia

Extraperitoneal (fascia) fat

Peritoneum – parietal + visceral

43
Q

How does the innervation of the peritoneum affect pain?

A

Parietal = somatic afferent fibres = well-localised pain

Visceral = visceral afferent fibres = poorly localised (referred pain)

44
Q

What regions are the stomach divided into?

A

Cardiac region

Fundus

body

Pyloric region (antrum and canal)