The Endocrine System PDF

The Endocrine System  The Endocrine System Endocrine system: the body’s system of ductless glands that release hormones directly into the bloodstream Glands: organs that secrete one or more chemical substances suc...

The Endocrine System  The Endocrine System Endocrine system: the body’s system of ductless glands that release hormones directly into the bloodstream Glands: organs that secrete one or more chemical substances such as hormones, saliva, or milk Hormone: a substance secreted by an endocrine gland regulates various body functions, including homeostasis, growth, metabolism, and some behaviours, hence of interest to psychologists 2-32 Copyright © 2023 by Cengage Canada  2-33 Copyright © 2023 by Cengage Canada  The Pituitary, Hypothalamus, and Pineal Gland The pituitary gland and the hypothalamus work in close cooperation. The pituitary gland is labelled as a “master gland.” It lies below the hypothalamus, its “commander.” It secretes growth hormone, prolactin, antidiuretic hormone, and other hormones. pineal gland: secretes hormone melatonin that regulates sleep-wake cycle 2-34 Copyright © 2023 by Cengage Canada  The Thyroid Gland The thyroid gland produces thyroxin, which affects the body’s metabolism. Deficiencies in thyroxin are associated with hypothyroidism and cretinism. Excesses of thyroxin result in hyperthyroidism. 2-35 Copyright © 2023 by Cengage Canada  The Adrenal Glands Adrenal glands are located above the kidneys. They secrete corticosteroids, which increase resistance to stress, promote muscle development, and increase the body’s energy supply. The sympathetic branch of the ANS causes secretion of epinephrine and norepinephrine, which help the body to respond effectively in threatening situations Epinephrine intensifies emotions, especially fear and anxiety. 2-36 Copyright © 2023 by Cengage Canada  The Testes and the Ovaries Testosterone is produced primarily by testes and triggers the development of male sex characteristics Estrogen is produced by ovaries and fosters female reproductive capacity and sex characteristics 2-37 Copyright © 2023 by Cengage Canada  HPA Axis Figure 1. Stress Response in the Human Body. In response to stress, cerebral cortex signaling stimulates the hypothalamus to release corticotropin-releasing hormone (CRH). In turn, CRH stimulates the pituitary gland to produce and release adrenocorticotropic hormone (ACTH) into the blood. ACTH then activates pathways in the adrenal glands for the synthesis and release of the stress hormone cortisol. As a consequence of chronic stress, such as repeated test anxiety, over- stimulation by cortisol can lead to the indicated deleterious side effects in the brain and central nervous system. https://www.mdpi.com/2673-7140/2/1/11 Assignment