Digestion and Excretion Flashcards
What happens to the bile salts once they’ve emulsified the fats?
- They are excreted in faeces
- They are broken down in the Ileum
- They are reabsorbed in the Ileum then broken down by the liver
- They are reabsorbed and reused by the liver for bile
- They react with the fat and remain in contact with it until it is deposited in adipose tissues
4.They are reabsorbed and reused by the liver for bile
What enzyme normally breaks down triglyceride in the blood? A.Beta oxidase B.HMG-CoA reductase C.Lipoprotein lipase D.Pancreatic lipase E.Phospholipase A2
C.Lipoprotein lipase
The action of histamine exemplifies what kind of signalling? A.Autocrine B.Endocrine C.Exocrine D.Neuroendocrine E.Paracrine
E.Paracrine
A man is stabbed and develops paleness, fatigue and loss of weight. What is the most likely cause of his symptoms?
- Septicaemia
- Vitamin B12 malabsorption
- Haemorrhagic anaemia
- Infected wound
- Aplastic anaemia
2.Vitamin B12 malabsorption
Angiotensin 11 is synthesised and released from which structure? A.Adrenal cortex B.Anterior pituitary C.Hypothalamus D.Kidney E.Posterior pituitary
A.Adrenal cortex
Which of the following cells within gastric pits release intrinsic factor? A) Chief cells B) Parietal cells C) D cells D) G cells
B) Parietal cells
Which of the following cells are not found in gastric pits located in the fundus of the stomach? (more than one) A) Chief cells B) Parietal cells C) D cells D) G cells
C) D cells
D) G cells
Which of the following statements relating to gastric acid release is/are true? (more than one)
A) Gastric acid is released in response primarily to proteins arriving within the stomach
B) Gastrin is an important paracrine mediator of gastric acid release
C) The parasympathetic nervous system can increase gastric acid release indirectly via gastrin
D) H2 receptor agonists are used as antacids in the treatment of stomach ulcers
A) Gastric acid is released in response primarily to proteins arriving within the stomach
C) The parasympathetic nervous system can increase gastric acid release indirectly via gastrin
Which of the following statements relating to gastric emptying is correct?
A) Gastric emptying is controlled only by the autonomic nervous system
B) An increase in osmolarity within the duodenum speeds up gastric emptying
C) Gastric emptying is controlled mainly by the release of gastrin and somatostatin from the stomach mucosa
D) Gastric emptying is influenced primarily by regulators released from the duodenum, which are mainly inhibitory
D) Gastric emptying is influenced primarily by regulators released from the duodenum, which are mainly inhibitory
Which of the following statements relating to absorption is correct?
A) Most nutrients are absorbed across the membranes of GI epithelial cells by passive transport
B) Chemical digestion by secreted enzymes within the GI lumen is sufficient to produce molecules that are small enough to be absorbed
C) Lipids are absorbed from the GI lumen into GI epithelial cells in the form of chylomicrons
D) Amino acids rely on active secondary transport to cross the intestinal epithelium
C) Lipids are absorbed from the GI lumen into GI epithelial cells in the form of chylomicrons
Which of the following statements is correct?
A) The gall bladder synthesises and stores bile between meals
B) The hormones secretin and CCK promote pancreatic secretions
C) Bile salts are recycled via the enterohepatic circulation
D) Pancreatic and biliary secretions are stimulated by an increase in pH within the duodenum
B) The hormones secretin and CCK promote pancreatic secretions
C) Bile salts are recycled via the enterohepatic circulation
Which of the following describes the effects of statins on cholesterol metabolism?
A) Statins inhibit the synthesis of cholesterol within the liver
B) Statins inhibit the absorption of cholesterol from the GI tract
C) Statins upregulate LDL receptors in liver cells
D) Statins increase LDL levels
A) Statins inhibit the synthesis of cholesterol within the liver
C) Statins upregulate LDL receptors in liver cells
What secretes the enzyme that normally breaks down fat in the intestine?
A. Gall bladder B. Liver C. Pancreas D. Small intestine E. Stomach
Answer: C
Learning point: Endo/Exocrine secretions in the GI tract
- A baby is identified as having a genetic disorder which interferes with normal cholesterol production.
What biological molecules are dependent on this compound for synthesis?
A. Nucleic acids B. Polypeptides C. Polysaccharides D. Steroids E. Triglycerides
Answer: D
Learning point: Steroid synthesis
- The kidney secretes a protein that triggers a cascade which regulates blood sodium concentration and blood pressure.
What is the name of this protein?
A. Angiotensin II B. Angiotensinogen C. Erythropoietin D. Renin E. Vasopressin
Answer: D
Learning point: function of the kidney
- A fit and healthy 21 year old male Medical Science student with normal kidneys decreases his intake of dietary sodium by half over a period of two months.
Which of the following would be expected to be increased in response to this restriction of dietary sodium?
A. Arterial pressure B. Extracellular fluid volume C. Release of Atrial Natriuretic Peptide (ANP) D. Release of renin E. Sodium excretion
Answer: D
Learning Point: Fluid Homeostasis
- A 25 year old man suffers from a stab wound in the abdomen, requiring a removal of 150 cm of terminal ileum. Two years after the surgery, he complains of increasing malaise and watery diarrhoea. He reports eating a normal and unrestricted diet. A diagnosis of anaemia is made.
What is the most likely cause of his anaemia?
A. Folate malabsorption B. Impaired secretion of intrinsic factor (IF) C. Iron deficiency D. Malabsorption of IF-B12 complex E. Pancreatic insufficiency
Answer: D
Learning Point: Absorption in the GI tract
What is the order of the layers of the stomach?
A) Serosa, adventitia, muscularis propria, submucosa, mucosa
B) Serosa, muscularis propria, mucosa, submucosa
C) Mucosa, Muscularis propria, Serosa, Adventitia
D) Serosa, muscularis propria, adventitia, submucosa, mucosa
A) Serosa, adventitia, muscularis propria, submucosa, mucosa
Which cell secretes HCL and IF
Parietal
Which cells secretes pepsinogen and gastric lipase
chief
G cells secrete what?
gastrin
Which cells secrete somatostatin?
D cell
ECL cells secrete what?
Histamine
What is the order of the small intestine? A) Duodenum, Ileum, Jejunum B) Duodenum, Jejunum, Ileum C) Jejunum, Ileum, Duodenum D) Ileum, Jejunum, Duodenum
A) Duodenum, Ileum, Jejunum
Which nerve innervates the stomach? A) Iliac B) Gastric C) Sciatic D) Vagus
D) Vagus
Fill in the blank: the duodenum has broad villi which contain -------- glands, to produce an alkaline substance to neutralise chyme. A) Bartolin B) Seminiferous C) Brunners D) Acinar
C) Brunners
What is the main function of the colon?
reabsorption of water and nutrients
What stimulates the cephalic phase of gastric digestion?
A) Sensory receptors- e.g. sight or smell of food
B) Protein in the duodenum
C) Somatostatin
D) Gastrin
A) Sensory receptors- e.g. sight or smell of food
What stimulates the gastric phase of gastric digestion?
A) Sensory receptors- e.g. sight or smell of food
B) Protein in the duodenum
C) Somatostatin
D) Gastrin
D) Gastrin
What stimulates the intestinal phase of gastric digestion? (2 answers)
A) Sensory receptors- e.g. sight or smell of food
B) Protein in the duodenum
C) Somatostatin
D) Gastrin
B) Protein in the duodenum
C) Somatostatin
Which of these is not involved in mechanical digestion? A) oesophageal peristalsis B) retropulsion C) distention D) antral peristalsis
A) oesophageal peristalsis
What emulsifies fats in the duodenum? A) Chylomicrons B) Micelles C) Bile salts D) Gall bladder
C) Bile salts
What constitutes a micelle? A) fat droplets B) fat droplets + triglycerides C) fat droplets + monoglycerides D) fat droplets + diglycerides
C) fat droplets + monoglycerides
How do fats enter the cells of the small intestine? A) Facilitated diffusion B) Simple diffusion C) Active transport D) Secondary active transport with Na+ E) Secondary active transport with H+
B) Simple diffusion
How do glucose + galactose enter the cells of the small intestine? A) Facilitated diffusion B) Simple diffusion C) Active transport D) Secondary active transport with Na+ E) Secondary active transport with H+
D) Secondary active transport with Na+
How does fructose enter the cells of the small intestine? A) Facilitated diffusion B) Simple diffusion C) Active transport D) Secondary active transport with Na+ E) Secondary active transport with H+
A) Facilitated diffusion
How do amino acids enter the cells of the small intestine? A) Facilitated diffusion B) Simple diffusion C) Active transport D) Secondary active transport with Na+ E) Secondary active transport with H+
D) Secondary active transport with Na+
How do dipeptides + tripeptides enter the cells of the small intestine? A) Facilitated diffusion B) Simple diffusion C) Active transport D) Secondary active transport with Na+ E) Secondary active transport with H+
E) Secondary active transport with H+
Which pathway produces cholesterol? A) Gastric B) Glycolysis C) Mevalonate D) De novo synthesis
C) Mevalonate
Which enzyme do statins effect? A) Lipase B) Mevalonic Acid Reductase C) Acetyl CoA Reductase D) HMG-CoA Reducatase
D) HMG-CoA Reducatase
What is the initial precursor for cholesterol? A) HMG-CoA B) Acetyl CoA C) LDL D) HDL
B) Acetyl CoA
Why do statins work to reduce cholesterol?
Because they inhibit HMG CoA Reductase which is the enzyme needed to convert HMG CoA into mevalonic acid and into cholesterol.
What is an atheroscelrotic plaque caused by?
Accumulation of LDL
What is the order of the structures of the nephron?
A) Bowmans Capsule, DCT, Loop of Henle, PCT, Collecting Duct
B) Loop of henle, PCT, DCT, collecting duct
C) Bowmans capsule, PCT, loop of henle, DCT, collecting duct
C) Bowmans capsule, PCT, loop of henle, DCT, collecting duct
If a lady has proteins present in their urine, which could this not indicate out of the following? A) she's pregnant B) she's got a fever C) she's got high blood pressure D) she's got high GFR
B) she’s got a fever
What causes frothy urine? A) too much HCO3 B) proteinuria C) Dyspnea D) Alkalosis
B) proteinuria
What is the order (from outside in) of kidney layers A) cortex, medulla, pelvis B) pelvis, cortex, medulla C) Cortex, pelvis, medulla oblongata D) cortex, medulla oblongata, pelvis
A) cortex, medulla, pelvis
Which of these is not a part of the renal corpuscle? A) Basal Lamina B) Glomerulus C) Afferent Arteriole D) Bowmans Capsule
C) Afferent Arteriole
What is the epithelium lining the PCT?
Cuboidal (with brush border)
What organelle is particularly present in the PCT cells? A) Chloroplasts B) Rough ER C) Golgi Apparatus D) Mitochondria
D) Mitochondria
Which of these is not a function of the PCT?
A) Reabsorption of glucose, amino acids and ions
B) Secretion of some toxins & urea
C) Reabsorption of H+
D) Recovery of bicarbonate ions
C) Reabsorption of H+
what are the two types of loops (of henle)
Juxtamedullary and Cortical
Roughly, on average, how much urine do kidneys form each minute? A) 115 ml/min B) 2 l/min C) 50 ml/min D) 500 ml/min
A) 115 ml/min
Diabetes is an example of a condition which typically has:
A) too high GFR
B) too low GFR
C) No GFR
A) too high GFR
If GFR is too low then…..
A) ….filtrate moves too quickly and is not reabsorbed
B) ….filtrate backs up to the kidneys
C) ….filtrate moves too slowly and too much is reabsorbed
D) ….Blood pressure is too low
C) ….filtrate moves too slowly and too much is reabsorbed
Which of these corresponds to a GFR control system which causes vasoconstriction/dilation of the afferent arteriole in response to BP
A)Tubuloglomerular Feedback
B)Sympathetic innervation
C)Myogenic autoregulation
C)Myogenic autoregulation
Which of these corresponds to a GFR control system which uses macula densa cells
A)Tubuloglomerular Feedback
B)Sympathetic innervation
C)Myogenic autoregulation
A)Tubuloglomerular Feedback
What is the role of a macula densa cell?
A) Monitor Na+ and control GFR
B) Monitor osmolality in the collecting duct
C) Control the vasodilation/constriction of the nephron
D) Increase ADH secretion
A) Monitor Na+ and control GFR
Which of these corresponds to a GFR control system which effects the glomerular capillary vasoconstriction/dilation
A)Tubuloglomerular Feedback
B)Sympathetic innervation
C)Myogenic autoregulation
B)Sympathetic innervation
What effect does vasopressin have? A) Increases calcium reabsorption B) Stimulates production of aquaporins C) Natriuresis D) Increases GFR
B) Stimulates production of aquaporins
Describe the effect of ANP….
Decreases blood Na-
Decreasing blood pressure and volume
–> by counteracting ang 2
Where is aldosterone released from? A) the hypothalamus B) the anterior pituitary C) the kidney D) the adrenal cortex
D) the adrenal cortex
Which structures are the principle detectors for RAAS A) Macula Densa cells B) Renal corpuscle C) Juxta-glomerular D) Granular cells
C) Juxta-glomerular
Where would ACE inhibitors intervene? A) HMG-CoA --> Mevalonate B) Ang 1 --> Ang 2 C) Angiotensinogen --> Ang 1 D) Renin
B) Ang 1 –> Ang 2
What result would thiazides have?
A) Act on DCT and collecting duct blocking NA+
B) Inhibit Na/K/2Cl Co transporter in loop
C) Block Na/Cl co-transporter in DCT
D) Decrease natriuresis
C) Block Na/Cl co-transporter in DCT
Which of the following organs is supported by a layer of adventitia rather than serosa? A) esophagus B) stomach C) small intestine D) large intestine
A) oesophagus
Which of the following membranes covers the stomach? A) falciform ligament B) mesocolon C) parietal peritoneum D) visceral peritoneum
D) visceral peritoneum
