GEM 2nd Flashcards
(177 cards)
1
Q
What is the design and structure of the anulus fibrosis?
A
The AF is a highly fibrous and well-organised tissue surrounding the outer region of the intervertebral disk. It has a basket weave formation, resisting forces from opposing directions (torsion)
2
Q
Where is the most common direction for an intervertebral disc prolapse?
A
Lateral to the posterior longitudinal ligament. This results in unilateral compression of one or two spinal nerves.
In the lumber / sacral region, this compression can cause sciatica
3
Q
What are the main spinal ligaments called and where are they located in relation to the vertebrae?
A
Posterior longitudinal lig.
Anterior longitudinal lig.
Ligamentum flavum
Interspinous lig.
Supraspinous lig.
4
Q
Where are the thenar and hypothenar emimences located?
A
Thenar = muscular bulge at the base of the first metacarpal (thumb)
Hypothenar = smaller bulge at the base of the fifth metacarpal (little finger)
5
Q
Which nerve is compressed during carpal tunnel syndrome?
A
Median nerve
6
Q
Which of the following are forms of allostatic overload?
A) Chronic, high carbohydrate diet
B) Chronic exposure to microtrauma
C) Paroxysmal elevated cortisol due to diurnal response
D) All of the above
A
A and B.
Allostatic overload occurs when an organism’s neurological or endocrinological load exceeds it’s normal range for an extended period. Paroxysmal cortisol spikes are observed as part of daily circadian function. A and B are both examples of allostatic load which exceeds capacity.
7
Q
How does the allostatic model differ from the homeostatic model?
A
Homeostasis: Stability by keeping internal conditions constant.
Allostasis: Stability by adapting and changing in response to external and internal challenges. For example, predictive, fluctuating circadian hormone levels (within a normal range).
8
Q
McEwen and Stellar proposed which model which concerns cumulative wear and tear from a neurological and neuroendocrine standpoint?
A) Allostatic load
B) Health belief model
C) Biopsychosocial model
D) Social cognitive theory
A
A. Allostasis refers to an organisms ability to maintain homeostasis with the presence of insults. Allostatic overload occurs with chronic insult without respite.
9
Q
In the context of McEwen and Stellar’s model, which of the following is considered a primary mediator contributing to allostatic load?
A. Persistent, elevated cortisol and adrenaline which to physiological dysregulation.
B. An individual’s perceived susceptibility to disease.
C. The role of self-efficacy in determining health behaviour.
D. Socioeconomic factors that influence health outcomes.
A
A = correct
B (Health belief model)
C (Social cognitive theory)
D (Social determinants of health model)
10
Q
Which of the following is an example of a nudge intervention designed to increase organ donation rates?
A. Mandatory organ donation legislation.
B. Default enrollment in organ donation programs with an option to opt out.
C. Offering financial incentives to donor families.
D. Launching a mass media campaign promoting organ donation.
A
B. This option creates a subtle psychological incentive to participate. The other options will generate behaviour change, but they are more direct laws/incentives and therefore less relevant to the nudge theory.
11
Q
Which intervention best illustrates a nudge to encourage healthier eating in a school cafeteria?
A. Removing all unhealthy food options from the menu.
B. Increasing the price of junk food items.
C. Placing healthier food items at eye level and in prominent locations.
D. Implementing mandatory nutrition classes for students.
A
C.
A nudge is a behavioural intervention that encourages behaviour without restricting options (subtle cues). A and B are both direct examples. D may result in behaviour change but would not be considered a nudge as this falls more within an education intervention (although there is some crossover here)
12
Q
What is the function of acetylcholine?
A
Neurotransmitter used to cause muscle contraction. Widely used in autonomic nervous system (especially parasympathetic).
13
Q
What are the two types of acetylcholine receptor.
A
Acetylcholine = Cholinergic
Nicotinic (nAChRs) and Muscarinic (mAChRs) receptors. Both named as nicotine and muscarine act as acetylcholine agonists.
14
Q
What is the role of Beta 1 adrenoceptors (ADRB1)?
A
ADRB1 increase heart rate and contractile force when activated. This increases stroke volume (per beat) and cardiac output (per minute)
Agonists = Dobutamine, Epinephrine (non selective)
Antagonists = Atenolol, Bisoprolol
15
Q
What are the main causes of orthostatic hypotension?
A
- Medication (antihypertensives)
- Volume depletion (dehydration)
- Poor autonomic control
- Postprandial hypotension
- Reduced baroreceptor sensitivity
16
Q
Around 50% of older patients may not be taking medication as intended. Why?
A
- Impaired cognitive function
- Low manual dexterity
- Polypharmacy
- Health beliefs
17
Q
By roughly what percentage does drug elimination decrease in patients as they age (per year)?
A
Typical drug clearance ability decreases by around 1% per year. This is relevant as drugs will remain within an elderly patient’s system for longer
18
Q
What are the two types of cholinergic receptors?
A
- Nicotinic receptors
- Muscarinic receptors
19
Q
Why are glucocorticoids administered through different routes?
A
Glucocorticoid receptors are ubiquitous, so localised administration can provide more targeted effects.
20
Q
Which administration route offers the least systemic effects:
Oral, injectible, intranasal, topical, inhaled
A
Intranasal provides the most targeted delivery
21
Q
Which of these conditions is most likely to be treated with a synthetic glucocorticoid?
A) T1DM
B) Iron-Deficiency Anaemia
C) Osteoporosis
D) Acute Asthma
A
Acute Asthma (D). Glucocorticoids have anti inflammatory and immunosuppressant properties.
Diabetes = Insulin
Iron Deficiency Anaemia = Ferrous Sulfate
Osteoporosis = Bisphosphonates
22
Q
Which two main groups of steroids are there?
A
Corticosteroids
- Progestogens
- Glucocorticoids
- Mineralocorticoids
Gonadocorticoids
- Androgens
- Estrogens
23
Q
Define steroidogenesis and name the 5 major stages
A
The process by which cholesterol is converted into steroid hormones.
Progestogens are the precursor. Progestogens differentiate into Mineralocorticoids and glucocorticoids. Progestogens can differentiate into androgens and estrogens.
24
Q
What is the clinical significance of the hook of hamate
A
The hook of the hamate is a bony projection on the palmar side of the hamate bone in the wrist.
It forms the lateral border of Guyon’s canal, where the ulnar nerve and artery pass. Fractures or abnormalities in the hook can cause ulnar nerve compression.
25
Where are the radial and ulnar styloid processes located?
Distal end of the radius (lateral) and ulnar (medial) bones. These processes are palpable in the wrists and mark the beginning of the carpal bones
26
What is the difference between Carpal Tunnel and Guyon's Canal Syndrome, specifically referring to the region of symptoms?
Guyon's Canal = Ulnar Nerve
- 5th digit symptoms
- 4th digit partial symptoms
Carpal Tunnel = Median Nerve
- 1st to 3rd digit symptoms
- 4th digit partial symptoms
27
What is the clinical significance of the interosseous membrane?
The interosseous membrane is a fibrous sheet connecting the radius and ulna in the forearm (and tibia and fibula in the leg).
1. Provides stability, spacing, and force dispersion (pronation and supernation)
2. Is a muscle attachment site
3. Compartmentalises limb into anterior (flexor) and posterior (extensor) compartments.
28
List the layers of muscle in the back and their functions
Superficial Layer
- Movement of the upper limb
- Trapezius, Latissimus Dorsi, Levator Scapulae, Rhomboid Major, Rhomboid Minor
Intermediate Layer
- Assists in respiration and thoracic movement
- Serratus Posterior Superior and Serratus Posterior Inferior
Deep (intrinsic) Layer
- Movement / stabilisation of vertebral column
- Spinotransversales, Erector Spinae, Transversospinales muscle groups
29
List the three deep (intrinsic) muscle subgroups of the back and the muscles found within
Spinotransversales
- Splenius capitis, splenius cervicis
- Maintains posture and moves head and neck
Erector Spinae (intermediate intrinsic)
- Iliocostalis, Longissimus, Spinalis
- Maintainance of correct posture
- ‘I Love Spaghetti’
Transversiospinales (deep intrinsic)
- Semispinalis, Multifidus, Rotatores
- Stabilises spine, controls posture
30
Outline the mnemonic for the erector Spinae muscles and name the individual muscles of the group
I - Iliocostalis (most lateral)
Love - Longissimus (intermediate)
Spaghetti - Spinalis (most medial)
31
Name the 5 extrinsic muscles of the back
Trapezius
Latissimus Dorsi
Levator Scapulae
Rhomboid Major
Rhomboid Minor
32
What fracture is this and what is the common cause?
Colles' fracture
Swan neck deformity is typical of a fall on an outstretched hand (FOOSH)
33
What type of fracture is this and what is the standard cause?
Smith's fracture
Displacement of the hand is often caused by a FOOSH onto the outside of the hand
34
What fracture is this and what is the common cause?
Galeazzi fracture
A fracture of the distal third of the radius with dislocation or subluxation of the distal radioulnar joint. Caused either by direct trauma or FOOSH with forced pronation/supination
35
What fracture is this and what is the common cause?
Monteggia fracture
Fracture of the proximal third of the ulna with dislocation of the radial head at the elbow. Caused by FOOSH with pronation, or direct trauma
36
What is the role of the iliopsoas and what are it's constituent muscles?
The iliopsoas is a major muscle group in the hip region, consisting of the psoas major, psoas minor (if present), and iliacus.
The iliopsoas is the strongest hip flexor. It also supports upright posture and stabilizes the spine. Dysfunction or tightness in the iliopsoas can contribute to lower back pain, hip pain, and postural imbalances.
37
Outline the 5 adductor muscles of the thigh
Pectineus
Adductor brevis
Adductor longus
Adductor Magnus
Gracilis
*The sartorius can also operate as an adductor, amongst other functions
38
What are the 3 primary hip abductors?
1. Gluteus medius (main abductor)
2. Gluteus minimus
3. Tensor Fasciae Latae (attaches to IT band, stabilises the knee)
39
How many calories are found in each of the four major macronutrients?
Protein = 4
Carbohydrate = 4
Fat = 9
Alcohol = 7
40
What are the two components of stroke volume?
Preload: Amount of blood in ventricles prior to contraction. Determined during diastole (relaxation of the heart). Higher preload = stronger contraction during subsequent systole.
Afterload: Resistance that ventricles overcome to eject blood during systole. Determined by systemic vascular resistance (SVR). Higher afterload = systolic resistance and reduced stroke volume
41
What is the formula for blood pressure?
BP = CO x SVR
Blood pressure is cardiac output (SVxHR) x systemic vascular resistance.
42
What are the four types of haemodynamic shock?
Cardiogenic = pump failure
Mechanical = ventricles not filling
Hypovolaemic = low blood volume
Distributive = profound vasodilation (sepsis)
43
Define cardiac tamponade
Medical emergency. Fluid builds up within the pericardial sac, increasing pressure and reducing stroke volume.
Pericardiocentesis is required to drain
44
What is Beck’s triad?
Clinical signs observed during cardiac tamponade.
1. Hypotension
2. Jugular Venous Distension
3. Muffled Heart Sounds
45
What are immunoglobulins also referred to as?
Antibodies
46
What is the difference between these fractures:
oblique, segmented, transverse, communated, compound, avulsion
Oblique: Angled break across the bone
Segmented: Broken in 2 places
Transverse: Straight break across a line
Communated: Broken in 3 or more places
Compound: Breaks the skin (open fracture)
Avulsion: Bone broken by tendon involvement
47
A new screening test has a high sensitivity. What does this imply?
A) The test correctly identifies most people without the disease
B) The test is likely to produce many false positives
C) The test correctly identifies most people with the disease
The test is more specific than the gold standard
C. Sensitivity is a test’s ability to correctly identify true positives.
48
Which immune cells are the primary effectors in acute organ rejection?
A) Basophils
B) Th1 helper cells
C) Eosinophils
D) Cytotoxic T cells
D. Cytotoxic T Cells directly attack foreign antigens on the transplanted liver
49
A test with low specificity is likely to:
Produce a high number of false positives.
High specificity would allow the test to correctly rule out true negatives
50
The proportion of people without a disease who are correctly identified by a test is called...
Specificity
51
Outline the 4 types of hypersensitivity reaction?
(There is a mnemonic)
'ACID'
Anaphylactic (type I)
Cytotoxic (type II)
Immune Complex (type III)
Delayed (Type IV)
52
How many types of hypersensitivity reaction are found in the Gell and Coombs classification?
4. (Type I, II, III, IV)
Anaphylactic, Cytotoxic, Immune Complex, Delayed
53
Which type of hypersensitivity reaction is Rheumatoid Arthritis?
Mixed mechanism. Type III (Immune Complex ) and type IV (Delayed).
*Early disease involves immune complex deposition (rheumatoid factor) in synovial joints. Complement system is activated and inflammation occurs.
*Later disease involves CD4+ helper cell cytokine release. Promotes chronic inflammation, macrophage activation, and structural changes
54
What are the 4 muscles of the upper arm?
Anterior compartment:
Biceps Brachii
Brachialis
Coracobrachialis
Posterior compartment:
Triceps Brachii
55
What are the four nucleotide bases in DNA and how to they connect to one another?
'At The Golf Course'
Adenine - Thiamine
Guanine - Cytosine
*Thiamine swaps with Uracil in RNA
56
What is the central dogma of cell biology?
The flow of genetic information from DNA to RNA to protein
57
Which enzyme unzips DNA to initiate transcription?
DNA Helicase
58
Which enzyme synthesizes RNA from a DNA template by adding ribonucelotides?
RNA Polymerase
59
What process converts DNA into RNA and where does this occur?
Transcription. Occurs in the nucleus
60
What is the product of transcription?
mRNA (Messenger RNA)
61
What process converts RNA into protein and where does this occur?
Translation. In the cytoplasm, at ribosomes
62
What are codons?
Triplets of nucleotides on mRNA that code for specific amino acids
63
What is the role of tRNA in translation?
tRNA brings amino acids to the ribosome and matches them to the codons on mRNA
64
What is the start codon and which amino acid does it code for?
AUG , Methionine
65
What are the stop codons in transcription and translation?
Transcription: TAA, TAG, TGA
Translation: UAA, UAG, UGA
66
What is a gene?
A sequence of DNA that codes for a specific protein
67
What are exons?
Coding regions of a gene that remain in mRNA after splicing
68
What are introns?
Non-coding regions of a gene that are removed during mRNA processing
69
What is reverse transcription?
The process of converting RNA back to DNA, used by retroviruses
70
Which enzyme performs reverse transcription?
Reverse Transcriptase
71
What is a ribosome made of?
rRNA and proteins
*rRNA is non-coding and forms part of the machinery that makes up a ribosome
72
What is the difference in function between the smooth and rough endoplasmic reticulum?
Rough = protein synthesis
Smooth = lipid synthesis
73
Are cytoplasmic ribosomes intracellular or extracellular?
Cytoplasmic ribosomes synthesise proteins for intracellular use.
*Travel within the city can be done by bike (freely). Travel outside of the city requires a train from the station (RER)
74
How many amino acids are there in protein synthesis and how many of these are essential?
20 amino acids
9 essential amino acids
75
What are the 9 essential amino acids?
'Pvt. Tim Hall'
Phenylalanine, Valine, Threonine
Tryptophan, Isoleucine, Methionine
Histidine, Arginine, Leucine, Lysine
*Arginine is conditionally essential, not absolutely essential
76
Outline the basic structure of a codon chart
77
Which two bones are linked by the acromioclavicular joint?
Scapula and clavicle
78
Outline the key bony structures of the shoulder joint
79
What are the three joints of the shoulder?
Glenohumeral (ball and socket)
Accromioclavicular (plane)
Sternoclavicular (saddle)
80
Outline the 8 carpal bones
'she looks too pretty, try to catch her'
81
What type of fracture is this?
Monteggia fracture
In this case, an oblique ulnar fracture at the proximal third of the bone. This has displaced and subsequently dislocated the radius at the radiohumeral joint. This appears to be a simple fracture (non-compound)
82
What type of fracture is this?
Galeazzi fracture
In this case, an oblique fracture of the distal third radius. This has displaced and subsequently dislocated the ulner at the ulnocarpal joint. It is unclear from the image whether this is a compound or simple fracture
83
What is the order of brachial plexus structures?
'Randy Travis Drinks Cold Beer'
Roots
Trunks
Divisions
Cords
Branches
84
What spinal nerve roots form the brachial plexus?
C5, C6, C7, C8, T1
85
At what vertebral level does the nomenclature for spinal nerves change?
C7 (vertebra prominens)
*Cervical nerves are numbered C1-C8. C8 sits below vertebra C7. From there onwards, all nerves share the name with the vertebrae that sits superior to them (e.g. T10 vertebra has T9 superiorly and T10 inferiorly)
86
What are the three trunks of the brachial plexus?
Superior (C5-C6)
Middle (C7)
Inferior (C8-T1)
87
At which nerve level is the middle trunk off the brachial plexus?
C7
88
How does the function of the deltoid differ to that if the rotator cuff muscles?
Deltoid: Primary mover for big shoulder motions.
Rotator Cuff: Stabilises the humeral head and glenoid cavity. Supports fine motor movements.
89
What actions do the rotator cuff muscles complete?
Supraspinatus: Abduction (0-15°)
Infraspinatus: External Rotation
Teres Minor: External Rotation
Subscapularis: Internal Rotation
90
What is the simplest and most abundant amino acid in the body?
Glycine.
Non-essential amino acid that plays a role in collagen synthesis
91
What is the origin, insertion, and clinical relevance of the coracobrachialis muscle?
Origin: Coracoid process
Insertion: medial side, mid humeral shaft
Relevance: Stabilising muscle during adduction. Musculocutaneous nerve pierces muscle which can cause entrapment
92
Where are the greater and lesser tubercles situated
Greater = lateral head of he humerus
Lesser = medial head of the humerus
*Analogous to the greater and lesser trochanter in femur
93
What is the clinical relevance of the intertubercular sulcus?
It is the groove which falls between the greater and lesser tubercles of the humerus.
The long head of the biceps Brachii tendon passes through this groove. Bicipital tendinitis can occur here
94
What is the rough prevalence and clinical significance of the 3 fetal shunts?
Patent ductus arteriosclerosis:
- Uncommon
- Common in preterm babies
- Significant impact due to left-right shunt
Patent ductus arteriosus:
- Exceedingly rare
Patent foramen ovale:
- Common (30% adults)
- Insignificant, unless embolism forms
95
Where is vascular resistance highest in fetal circulation?
Pulmonary vascular resistance is very high in the fetus due to collapsed lungs.
Systemic vascular resistance is low, as the placenta acts as a pressure release valve.
This results in right-to-left heart blood flow in the fetus
96
Where is pressure highest in newborn circulation (compared to fetal circulation)?
Pulmonary resistance decreases (due to lung dilation).
Systemic resistance increases due to placental clamping
Circulation changes from right-left to left-right (due to pressure gradient)
97
What is the difference in function and anatomical positioning of the Gastrocnemius and Soleus Muscles
Gastrocnemius:
- Superficial, fast twitch
- Originates at femoral condyles
- Inserts at calcaneus (Achilles)
Soleus:
- Deep, slow twitch
- Originates at posterior tibia & fibular (two heads, not as obvious as gastrocnemius)
- Inserts at calcaneus (Achilles)
98
Define claudication
Claudication is pain caused by lack of perfusion to the appendages.
This is a common symptom of peripheral artery disease
99
What are the three types of joints in humans and provide an example of each?
Fibrous (solid)
- cranial sutures, interosseous
Cartilaginous (solid)
- pubic symphasis, vertebral disks
Synovial
- glenohumeral, PIP/DIP
100
What is nominal data? Provide some examples?
Named data only. No rank or numerical value
Colours, nationality, cohort data, sex
101
What is ordinal data? Provid examples?
Named data which is ordered or ranked.
Likert scales, medals awarded, alcohol consumption (high, medium, low)
102
What are the three main types of epidemiological study?
Cross sectional survey
Cohort study (prospective)
Case control study (retrospective)
103
What are the four main types of data in statistics?
'NOIR'
Nominal (categories)
Ordinal (ranks)
Interval (numerical, from an arbitrary point)
Ratio (numerical, from a true zero point)
104
What 3 parameters does an FBC measure?
Red Blood Cells (RBC)
White Blood Cells (WBC)
Platelets (Plt)
105
What are the three different categories of anaemia and name examples of each?
Microcytic, hypochromic
- Low MCV / MCH
- iron deficiency, haemoglobinopathies
Normochromic, normocytic
- Normal MCV / MCH
- chronic diseases such as RA or renal failure
Macrocytic
- High MCV / MCH
- B12 or folate deficiency, alcohol use
106
Why do RBCs increase in size in macrocytic anaemia?
B12 and/or folate deficiency impairs DNA synthesis
Nuclear division is then affected, so immature RBCs fail to divide as much as normal. This leads to larger cell size with fewer RBCs in circulation
107
What is the relationship between cobalamin and folate in DNA synthesis?
Folate donates methyl groups for DNA synthesis.
B12 (cobalamin) helps regenerate active folate.
108
Why are RBCs particularly affected by impaired DNA synthesis (from B12 / B9 deficiency)?
RBCs have a high turnover and bone marrow is one of the most rapidly dividing tissues in the body
109
What are the main functions of vitamin A?
Vision,
immune support,
skin and mucous membranes
110
What are the main functions of Vitamin D?
Calcium and phosphate metabolism
Bone health
Immune support
111
What are the main functions of vitamin E?
Antioxidant (protects cell membranes)
Supports immune function
112
What are the main functions of vitamin K?
Blood clotting (synthesis of clotting factors)
Bone metabolism
113
What are the main functions of Thiamine (B1)?
Energy metabolism
Nerve function
114
What are the main functions of riboflavin (B2)?
Energy production
Skin and eye health
115
What are the main functions of niacin (B3)?
Energy metabolism
Skin and digestion
116
What are the main functions of pantothenic acid (B5)?
Fatty acid synthesis and metabolism
117
What are the main functions of pyridoxine (B6)?
Amino acid metabolism
Neurotransmitter synthesis
118
What are the main functions of biotin (B7)?
Fatty acid synthesis
Gluconeogenesis
Hair/skin health
119
What are the main functions of folate (B9)?
DNA synthesis and repair (donation of methyl groups)
RBC production (same mechanism as above)
120
What are the main functions of cobalamin (B12)
DNA synthesis (replenishing active Folate) and RBC production
Neurological function
121
What are the main functions of ascorbic acid (vitamin C)?
Antioxidant and immune support
Collagen synthesis
Iron absorption
122
What is the long term complication of cobalamin deficiency?
Neuropathy, caused by demyelination of neurons
123
What does a high serum ferritin concentration indicate?
This indicates inflammation, as serum ferritin is an acute phase reactant.
124
What is the function of hepcidin?
Hepcidin is a hormone.
- Inhibits iron absorption in the gut
- Prevents iron release from macrophages and liver
- Traps iron inside cells (as ferritin) to starve pathogens
125
Apart from active iron (in haemoglobin), where is the bulk of iron stored in the body?
As ferritin.
Most ferritin is stored in the liver, spleen, and bone marrow
126
What does low serum ferritin indicate?
Low iron in storage (as ferritin). May indicate anaemia
127
What is transferrin?
Main transport protein for iron in plasma (free iron is toxic).
*Iron is delivered to the bone marrow (haemoglobin production), liver (storage), and muscle (myoglobin)
128
What is the difference between ferritin and hemosiderin?
Ferritin = soluble intracellular iron storage protein (can release when needed)
Hemosiderin = insoluble long term iron storage (accumulates during iron excess)
129
What is the function of myoglobin?
Functionally similar to haemoglobin. Stores iron within muscle cells and releases oxygen quickly during contraction.
Found exclusively in skeletal and cardiac muscle (not smooth)
130
In an elevated WBC measurement, which leucocyte is most likely to be raised?
Neutrophils. Elevated in acute bacterial infection, trauma or stress
(First line responders which clear cellular debris)
131
What does a high neutrophil count likely indicate?
Acute bacterial infection
132
What does a high eosinophil count likely indicate?
Increased allergy and/or parasitic defence
133
What does a high basophil count indicate?
Rare. Likely indicates chronic allergy, inflammatory, or cancerous states
Basophils and involved in histamine release and chronic immune responses.
134
What does a high lymphocyte count likely indicate?
Viral infection (activation of the adaptive immune response)
135
Which type of stem cell is the progenitor for haematopoiesis in bone marrow?
Pluripotent stem cell
136
Which cell types are involved in humoral immunity?
B lymphocytes. These cells produce antibodies and neutralise pathogens
1. Naïve
2. Plasma
3. Memory B cells
137
Which cell types are involved in cell-mediated immunity?
T lymphocytes.
1. CD4+ (helper)
2. CD8+ (Cytotoxic)
3. Memory T cells
138
What are the two branches of the adaptive immune system?
Humoral (B cells)
Cell-mediated (T cells)
139
What is opsonisation?
Where immunoglobulins tag microbes for phagocytosis
140
How do helper T cells (CD4+) operate?
1. CD4+ cells recognise MHC II complexes on dendritic cells or macrophages
2. CD4+ cells activate and then activate B cells (naïve to plasma cells), and stimulate CD4+ cells and macrophages, as well as producing cytokines
141
What are the different types of cytokine?
1. Interleukins (communication between blood cells)
2. Interferons (antiviral response)
3. Tumour Necrosis Factors (promote inflammation and apoptosis)
4. Chemokines (stimulates cell movement to infection sites via chemotaxis)
5. Colony stimulating factors (stimulates blood cell production in bone marrow)
142
What does raised ESR indicate?
Non-specific marker of inflammation.
*Fibrinogen and immunoglobulins cause erythrocytes to clump together during inflammation. This then speeds up the sedimentation rate in a tube of blood.
143
What is CRP and what does this show in a blood test?
CRP is an acute phase protein.
It is a marker of inflammation
144
Which enzyme is more liver specific - AST or ALT?
ALT. Elevated in liver damage and hepatitis
*AST is elevated in liver, muscle, and heart damage
145
A raised ALP and GGT suggest which kind of liver problem?
Cholestasis (bile flow obstruction)
146
Low albumin could suggest what?
Chronic liver disease
Malnutrition
Nephrotic syndrome
147
Which enzyme is raised in alcohol misuse?
GGT (often alongside elevated AST > ALT
148
Which cell is the precursor to thrombocytes?
Megakaryocyte
149
Are dendritic cells myeloid or lymphoid in lineage?
Both. Dendritic cells can be created from monocytes (myeloid) or directly from lymphoid progenitors
150
What is the precursor cell for dendritic cells and macrophages?
Monocyte
151
How do dendritic cells operate?
1. Link between innate and adaptive immune systems
2. Patrol and detect peripheral tissues (skin, mucosa, organs) using PRRs
3. Engulfs pathogens and presents them on MHC II molecules (CD4+) or MHC I (CD8+)
4. Macrophages release cytokines and then migrate to lymph nodes
152
What are the two genera of gram+ cocci?
1. Staphylococci
2. Streptococci (including enterococci)
153
What are the two main genera of gram- cocci?
1. Neisseria (N. meningitidis, N. gonorrhoeae)
2. Moraxella
*'n' is for negative. 'm' is next to 'n' in the alphabet
154
Name the 5 gram+ bacilli (rods)?
'ABCC Loser'
Actinomyces
Bacillus
Clostridium
Corynebacterium
Listeria
*All other bacilli are gram-
155
What is the structure of staphylococci bacteria and provide 3 common examples?
Gram+ cocci. Form grape-like clusters
1. S. aureus
- Normal skin flora
- Wounds and prosthetics
2. S. epidermidis
- Normal skin flora.
- Device-associated infections (valves, catheters, implants)
3. S. saprophyticus
- Urogenital flora
- UTIs
156
What are the most common bacteria species found in UTIs?
1. Escherichia coli
- most common cause 70-90%
- from patient gut flora
2. Staphylococcus saprophyticus
- sexually active women
- from perineum
3. Hospital- and catheter-associated infections are often polymicrobial by comparison
157
What is the structure of streptococci bacteria and provide 4 common examples?
Gram+ cocci. Forms chains or pairs
1. S. pyogenes (group A strep)
- Respiratory droplets
- Tonsillitis, pharyngitis, scarlet fever, impetigo, cellulitis
2. S. agalactiae (group B strep)
- Maternal genitourinary tract
- Neonatal sepsis/meningitis, pneumonia
3. S. pneumoniae
- Respiratory droplets
- Community-acquired pneumonia, meningitis, otitis media
4. Viridans group Streptococci
- Normal oral flora
- Endocarditis risk if spread to bloodstream
158
What is the structure of Neisseria bacteria and provide 2 common examples?
Gram- cocci
1. N. gonorrhoeae
- STIs
2. N. meningitidis
- Respiratory droplets
159
What is the structure of Moraxella bacteria and provide a common example?
Gram- cocci
Moraxella catarrhalis is the only common clinical pathogen in this group. Normal URT flora. Frequent cause of otitis media (children) and COPD exacerbation in adults.
*Produces beta-lactamase, so is often treated with co-amoxiclav.
160
What is the structure of Actinomyces bacteria and provide common examples?
Gram+ bacilli
Trick question as Actinomyces infections are uncommon in the UK.
161
What is the structure of Bacillus bacteria and provide 1 clinically relevant example?
Gram+ bacilli
Bacillus cereus is occasional in the UK and has emetic (reheated rice) and diarrhoeal (contaminated food) varieties.
All other Bacillus strains, including Bacillus anthracis (soil or spores inhalation) are rare in the UK.
162
What is the structure of Clostridium bacteria and provide 1 clinically relevant example?
Gram+ bacilli
Clostridium difficile (renamed clostridioides)
- Normal gut flora
- Overgrowth after antibiotic use, which can cause diarrhoea and colitis
*Other Clostridium bacteria are rare in the UK but can be significant (C. perfringens, tetani, botulinum, sordellii)
163
What is the structure of Corynebacterium and provide 1 historically significant example?
Gram+ bacilli
Most strains are not significant in the UK context. Corynebacterium diphtheriae was a concern until routine immunisation programmes were rolled out.
164
What is the structure of Listeria bacteria and provide 1 clinically relevant example?
Gram+ Bacilli
Listeria monocytogenes occurs in contaminated food (unpasteurised dairy, soft cheeses, deli meats).
Causes Listeriosis (mild gastroenteritis) in healthy patients. Sepsis, meningitis, miscarriage, or stillbirth in neonates, pregnancy, and elderly patients
165
Provide 5 clinically relevant examples of gram- bacilli bacteria
1. Escherichia coli (normal gut flora)
- UTIs and gastroenteritis
2. Campylobacter jejuni (foodborne)
- Most frequent cause of bacterial gastroenteritis in UK
3. Salmonella enterica (foodborne)
- Gastroenteritis (poultry)
4. Salmonella typhi (water / foodborne)
- Typhoid (enteric fever)
5. Legionella (waterborne)
- Legionnaires disease
166
Considering the 4 major groups of bacteria as a threat matrix of clinical importance, severity, frequency, and drug resistance, rank each group accordingly.
1. Gram- bacilli
(Escherichia coli, Campylobacter jejuni)
2. Gram+ cocci
(Staphylococcus aureus, Streptococcus pyogenes)
3. Gram+ bacilli
(Clostridium difficile, Listeria monocytogenes)
4. Gram- cocci
(Neisseria meningitidis, Neisseria gonorrhoeae, Moraxella catarrhalis)
167
What are pseudomonas?
(Genus, structure, symptoms, conditions)
Pseudomonas are gram- bacilli with flagella. They produce blue-green pigment and biofilms (antibiotic/immune resistance).
Thrive in moist environments (sinks, catheters, ventilators). It is an opportunistic pathogen
168
Briefly outline the brachial plexus from Roots to Branches
Roots: C5, C6, C7, C8, T1
Trunks: superior, middle, inferior
Divisions: anterior, posterior
Cords: lateral, posterior, medial
Branches:
1. Musculocutaneous
2. Axilary
3. Median
4. Radial
5. Ulnar
*Remember 5,3,2,3,5 (like a pyramid set)
169
What are the 5 brachial plexus branches from superior to inferior?
'MARMU'
Musculocutaneous
Axillary
Radial
Median
Ulnar
170
What are the 5 main nerves of the arm
'MARMU'
Musculocutaneous
Axillary
Radial
Median
Ulnar
171
What does the musculocutaneous nerve innervate (motor and sensory)
Motor: Biceps Brachii, brachialis, coracobrachialis
Sensory: Lateral forearm
172
What does the axillary nerve innervate (motor and sensory)
Motor: Deltoid, Teres Minor
Sensory: Skin over deltoid
173
What does the radial nerve innervate (motor and sensory)
Motor: all extensors of upper and lower arm, wrist, and fingers
Sensory: posterior arm, posterior forearm, back of hand
174
What does the median nerve innervate (motor and sensory)
Motor: most anterior forearm muscles, thenar muscles
Sensory: palmar surface of most fingers (small areas of palm)
175
What does the ulnar nerve innervate (motor and sensory)
Motor: flexor carpi ulnaris, ulnar half of flexor digitorum profundus, intrinsic hand muscles (apart from thenar)
Sensory: little finger and most of palm
176
What is the role of the flexor digitorum profundus and flexor pollicis longus, respectively
Both deep muscles of the forearm.
FDP allows flexion of the 4 fingers at the distal interphalangeal joints (DIPs) and supports flexion at the MCP joint (assisting flexor digitorum superficialis)
Flexor pollicis longus allows flexion of the thumb at the IP joint
177
What are the 3 muscles of the 'hamstring
Semitendinosus
Semimembranosus
Biceps femoris
