Week 1 Flashcards
1
Q
What are some common problems in insulin treatment?
A
Giving an incorrect dose
Omitting insulin (forgetting, if ill etc.)
Giving the wrong type of insulin
2
Q
Which structure in the neck is the first complete cartilagenous ring (if travelling superiorly to inferiorly)?
A
The cricoid cartilage
The thyroid cartilage isn’t a complete ring!
3
Q
How many ATP are produced per glucose molecule?`
A
36
4
Q
The carotid sheaths blend inferiorly with which structure?
At what level does the common carotid bifurcate, and which branch remains within the carotid sheath?
A
Blends with the mediastinal fascia
Bifurcates at the level of C4, and the internal carotid artery remains within the carotid sheath
5
Q
Very generally, how do Type I and Type II Diabetes Mellitus differ?
A
Type I - loss of most of the beta cells responsible for secreting insulin, resuling in high levels of blood Glucose
Type II - beta cells lose the ability to sense changes in blood Glucose due to hyperglycaemia taking Glucose concentrations outwith the Km of Glucokinase, the beta cells have “been worked very hard and are likely to be very stressed”
6
Q
Can hormones bound to a carrier molecule cross capillary walls and activate receptors?
A
No - only ‘free’ (i.e. unbound) hormones can cross the capillary wall
7
Q
Glucagon (lowers/raises) blood glucose.
How does it do this?
What other hormone is involved?
A
Glucagon raises blood glucose
It does this by stimulating hepatic glycogenolysis and gluconeogenesis
Unlike insulin, it does not affect the uptake of glucose into muscle and adipose tissue. However, adrenaline does inhibit this, resulting in an increased plasma glucose
8
Q
How is control of Diabetes measured?
A
Home blood glucose monitoring - used in day-to-day diabetes management and allows for adjustments in insulin dose, but only provides a snapshot at one particular time point. Continuous glucose monitoring provides the whole picture
Urinalysis to measure ketones and glucose
HbA1c measurements
9
Q
What are some of the functions that carrier proteins provide?
A
Allow for a reserve of hormones
Increase the amount of hormones transported in the blood
Extend the half-life of the hormone in circulation
10
Q
Describe the synthesis and structure of insulin
A
Synthesised in the Rough ER of pancreatic Beta cells as a larger single chain prehormone - Preproinsulin
Preproinsulin is then cleaved to form Insulin
Insulin contains 2 polypeptide chains linked by disulphide bonds
11
Q
What is the early clinical effect on vision of a pituitary gland tumour?
A
A pituitary tumour will initially result in midline compression of the optic chiasm
This results in disruption of the action potentials from the nasal retinas, meaning the patient loses the ability to see structures in the temporal side of the visual field, bilaterally
This is known as bilateral hemianopia
12
Q
Insulin (lowers/raises) blood glucose.
How does it do this?
A
Insulin lowers blood glucose by inhibiting hepatic glycogenolysis and gluconeogenesis
It also stimulates uptake of glucose into muscle and adipose tissue
13
Q
In embryological development, at what time does the thyroid gland reach its final position in relation to the larynx/trachea?
A
7th week of development
14
Q
How does T1DM classically present?
Is there typically evidence of microvascular disease at the time of diagnosis?
A
Pre-school and peri-puberty, with a small secondary peak in late 30s
Usually lean
Acute onset and severe weight loss, thirst, polyuria
Weakness, fatigue, lethargy, blurred vision. Possibly presenting with thrush
Ketonuria +/- metabolic acidosis
Typically no signs of microvascular disease at the time of diagnosis
15
Q
Name to surgical approaches to accessing the pituitary fossa
A
Transcranial - under the frontal lobe
Transsphenoidal - via the nasal cavities and sphenoid sinus
16
Q
What is the name of the structure that connects the Hypothalamus to the Pituitary gland?
A
The infundibulum
17
Q
What are the blood glucose targets in insulin treatment pre- and post meal?
A
3.9-7.2 mmol/L pre-meal
<10 mmol/L 1-2 hours following a meal
18
Q
Insulin is a hormone of the ____ state.
What happens to Insulin upon feeding? What is it’s action?
A
FED state
Insuline is RELEASED from pancreatic beta cells in response to feeding. This results in a LOWERING of blood Glucose
19
Q
To what group do the platysma muscles belong to? What is their nerve innervation?
A
The muscles of facial expression
The facial nerve (CNVII)
20
Q
What structures lie near the Thyroid gland?
Describe the order of contents in the Carotid Sheath
A
Thyroid gland is covered in pretracheal fascia
Trachea (anterior) and Oesophagus (posterior) lie in the centre line. In between these are the Recurrent Laryngeal Nerves
Either side of the Thyroid gland, outside the pretracheal fascia, are the carotid sheaths, and laterally to medially these go Internal Jugular Vein, Vagus Nerve, Carotid Artery
21
Q
What common embryological variations are seen in the thyroid?
A
Pyramidal lobe - 28-55% prevalence, most commonly originating from the left lateral lobe
Incomplete/missing isthmus
22
Q
What structures are found within the carotid sheath?
A
Vagus nerves
Carotid arteries - common then internal
Internal jugular vein
Deep cervical lymph nodes
23
Q
In the transsphenoidal transnasal surgical approach to the pituitary, which sinuses of which bone need to be passed through?
A
This approach requires the surgical fracture of the nasal septum, as well as the floor and roof of the sphenoid sinuses, which are located in the sphenoid bone
24
Q
Describe the secretion of Insulin
A
Glucose enters Beta cells through the GLUT2 glucose transporter and is phosphorylated by glucokinase
This increased metabolism of Glucose results in an increase in intracellular ATP, which inhibits the ATP-sensitive K+ channel, KATP
Inhibition of KATP = depolarisation of cell membrane = opening of voltage-gated Ca2+ channels
Opening of Ca2+ = fusion of secreteory vesicles with cell membrane = RELEASE OF INSULIN
25
Generally, what is the difference between the anterior and posterior lobes of the pituitary gland? What do they secrete?
**Anterior Lobe**
* more glandular than posterior lobe due to different embryological origin
* Secretes:
* Thyroid stimulating hormone (TSH)
* ACTH
* FSH and LH
* Growth Hormone (GH)
* Prolactin
* Endorphins
**Posterior Lobe**
* collection of nerve cells
* embryologically originates in the hypothalamus and migrates downwards
* Secretes:
* ADH (a.k.a. vasopressin)
* Oxytocin
26
What is an insulin pump?
medical device that acts as a **continuous administrator of short-acting insulin**
Delivers a background insulin dictated by **basal rate**
Delivers a manually activated **bolus** of insulin to cover meals
27
For each of the following, state whether they are pre-synthesised and stored or synthesised and released on demand
- Amines
- Peptides and proteins
- Steroids
**Amines** - pre-synthesised and stored in vesicles, then released in response to Ca2+-dependent exocytosis
**Peptides and proteins** - as with amines, pre-synthesised and stored in vesicles, then released in response to Ca2+-dependent exocytosis
**Steroids** - synthesised from cholesterol and secreted on demand
28
What is the definition of Type I DM?
A state of absolute insulin deficiency
"in all probability caused by an environmental trigger in a genetically susceptible individual mediated for the most part by an autoimmune process of varying degree of severity within the pancreatic beta cell
29
At the level of what cartilages does the isthmus lie?
Anterior to the 2nd and 3rd cartilages of the trachea
30
Briefly describe insulin physiology in the healthy individual
Insulin is secreted at a low basal rate, which accounts for approx 50% of total insulin production
Post-prandial insulin is secreted in response to post-meal surges in glucose
31
Briefly describe age of onset, family history and duration/severity of symptoms in the various types of Diabetes listed below:
- Type I
- Type II
- Monogenic
- Secondary
Type I
* Age - peaks \<5 and between 10 and 14
* Family history - possible
* duration/severity - short, severe
Type II
* Age - unusual in under 25s
* Family history - frequent, 30%
* Duration/severity - months, usually mild
Monogenic
* Age - neonate to adulthood
* Family history - almost always
* Duration/severity - months, usually mild
Secondary
* Age - usually later in life
* Family history - rare
* Duration/severity - weeks/months, severity depends on cause
32
Cell types in the pancreatic islets - what do each secrete?
- Alpha cells
- Beta cells
- Delta cells
- PP cells
Alpha - GLUCAGON
Beta - INSULIN
Delta - SOMATOSTATIN
PP - PANCREATIC POLYPEPTIDE
33
What anatomical structure in the osteology of the skull does the pituitary gland sit in?
Pituitary gland is a midline structure in the **pituitary fossa of the sphenoid bone**
The pituitary fossa lies within the **sella turcica** (Turkish saddle)
34
Through what transporter does glucose enter beta cells?
How does a change in glucose conc. affect glucokinase activity?
Glucose enters beta cells via **GLUT2 glucose transporters** and is phosphorylated by glucokinase
Change in glucose conc results in a **dramatic change in glucokinase activity**
35
Name the specific carrier molecules for the following steroids
- thyroxine (T4)
- cortisol
- sex steroids (testosterone and oestradiol)
What are some "general" carrier proteins that are worth knowing?
Thyroxine - **thyroxine-binding globulin (TBG)**
Cortisol - **cortisol-binding globulin (CBG)**
Sex steroids - **sex steroid-binding globulin (SSBG)**
**Albumin** and **Transthyretin** bind both steroids and thyroxine
36
Describe the phasic pattern of Insulin release.
Why does this occur?
**Biphasic** - 1st initial larger spike, followed by a 2nd phase
**5% of insulin granules are immediately available for release** (RRP - readily releasable pool)
The **'Reserve Pool'** **must undergo preparatory reactions** to become mobilised before it is available for release
37
What structures are found within the pretracheal fascia?
(Located anteriorly)
Oesophagus
Trachea
Thyroid gland
Strap muscles
Recurrent laryngeal nerves
38
What two courses on Diabetes management are made available to everyone diagnosed?
DAFNE (dose adjustment for normal eating) and TIM (Tayside insulin management)
39
Name some Short Acting and Rapid Acting forms of Insulin
Short Acting
* Humulin S
* Actrapid
* Insuman Rapid
Rapid Acting
* Humalog
* NovoRapid
* Apidra
40
Where is the precursor to insulin formed, and what is it cleaved into?
Large, single prehormone called **preproinsulin** is formed in the **rough ER of pancreatic beta cells**
Cleaved to form insulin and C-peptide
41
Describe the two layers of Strap Muscles
Superficial Layer
* **Sternohyoid -** travels from the Hyoid bone to the body of the sternum
* **Omohyoid -** has 2 bellies - superior and inferior, with a **fascial sling** attaching the intermediate tendon between the two bellies to the clavicle
Inferior Layer
* **Thyrohyoid -** attaches the Hyoid to the Thyroid
* **Sternothyroid** - attaches the Thyroid to the Sternum
42
What are some of the environmental triggers of T1DM?
viral factors
maternal factors
weight gain
43
What pattern of insulin administration is the Gold Standard for mimicking normal insulin release?
Basal bolus - take a long-acting dose once a day (in the evening) and a bolus of rapid-acting insulin before each meal
44
What is glycated haemoglobin?
HbA1c
Formed by non-enzymatic glycation of haemoglobin on exposure to glucose
Increases in a predictable way in response to glucose
Used as a measure of average blood glucose over a prolonged period of time (e.g. a couple of months)
45
Describe the visual pathway of the optic nerves through the skull, and how signals travel down this pathway in response to light hitting the temporal and nasal retinas
The **left and right optic nerves (CNII)** form the **optic chiasm**, which lies directly superiorly to the pituitary gland.
From the optic chiasm, the **optic tracts** pass posteriorly
After synapsing in the thalamus, the next axons in the chain pass via the **optic radiation** to the **visual cortex** in the **visual lobe.**
Light hitting the **temporal retina** travels on the **same side** of the visual pathway
Light hitting the **nasal retina** travels on the **opposite side** of the visual pathway
46
What structures are found within the investing fascia?
Encloses **all other neck fascial compartments**
Also encloses 2 pairs of muscles:
* Trapezius
* Sternocleidomastoid
47
Give some of the biological effects of insulin
Increases uptake of amino acids into muscle
Increases DNA synthesis
Increases protein synthesis
Growth responses
Increases glucose uptake into muscle and adipose tissue
Lipogenesis in adipose tissue and liver
Glycogen synthesis in liver and muscle
48
What are the two options of prandial insulin available? How long do they last, when do they peak, and what are some examples?
Insulin analogue (majority of T1DM patients)
* NovoRapid, Humalog and Apidra
* Onset 10-15 mins
* Lasts 4-5 hours, with peak action at 60-90 mins
Soluble Insulins
* Actrapid, Humulin S
* Onset 30-60 mins
* Lasts 5-8 hours, with peak action at 2-4 hours
49
Describe venous drainage in the skull
What venous drainage surrounds the pituitary gland?
Venous channels are made via **folds in the Dura mater** - these **Dural Venous Sinuses** drain venous blood, but aren't actually veins
The pituitary gland is surrounded by the **cavernous** and **intercavernous sinuses**
50
1 unit of insulin equals how many grams of carbohydrate?
10 grams
51
How does the activity of Glucokinase change in response to Glucose?
Small change can result is a **dramatic change** in Glucokinase activity
52
What is the name of the thick adherent material that covers all of the internal aspects of the cranial vault?
What is the name given to the "tenting" of this structure over the cerebellum?
What is the name given to the area where this structure covers the pituitary fossa?
The **Dura Mater**
The **Tentorium cerebelli**
The **Diaphragm sellae**
53
How is diabetes diagnosed? (3 different ways)
1. Symptoms of hyperglycaemia (polyuria, polydipsia, unexplained weight loss, visual blurring, genital thrush, lethargy) AND Raised venous glucose detected **once** - fasting of **7mmol/L** **and** **above** or random of **11.1mmol/L** **and above**
2. Raised venous glucose on **2 separate occasions** - fasting of **7mmol/L** **and** **above** or random of **11.1mmol/L** **and above** or oral glucose tolerance test (OGTT) - 2hour value of **11.1mmol/L** **and above**
3. HbA1c of **48mmol/L and above**, but below doesn't exclude DM
54
What level of blood glucose should Insulin be released in response to?
Above 5 mM
55
Briefly describe the possible complications at presentation, ketone levels and weight loss in the following types of Diabetes:
- Type I
- Type II
- Monogenic
- Secondary
Type I
* Complications - never(?)
* Ketones - +++
* Weight loss - usually seen
Type II
* Complications - up to 30%
* Ketones - usually none
* Weight loss - not usually
Monogenic
* Complications - unusual
* Ketones - usually none
* Weight loss - not usually
Secondary
* Complications - unusual
* Ketones - ++/-
* Weight loss - depends on the primary cause
56
What hormones does the anterior pituitary secrete? Bonus points for what hormone they are triggered by (6)
**ACTH** - (corticotropin-releasing hormone)
**LH/FSH** - (Gonadotrophin-releasing hormone)
**TSH** - (thyrotropin releasing hormone)
**GH** - (growth hormone-releasing hormone)
**PRL** - (dopamine)
57
What are the clinical features of Bardet-Biedl Syndrome (hint: Diabetes is one of them!)
often very obese
polydactyly (extra fingers)
hypogonadal
visual and hearing impairment
mental retardation
diabetes
58
What 4 key checks should be done prior to giving a patient insulin?
1. verify the type and amount of insulin with the patient if possible BEFORE ADMINISTRATION
2. Only use specific insulin syringes for administration
3. ALWAYS ensure a second independent check of insulin doses prior to administration
4. Glucose should be used for all IV insulin infusions, except in cases of DKA
5. (never give more than 6 syringes at any one time, and avoid abbreviations when documenting doses etc.)
59
What two components make up the diencephalon?
The Thalamus and the Hypothalamus
60
In normal function, at what threshold of blood glucose do beta cells secrete insulin?
What pattern of release is seen?
Above **5 mM**
A **biphasic release** is seen in insulin resistance, with a large initial peak and a secondary smaller peak
61
What 2 proteins does the KATP channel consist of?
What class of drugs directly inhibits KATP, and therefore increases Insulin release?
What drug stimulates KATP, and therefore inhibits Insulin release?
**Kir6 -** inward rectifier subunit - **pore** subunit
**SUR1 -** a sulphonylurea receptor - **regulatory** subunit
Directly inhibited by the **sulphonylurea class** of drugs e.g. tolbutamide, glibenclamide
**Diazoxide** stimulates KATP, and therefore inhibits Insulin release
62
What structures pass through the cavernous sinuses?
Where do the dural venous sinuses drain into?
The **internal carotid artery** passes through the cavernous sinuses, as do **Cranial Nerves III, IV, V1 and V2**
The dural venous sinuses drain into the **internal jugular veins** at the **jugular foraminae**,
63
What structures are found within the prevertebral (deep) fascial compartment?
Postural neck muscles
Cervical vertebrae
64
What two forms of insulin are included in mixed administrations? Give some examples
Mixed insulin is made up of either Short or Rapid Acting and Intermediate
Rapid Acting/Intermediate mix
* Humalog Mix25/Mix50
* NovoMix30
Short Acting/Intermediate mix
* Humulin M3
* Insuman Comb 15, 25, 50
65
From Superior to Inferior, what are the three parts that make up the brainstem?
Midbrain
Pons
Medulla (oblongata)
66
What arteries supply the brain?
The left and right **vertebral arteries** come together to form the **Basilar artery** which flows into the Circle of Willis
The left and right **internal carotid arteries** also feed into the Circle of Willis
67
What surgical fracture of the skull can be used to access the pituitary gland in more complicated cases?
**Le Fort I** fracture
68
What issue may occur at the injection site when administering insulin? How is this avoided?
Lipohypertrophy can occur - build up of fat at injection site, preventing the absorption of the insulin injection
This is prevented by ensuring that the patient is rotating their injection sites
Ask to look at the patient's injection site to assess
69
What antibodies are present in T1DM?
Usually characterised by the presence of **anti-GAD/anti-islet cell antibodies**
70
What are the typical presenting symptom of T1DM?
Classic Triad
* polyuria
* polydipsia
* weight loss
Fatigue
Blurred vision
Candidal infection
Ketoacidosis
71
What are the two options of basal insulin available? Again, give examples of each, duration and peaks
Isophane basal insulins
* Insulatard, Humulin I
* Duration of 12 hours, with peak of activity 4-6 hours
Analogue basal insulins
* Lantus, Levemir
* Longer duration of activity than the above, but less of a peak seen (flatter profile)
72
What are the aims of therapy in treating T1DM?
Prevent hyperglycaemia
* thirst, tiredness, blurred vision, weight loss, polyuria, nocturia, fungal infections
* cognitive effects, mood state, information processing, memory
* Potential risk of **DKA**
Avoid hypoglycaemia
* pallor, sweating, tremor, palpitations, confusion, nausea, hunger
* tense-tiredness, poor information processing and working memory, coma
Reduce chronic complications
* avoidance of micro/macrovascular disease
* avoidance of acute metabolic complications
73
Of the three nasal concha, which is the only one that exists as a bone it it's own right?
The **inferior nasal concha** is the only concha to exist as a bone in it's own right
The **superior nasal concha** and **middle nasal concha** are both parts of the **ethmoid bone**
74
Which HLA types are associated with T1DM?
**HLA-DR3** and **HLA-DR4**
75
What is the name of the bridging section between the right and left lobes of the thyroid gland?
The isthmus
76
Describe the route of the Vagus Nerve (CNX), superiorly to inferiorly
Branches from the **medulla oblongata**, then exits the skull through the **jugular foramen** and travels within the **carotid sheath**
Descends through the chest and splits:
* **Right -** lateral to the **trachea**
* **Left -** left side of the **aortic arch**
* **Both -** posterior to the **lung hilum** and on the oesophagus
Both Vagus Nerves pass **through the** **diaphragm with the oesophagus**
Divide into their terminal branches on the surface of the **stomach** and supply the abdominal organs with parasympathetic axons to the **distal midgut**
77
What caution must be taken when administering insulin to ensure the patient is receiving the correct dose?
That the right type of insulin is being given and with an appropriate syringe...
Insulin syringes deliver 1 unit of insulin, and using a non-insulin syringe can lead to gross inaccuracies in insulin amount
78
How much of a steroid is biologically active at any one time?
Only 10%!
Steroids are hydrophobic and have to be transported bound to plasma proteins. In this form, they are not active i.e. only unbound steroids are biologically active
79
What antibody is associated with Coeliac disease?
**Anti-TTG antibodies**
80
# Define Latent Onset Diabetes in Adulthood (LADA)
When would you suspect it?
presence of elevated pancreatic auto-antibodies in patients with 'recently diagnosed' diabetes who do not initially require insulin
Suspect when...
* age 25-40
* male preponderance
* usually non-obese
* **auto-antibody positive**
* associated autoimmune conditions
* non-insulin requiring at diagnosis
81
What non-insulin adjunct therapies can be used in the treatment of T1DM?
Metformin
Leptin
GLP-1
SGLT-2
(all of these protect beta cells, maybe not Metformin?)
82
What structures do the left and right Recurrent Laryngeal Nerves pass under?
How might injury to the Recurrent Laryngeal Nerves present?
**Left** RL Nerve passes **under the arch of the aorta**
**Right** RL Nerve passes **under the right subclavian artery**
Injury to the RL Nerves can affect phonation i.e. ability to make noise with the larynx, as seen in hoarseness causes by metastatic throat cancer
83
Name the four fascial compartments found in the neck
Prevertebral (deep) fascia
Investing fascia
Carotid sheaths (x2)
Pretracheal fasica
84
What is the downside of the twice daily insulin injection regimen?
Individuals need to eat at the correct time or risk hypoglycaemia
85
What are some of the risk factors and disease markers for clinical diabetes?
Risk factors (accelerating factors)
* infection
* insulin resistance
* puberty
* diet/weight
* stress
Disease markers
* **raised glucose**
* **ketones**
* low insulin
* low beta cell mass
* low C-peptide
86
Name some Intermediate Acting forms of Insulin
Insulatard
Humulin I
Insuman Basal
87
Describe the arterial blood supply to the thyroid and parathyroid glands, along with the vessels they originate from.
What anatomical variation exists in quite a large proportion of people and must be kept in consideration when performing a tracheotomy?
**TWO IN**
Thyroid and Parathyroid are supplied by the **Superior** and **Inferior Thyroid arteries** (parathyroid is mostly done by inferior)
Superior Thyroid artery is a branch of the **External Carotid artery**
Inferior Thyroid is a branch of the **Subclavian artery**
The **Thyroid Ima artery** is a common variation, and branches from the **Right Common Carotid artery,** running up the midline to supply the Thyroid gland at the Isthmus
88
Describe the anatomy of the sternocleidomastoid muscle, including attachments, nerve innervation, and close venous anatomical relations.
Where are these veins located and where do they drain to?
2 heads
* **Sternal head -** attaches to the **manubrium** of the sternum (inferiorly), and the **mastoid process of the temporal bone** (superiorly)
* **Clavicular head -** attaches to the **medial end of the clavicle**, and the **mastoid process of the temporal bone** (superiorly)
Innervation
* **Spinal accessory nerve** (CNXI), also supplies the **Trapezius**
Close anatomical relations
* **External jugular vein -** runs within the **superficial fascia**, drains into the **subclavian vein**
* **Anterior jugular vein** - runs within the **superficial fascia**, and drains into the **external jugular vein**
89
What fascial compartment does the platysma sit in?
In the **superficial fascia** of the neck
90
Describe the venous drainage to the Thyroid and Parathyroid glands, along with the vessels they drain to.
**THREE OUT**
**Superior** Thyroid vein - drains to the **internal jugular vein**
**Middle** Thyroid vein - drains to the **internal jugular vein**
**Inferior** Thyroid vein - both left and right drain to the **left brachiocephalic vein**
91
At what ages do the various types of diabetes mellitus typically present?
Neonatal - just after birth
T1DM - at any point between 1 year old and up to 30s. Peaks seen around 10-15 and again at late 30s
MODY - early teens to 30s, strong family history component
LADA - basically T1DM diagnosed later on, early 20s and above
T2DM - late teens and above
92
In a young patient presenting with symptoms of diabetes, a strong family history of diabetes, associated features (e.g. renal cysts) but GAD -ve and C-peptide +ve (produced whenever a molecule of insulin is produced), what might the diagnosis be?
**Monogenic diabetes** (rare cause of diabetes in which the genetic defect is in only a single gene)
93
How do sulphonylureas work?
Give some examples of this class of drug
Directly inhibit KATP by binding to **SUR1**, increasing insulin secretion
Examples - tolbutamide, glibenclamide
94
At what vertebral level is the thyroid gland?
C5-T1
95
Classify the following types of Diabetes based on the age of patient in which they may present:
* neonatal diabetes
* T1DM
* T2DM
* MODY
* LADA
* Secondary diabetes (brought about by another condition e.g. cystic fibrosis)
Neonatal - from birth to 1 years old
T1DM - birth to 30s
T2DM - 10 years old onwards
MODY - early teens to 30s
LADA - early 20s to 30s
Secondary diabetes - late teens onwards
96
Describe the lymph drainage of the Thyroid and Parathyroid glands
The Internal Jugular vein has on its surface the **Superior (deep) cervical lymph nodes** and the **Inferior (deep) cervical lymph nodes**
On the RIGHT SIDE, lymph drains into the **Right lymphatic duct** and then into the **Right Venous Angle**
On the LEFT SIDE, lymph drains into the **Thoracic duct** and then into the **Left Venous Angle**
Further lymph nodes are also present on the trachea, these being the **Pretracheal lymph nodes** and the **Paratracheal lymph nodes**
97
How is diabetes diagnosed?
How is the type of diabetes diagnosed?
* fasting glucose greater than 7 mmol/L
* random blood glucose of greater than 11.1 mmol/L
* and symptoms, OR on repeat of a test
Diagnosing the type of diabetes
* type I is often diagnosed on the history and presentation (e.g. DKA) alone
* if in doubt, **GAD/IA2 antibodies and C-peptide** may help
98
What do the lobes of the thyroid gland attach to?
Lateral aspects of the thyroid and cricoid cartilages, and the trachea
99
What are some of the risk factors and disease markers for pre-diabetes?
Risk factors (autoimmune trigger factors)
* viral infection
* vitamin D deficiency
* dietary factors
* environmental toxins
Disease markers
* Autoantibodies (GAD65, IA2)
* Candidate antigens
* Insulitis
100
What are the general HbA1c targets for diabetic individuals?
Differs based on the individual (i.e. age etc.), but generally aiming for between 48 mmol/L and 53 mmol/L
101
Describe the location of the parathyroid glands
Located on the surface of the thyroid gland.
Usually 4 with 2 on each lobe, but anatomical variation is seen - can be 3 on each side, 3 on one and 1 on the other etc.
102
Glucagon is a hormone of the ____ state.
What happens to Glucagon upon fasting? What is it's action?
STARVED state
Glucagon is RELEASED from pancreatic alpha cells in response to increased hepatic glucose output, and this RAISES blood glucose
103
What respiratory condition is Diabetes commonly associated with?
Cystic fibrosis - \>25% at 20 years
usually found in 'severe' mutations e.g. delta508
prone to complications
Insulin therapy is preferred
104
What is HbA1c useful for assessing? What % reduction in complications associated with diabetes does a 1% in HbA1c correspond to?
HbA1c is useful for measuring **longer-term control of blood glucose**
1% drop in HbA1c = 22% drop in likelihood of complications
105
What is the HLA association with T1DM? What are the highest risk genotypes?
HLA genes represent more than 50% of familial T1DM risk
Highest risk genotypes are **DR3-DQ2** and **DR4-DQ8**, which confer a 19 fold increase in risk
95% of those diagnosed with T1DM under the age of 30 have one or both of these genotypes
106
Checklist for the newly presenting Diabetic patient
Has diabetes been confirmed?
If so, what type is it? - **antibody testing**
Is hospitalisation required? - **DKA, ketonaemia, significant vomiting**
Is he/she at school/college/university?
Are they employed?
Do they drive?
107
What are some of the causes of type III DM? (think pancreatic diseases, endocrine diseases and drug-induced causes)
Pancreatic disease - chronic/recurrent pancreatitis, haemachromatosis, cystic fibrosis
Endocrine disease - Cushing's, Acromegaly, Phaeochromocytoma, glucagonoma
Drug-induced - glucocorticoids, diuretics, beta-blockers
108
Briefly describe how Insulin is normally secreted
Biphasic release in response to meals
* initial rapid phase of pre-formed insulin that lasts 5-10 mins
* slower phase released over 1-2 hours
Insulin is secreted into the portal vein, and is in response to multiple factors
109
List some of the endocrine glands
* Cranial cavity
* hypothalamus
* pituitary
* Neck
* 4 parathyroid glands (some anatomical variation)
* thyroid gland
* Abdomen
* 2 andrenal glands
* pancreas
* Pelvis (female)
* ovaries
* Perineum (male)
* testes
110
What type of receptor do the following act on...
- Insulin
- Growth Hormone
- Calcium
Insulin - **receptor kinases**, binding of insulin causes autophosphorylation
Growth Hormone - JAK2 kinase receptor
Calcium - GPCR
111
Name some Long Acting forms of Insulin
Lantus
Levemir
112
What are some of the Autoimmune conditions associated with Diabetes?
Common
* Thyroid disease
* Coeliac disease
* Pernicious anaemia
* Addison's disease
* IgA deficiency
Rare/V.rare
* autoimmune polyglandular syndromes
* AIRE mutations
* IPEX syndrome
113
What is the name of the ligament that attaches the Thyroid gland to the trachea?
Cutting this ligament during surgery can risk damage to which nerve?
How might damage to this nerve present?
**Berry's Ligament**
The **Right Recurrent Laryngeal Nerve** runs in very close proximity to Berry's ligament and surgery here can risk cutting the nerve
Injury to this nerve presents as paralysis of the vocal cords which can be either **unilateral** (hoarseness/weakness of the voice & weak cough) or **bilateral** (aphonia, the complete inability to produce sound, and the inability to close the **rima glottidis,** prevent aspiration or produce a good cough)
114
What pattern of release does cortisol normally exhibit?
When are they at their highest and lowest?
**Diurnal** (circadian rhythm) due to external cues e.g. night and day
Highest levels are about noon, and lowest levels are seen overnight. This is important when considering suppression/stimulation testing
