Endocrine System

• Body is designed to respond to different stimuli and changes resulting from various activities
• Body needs to send appropriate signals to other organs to convey information and carry out necessary responses properly
• Internal communication is usually performed through electrical and chemical signaling by the nervous and endocrine systems
• Internal communication


  Performed through electrical and chemical signaling by the nervous and endocrine systems
• Organs of the body have varying responses to internal and external changes
• A certain response often involves the action of different organs or organ systems rather than an individual tissue or organ
• Bodily Responses


  Identify the responses or changes in our bodies given a particular set of activities
• Chemical and Nervous Control in Humans

  Unit 12: Plant and Animal Organ Systems and Processes: Chemical and Nervous Control
• Guide Questions


  What are the examples of bodily processes involved in each of the provided activities? Why is it essential for the body to have regulatory processes when certain activities are performed? What will happen if these processes fail to function correctly?
• Chemical Control: The Endocrine System

  In the previous lessons, you have learned that the nervous system is responsible for shuttling information around the body in the form of both electrical and chemical signals. The body, however, utilizes another organ system to coordinate various functions that contribute to our survival. This organ system is the endocrine system, and it utilizes substances called hormones to coordinate the functions of almost all other organ systems.
• Endocrine system


  Coordinates various functions that contribute to our survival using hormones
• Endocrine system functions


  Synthesize, store, and release hormones that serve as chemical signals for other body tissues to perform specific tasks
• Major glands of the Endocrine System

  Multiple glands that release hormones directly into the bloodstream
• The endocrine system is made up of multiple glands that release hormones directly into the bloodstream
• The hypothalamus is one of the major endocrine organs that maintain homeostasis in the human body
• Homeostasis


  Maintenance of a state of balance in the body involving processes such as pH, temperature, or salt level regulation
• Hypothalamus function


  Maintains homeostasis by controlling other endocrine glands or by exerting direct effects on non-endocrine tissues
• Hypothalamus


  Plays an important role in linking together the functions of the endocrine and nervous systems
• The pituitary glands, also known as the master gland, control many other endocrine glands' functions and activities
• The pituitary gland has two distinct lobes, the anterior and posterior pituitary lobes
• Pituitary Gland


  A small gland located at the base of the brain with two distinct lobes, the anterior and posterior pituitary lobes
• The pituitary gland


  Is known as the master gland, many of its functions are influenced by the hypothalamus
• The pituitary gland has a direct anatomical connection with the hypothalamus
• Details of pituitary functions will be discussed later in this lesson
• Pineal Gland


  Another endocrine gland located in the brain, important for producing the hormone melatonin
• Melatonin plays an important role in regulating sleep-wake patterns or an animal’s circadian rhythm
• Circadian Rhythm


  A repeating daily pattern of sleep-wake cycles in humans
• The pineal gland increases its melatonin secretion at night to promote sleep
• Taking melatonin supplements, with a doctor’s prescription, can help a person sleep well, especially useful for those who want to change their sleeping patterns
• The thyroid gland is located near the base of the human neck and produces important hormones that help regulate the metabolic rate of the body
• The effects of thyroid hormones influence almost all tissues of the body, particularly bones and muscles
• Two important hormones produced by the thyroid gland are triiodothyronine and thyroxine, collectively referred to as thyroid hormones
• Thyroid hormones perform important functions such as metabolic regulation, nervous system development, and heightening of protein synthesis rate
• Another hormone produced by the thyroid gland is calcitonin, which is important for
• Thyroid gland


  Produces hormones important for metabolic rate, nervous system development, and heightening of protein synthesis rate
• Calcitonin


  Regulates the body's calcium, phosphate, and potassium levels by reducing calcium levels in the blood
• Inhibiting bone resorption


  "Digestion" of the bone tissue matrix by osteoclasts
• The thyroid gland requires an adequate amount of iodine from the bloodstream to synthesize thyroid hormones
• An insufficient amount of iodine in the body can lead to abnormalities in thyroid function
• The accumulation of the colloidal thyroid hormone precursor in the thyroid glands due to iodine deficiency leads to goiter