Endocrine System & Glands

What is the overall effect of calcitonin ?

The overall effect of calcitonin is to lower the concentration of calcium in the blood when it rises above the normal value.

What are functions of pancreatic polypeptide ?

-Increases gut motility -Gastric emptying -Inhibits the secretion of pancreatic enzymes -Contraction of the gall bladdr

By which processes parathyroid hormone accomplish its function?

1.Mobilizes calcium from the bone 2.Enhances the absorption of calcium from the small intestine 3.Supression of calcium loss from the urine. The production of the active form of vit. D in the kidney is stimulated.

What are the 4 types of cells produced by the islets of langerhans ?

1.βcells which produce insulin 2.αcells produce glucagon 3.D cells produce somatostatin 4.F or PP cells produce pancreatic polypeptide

Which hormone is released from preganglionic nerves?

Acetylcholine

Where are the receptors for the catecholamines ?

Adrenergic receptors that are located on target tissues.

What two hormones force contraction of heart rate?

Both epinephrine and norepinephrine interact with β1 receptors to increase both the force of contraction and the heart rate.

This hormone is responsible for "fight-or-flight" response a Thyroxine and melatonin b insulin and glucagon c epinephrine and norepinephrine d oestrogen and progesterone E Melatonin and insulin

c epinephrine and norepinephrine

What does calcitonin act as ?

Calcitonin acts as a counterbalance to PTH because it causes hypocalcemia and hypophosphatemia.

What molecule does calcitonin increase the movement of ?

Calcitonin increases movement of phosphate from the ECF into bone.

How do catecholamines promote arteriolar constriction?

Catecholamines may also promote arteriolar constriction through interaction with α receptors.

Which substances stimulate the secretion of pancreatic polypeptide ?

Cholecystokinin, secretin and gastrin

What are the cells called which synthesise catecholamines?

Chromaffin cells

Which diabetes is most common in dogs ?

DM type 1 is most common in dogs

Diabetes Mellitus

Deficiency of insulin production produces a syndrome called diabetes mellitus(DM).

Which is the main hormone of the adrenal medulla ?

Epinepherine

What does epinephrine relax ?

Epinephrine causes relaxation of bronchial smooth muscle and relaxation of the uterus.

How does epinephrine promote erection?

Epinephrine promotes erection through vasodilation of the vasculature mediated by βreceptors.

How does epinephrine promote lipolysis ?

Epinephrine promotes lipolysis through interaction with two receptors on adipose cells.

What causes dilation of blood vessels ?

Epinephrine through its high affinity for β2 receptors, causes the dilation of blood vessels both in the heart and in skeletal muscle.

What produces pancreatic polypeptides ?

F cells in the pancreas

Stimulation of which nerve fibers cause epinephrine and norepinephrine to be released ?

Following stimulation of preganglionic nerve fibers of the adrenal medulla, norepinephrine and epinephrine are released.

What type of glucagon is produced by the small intestine ?

Glicentin

What produces glucagon?

Glucagon is a protein hormone produced by the α cells of the islets of Langerhans.

When does glucagon secretion begin ?

Glucagon secretion begins with the ingestion of food and increases during the fasting period and blood glucose concentrations begin to decline.

What does epinephrine do in the eye ?

In the eye, epinephrine causes relaxation of the lens through stimulation ofβreceptors on the ciliary muscles.

What is the function of Parathyroid glands?

Increase calcium and decrease phosphate concentrations in ECF's

What is the purpose of insulin ?

Insulin is a hormone that regulates the level of sugar (glucose) in the blood .Insulin is secreted when the level of blood glucose rises.

How is insulin metabolised ?

Insulin is metabolized mainly by the liver and kidney.

What types of cells make up the pancreas ?

Islets of the Langerhans

In which organs is Parathyroid organ(PTH) rapidly metabolised?

Liver and Kidneys

How are most vitamin D molecules carried ?

Most of vitamin D is carried in association with a specificαglobulin called transcalciferin (vitamin D binding protein),a molecule synthesized by the liver.

Which two hormones are catecholamines ?

Norepinephrine and Epinephrine

In what area of the kidneys does PTH act on ?

PTH acts on the distal convoluted tubules of the kidneys to increase absorption of calcium and decrease renal phosphate reabsorption through an effect on the proximal tubule.

Which organ is the main organ involved in the control of calcium and phosphate metabolism ?

Parathyroid Gland

Which animal only has one pair of parathyroid glands?

Pig, lies anterior to the thyroid

What inhibits the secretion of insulin ?

Somatostatin

What reduces the motility and secretory activity of the G.I tract ?

Somatostatin

What is somatostatin ?

Somatostatin is also called growth hormone-inhibiting hormone, and inhibits hormones released from the anterior pituitary gland and gastrointestinal system as well as the pancreas.

What does Parathyroid hormone promote?

The PTH promotes the transfer of calcium across the osteoblast- osteocyte membrane and its major target cells are that of the bone and kidney.

What is the acute stress response ?

The fight or flight response

Why is the liver an important target organ?

The liver is an important target organ, in part because the pancreatic venous effluent passes directly to the liver

What is the main stimulus to glucagon ?

The main stimulus to glucagon is hypoglycemia

What is the main suppressor to glucagon ?

The main suppressor is hyperglycaemia

What type of glucagon does the stomach produce ?

The stomach also produces a molecule called gut glucagon.

What do beta cells do in relation to catecholamines?

These affect the heart, smooth muscle contraction and intermediary metabolism.(β1, β2)

What causes Type 1 diabetes ?

Type 1 is caused by an autoimmune destruction of the βcells of the pancreas and is characterized by complete insulin deficiency.

What is the most common type of diabetes in cats?

Type 2 is most common in cats. (DI)

What is the vitamin D regulate ?

Vitamin D is required for the regulation of calcium and phosphorus found in the body and is important for the absorption of calcium from the gut.

Effects of hypothyroidism include all but this a. Diarrhea b. lethargy c. Alopecia d. Weight gain e. Anemia

a. Diarrhea

Which of these glands is not an endocrine gland a Adrenal b Pituitary c Lacrimal d Thyroid

c Lacrimal

Which one of these syndromes is caused by a dysfunction of the pituitary glands? a. Cushing'sDisease b. Addison's diseases c. Diabetes insipidus d. Goiter e. Gravesdisease

c. Diabetes insipidus

The main functions of the catecholamines are to allow rapid body responses to acute stimuli, which include the mobilization of glucose. The catecholamines are secreted by the sympathetic portion of the autonomic nervous system. The main neuro- transmitter of the sympathetic nervous system is ___________,whereas __________________ is the main hormone produced by the postganglionic cells of the adrenal medulla. a. Serotonin; epinephrine b.Epinephrine; serotonin c. Epinephrine; norepinephrine d. Norepinephrine; epinephrine e. Serotonin; melatonin

c. Epinephrine; norepinephrine

What do alpha cells control ?

control catecholamine release from sympathetic nerve ending.(α1,α2)

Twohormonesplayanimportantroleincalciumhomeostasis. The two hormones, __________ and _________________,cause an increase and a decrease in calcium concentrations respectively: a. Calcitonin; glucagon b. Somatostatin; calcitonin c. Calcitonin; parathyroid hormone d. Parathyroid hormone; calcitonin e. Parathyroid hormone; glucagon

d. Parathyroid hormone; calcitonin

Which amino acids are precursors to catecholamines?

phenylalanine and tyrosine