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

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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!

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3
Q

How many ATP are produced per glucose molecule?`

A

36

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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

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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”

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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16
Q

What is the name of the structure that connects the Hypothalamus to the Pituitary gland?

A

The infundibulum

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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

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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

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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)

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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

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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

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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

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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

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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

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25
Q

Generally, what is the difference between the anterior and posterior lobes of the pituitary gland? What do they secrete?

A

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
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26
Q

What is an insulin pump?

A

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

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27
Q

For each of the following, state whether they are pre-synthesised and stored or synthesised and released on demand

  • Amines
  • Peptides and proteins
  • Steroids
A

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

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28
Q

What is the definition of Type I DM?

A

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

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29
Q

At the level of what cartilages does the isthmus lie?

A

Anterior to the 2nd and 3rd cartilages of the trachea

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30
Q

Briefly describe insulin physiology in the healthy individual

A

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

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31
Q

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
A

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
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32
Q

Cell types in the pancreatic islets - what do each secrete?

  • Alpha cells
  • Beta cells
  • Delta cells
  • PP cells
A

Alpha - GLUCAGON

Beta - INSULIN

Delta - SOMATOSTATIN

PP - PANCREATIC POLYPEPTIDE

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33
Q

What anatomical structure in the osteology of the skull does the pituitary gland sit in?

A

Pituitary gland is a midline structure in the pituitary fossa of the sphenoid bone

The pituitary fossa lies within the sella turcica (Turkish saddle)

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34
Q

Through what transporter does glucose enter beta cells?

How does a change in glucose conc. affect glucokinase activity?

A

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

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35
Q

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?

A

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

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36
Q

Describe the phasic pattern of Insulin release.

Why does this occur?

A

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

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37
Q

What structures are found within the pretracheal fascia?

A

(Located anteriorly)

Oesophagus

Trachea

Thyroid gland

Strap muscles

Recurrent laryngeal nerves

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38
Q

What two courses on Diabetes management are made available to everyone diagnosed?

A

DAFNE (dose adjustment for normal eating) and TIM (Tayside insulin management)

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39
Q

Name some Short Acting and Rapid Acting forms of Insulin

A

Short Acting

  • Humulin S
  • Actrapid
  • Insuman Rapid

Rapid Acting

  • Humalog
  • NovoRapid
  • Apidra
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40
Q

Where is the precursor to insulin formed, and what is it cleaved into?

A

Large, single prehormone called preproinsulin is formed in the rough ER of pancreatic beta cells

Cleaved to form insulin and C-peptide

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41
Q

Describe the two layers of Strap Muscles

A

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
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42
Q

What are some of the environmental triggers of T1DM?

A

viral factors

maternal factors

weight gain

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43
Q

What pattern of insulin administration is the Gold Standard for mimicking normal insulin release?

A

Basal bolus - take a long-acting dose once a day (in the evening) and a bolus of rapid-acting insulin before each meal

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44
Q

What is glycated haemoglobin?

A

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)

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45
Q

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

A

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

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46
Q

What structures are found within the investing fascia?

A

Encloses all other neck fascial compartments

Also encloses 2 pairs of muscles:

  • Trapezius
  • Sternocleidomastoid
47
Q

Give some of the biological effects of insulin

A

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
Q

What are the two options of prandial insulin available? How long do they last, when do they peak, and what are some examples?

A

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
Q

Describe venous drainage in the skull

What venous drainage surrounds the pituitary gland?

A

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
Q

1 unit of insulin equals how many grams of carbohydrate?

A

10 grams

51
Q

How does the activity of Glucokinase change in response to Glucose?

A

Small change can result is a dramatic change in Glucokinase activity

52
Q

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?

A

The Dura Mater

The Tentorium cerebelli

The Diaphragm sellae

53
Q

How is diabetes diagnosed? (3 different ways)

A
  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
Q

What level of blood glucose should Insulin be released in response to?

A

Above 5 mM

55
Q

Briefly describe the possible complications at presentation, ketone levels and weight loss in the following types of Diabetes:

  • Type I
  • Type II
  • Monogenic
  • Secondary
A

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
Q

What hormones does the anterior pituitary secrete? Bonus points for what hormone they are triggered by (6)

A

ACTH - (corticotropin-releasing hormone)

LH/FSH - (Gonadotrophin-releasing hormone)

TSH - (thyrotropin releasing hormone)

GH - (growth hormone-releasing hormone)

PRL - (dopamine)

57
Q

What are the clinical features of Bardet-Biedl Syndrome (hint: Diabetes is one of them!)

A

often very obese

polydactyly (extra fingers)

hypogonadal

visual and hearing impairment

mental retardation

diabetes

58
Q

What 4 key checks should be done prior to giving a patient insulin?

A
  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
Q

What two components make up the diencephalon?

A

The Thalamus and the Hypothalamus

60
Q

In normal function, at what threshold of blood glucose do beta cells secrete insulin?

What pattern of release is seen?

A

Above 5 mM

A biphasic release is seen in insulin resistance, with a large initial peak and a secondary smaller peak

61
Q

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?

A

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
Q

What structures pass through the cavernous sinuses?

Where do the dural venous sinuses drain into?

A

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
Q

What structures are found within the prevertebral (deep) fascial compartment?

A

Postural neck muscles

Cervical vertebrae

64
Q

What two forms of insulin are included in mixed administrations? Give some examples

A

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
Q

From Superior to Inferior, what are the three parts that make up the brainstem?

A

Midbrain

Pons

Medulla (oblongata)

66
Q

What arteries supply the brain?

A

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
Q

What surgical fracture of the skull can be used to access the pituitary gland in more complicated cases?

A

Le Fort I fracture

68
Q

What issue may occur at the injection site when administering insulin? How is this avoided?

A

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
Q

What antibodies are present in T1DM?

A

Usually characterised by the presence of anti-GAD/anti-islet cell antibodies

70
Q

What are the typical presenting symptom of T1DM?

A

Classic Triad

  • polyuria
  • polydipsia
  • weight loss

Fatigue

Blurred vision

Candidal infection

Ketoacidosis

71
Q

What are the two options of basal insulin available? Again, give examples of each, duration and peaks

A

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
Q

What are the aims of therapy in treating T1DM?

A

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
Q

Of the three nasal concha, which is the only one that exists as a bone it it’s own right?

A

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
Q

Which HLA types are associated with T1DM?

A

HLA-DR3 and HLA-DR4

75
Q

What is the name of the bridging section between the right and left lobes of the thyroid gland?

A

The isthmus

76
Q

Describe the route of the Vagus Nerve (CNX), superiorly to inferiorly

A

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
Q

What caution must be taken when administering insulin to ensure the patient is receiving the correct dose?

A

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
Q

How much of a steroid is biologically active at any one time?

A

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
Q

What antibody is associated with Coeliac disease?

A

Anti-TTG antibodies

80
Q

Define Latent Onset Diabetes in Adulthood (LADA)

When would you suspect it?

A

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
Q

What non-insulin adjunct therapies can be used in the treatment of T1DM?

A

Metformin

Leptin

GLP-1

SGLT-2

(all of these protect beta cells, maybe not Metformin?)

82
Q

What structures do the left and right Recurrent Laryngeal Nerves pass under?

How might injury to the Recurrent Laryngeal Nerves present?

A

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
Q

Name the four fascial compartments found in the neck

A

Prevertebral (deep) fascia

Investing fascia

Carotid sheaths (x2)

Pretracheal fasica

84
Q

What is the downside of the twice daily insulin injection regimen?

A

Individuals need to eat at the correct time or risk hypoglycaemia

85
Q

What are some of the risk factors and disease markers for clinical diabetes?

A

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
Q

Name some Intermediate Acting forms of Insulin

A

Insulatard

Humulin I

Insuman Basal

87
Q

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?

A

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
Q

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?

A

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
Q

What fascial compartment does the platysma sit in?

A

In the superficial fascia of the neck

90
Q

Describe the venous drainage to the Thyroid and Parathyroid glands, along with the vessels they drain to.

A

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
Q

At what ages do the various types of diabetes mellitus typically present?

A

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
Q

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?

A

Monogenic diabetes (rare cause of diabetes in which the genetic defect is in only a single gene)

93
Q

How do sulphonylureas work?

Give some examples of this class of drug

A

Directly inhibit KATP by binding to SUR1, increasing insulin secretion

Examples - tolbutamide, glibenclamide

94
Q

At what vertebral level is the thyroid gland?

A

C5-T1

95
Q

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)
A

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
Q

Describe the lymph drainage of the Thyroid and Parathyroid glands

A

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
Q

How is diabetes diagnosed?

How is the type of diabetes diagnosed?

A
  • 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
Q

What do the lobes of the thyroid gland attach to?

A

Lateral aspects of the thyroid and cricoid cartilages, and the trachea

99
Q

What are some of the risk factors and disease markers for pre-diabetes?

A

Risk factors (autoimmune trigger factors)

  • viral infection
  • vitamin D deficiency
  • dietary factors
  • environmental toxins

Disease markers

  • Autoantibodies (GAD65, IA2)
  • Candidate antigens
  • Insulitis
100
Q

What are the general HbA1c targets for diabetic individuals?

A

Differs based on the individual (i.e. age etc.), but generally aiming for between 48 mmol/L and 53 mmol/L

101
Q

Describe the location of the parathyroid glands

A

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
Q

Glucagon is a hormone of the ____ state.

What happens to Glucagon upon fasting? What is it’s action?

A

STARVED state

Glucagon is RELEASED from pancreatic alpha cells in response to increased hepatic glucose output, and this RAISES blood glucose

103
Q

What respiratory condition is Diabetes commonly associated with?

A

Cystic fibrosis - >25% at 20 years

usually found in ‘severe’ mutations e.g. delta508

prone to complications

Insulin therapy is preferred

104
Q

What is HbA1c useful for assessing? What % reduction in complications associated with diabetes does a 1% in HbA1c correspond to?

A

HbA1c is useful for measuring longer-term control of blood glucose

1% drop in HbA1c = 22% drop in likelihood of complications

105
Q

What is the HLA association with T1DM? What are the highest risk genotypes?

A

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
Q

Checklist for the newly presenting Diabetic patient

A

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
Q

What are some of the causes of type III DM? (think pancreatic diseases, endocrine diseases and drug-induced causes)

A

Pancreatic disease - chronic/recurrent pancreatitis, haemachromatosis, cystic fibrosis

Endocrine disease - Cushing’s, Acromegaly, Phaeochromocytoma, glucagonoma

Drug-induced - glucocorticoids, diuretics, beta-blockers

108
Q

Briefly describe how Insulin is normally secreted

A

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
Q

List some of the endocrine glands

A
  • 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
Q

What type of receptor do the following act on…

  • Insulin
  • Growth Hormone
  • Calcium
A

Insulin - receptor kinases, binding of insulin causes autophosphorylation

Growth Hormone - JAK2 kinase receptor

Calcium - GPCR

111
Q

Name some Long Acting forms of Insulin

A

Lantus

Levemir

112
Q

What are some of the Autoimmune conditions associated with Diabetes?

A

Common

  • Thyroid disease
  • Coeliac disease
  • Pernicious anaemia
  • Addison’s disease
  • IgA deficiency

Rare/V.rare

  • autoimmune polyglandular syndromes
  • AIRE mutations
  • IPEX syndrome
113
Q

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?

A

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
Q

What pattern of release does cortisol normally exhibit?

When are they at their highest and lowest?

A

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