BISC220 Exam #4 (Final)

What is the endocrine system's primary function?

Maintaining homeostasis through the production and release of hormones.

What are hormones?

Chemical signaling molecules that are typically capable of travelling long distances through the bloodstream to reach organs in the periphery.

What are central hormones?

Hormones produced in the hypothalamus and stored and released from the pituitary glands.

What are peripheral hormones?

Hormones produced in peripheral glands in response to a central hormone.

What are trophic hormones?

Hormones that target cells that produce hormones in response.

What are non-trophic hormones?

Hormones that do not lead to downstream hormone production.

What are amine hormones?

Polar hormones that contain amine groups (NH).

What are peptide/protein hormones?

Polar hormones that are made from amino acids.

What are steroid hormones?

Nonpolar hormones derived from cholesterol and considered to be lipids.

Steroid hormones mostly consist of what type of hormones?

Sex hormones

Which pituitary gland is directly connected to the hypothalamus?

Posterior pituitary gland

Which pituitary gland is not directly connected to the hypothalamus?

Anterior pituitary gland

How do hormones produced in the hypothalamus reach the anterior pituitary gland?

The portal vein system

Why is the portal vein system a misnomer?

It is actually a capillary system

What type of hormones are released from the hypothalamus?

Primary central hormones

Which primary central hormones travel from the hypothalamus to the anterior pituitary gland?

Thyrotropin Releasing Hormone (TRH)

Gonadotropin Releasing Hormone (GnRH)

Corticotropin Releasing Hormone (CRH)

Prolactin Releasing Hormone (PRH)

Growth Hormone Releasing Hormone (GHRH)

Which primary central hormones travel from the hypothalamus to the posterior pituitary gland?

Oxytocin

Vasopressin (Antidiuretic Hormone (ADH))

What part of the hypothalamus houses the hunger response?

Arcuate nucleus

What hormone induces hunger?

Ghrelin

Where is ghrelin made, and what type of hormone is it?

In the stomach; peptide

What two hormones induce satiety (fullness)?

Leptin and insulin

Where is leptin made?

Adipose (fat) tissue

Where is insulin made?

Pancreas

What hormone made in the small intestine also induces satiety?

Cholecystokinin (CCK)

What does it mean for a drug to be an agonist?

It mimics a hormone/neurotransmitter

GLP-1 is an example of what type of hormone?

Leptogenic hormones, which increase satiety.

What is another name for the posterior pituitary gland?

Neurohypophysis

Which pituitary gland is part of the CNS?

Posterior pituitary gland

Which pituitary gland is larger?

Anterior pituitary gland

Which pituitary gland produces its own hormones?

Anterior pituitary gland

How does the posterior pituitary gland function?

It stores and releases oxytocin and vasopressin in response to feedback from peripheral organs and glands.

The anterior pituitary gland is also known by what name?

Adenohypophysis

What hormones are produced in the anterior pituitary gland?

Thyroid Stimulating Hormone (TSH)

Adrenocorticotropic Hormone (ACTH)

Follicle Stimulating Hormone (FSH)

Lutenizing Hormone (LH)

Growth Hormone (GH)

Prolactin (PRL)

The Hypothalamic-Pituitary-Gonad (HPG) Axis is mostly dormant until what event?

Puberty

What is short-loop inhibition?

When products inhibit the reaction leading to their production

What is long loop inhibition?

When products inhibit a reaction earlier in the pathway leading to their production that is not the reaction directly before

Gonadotropin-releasing hormone (GRH) triggers the production and secretion of what hormones?

Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH)

FSH and LH trigger the production of what in the gonads?

Sperm, eggs, and sex hormones

Thyroid releasing hormone (TRH) leads to the production of what hormone?

Thyroid Stimulating Hormone (TSH)

TSH triggers the production of what hormones in the thyroid?

Triiodothyronine (T3) and Thyroxine (T4)

Where does almost 100% of dietary iodine go to in the body?

Thyroid (to produce T3 and T4)

T3 and T4 regulate which processes?

Hair/nail growth

Skin cell replenishment

Weight and metabolism

Energy

What hormone is produced in the parathyroid glands?

Parathyroid hormone (PTH)

What is the main function of PTH?

Maintain blood calcium homeostasis

When blood calcium levels are high, what is activated?

Osteoblasts, which increase deposition of calcium into bone tissue

When blood calcium levels are low, what is activated?

Osteoclasts, which break down calcium in bone tissue and restore it to blood

Corticotropin releasing hormone (CRH) leads to the production and secretion of what hormone?

Adrenocorticotropic Hormone (ACTH)

ACTH triggers the production of what hormone in the adrenal glands?

Cortisol

What is cortisol's main function?

Regulate stress response

What type of hormone is cortisol?

Steroid hormone

What are the symptoms of hypothyroidism?

Cold intolerance

Dry hair

Puffy face

Goiter

Slow heartbeat

Weight gain

Constipation

What are the symptoms of hyperthyroidism?

Heat intolerance

Hair loss

Bulging eyes

Goiter

Rapid heartbeat

Weight loss

Diarrhea

What are examples of hyperthyroid diseases?

Graves' disease and Thyroid Eye Disease (TED)

What is goiter?

The swelling of the thyroid gland

What is the main cause of goiter?

Lack of iodine

What does the liver do when body cells (especially muscles and neurons) require energy?

Break down glycogen into glucose

What hormone is released from the pancreas when blood sugar increases?

Insulin

What does insulin trigger?

The liver to build glycogen from glucose

What hormone is released from the pancreas when blood sugar decreases?

Glucagon

What does glucagon trigger?

The liver to break down glycogen into glucose

What is the homeostatic blood glucose level?

90 mg glucose per 100 mL blood

What type of diabetes mellitus is usually genetic?

Type I diabetes

What type of diabetes mellitus is usually lifestyle-related?

Type II diabetes

What is type I diabetes?

When the pancreas is unable to produce enough insulin

What is type II diabetes?

When the body has developed a high tolerance to insulin

What does A1C measure?

The percentage of hemoglobin that is binding glucose (glycated hemoglobin)

What is healthy A1C?

Less than or equal to 5.7

What is prediabetic A1C?

5.7 to 6.5

What is diabetic A1C?

7 or higher

how do lipids used to synthesize hormones move through the bloodstream?

They travel in protein shells (called lipoproteins)

High-density Lipoproteins (HDL) are associated with what?

Lipid transport to the liver (out of blood)

Low-density Lipoproteins (LDL) are associated with what?

Lipid accumulation in blood

Where are lipoproteins made?

Liver and small intestine

What is the base molecule of lipoproteins?

Chylomicron

What are organization changes?

Changes that typically occur before birth

What are activational changes?

Changes that typically occur after birth

Why do men have nipples?

Nipples form in week 4 of embryonic development, while the SRY gene that initiates masculinization is activated around week 7.

What cells secrete testosterone?

Leydig cells

What is the male gamete?

Spermatozoa

What is the female gamete?

Ova

What is the male sex hormone?

Testosterone

What is the female sex hormone?

Estrogen and progesterone

How do hermaphroditic species asexually reproduce?

They are capable of possessing both male and female reproductive organs

How do parthenogenetic species asexually reproduce?

They can asexually reproduce without fertilizing eggs

What sex do the wolffian ducts correspond to?

Males

What causes wolffian ducts to mature?

The activation of the SRY gene and increased levels of testosterone and testis-determining factor (TDF)

What sex do müllerian ducts correspond to?

Females

What causes müllerian ducts to mature?

Absense of the SRY gene

What causes müllerian ducts to disappear?

Increased levels of müllerian-inhibiting substance (MIS) during defeminization

What are aromatases?

Enzymes that convert testosterone to estrogen

Increased testosterone leads to increased activation of what receptors?

Androgen receptors (AR)

What results from the activation of androgen receptors?

Masculinization of certain brain regions

What are the external structures of the male reproductive system?

Penis

Scrotum

What are the internal structures of the male reproductive system?

Accessory Glands

Vas Deferens

Epididymis

Testes

Where do sperm mature and where are mature sperm stored?

Epididymis

Which accessory gland do mature semen pass through first?

Seminal vesicles

What is found in the fluid produced in the seminal vesicles?

Fructose, Vitamins, Enzymes, and Prostaglandins

What is in prostatic fluid (produced in the prostate gland)?

Citric acid and other enzymes

Why are fructose and citric acid important for the transportation of sperm?

They aid ATP production

Which accessory gland contracts to prevent backflow of semen into the bladder?

Prostate gland