Endocrine System Flashcards

Questions and Answers

How are the endocrine and nervous systems similar and different?

They both maintain homeostasis. However, the endocrine system has slow, long-term effects while the nervous system has fast, short-lived effects.

Why do cells communicate?

To coordinate activities and preserve homeostasis.

What are the four different mechanisms of cell communication?

Direct, paracrine, endocrine, and synaptic.

How are hormones categorized by chemical structure?

Amino Acid Derivatives, Peptide hormones, and Lipid derivatives. Signup and view all the answers

What can happen to a hormone that is freely circulating through the bloodstream?

It can remain functional for less than an hour, diffuse out of the bloodstream, or get broken down. Signup and view all the answers

How does binding with a carrier protein affect the stability of a hormone?

It will remain much longer in the bloodstream. Signup and view all the answers

How is specificity achieved in hormone response?

It is achieved through the ability of a cell to bind to a specific carrier protein. Signup and view all the answers

What type of hormones would interact with a membrane receptor and what type would interact with an intracellular receptor?

Membrane receptors interact with peptide and amino acid-derived hormones; intracellular receptors interact with lipid-soluble hormones. Signup and view all the answers

Why are second messengers sometimes necessary?

They amplify the information and change intracellular functions. Signup and view all the answers

How can target cell activity change in response to a hormone?

The target cell can alter its metabolism, gene expression, or function in response to a hormone. Signup and view all the answers

What kinds of stimuli can cause an endocrine reflex to occur?

Humoral, hormonal, and neural. Signup and view all the answers

What is the difference between a simple endocrine reflex and a complex endocrine reflex?

A simple reflex involves only one hormone; a complex reflex involves intermediary steps and two or more hormones. Signup and view all the answers

In what three ways does the hypothalamus control the endocrine system?

Production of ADH and oxytocin, secretion of regulatory hormones to control the anterior pituitary gland, control of sympathetic output to adrenal medullae. Signup and view all the answers

What is the relationship between the structure and function of the hypophyseal portal system?

It connects the hypothalamus to the anterior pituitary, facilitating hormone transport. Signup and view all the answers

How do hypothalamic hormones regulate the activity of the anterior pituitary gland?

They stimulate or inhibit the synthesis and secretion of hormones from the anterior lobe. Signup and view all the answers

Which seven hormones are secreted by the anterior pituitary gland?

TSH, ACTH, FSH, LH, prolactin, growth hormone, melanocyte-stimulating hormone. Signup and view all the answers

What is the function of TSH, and how is its secretion regulated?

It stimulates the release of TH from the thyroid gland and is regulated by TRH from the hypothalamus. Signup and view all the answers

What is the function of ACTH, and how is its secretion regulated?

It stimulates the release of glucocorticoids by the adrenal cortex and is regulated by CRH from the hypothalamus. Signup and view all the answers

What are the functions of FSH and LH, and how is the secretion of gonadotropins regulated?

FSH promotes follicle development and estrogen secretion in females, and sperm maturation in males; LH promotes ovulation and progesterone secretion in females, and testosterone secretion in males. Their secretion is regulated by gonadal activity. Signup and view all the answers

What is the function of PRL, and how is its secretion regulated?

It stimulates mammary gland development and milk production; secretion is stimulated by prolactin-releasing factors from the hypothalamus. Signup and view all the answers

What is the function of GH, and how is its secretion regulated?

It stimulates cell growth and production of somatomedins; secretion is stimulated by GH-RH from the hypothalamus. Signup and view all the answers

What is the function of MSH?

It stimulates the production of melanin by melanocytes. Signup and view all the answers

How is the structure of the hypothalamus integrated with the neurohypophysis?

The hypothalamus sends hormones directly to the posterior pituitary for storage and release. Signup and view all the answers

Study Notes

Endocrine and Nervous System

Both systems maintain homeostasis.
Endocrine system operates slowly with long-term effects; nervous system operates quickly with short-lived effects.

Purpose of Cell Communication

Cells communicate to coordinate activities.
Communication preserves homeostasis.

Mechanisms of Cell Communication

Direct: Exchange across gap junctions, important in cardiac muscle contractions.
Paracrine: Chemical signals communicate with adjacent cells, prevalent communication form.
Endocrine: Hormones are released into the bloodstream to target specific cells.
Synaptic: Involves neurotransmitters across synaptic clefts for rapid response.

Hormone Structure Categorization

Hormones categorized into three types:
- Amino Acid Derivatives
- Peptide Hormones
- Lipid Derivatives

Hormone Circulation

Freely circulating hormones are functional for less than an hour.
They may diffuse out of the bloodstream or be broken down.

Carrier Proteins and Hormonal Stability

Hormones bound to carrier proteins remain in the bloodstream longer, enhancing stability.

Specificity of Hormonal Response

Specific target cell response is achieved through binding to specific carrier proteins.

Hormones and Receptors

Membrane receptors are interacted with by certain hormones, while intracellular receptors respond to other hormone types.

Role of Second Messengers

Second messengers amplify signals, modifying intracellular functions for enhanced communication.

Endocrine Reflex Stimuli

Reflex can be triggered by three types of stimuli: humoral, hormonal, and neural.

Simple vs. Complex Endocrine Reflexes

Simple reflex involves a single hormone; complex reflex entails multiple hormones and intermediary steps.

Hypothalamus and the Endocrine System

Hypothalamus controls the endocrine system through:
- Production of ADH and oxytocin.
- Secretion of regulatory hormones influencing the anterior pituitary.
- Control of sympathetic output to adrenal medullae.

Hypophyseal Portal System

Structure and function relate to the delivery of regulatory hormones from the hypothalamus to the anterior pituitary.

Hypothalamic Regulation of Anterior Pituitary

Hypothalamic hormones stimulate or inhibit the synthesis and secretion of anterior pituitary hormones.

Anterior Pituitary Hormones

Seven hormones secreted: TSH, ACTH, FSH, LH, prolactin, growth hormone, and melanocyte-stimulating hormone (MSH).

Functions and Regulation of TSH

Function: Stimulates thyroid hormone release.
Regulation: Triggered by TRH from the hypothalamus.

Functions and Regulation of ACTH

Function: Stimulates glucocorticoid release from the adrenal cortex.
Regulation: Released in response to CRH from the hypothalamus.

Functions and Regulation of FSH and LH

FSH Function: Supports follicle development and sperm maturation.
LH Function: Promotes ovulation and testosterone secretion.
Regulation: Dependent on gonadal activity.

Functions and Regulation of Prolactin

Function: Stimulates mammary gland development and milk production.
Regulation: Stimulated by prolactin-releasing factors from the hypothalamus.

Functions and Regulation of Growth Hormone

Function: Stimulates growth and somatomedin production.
Regulation: Stimulated by GH-RH from the hypothalamus.

Function of MSH

Function: Stimulates melanin production by melanocytes.
Regulation: Release inhibited by dopamine.

Integration of Hypothalamus and Neurohypophysis

The structural relationship facilitates hormone release from the posterior pituitary based on hypothalamic signals.

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Description

Test your knowledge on the endocrine system with these flashcards. Gain insights into how the endocrine and nervous systems function, their similarities and differences, and the mechanisms of cell communication. Perfect for students looking to enhance their understanding of human biology.