Chapter 16: Pineal Gland and Organ Hormones

Describe the pineal gland?

Small gland hanging from roof of third ventricle

What do pinealocytes secrete?

Melatonin, derived from serotonin

What does melatonin affect?

- Timing of sexual maturation and puberty

- Day/night cycles

- Physiological processes

- production of antioxidant/detoxification in cells

What physiological process can melatonin affect?

Body temperature, sleep, appetite

The pancreas has both _____ and ______ cells.

Exocrine and Endocrine

What does Acinar cells produce?

Exocrine cells that are enzyme rich juice for digestion

What do Pancreatic islets contain?

Endocrine cells: Alpha and Beta cells

What do alpha cells produce?

Glucagon (hyperglycemic hormone)

What do Beta cells produce?

Insulin (hypoglycemic hormone)

Acinar cells are ______ and produce ____ rich juice. Pancreatic islets contain ____ cells, consisting of Alpha cells that produce glucagon (______ hormone) and Beta cells that produce insulin (______ hormone).

Exocrine, enzyme, endocrine, hyperglycemic, hypoglycemic

Glucagon is a extremely potent hyperglycemic agent that is triggered by what?

- Decreased blood glucose levels

- Rising amino acid levels

- Sympathetic NS

How does glucagon raise blood glucose levels by targeting the liver?

- Glycogenolysis

- Gluconeogenesis

- Release glucose into blood

What do Glycogenolysis, Lipolysis, and Lipogenesis have in common?

Are catabolic

What do Gluconeogenesis and Glycogenesis have in common?

Are anabolic

Glucagon is _____ and Insulin is _____

Catabolic, Anabolic

What is secreted when blood glucose levels increase?

Insulin

What is insulin synthesized as?

Proinsulin and then is modified

How does insulin lower blood glucose?

• Enhances membrane transport of glucose into fat and muscle cells

• Inhibits glycogenolysis, gluconeogenesis, and lipolysis

What regions of the body are not needed for glucose uptake?

Brain, Kidney, and Liver

What plays a role in neuronal development, learning, and memory?

Insulin

What triggers a cell to increase glucose uptake?

Insulin binding to tyrosine kinase enzyme receptor

What is Insulins first priority when triggering cells?

To catalyze oxidation of glucose for ATP production

Insulin triggers cells to convert glucose into _____.

Fat (adipose tissue)

- lipogenesis

Insulin triggers cells to polymerize glucose to form ______.

Glycogen (muscle tissue)

- Glycogenesis

What factors influence insulin release?

- Elevated blood glucose levels (primary stimulus)

- Rising blood levels of amino acids and fatty acids

- Release of acetylcholine

- Glucagon, Epinephrine, thyroxine, GH

What inhibits insulin release?

Somatostatin and Sympathetic NS

What can diabetes mellitus (DM) be caused by?

Hyposecretion of insulin (Type 1) and Hypoactivity of insulin (Type 2)

What are three cardinal signs of diabetes mellitus?

- Polyuria (huge urine output)

- Polydipsia (excessive thirst)

- Polyphagia (excessive hunger)

What is Polyuria?

Huge urine output; Glucose acts as osmotic diuretic

What is Polydipsia?

Excessive thirst from water loss due to polyuria

What is Polyphagia?

Excessive hunger and food consumption

- cells cannot take up glucose and are "starving"

What happens when sugars cannot be used as fuel?

Fats are used causing lipidemia (high levels of fatty acids in blood)

Fatty acid metabolism results in the formation of what?

Ketones (ketone bodies)

What can the build-up of ketones in blood cause?

Ketoacidosis

Are ketones acidic or alkaline?

Acidic

What is Ketonuria?

Ketone bodies in urine

What does untreated ketoacidosis cause?

Hyperpnea, disrupted heart activity, severe depression of nervous system

True/False

Gonads produce same steroid sex hormones as those of adrenal cortex in lesser amounts

True

What do the ovaries produce

Estrogen and Progesterone

What is estrogen

Maturation of reproductive organs and Appearance of secondary sexual characteristics

What does progesterone cause?

Breast development and Cyclic changes in uterine mucosa

What do the testes produce and function as?

Testosterone

- maturation of reproductive organs

- appearance of sexual characteristics and sex drive

- sperm production

What is necessary for sperm production?

Testes

What does the placenta secrete?

Estrogens, Progesterone, and Human chorionic gonadotropin (hCG)

What hormone does Adipose tissue secrete?

Leptin

- appetite control and stimulates increased energy

What hormone does the gastrointestinal tract secrete?

Enteroendocrine cells secrete Gastrin, Ghrelin, Secretin, and CCK

What hormones does the heart secrete?

Atrial natriuretic peptide (ANP)

-

What hormones does the kidneys secrete?

Erythropoietin and Renin

What hormones does the skin secrete?

Cholecalciferol and Calcitriol

The thymus is _____ in infants and _____ with age.

large, shrinks

What hormones does the thymus secrete?

Thymulin, Thymopoietin's and Thymosins

What is Calcitriol?

Active form of vitamin D; absorbs Ca+ from intestine, decreases infammation, anticancer agent, + immunity

What is the hormone Leptin?

Appetite control (full) and stimulates increased energy

What hormones is known as the “hungry hormone” and stimulates food intake?

Ghrelin