Endocrine disorders Flashcards
1
Q
causes of hypersecretion
A
- secretory tumor
- increased trophic stimulation
- defective negative feedback loop
2
Q
causes of hyposecretion (and examples)
A
- no trophic stimulation (atrophy)
- receptor defect (nephrogenic diabetes insipidus)
- immune disorder (autoimmunity)
- suppressive therapy (overcorrection; hyper to hypo)
- dietary deficiency (iodine for thyroid)
- metabolism defect (missing enzyme)
3
Q
In the islets of langerhans, beta cells produce ____ and alpha cells produce _____
A
insulin
glucagon
4
Q
what is diabetes mellitus
A
defective insulin secretion and/or action
5
Q
what are the 2 types of insulin deficiency
A
- absolute deficiency (absent/little produced)
- relative deficiency (present but ineffective)
6
Q
type 1 diabetes mellitus is what type of deficiency
A
absolute
7
Q
what type of diabetes mellitus is early onset
A
type 1
8
Q
what are the 2 types of type 1 diabetes mellitus and what are their cause and prevalance
A
1A: immune-mediated: 90-95%
1B: idiopathic: 5-10%
9
Q
what % of diabetes mellitus is type 1
A
10%
10
Q
what % of diabetes mellitus is type 2
A
90%
11
Q
type 2 diabetes mellitus is what type of deficiency
A
relative
12
Q
what is LADA
A
latent autoimmune diabetes in adults
type 1A manifesting in adults
13
Q
what is MODY
A
maturity-onset diabetes in the young
type 2 in the young d/t poor lifestyle
14
Q
diabetes mellitus is what type of genetic abnormality
A
complex trait (multifactorial) genetics + environment
15
Q
type 1 diabetes mellitus has what type of risk
A
familial risk (10x)
16
Q
causes of type 1 diabetes mellitus
A
- defective insulin gene on chromosome 11
- T cell hypersensitivity to beta cell Ag
- defective MHC genes on chromosome 6
17
Q
40% of type 1 diabetes mellitus is caused by
A
defective MHC genes on chromosome 6
18
Q
the insulin gene on chromosome 11 codes for
A
a protein that regulates division and functioning of beta cells (therefore insulin secretion)
19
Q
how does a defective MHC gene cause type 1 diabetes mellitus
A
beta cells are recognized as foreign, Ab’s target and destroy them
20
Q
type 2 diabetes mellitus has a strong but ______ genetic involvement
A
unclear
21
Q
50% of type 2 diabetes mellitus is caused by
A
a defective glucokinase gene on chromosome 7
22
Q
the glucokinase gene codes for
A
a protein called glucokinase enzyme which is responsible for phosphorylation
23
Q
what is phosphorylation
A
when glucose enters a cell and attaches to phosphate it becomes phosphorylated and cannot leave the cell
24
Q
what are the criteria for prediabetes
A
- IFG (impaired fasting glucose) 6.1-6.9
- IGT (impaired glucose tolerance) 7.8-11
- HbA1C 6-6.4%
25
what is a fasting glucose test
testing after a 10 hour fast
26
what is a normal fasting glucose test range
3.5-5.5
27
what is a glucose tolerance test
fasting, oral glucose solution give, monitor BG for 2 hours
28
what does HbA1C measure
the 1C form of Hb
29
glucose binds HbA1C d/t
high affinity
30
what does metabolic syndrome predispose someone to
CVD
| type 2 diabetes mellitus
31
parameters of metabolic syndrome
- IFG
- IGT
- insulin resistance
- hyperlipidemia
- abdominal obesity
- HTN
32
in type 1 diabetes mellitus with a defective MHC gene, Ab's target
self-antigens on the surface of beta cells and islet cells
33
in type 1 diabetes mellitus with T cell hypersensitivity, T cells infiltrate ______ causing ______
islets of Langerhans, causing insulitis
34
what is insulitis
inflammation of the islets of Langerhans
35
what are the 4 types of relative insulin deficiency in type 2 diabetes mellitus
- delayed secretion
- target cell problem
- insulin resistance
- hepatic glucogenesis
36
in type 2 diabetes insulin levels are
normal, high, or low
37
in type 1 diabetes, insulin levels are
low and none at all
38
how is degree of damage determined in type 2 diabetes mellitus
amyloid deposits in the islets of Langerhans
39
in type 2 diabetes mellitus, increased hepatic glucose output is caused by
a perceived lack of glucose d/t mutated glucokinase preventing phosphorylation
40
in type 2 diabetes mellitus, there is decreased glucose uptake due to
mutated glucokinase preventing phosphorylation
41
insulin deficiency (absolute/relative) causes
impaired glucose utilization and increased hepatic glucogenesis d/t a perceived lack of glucose
42
when hyperglycemia occurs, ____ is exceeded causing ______
the renal threshold for glucose causing glucosuria
43
glucosuria causes what to increase
osmotic pressure in the filtrate
44
increased osmotic pressure in the filtrate causes increased ________, causing ____
fluid movement to the filtrate, causing polyuria
45
polyuria causes ____ and ____
dehydration and polydipsia
46
once above the renal threshold everything else will be ___
excreted
47
impaired glucose utilization by cells will cause
increased mobilization and use of lipids and proteins
48
mobilization and use of lipids and proteins will increase what
metabolites in the blood (ketones)
49
elevated levels of ketones cause
ketonuria
50
manifestations of diabetes mellitus
```
3 P's:
- polyuria
- polydipsia
- polyphagia
type 1: weight loss
type 2: obesity
complications
```
51
why does type 1 diabetes mellitus cause weight loss
d/t glucose not being stored
52
why is insulin not take PO
because it is a hormone and also a protein that will be broken down by enzymes in the stomach
53
hypoglycemia is more frequent in type _ DM because
1
| they are taking insulin injections
54
causes of hypoglycemia
- insulin overdose/mismanagement
- missed meal
- overexertion (depletion of glucose/glycogen stores)
55
hypoglycemia = < __ mmol/L
4
56
neurons rely on _____ for energy but do not require _____
glucose
| insulin
57
severe hypoglycemia = < _ mmol/L
2.8
58
treatment of mild hypoglycemia
15g CHO
59
treatment of severe hypoglycemia
20g CHO
60
a byproduct of lipid metabolism is
ketones
61
the breakdown of free fatty acids from _____ stores in _____ tissue produces _______
triglyceride
adipose
ketones
62
formation of glucose from a non-carbohydrate source is called
gluconeogenesis
63
diabetic ketoacidosis can cause _____ shock d/t ______
hypovolemic shock d/t dehydration
64
diabetic ketoacidosis presents as
intoxication
65
hypoglycemia affects _____ function and activates the ____
cerebral function
| ANS
66
hypoglycemia coma is caused by
glucose deprivation in the brain
67
treatment of hypoglycemic coma
1mg glucagon IM/SC
| 20-50mL 50% glucose IV
68
requirements for diabetic ketoacidosis
- hyperglycemia
- ketosis
- metabolic acidosis
69
the breakdown of lipids is called
lipolysis
70
lipolysis forms
- free fatty acids
| - glycerol
71
FFA are metabolized by the ____ and release ____
liver
| ketones
72
diabetic ketoacidosis usually occurs in type _ DM
1
73
HHS usually occurs in type _ DM and ____
2
| the elderly
74
why does ketoacidosis not occur in type 2 DM
because insulin is present so there is no lipolysis
75
hyperosmolar hyperglycemic state is a state of
elevated blood glucose and elevated glucose concentration
76
HHS is caused by
- excessive CHO intake
| - persistently elevated insulin resistance
77
other ways HHS can occur are
- MI
- severe infection
- pancreatitis
78
in HHS, hyperglycemia --> ________ --> cellular efflux --> _________ --> fluid loss --> _______
hyperosmolarity
glucosuria
dehydration
79
acute complications of diabetes
- hypoglycemia
- diabetic ketoacidosis
- hyperosmolar hyperglycemic state
80
chronic complications of diabetes
- microvascular (nephropathy, retinopathy, neuropathy)
- macrovascular (atherosclerosis, CAD, MI, CVA, PVD)
- infections
81
chronic complications of diabetes are due to
altered metabolites and vascular damage
82
chronic complications of diabetes occur
10-15 years post-onset
83
increased blood glucose will cause proteins to become ______ and _______
glucosylated
| dysfunctional
84
microvascular damage involves
capillaries
85
macrovascular damage involves
arteries
86
causes of vascular damage in diabetes mellitus
- altered metabolism
- glycosylated proteins
- proliferation of anaerobic bacteria
- poor healing
87
glycosylated proteins deposit on the ___________ causing
endothelial surface
| impaired function of the trans-capillary exchange, platelet aggregation and decreased perfusion
88
Hb not offloading oxygen properly (decreased delivery) is an example of a _____ ______ becoming dysfunctional
glycosylated protein
89
why does proliferation of anaerobic bacteria occur in diabetes
- thrives in low oxygen conditions
| - damaged vessels cause impaired perfusion (low oxygen)
90
poor healing in diabetics is due to
damaged vessels have low perfusion
| delivery of defense cells and oxygen is low and waste removal is slow
91
5 things oral hypoglycemics do
- stimulate the release of insulin
- increase tissue response to insulin
- decrease hepatic glucogenesis
- delays breakdown and absorption of CHO
- blocks DPP-4 enzyme (increases release of insulin after a rise in BG)
92
what hormones does the thyroid release
T3 (triiodothyronine)
| T4 (thyroxine)
93
iodine is required for the synthesis of
thyroid hormones
94
why is T4 given instead of T3 for hypothyroid treatment
- T4 is naturally converted to T3 in the body (allows natural process to occur)
- the half-life of T4 is longer than T3
95
how does T4 become T3
when T4 contacts blood cells, iodine is removed and becomes T3
96
what hormones does the adrenal medulla secrete
epinephrine and norepinephrine
97
what groups of hormones does the adrenal cortex secrete (and an example of each)
- glucocorticoids (ex. cortisol)
- mineralocorticoids (ex. aldosterone)
- androgens (ex. testosterone, DHT)
98
what hormones does the hypothalamus release
- oxytocin
- ADH
- thyroid releasing hormone (TRH)
99
what hormones does the posterior pituitary synthesize
none
| it stores oxytocin and ADH until triggered to release them
100
what hormones does the anterior pituitary synthesize
- thyroid-stimulating hormone (TSH)
| - adrenocorticotropic hormone (ACTH)
101
what disease is an example of hyperthyroidism
Grave's disease
102
what disease is an example of hypothyroidism
Hashimoto's thyroiditis
103
a toxic goiter has what type of secretion
hypersecretion
104
an endemic goiter has what type of secretion
hyposecretion
105
a toxic goiter will present as what
a nodular gland
106
iodine deficiency causes
decreased levels of T3/T4 and compensatory high levels of TSH
107
what are the 3 hallmarks of Grave's disease
- hyperthyroidism
- goiter
- exophthalmos
108
what are protruding eyes called (as in Grave's disease)
exophthalmos
109
what do 1st, 2nd, and 3rd degree hypothyroidism affect
1: thyroid
2: pituitary
3: hypothalamus
110
what are the 2 main steps in hashimoto's thyroiditis
- Ab's recognize and block TSH receptors (preventing TSH binding) leading to decreased T3/T4 levels
- lymphocytes infiltrate and destroy the gland
111
what are the 2 main steps in Grave's disease
- TSAb's (thyroid stimulating antibodies) target TSH receptors and mimic TSH, increasing stimulation and T3/T4 release
- increased TH release triggers the negative feedback loop and decreases TSH release
112
what is the main complication of hyperthyroidism
thyrotoxicosis
113
3 things glucocorticoids do
- decrease inflammation
- suppress the immune response
- altered metabolism of proteins and fats
114
6 things Cushing's syndrome causes
- gluconeogenesis (protein catabolism)
- hyperglycemia & insulin resistance
- HTN & hypokalemia
- fat deposits
- infection
- male sex characteristics in women
115
3 causes of adrenal hypersecretion
- cortical tumor
- anterior pituitary tumor
- ectopic secretory tumor
116
what is dexamethasone and what is it used to diagnose
a potent glucocorticoid (steroid)
| Cushing's Syndrome
117
how is dexamethasone used to diagnose Cushing's
administration will trigger the negative feedback loop and decrease ACTH release, therefore cortisol should decrease
if upon admin ACTH levels do not decrease, it is being released from somewhere else (ectopic tumor)
118
why does hyperpigmentation occur with addison's disease
low aldosterone levels will not trigger the negative feedback loop... increased levels of ACTH release
when ACTH is broken down the intermediate is MSH (melanocyte stimulating hormone)
increased levels of MSH stimulate melanocytes which are responsible for melanin secretion which causes pigment
119
ADH is also known as
vasopressin
120
Is Conn syndrome hypo or hypersecretion and of what
hyperaldosteronism
121
what are 3 manifestations of Conn syndrome
- HTN
- hypokalemia
- alkalosis
122
what type of secretory disease is Addison's Disease
hypoaldosteronism
123
what are 2 causes of Addison's disease
classic autoimmunity
| increased steroid treatment causing decreased ACTH
124
what are 5 manifestations of Addison's disease
- hypotension
- hyperkalemia
- appetite and weight loss
- hyperpigmentation
- weakness and fatigue
125
which pituitary disorder involves ADH hypersecretion
Syndrome of inappropriate ADH (SIADH)
126
what does SIADH cause
water retention causing dilutional hyponatremia
127
diabetes insipidus is hypo or hyper secretion of what
hyposecretion of ADH
128
someone with diabetes insipidus is unable to do what
concentrate their urine d/t a lack of aquaporins
129
2 manifestations of diabetes insipidus
- polyuria
| - polydipsia
130
2 types of diabetes insipidus
neurogenic (central)
| nephrogenic
131
neurogenic diabetes insipidus is a defect in what
the synthesis or release of ADH
132
nephrogenic diabetes insipidus happens because the ______ don't respond to _____
kidneys don't respond to ADH
133
complications of diabetes insipidus
dehydration (low BP, high HR, headache, kidney damage)
134
what are 2 drugs that can be given to someone with diabetes insipidus
ADH
| a thiazide diuretic
