Chapter 28: The Endocrine System Overview

Endocrine System

Network of glands producing hormones for regulation.

Hormones

Chemical messengers regulating physiological processes.

Glands

Organs that secrete hormones into the bloodstream.

Homeostasis

Stable internal environment maintained by endocrine functions.

Feedback Mechanism

Process regulating hormone levels through feedback loops.

Endocrine System

Network of glands regulating body functions via hormones.

Homeostasis

Maintenance of stable internal body conditions.

Hormones

Chemical messengers secreted by endocrine glands.

Glands

Organs that secrete hormones into bloodstream.

Insulin

Hormone lowering blood sugar levels after meals.

Glucagon

Hormone raising blood sugar levels when low.

Pituitary Gland

Master gland controlling other endocrine glands.

Thyroid Gland

Regulates metabolism and body temperature via hormones.

Parathyroid Glands

Regulate calcium levels in the blood.

Adrenal Glands

Produce hormones for stress response and metabolism.

Thymus

Gland involved in immune system development.

Pineal Gland

Regulates sleep-wake cycles via melatonin.

Gonads

Ovaries and testes; produce sex hormones.

Oxytocin

Hormone involved in childbirth and bonding.

Antidiuretic Hormone (ADH)

Regulates water balance in the body.

Thyroxine (T4)

Hormone regulating metabolism and cholesterol levels.

Triiodothyronine (T3)

More active form of thyroid hormone.

Calcitonin

Lowers blood calcium levels.

Epinephrine

Short-acting hormone for fight-or-flight response.

Norepinephrine

Long-acting hormone increasing heart rate and blood pressure.

Adrenocorticotropic Hormone (ACTH)

Controls adrenal gland hormone production.

Peptide Hormones

Hormones made of amino acids, like insulin.

Fatty Acid Hormones

Hormones derived from fatty acids, like prostaglandins.

Steroid Hormones

Hormones derived from cholesterol, like cortisol.

Amino Acid Hormones

Hormones derived from amino acids, like thyroid hormones.

Metabolism

Chemical processes converting food into energy.

Blood Sugar Regulation

Insulin and glucagon maintain glucose levels.

Hormone Receptors

Proteins that bind hormones to initiate effects.

Feedback Mechanism

Process regulating hormone levels in the body.

Blood sugar levels

Can be too high, too low, or normal.

Pituitary gland

Gland likely malfunctioning in abnormal growth.

Thyroid gland

Gland involved in metabolism regulation.

Pancreas

Gland that regulates blood sugar levels.

Thymus gland

Matures T lymphocytes; immunologic functions.

Pineal gland

Regulates body rhythms; functions not fully understood.

Gonads

Reproductive glands producing sex hormones.

Testes

Male gonads producing testosterone and estrogen.

Ovaries

Female gonads producing estrogen and progesterone.

Estrogen

Produced by follicles; signals estrus onset.

Progesterone

Maintains pregnancy after ovulation.

Hormones

Chemical messengers regulating body functions.

Fatty acids

Control hormones involved in estrus.

Steroids

Regulate essential life function chemicals.

Amino acids

Building blocks of proteins forming hormones.

Peptides

Control proteins in the body.

Target cells

Cells receiving hormones like a key fits a lock.

Enzymes

Create and release needed hormones.

Luteinizing hormone (LH)

Stimulates testosterone production and ovulation.

Follicle-stimulating hormone (FSH)

Regulates sperm production and female estrus cycle.

Gonadotropin-releasing hormone (GnRH)

Maintains normal estrus cycle.

Corpus luteum (CL)

Formed during reproductive cycle by LH.

Estrus cycle

Female reproductive cycle regulated by hormones.

Sperm production

Stimulated by follicle-stimulating hormone (FSH).

Ovulation

Triggered by luteinizing hormone (LH).

Hypothyroidism

Decreased thyroxine production by thyroid gland.

Signs of Hypothyroidism

Weight gain, lethargy, hair/skin problems.

Alopecia

Hair loss commonly associated with hypothyroidism.

Dermatitis

Skin inflammation often seen in hypothyroidism.

Thyroxine supplementation

Lifetime therapy for hypothyroidism treatment.

Hyperthyroidism

Increased thyroxine production in cats.

Signs of Hyperthyroidism

Weight loss, increased appetite, PU/PD.

Thyroidectomy

Surgical removal of the thyroid gland.

Methimazole

Blocks thyroxine synthesis in hyperthyroidism.

Diabetes Mellitus

High blood glucose levels causing multiple symptoms.

Signs of Diabetes Mellitus

Increased appetite, weight loss, PU/PD.

Insulin therapy

Injection treatment for managing diabetes.

Insulin resistance

Condition where insulin effectiveness is reduced.

Diabetes Insipidus

Caused by ADH release issues from pituitary.

Signs of Diabetes Insipidus

Uncontrolled thirst and increased urination.

Hyperadrenocorticism

Cushing's Disease; excess cortisol production.

Signs of Hyperadrenocorticism

PU/PD, increased appetite, thin skin.

ACTH stimulation test

Diagnosis method for Addison's and Cushing's.

Hypoadrenocorticism

Addison's Disease; decreased corticosteroid production.

Signs of Hypoadrenocorticism

Lethargy, weakness, vomiting, diarrhea.

Hyponatremia

Low sodium concentration in blood.

Hyperkalemia

Increased potassium levels in blood.

Dexamethasone suppression test

Measures cortisol levels for Cushing's diagnosis.

Endocrine glands

Regulate homeostasis via hormone secretion.

Homeostasis

Stable internal environment maintained by endocrine system.

Clinical signs

Observable symptoms indicating a potential health issue.

Emergency signs in pets

Weight loss, excessive drinking, increased urination.

Veterinary assistant role

Support veterinarians in diagnosing and treating animals.

Regular diet importance

Essential for managing diabetes effectively.