Pathophysiology: Exam 3

secrete somatostatin

delta cells

polypeptide molecule secreted by the alpha cells that maintains blood glucose between meals and during fasting by initiating glycogenolysis in the liver

glucagon

Body tissues obtain glucose from the blood. After meals, blood glucose levels rise and insulin is secreted to regulate blood serum levels by moving glucose into body tissues or into the liver for storage. Between meals glucose levels fall below normal causing the liver to synthesize glucose from amino acids, glycerol, and lactic acid in a process called ___ for either release into the circulation or storage as glycogen. ____ occurs when the glycogen in the liver is broken down and glucose is released into the bloodstream.

gluconeogenesis; Glycogenolysis

When produced as part of the stress response, ___ hormones aid in regulating the metabolic functions of the body and in controlling the inflammatory response. ____ stimulates glucose production by the liver, promotes protein breakdown, and causes mobilization of fatty acids.

glucosteroid; Cortisol

increase in the size of the thyroid gland

goiter

Several hormones are essential for normal body growth and maturation, including _____ .

growth hormone, insulin, thyroid hormone, and androgens

glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide that stimulate insulin secretion after heavy carbohydrate meal

gut-derived hormones

Growth hormone cannot directly produce bone growth; instead, it acts indirectly by causing the liver to produce insulin-like growth factor. The secretion is stimulated by ____ .

heavy exercise, emotional stress, hypoglycemia, fasting, starvation, increased blood levels of amino acids

decreased secretion of pituitary hormones

hypopituitarism

In an acute adrenal crisis, the onset of symptoms is sudden, and in the case of Addison disease, can be precipitated by exposure to a minor illness or stress. Mark all of those manifestions of an acute adrenal crisis.

hypotension, dehydration, vascular collapse, muscle weakness

Select the major functions of the thyroid hormone that make it necessary for growth and development in children.

increases metabolism and protein synthesis

either synthetic hormone analog of GLP-1 (Exenatide) or enzyme DPP-4 inhibitor (Sitaglipitin)

incretin-based agents

Release of insulin from the pancreatic beta cells is regulated by blood glucose levels, increasing as blood glucose levels rise and decreasing when blood glucose levels decline. What are the actions of insulin in lowering blood glucose levels? Select all that apply.

inhibits protein breakdown and increases protein synthesis by active transport of amino acids into body cells and prevents use of amino acids for gluconeogenesis provides for glucose storage in liver by entering portal circulation and traveling directly to the liver when secreted by beta cells and promotes glucose uptake by target cells by binding to membrane receptor promotes fat storage by increasing transport of glucose into fat cells, facilitating triglyceride synthesis from fat cells and inhibiting intracellular breakdown of stored triglycerides

only hormone that directly lowers blood glucose levels by glucose uptake in cells and tissues and glucose storage in liver as glycogen

insulin

act on beta cells to stimulate insulin secretion; classes include sulfonylureas and meglitinides

insulin secretagogues

primary adrenal insufficiency caused by destruction of adrenal gland

Addison disease

growth hormone levels normal or elevated, but person has a hereditary defect in insulin-like growth factor production

Laron-type dwarfism

coronary heart disease, stroke and peripheral vascular disease due to combination of unregulated blood glucose, elevated BP, and hyperlipdemia

Macrovascular disorders

biologically inactive peptide chain connecting A and B chains and released simultaneously with active insulin from the beta cells; can be used to measure beta cell function

C-peptide chain

glucose transporter present in all tissues and does not require insulin action to transport glucose into cells of the nervous system

GLUT-1

major transporter of glucose into beta cells and liver cells only when plasma glucose levels are high (e.g., after a meal)

GLUT-2

insulin-dependent glucose transporter that is sequestered inside the membrane of skeletal muscle and adipose tissue cells

GLUT-4

The most common cause of hyperthyroidism is _____, which is accompanied by ophthalmopathy and diffuse goiter. Many of the manifestations of hyperthyroidism are related to the increase in ____ consumption and use of ____ fuels associated with the hypermetabolic state, as well as to the increase in sympathetic nervous system activity.

Graves disease; oxygen; metabolic

autoimmune disorder in which the thyroid gland may be totally destroyed; presents with hypothyroid

Hashimoto thyroiditis

Immediately life-threatening complications of impaired blood glucose regulation include the following. Select all true statements.

Insidious onset of HHS with glucose >600 mg/dL, plasma osmolarity >320 mOsm/L, and dehydration, absence of ketoacidosis, and depression of sensorium resulting in seizures and coma with a poor prognosis even when treated medically by correcting hyperglycemia and hypokalemia. DKA with hyperglycemia (glucose >250 mg/dL) ketosis (+ urine and serum ketones) and metabolic acidosis (low serum bicarbonate and arterial pH) leading to osmotic diuresis, dehydration, loss of electrolytes progressing to stupor and coma; treated by improving circulatory volume and tissue perfusion and correcting hyperglycemia, acidosis and electrolyte imbalances. A rapid onset insulin reaction that occurs from a relative excess of insulin in the blood and hypoglycemia with progression of altered cerebral function and activation of the ANS, which if not treated with glucose in a concentrated source, can result in coma and seizures.

condition of goiter and congenital deafness

Pendred syndrome

closely linked to elevations in glucose and hyperlipidemia in uncontrolled DM; leading cause of blindness

Retinopathy

Pathogenesis of type 2 diabetes mellitus involves both genetic and acquired factors. Select all correct statements about this condition.

Sedentary lifestyles coupled with obesity predispose an individual with a family history to type 2 diabetes mellitus. Individuals with central obesity and/or metabolic syndrome are more likely to develop type 2 diabetes mellitus. Excessive and chronic elevation of free fatty acids can cause beta cell dysfunction, insulin resistance and glucose underutilization in peripheral tissues and, in conjunction with accumulation of triglycerides, reduce hepatic insulin sensitivity resulting in hyperglycemia and possible nonalcoholic fatty liver disease. While a positive family history results in a 2-4 times increased risk DM of occurrence, the genetics is poorly defined. As the BMI increases, the risk of developing diabetes increases due to decreasing sensitivity of tissues to insulin.

____ is the clinical syndrome that results when tissues are exposed to high levels of circulating thyroid hormone; and ____ is manifested by a very high fever, extreme cardiovascular effects, and severe CNS effects.

Thyrotoxicosis; thyroid storm

Diabetes mellitus is a disorder of insulin availability. Select all true statements about this condition.

Type 1 diabetes mellitus is characterized by destruction of the pancreatic beta cells and is either immune-mediated or idiopathic. Gestational diabetes is any degree of glucose intolerance that begins or is first recognized during pregnancy. Type 2 diabetes mellitus involves metabolic abnormalities resulting in insulin resistance, increased glucose production by the liver, and deranged secretion of insulin by the pancreatic beta cells. Secondary diabetes mellitus can occur with pancreatic disease, removal of pancreatic tissue, or with other endocrine diseases.

Type 1A immune-mediated diabetes mellitus is an autoimmune disorder in which there is destruction of beta cells. Select all true statements about this condition.

Type 1A diabetes-associated autoantibodies include insulin autoantibodies (IAA) and islet cell autoantibodies (GAD and protein tyrosine phosphatase IA-2). Most of type 1 cases of diabetes mellitus occur in individuals younger than 18 years of age and are type 1A. This condition is thought to result from diabetogenic genes; an environmental triggering event (e.g., infection); and a T-lymphocyte-mediated hypersensitivity reaction against some beta cell antigens. Inherited MHC genes on chromosome 6 that encode HLA-DQ and HLA-DR (especially DR-3 and DR-4) plus an insulin gene regulating beta cell replication and function on chromosome 11 are implicated in type 1A.

secrete glucagon

alpha cells

block action of intestinal brush border enzymes that break down complex carbohydrates delaying absorption of carbohydrates from the GI track and blunting postprandial increases in plasma glucose and insulin levels; e.g., acarbose, miglitol

alpha-glucosidase inhibitors

polypeptide co-secreted by beta cell and acts as a hormone producing inhibition of gastric emptying and glucagon secretion

amylin

secrete insulin and amylin

beta cells

inhibit heptatic glucose production and increase sensitivity of peripheral tissues to insulin; e.g., metformin

biguanides

Acromegaly is a disorder that is caused by production of excessive GH in the adult. Because the person cannot grow taller, the soft tissues continue to grow, presenting a very distinctive appearance. Select appropriate distinctive characteristic(s) of acromegaly.

broad, bulbous nose and a protruding lower jaw

The term Cushing syndrome refers to the manifestations of hypercortisolism from any cause. From the list below, mark all hallmark and other typical manifestations of this condition.

buffalo hump, thin extremities and muscle weakness, protruding abdomen, moon face

epinephrine

catecholamine that maintains blood glucose levels during periods of stress inhibits insulin release from beta cells and decreases movement of glucose into muscle cells increases breakdown of muscle glycogen stores and lypolysis of adipose cells thus conserving blood glucose for use by the brain and nervous system

growth hormone

chronic hypersecretion of this hormone, occurring in acromegaly, can lead to glucose intolerance and development of diabetes mellitus increases protein synthesis in all body cells, mobilizes fatty acids from adipose tissue and antagonizes effects of insulin

glucocorticoid hormones

cortisol, triggered by ACTH secretion by the anterior pituitary gland, stimulates gluconeogenesis by the liver prolonged hormonal secretion by the adrenal gland during periods of hypoglycemia and/or physical or emotional stress can result in hyperglycemia and diabetes mellitus in predisposed individuals steroid hormones synthesized in adrenal cortex that promote survival during periods of fasting and starvation

manifestations of untreated congenital hypothyroidism

cretinism

The term ______ implies the presence of a nonpitting mucus-type edema caused by the accumulation of hydrophobic extracellular matrix substances in the connective tissues of a number of body tissues.

myxedema

increased work demands and micoralbuminuria from poorly controlled blood glucose levels; leading cause of CKD

nephropathy

demyelinating effect of uncontrolled blood glucose resulting in autonomic and somatic nerve dysfunction

neuropathy

eyelid retraction, bulging eyes, light sensitivity, discomfort, double vision, and vision loss

ophthalmopathy

The pancreas is made up of 2 major tissue types. The ____ secrete digestive juices into the duodenum and the ___ secrete hormones into the blood.

pancreatic acini; islets of Langerhans

deficiency of all pituitary-derived hormones

panhypopituitarism

large molecule in the beta cells composed of A and B chains connected by a connecting peptide chain

proinsulin

polypetide hormone with 14 amino acids and short half-life secreted by delta cells; inhibits release of insulin and glucagon and extends the time during which food is absorbed into the blood

somatostatin

growth hormone-secreting cells

somatotropes

Hyperthyroidism that is inadequately treated can cause a life-threatening condition known as thyroid storm. What are the manifestations of a thyroid storm? Mark all that apply.

tachycardia, delirium, very high fever

target insulin resistance by increasing insulin sensitivity in insulin-responsive tissues (i.e., liver, skeletal muscle, and fat); can cause liver toxicity and fluid retention; e.g., pioglitazone, rosiglitazone

thiazolidinediones

Thyroid hormones are bound to ____ and other plasma proteins for transport in the blood. Measures of these thyroid hormones, T3, T4, and TSH, are obtained through _____ methods.

thyroxine-binding globulin; immunoassay