Endocrine System Review

Questions and Answers

Explain how the endocrine system helps maintain homeostasis.

The endocrine system functions along with the nervous system to help maintain homeostasis by regulating the activity of body cells through hormones.

What is a hormone and what is a target cell?

A hormone is a signaling molecule that affects cells with specific receptors, known as target cells.

How do steroid hormones work?

Steroid hormones enter a cell, bind to a protein receptor, form a hormone-receptor complex, and activate specific genes in the nucleus.

How do non-steroid hormones work?

Non-steroid hormones bind to receptors on the surface of the target cell and activate a second messenger like cAMP, which triggers chemical reactions. Signup and view all the answers

Where is the pituitary gland located and what is its function?

The pituitary gland is located at the base of the brain and regulates various hormonal functions. Signup and view all the answers

Where is the hypothalamus located and what hormones does it produce?

The hypothalamus is located above the pituitary gland and produces ADH and oxytocin. Signup and view all the answers

What is the location and function of the pineal gland?

The pineal gland is located in the brain and produces melatonin. Signup and view all the answers

Where is the thyroid gland located and what are its functions?

The thyroid gland is located in the neck and produces thyroxin and calcitonin. Signup and view all the answers

Where are the parathyroid glands located and what do they do?

The parathyroid glands are located on the thyroid gland and regulate calcium levels. Signup and view all the answers

Where is the adrenal cortex located and what is its function?

The adrenal cortex is located on top of the kidneys and produces cortisol and aldosterone. Signup and view all the answers

What hormones does the adrenal medulla produce and what is their function?

The adrenal medulla produces adrenaline and noradrenaline. Signup and view all the answers

What is the location and function of the pancreas?

The pancreas is located below the stomach and produces insulin and glucagon. Signup and view all the answers

Where is the thymus located and what does it produce?

The thymus is located in the chest area and produces thymosin. Signup and view all the answers

What hormones do the ovaries produce and what are their functions?

The ovaries are located in the abdominal cavity and produce estrogen and progesterone. Signup and view all the answers

What hormone do the testes produce and what is its function?

The testes are located in the scrotum and produce testosterone. Signup and view all the answers

Study Notes

Endocrine System Overview

The endocrine system works with the nervous system to maintain homeostasis.
Hormones regulate body cell activity by altering secretion levels.
Example: Antidiuretic hormone (ADH) controls water balance.

Hormones and Target Cells

Target cells possess specific receptors for corresponding hormones.
Cells without the matching receptors do not react to hormones in the bloodstream.

Steroid Hormones

Derived from cholesterol, thus fat-soluble.
Enter cells and bind to internal protein receptors forming a hormone-receptor complex.
The complex activates specific genes in the nucleus, producing proteins that initiate chemical reactions.
Receptors are located within the cell.
End result: Gene activation leads to protein synthesis.

Non-Steroid Hormones

Not fat-soluble and cannot penetrate cell membranes.
Bind to surface receptors on target cells.
The binding converts ATP into cyclic AMP (cAMP), acting as a second messenger that triggers reactions within the cell.
Receptors are located on the cell surface.
End result: cAMP initiates a series of chemical reactions.

Principal Endocrine Glands

Pituitary Gland

Often referred to as the "master gland" due to its regulatory role over other glands and functions.

Hypothalamus

Located above the pituitary gland.
Produces ADH for water balance and oxytocin for uterine contractions.

Pineal Gland

Located in the brain.
Secretes melatonin, which promotes sleepiness.

Thyroid Gland

Situated in the neck.
Produces thyroxin which regulates metabolism and calcitonin to move calcium from blood to bones.

Parathyroid Glands

Located on the thyroid gland.
Secrete parathyroid hormone (PTH), converting bone calcium into blood calcium.

Adrenal Cortex

Found atop each kidney.
Produces cortisol, aiding stress response and aldosterone for blood pressure regulation and salt-water balance.

Adrenal Medulla

Also located on top of the kidney.
Emits adrenaline and noradrenaline, triggering the fight-or-flight response.

Pancreas (Islets of Langerhans)

Positioned below the stomach.
Produces insulin to lower blood sugar and glucagon to raise blood sugar by converting glycogen to glucose.

Thymus

Located in the chest area.
Produces thymosin, important for T-cell production and immune function.

Ovaries

Found in the abdominal cavity.
Produce estrogen, contributing to female secondary sex characteristics, and progesterone, which maintains the uterus lining.

Testes

Located in the scrotum.
Produce testosterone, crucial for male secondary sex characteristics and reproductive functions.

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Description

This quiz focuses on the functions of the endocrine system and its role in maintaining homeostasis in the body. You will explore how hormones regulate various physiological processes and contribute to overall balance. Perfect for students seeking to deepen their understanding of this vital biological system.