Endocrine system Flashcards
Define homeostasis
Self regulating process by which biological systems maintain stability while adjusting to changing external conditions
Explain the importance of homeostasis
Homeostasis ensures that internal conditions, such as body temperature, pH levels, and nutrient levels, are kept within a narrow and optimal range. This allows enzymes and metabolic processes to function most efficiently.
Define hormone
A hormone is a chemical messenger produced by glands in the endocrine system and released into the bloodstream to regulate various physiological processes within the body
Name the chemical classes of hormones
lipid-derived, amino acid-derived, and peptide (peptide and proteins) hormones
Identify the 7 major endocrine glands
- Pituitary Gland
- Thyroid Gland
- Parathyroid Glands
- Adrenal Glands
- Pancreatic islets
- Ovaries
- Testes
What hormone does the anterior pituitary gland produce?
Growth Hormone: Stimulates growth, cell reproduction, and regeneration.
Thyroid-Stimulating Hormone: Stimulates the thyroid gland to produce thyroid hormones that regulate metabolism.
What hormone does the thyroid gland produce?
Produces thyroxine - stimulates metabolism and binds to receptors in most of the cells in the body
What hormone does the parathyroid gland produce?
parathyroid hormone central role in maintaining calcium homeostasis in the body
What hormone does the adrenal gland produce?
Adrenaline and noradrenaline, which initiate the flight or fight response and have similar functions.
Cortisol, which helps control the body’s use of fats, proteins and carbohydrates.
Aldosterone, which regulates the balance of salt and water in the body.
What hormone does the pancreatic islets produce?
Insulin - produced by beta cells
Glucagon - produced by alpha cells
What hormone do the ovaries produce?
Progesterone crucial for preparing and maintaining the uterine lining
Oestrogens central role in the development and maintenance of female reproductive tissues and regulates menstrual cycle
What hormone do the testes produce?
Testosterone steroid hormone that plays a crucial role in the development and maintenance of male reproductive tissues
What hormone does the posterior pituitary gland produce?
Antidiuretic Hormone: Regulates water balance by controlling water reabsorption in the kidneys. Also, constricts blood vessels to increase blood pressure.
Oxytocin: Stimulates uterine contractions during childbirth and milk ejection during breastfeeding.
What is the main difference between the anterior and posterior pituitary glands?
The anterior pituitary produces and releases its own hormones, while the posterior pituitary primarily stores and releases hormones produced by the hypothalamus
What is the purpose of negative feedback?
Maintains stability and homeostasis by counteracting deviations from a set point.
What is the body’s response to negative feedback?
The system’s response opposes or negates the initial change, bringing the system back toward the set point.
What is an example of negative feedback?
Regulation of body temperature—when the body gets too warm, sweating and increased blood flow to the skin help cool it down.
Regulating blood glucose levels by insulin (lower blood sugar B cells) and glucagon (increase blood sugar a cells).
What is the purpose of positive feedback?
Amplifies or reinforces a change, often leading to an escalation of the initial stimulus.
What is the body’s response to positive feedback?
The system’s response enhances the initial change, pushing it further away from the set point.
What is an example of positive feedback?
Blood clotting—when a blood vessel is injured, platelets release chemicals that attract more platelets, leading to the formation of a blood clot. The process continues until the clot is sufficient to stop bleeding
Describe how hormones are transported?
Hormones travel through the bloodstream, which acts as a transportation system throughout the body.
How do hormones act on cells?
Hormones bind to their specific receptors on the surface of or inside the target cells.
This triggers a cellular response, leading to the physiological effects associated with that particular hormone.
How is hormone secretion controlled?
Through negative and positive feedback
What is the relationship between hypothalamus and pituitary gland (anterior and posterior)?
The hypothalamus releases hormones that either stimulate or inhibit the secretion of hormones from the anterior pituitary. The posterior pituitary stores and releases hormones produced by the hypothalamus.
