Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Life Maintenance > Week 10 > Flashcards

Week 10 Flashcards

1
Q

What are the cells of the liver and their roles (4)

A

Hepatocytes - secrete bile
Kupffer cells - fixed macrophages that clean blood
Liver endothelial cells
Stellate cells - fat storing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the biliary system

A

Bile secreted by hepatocytes
Moves through series of channels (canaliculi)
Move into small ducts, large ducts (hepatic ducts)
Anastomose onto common bile duct (and then into cystic duct if being stored in gallbladder)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What elements form protective barrier of the liver?

A

Kupffer cells in sinusoids clear endotoxins that arrive from gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the components of bile? Where does it come from?

A

water, electrolytes, organic molecules (bile acids, cholesterol, bilirubin, phospholipids)

Secreted in 2 stages: By hepatocytes (bile salts, cholesterol and other organics) and by epithelial cells lining bile ducts that release watery solution of Na+ and HCO3- )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe development of bile salts

A

Cholesterol is turned into cholic and chenodeoxycholic acid which are conjugated with glycine and taurine to make Na+ salts which are secreted into the intestines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does bile do? (3)

A

Fat digestion in prep for absorption
Bile + pancreatic juice neutralises gastric acid (Which aids digestive enzymes)
Aids elimination of waste products from blood (such as bilirubin and cholesterol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Bilirubin

A

Yellow pigment formed from breakdown of haemoglobin

Useless & toxic - needs to be excreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe formation and elimination of bilirubin

A

Bilirubin results from breakdown of haemoglobin during phagocyte destruction of RBC

Carried to hepatocyte by albumin and conjugated with glucuronic acid for excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is jaundice? Where is it seen?

A

Excessive free OR conjugated bilirubin in ECF

Yellow skin, mucus membranes, sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the three types of janudice?

A

Pre-hepatic (haemolytic) - excessive breakdown of RBC, excess unconjugated bilirubin
Hepatic - excess conjugated and/or unconjugated bilirubin, caused by cirrhosis, drugs, hepatitis A/B/C/E, Gilberts Syndrome
Post-hepatic (obstructive) - Excess conjugated bilirubin, obstruction to passage into duodenum, enter circulation and into urine, gallstones, carcinoma of pancreas/bile duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What transporter is involved in transporting blood glucose across hepatocyte cell walls?

A

GLUT2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe process and purpose of fat metabolism in the liver (3)

A

Triglycerides oxidised to PRODUCE ENERGY
SYNTHESIS og lipoproteins, cholesterol and phospholipids
CONVERSION or excess carbs/proteins to FA and TG for storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Quick overview of types of GLUT transporters (4 main ones - where are they located?)

A

GLUT1 - Placenta, muscle, adipose, brain, endothelium
GLUT2 - Pancreas B-cells, liver, small intestines, Rental PCT
GLUT3 - Neural, small intestine
GLUT4 - Muscle, heart, adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What substances does liver metabolise / excrete that would otherwise be toxic to body? (4)

A

Bilirubin
Ammonia
Hormones (androgens, oestrogens, aldosterone, thyroxine)
Drugs and exogenous toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe process of liver metabolism of drugs / hormones

A 
PHASE 1 (red/ox) - In smooth ER, cytochrome P450 makes substrate into polar compound
PHASE 2 (conjugation) - Makes it more water soluble for elimination via gallbladders or kidneys
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe detoxification process of Paracetamol

A

Metabolisation by 3 pathways
Glucoronidation (most common 45-55%)
Sulfation (20-30%)
N-hydroxylation & dehydration - Less than 15% but important as intermediate product NAPQI is toxic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe metabolism of alcohol

A

Ethanol to acetaldehyde (toxic) to acetate into circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe process of liver regeneration

A

Adult liver cells generally DO NOT undergo cell division
BUT if part of liver is removed, it will regenerate to previous mass
2 pathways involved - Growth factor mediated pathway (hepatocyte growth factor, transforming growth factor alpha)
Cytokine signalling pathway using IL-6 via TNFa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the role of liver in storage (7)

A

Stellate cells store fat soluble vit D, K, E, A
Vitamin B12 storage sufficient for 2-3 years
Folate
Iron stored as ferritin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe liver function tests used, what they can show (6)

A

Bilirubin - conjugated or not? - jaundice, where, severity of liver disease
Aminotransferase (ALT - hepatocellular damage) and (AST - progression of disease)
ALP - Diagnosing cholestasis, biliary obstruction, hepatic infiltration
Albumin - severity of chronic liver disease
PT - severity of hepatic synthetic function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

First pass metabolism

A

Concentration of a drug is reduced significantly once it passes through GIT and liver (before reaching systemic circulation). Significant in prescribing of oral medication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Zero vs first order kinetics

A

Zero order - a constant amount (eg. so many milligrams) of drug is eliminated per unit time
First order - a constant proportion (eg. a percentage) of drug is eliminated per unit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Nature of alcohol metabolism in terms of kinetics

A

First order up to 10mg/dl

Zero order above that

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Goal of metabolism of drugs

A

Making them more water soluble/polar for excretion (as body sees them as foreign)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Describe phase I of metabolism
More polar (and possible reactive site for conjugation) Oxidation Reduction Hydrolysis (insertion of H2O)
26
Effects of phase 1 reactions
inactivate the drug OR produce active metabolite OR produce toxic metabolite
27
Describe phase II reactiond
Conjugation - coupling of drug with one of several polar endogenous molecules (inert and water-soluble for excretion)
28
Describe normal metabolism of paracetamol
Either conjugated with glucuronide, sulphate | OR NAPQI needs to be conjugated by GSH
29
Describe what occurs during paracetamol overdose
Paracetamol usually conjugated with glucuronide and sulphate but in overdose that is saturated Metabolism to NAPQI which is toxic is only path left, you run out of the glutathione which conjugates the NAPQI so it is free to attack you
30
What do you prescribe in paracetamol overdose and how does it work?
N acetyl cysteine | Converted to glutathione which mops up excess NAPQI to be eliminated in urine
31
Cytochrome P450 - what is it and what phase of reactions is it involved in?
Large family of isoenzymes that oxidise drugs (Phase I metabolism) Essentially the CYP enzymes catalyse the phase 1 reactions, where the liver is turning lipid-soluble toxins to water-soluble for excretion
32
Cytochrome P450 inhibitors - what do they do, one example
Enzyme inhibition REDUCES metabolism of other drugs given at the same time Erythromycin reduces warfarin metabolism, increasing drug levels and anticoagulation ``` Erythromycin Ciprofloxacin Sodium Valproate Omeprazole Simvastatin Fluconazole/ketoconazole Isoniazid ```
33
Cytochrome P450 inducers (5) and what do they do
CRAPS (GP not at important as rarely used) Carbamazepine, Rifampicin, Alcohol, Phenytoin, Greseofulvin, Phenobarbitone, Smoking Enzyme inducers increase metabolism of other drugs given at the same time This reduces drug levels and reduces efficacy E.g. rifampicin increases metabolism of the contraceptive pill and co-prescription may increase the chance of pregnancy
34
How are drugs eliminated? (6)
``` Renal Faecal (via bile) Lungs Tears Sweat Breast milk ```
35
Describe how metabolism and elimination of a drug determine plasma half life
The half-life of a zero-order reaction decreases as the initial concentration of the reactant in the reaction decreases. The half-life of a first-order reaction is independent of concentration
36
Describe how and why drugs are metabolised by the liver
Phase I - metabolism Metabolism makes drug more polar (water soluble) and may create a reactive site for conjugation (phase II) Oxidation - loss of electron(s), majority of action by cytochrome p450 enzymes Reduction - gain of electron(s) Hydrolysis - insertion of H2O into drug by esterases or proteases
37
What three elements move through liver together?
Portal vein Hepatic artery bile ducts
38
Overview of acinar concept and significance of zones 1-3
The acinus is roughly divided into zones that correspond to distance from the arterial blood supply - those hepatocytes closest to the arterioles (zone 1 below) are the best oxygenated, while those farthest from the arterioles have the poorest supply of oxygen.
39
Describe roles and contents of space of disse
Ito (stellate) cells store vitamin A and can generate collagen
40
Clinical signs of liver damage
Jaundice Malaise Bruising Early sign may be high INR (due to clotting factors)
41
LFT interpretation - common tests and what variations may indicate (6)
Total bilirubin - Conjugated v unconjugated - Jaundice, severity of liver disease Alanine (ALT) - Diagnosis of hepatocellular damage Aspartate (AST) - Follow progression of disease Alkaline phosphatase (ALP) - Diagnosis of cholestasis, biliary obstruction, hepatic infiltration Albumin - Severity of chronic liver disease Prothrombin time - Severity of hepatic synthetic function (synthesis)
42
What does it mean if ALT is high but Alkaline phosphatase is normal?
Hepatocyte rather than biliary injury
43
Majors causes of liver disease (8)
``` Fatty liver disease Viral hepatitis Autoimmune hepatitis Metabolic / genetic disorders Bile duct diseases Vascular disorders Tumours and tumour-like lesions Drugs and toxins ```
44
Steatosis
Fatty liver
45
HAV, HBV, HCV - how are they passed? Which is the worst?
A - oral/faecal, acute B - bloodborne, 10% of adults will develop chronic, 90% of children C - bloodborne, worst one - leads to cirrhosis and HCC
46
Process of acute hepatitis at lobular level
Acute viral hepatitis inflammation is SCATTERED throughout lobule / portal tract
47
What do ground glass hepatocytes mean?
Hep B infection
48
At what point is fatty liver disease generally considered irreversible?
Fibrosis
49
What is occurring in cirrhosis? Why is it so bad? How can you measure it?
Diffuse throughout liver Fibrous septa Inflammation at borders or within nodules Doppler flow to measure speed, shunts
50
What does a patient likely have if they have plasma cell clusters?
Autoimmune hepatitis
51
Microscopic features of cirrhosis
Fat, Mallory's hyaline, neutrophil polymorphs
52
Long term complications of cirrhosis
Cirrhosis and chronic liver failure Portal hypertension Hepatocellular carcinoma
53
In a non-cirrotic liver, what is the most likely cause of a tumour found?
Metastisis from another part of the body
54
In a cirrotic liver, what is most likely cause of tumour found?
Primary hepatocellular carcinoma (HCC)
55
In what case might you see HCC in a non-cirrhotic liver?
Childhood-acquired chronic viral hepatitis (HBV or HCV)
56
Describe the endocrine system
Integrates body functions via secretion of biologically active substances in the body
57
Describe a hormone
Substance that is released in one tissue and travels via the blood stream (usually) to have an action in a remote tissue
58
Types of hormone (3)
Peptides - charged, largely negative Steroid - fat soluble Amino acid derivatives - variable
59
What are thyroid hormones?
Nuclear, Amino acid derivative
60
When looking at endocrine tests, where do you look first to judge function?
Peripheral hormones
61
What is the role of the hypothalamus?
To translate stimuli into hormone reaction
62
How does hormone response get switched off?
Negative feedback
63
Describe the pituitary
Two lobes Lies in Sella Turcica Anterior pituitary is glandular (creates its own hormones), posterior is not
64
Anterior pituitary hormones (5) and role
``` ACTH - regulation of adrenal cortex TSH- thyroid hormone regulation GH - growth LH/FSH - reproductive control PRL - breast milk production ```
65
Posterior pituitary hormones
ADH - water retention | Oxytocin - breast milk, labour, psych
66
Three considerations with pituitary tumours
Hormone hypersecretion Space occupying lesion Hormone deficiency states
67
Requirement of development of growth hormone
REM sleep
68
Effects of growth hormone excess in children vs adults
Giantism in children | In adults, MANY
69
Actions of cortisol (6)
``` Increase plasma glucose levels Increases lipolysis Proteins are catabolised Sodium and H2O retention Anti-inflammatory Increases gastric acid production ```
70
Describe Cushing's Syndrome
Caused by excess cortisol Changes in protein / fat metabolism Changes in sec hormones Salt and water retention
71
Describe positive feedback loop involved in breast feeding
Baby starts to feed Receptor senses, control centre compares to normal Adjustment in the SAME direction as initial event
72
Vision changes in pituitary tumour
Vision closing in from the sides
73
Which cranial nerve is most at risk of damage from pituitary tumour?
6 as it lies most medially
74
Treatment of pituitary tumours
Surgery Radiotherapy Drugs
75
Causes of pituitary failure
``` Tumour (mostly benign) Trauma Infection Inflammation Apoplexy - sudden vascular bleed Iatrogenic ```
76
Describe pituitary failure and treatments
``` Depends on the resulting effects of the pituitary failure Thyroid - thyroxine Sex steroids - testosterone / oestrogen Reduced cortisol - hydrocortisone Reduced GH - GH ```
77
What is nutrition?
Understanding the effects of food on the human body in health and disease
78
Macronutrients and their energy values
Fat - 9kcal/g Alcohol - 7kcal/g Protein - 4kcal/g Carbs - 4kcal/g
79
Micronutrients
Water soluble - B, C | Fat soluble - A, D, E, K
80
Biomarker of iron
ferritin (marker of iron storage) | BUT will also increase during inflammation or infection
81
Determinants of total energy expenditure
Basal metabolic rate Diet induced thermogenesis Activity Stress (illness / inflammation / surgery)
82
What affects nutrient requirements?
Age, gender, body size, physical activity, state of health, physiological status (pregnant? lactating?), growth
83
DRV
Dietary reference values | 1991 report, useful for group, not for individuals
84
Types of DRV (4)
Estimated Average Requirement Reference Nutrient Intake Lower Reference Nutrient Intake Safe Intake
85
Marasmus
Long term lack of protein / calories
86
Seropthalmia
Vitamin A deficiency, blindness
87
Kwashiorkor
Sudden onset protein malnutrition
88
Ricketts
Vitamin D and/or calcium deficiency
89
Why do we develop nutritional deficiencies?
``` Inadequate intake Reduced absorption Increased losses Increases demand Other conditions that prevent storage (liver cirrhosis) ```
90
Signs/symptoms of vitamin A deficiency
Low blood levels (as liver stores have been depleted) Increased risk of infection Xeropthalmia (non-blinding, blinding)
91
Terminal ileum uniquely responsible for absorbing...
Vitamin B12
92
Malnutrition
Not just under-nutrition, also over-nutrition | Deficiencies
93
Consequences of malnutrition (8)
``` Immune system Impaired wound healing Loss of muscle mass Kidneys impaired - over or dehydration Reduces fertility Neuro issues - apathy, depression Impaired temp regulation Micronutrient deficiencies ```
94
What does low albumin indicate?
Body is not absorbing enough protein
95
What does low urea indicate?
Poor protein intake (urea formed when protein is breaking down)
96
Why can albumin be normal in cases of starvation?
Long half life Increases due to dehydration Falls due to stress/infection Poorly correlated with nutritional status (normal levels can be seen in severe anorexia)
97
Outline metabolic response to startvation
``` Adaptive process BMR falls by 30% Loss of mass in metabolic tissues (Liver/ GI tract) Minimise loss of protein Maintain glucose supply to tissues ```
98
Outline metabolic response to injury, trauma, sepsis
Energy metabolised for defense / repair First few hours - ebb - shock First few days - catabolism, energy store breakdown Weeks - Anabolism, building energy stores, focus on nutritional therapy should be restoring protein synthesis
99
Functions of the liver (6)
``` Storage Filtration Synthesis Secretion Metabolism Detox ```
100
Encephalopathy
Confusion as liver cannot breakdown ammonia xxx
101
Risk factors for liver disease
``` Alcohol Drugs IV drug use Blood borne virus risks Other recreational drugs ```
102
Presentation of chronic vs acute liver disease
Acute may not present with any outward issues, may move into organ failure quite quickly Chronic will present with distension, jaundice, muscling wasting
103
What causes massive AST/ALT elevation?
Drugs / toxins - paracetamol Viruses Ischaemia Autoimmune hepatitis
104
Bud-Chiari syndrome
Thrombosis of hepatic veins
105
What is acute liver failure?
Severe liver injury, possibly reversible MUST include encephalopathy WIthin 8 weeks of first symptom in absence of pre-existing liver condition
106
Level of acute measurements in liver failure
Measured in time between jaundice and encephalopathy Hyperacute Acute Subacute
107
Patient presenting with hepatitis / jaundice - investigations to perform?
Ultrasound scan - is there an obstruction? or liver disease? Viral hep screen xxx
108
Encephalopathy grading (4)
1 - slight diorientation 2- more drowsy / disorientated / respond to verbal stimuli 3 - Extreme agitation 4 - Coma
109
What is causing increase in chronic liver disease?
Metabolic syndromes Obesity Alcohol Viruses
110
5 clinical stages of cirrhosis
No varices, varices, bleeding, ascites, ascites bleeding | not necessarily in this order
111
At what level of portal hypertension do you begin to develop varices?
about 10mmHg | Bleeding more likely from 12mmHg
112
Assessment of severity of chronic liver disease
Child Pugh score looks at Bilirubin, albumin, ascites, encephalopathy, INR to estimate 2 yr survival
113
Describe the process that creates increased portal hypertension
Loop where splanchnic and peripheral vasodilation indicate to body that blood volume is low which drives Na and water retention (which creates portal hypertension)
114
Compensated vs uncompensated liver disease
Compensated - cirrhosis with no other clinical complications | Decompensated - WITH xxx5 other things jaundice, ascites, encephalopathy, varices
115
Outline the 'public interest' required to break confidentiality
Real / serious risk of physical harm to an identifiable individual
116
Examples of shunts in portal hypertension
Left gastric with azygous - oesophageal varices Retroperitoneal with mesenteric - bare area Epigastric with paraumbilical veins - Caput medusa Splenic / IMA with superior rectal - Lower rectal varices / haemorrhoids

Life Maintenance (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions