Endocrinology of growth and diabetes Flashcards
What is the principle factor controlling potential for growth?
Genetics (non-endocrine factor)
What are the Endocrine factors for regulation for growth?
The hormones of the growth axis (GHRH—> GH —-> IGF-1) control growth by their actions in somatic tissue and the liver.
________ is necessary for fetal growth.
IGF-1
_______ becomes important later in development after IGF-1.
GH
_________ is required for synthesis of GH and manifestation of GH effects.
thyroid hormone
________ inhibit GHRH secretions.
Glucocorticoids
T or F, glucose regulating hormones also control growth.
True
_______ has actions that opposes GH and IGF-1.
Insulin
Which gonadal steroids have a role in growth?
Testosterone and E2
How do long bones grow?
They grow as epiphyseal plate cartilage is replaced by bone. This adds bone to both ends go the diaphysis
When do the epiphyseal plates ossify? How?
At puberty, due to the actions of E2
What two hormones regulate Growth hormone (GH) secretion?
Somatostatin (SS)
GHRH
T or F, GH has direct and indirect effects on growth.
True
GH is a _______. (method of action)
Mitogen = will stimulate cell division .
GH acts in opposition to _______.
Insulin
GH also acts in somatic tissue (muscle and bone) to do what?
stimulate protein synthesis
What is the principal effect of GH on growth?
To stimulate the secretion go insulin-like growth factor 1 (IGF-1) from the liver and other tissues.
______ and _____ inhibit GH and GHRH secretion.
IGF-1 and GH
*They also stimulate SS secretion!
_________ is elevated during sleep.
GHRH
______ is elevated during the day.
SS
_____ stimulates the maturation of chondroblasts in cartilage.
GH
________ stimulates cell division.
IGF-1
What do deficits in IGF-1 and GH lead to?
Reduced growth
T or F, there are many known deficits in IGF-1 synthesis.
False, there are no known deficits (Malnutrition impairs IGF-1 synthesis independent of GH)
GH is high during _____ and low during _______.
High during adolescence and low during adulthood.
_______ regulates GH synthesis.
Thyroid hormone
_________ has anti-growth effects.
Cortisol/glucocorticoids
What causes Gigantism?
Prepubertal onset of excess GH
What causes Acromegaly?
Post-pubertal onset of excess GH
What are the symptoms of Excess of GH?
- diabetic-like condition
- Macroglossia
- increased teeth spacing
- enlarged salivary glands
- excess cementum
What does GH insufficiency cause?
Abnormally reduced growth (common, but treated prepubertally with exogenous GH)
GH insensitivity or Dwarfism, is due to _______.
Absence of a functional GH receptor (no diabetes or cancer, but often obese) * treated with exogenous IGF-1
What is Achodontroplasia?
reduced growth due to constitutive activation of the fibroblast growth factor receptor (FGF).
What does the FGF receptor do?
Normally inhibits or regulates bone growth, and continued activation of its receptor results in abnormally impaired development of cartilage.
What dental effects will patients with GH insufficiency have?
- delayed tooth shedding and replacement
- decreased salivary function leading to more caries and periodontal disease.
Diabetes is caused by what?
A disruption in the normal function of insulin.
What does insulin do?
It is a peptide hormone produced in the pancreases that normally regulates glucose transport into cells, particularly muscle, fat and liver. Insulin is an anabolic hormone that acts to store nutrients.
What are the consequences of loss of insulin function?
Can be fatal when it leads to ketoacidosis.
Insulin is released in response to _______..
an increase in blood glucose or amino acids, and signals form the parasympathetic nervous system.
Insulin secretion is inhibited by ______.
SNS
What is the difference between Type 1 and 2 diabetes?
Type 1 = autoimmune disorder in which pancreatic beta cells are destroyed -> reduced insulin production.
Type 2 = combination of insulin resistance and insulin deficiency. The onset is usually later in life and can be managed with dietary and lifestyle monitoring.
Common symptoms of diabetes relate to _______.
Increases in circulating glucose.
- Polyuria
- fatigue
- blurred vison
Symptoms Chronic hyperglycemia are primarily due to ________.
increased plasma glucose.
- kidney failure
- vascular disease
- blindess
- skin and mucosal infections
- periodontal disease
What are the considerations for dental patients with diabetes?
- Dehydration can reduce salivary flow.
- Vascular disease affects teeth
- Increased risk of periodontal disease with a diminished immune response.
For Type 1 diabetics, you could…..
give snacks or insulin during prolonged procedures if necessary
For Type 2 diabetics you could….
Emphasize the importance of maintain glycemic controls.
Type 2 diabetics also frequently have ______ and ______.
Cardiovascular and renal disease.
