Endocrine System, it's function, structure and characteristics ., Schemes and Mind Maps of Psychology

Download Endocrine System, it's function, structure and characteristics . and more Schemes and Mind Maps Psychology in PDF only on Docsity! 🌸. ENDOCRINE SYSTEM Parts of the Endocrine System The endocrine system is made up of glands that secrete hormones. Think of hormones as messengers. They are chemicals that carry signals throughout the body. This as all about communication. Hormones do things like regulate hunger and sleep and are also related to things like mood. The glands that make up the endocrine system are connected and work together to regulate a number of functions in the human body. The pituitary gland is a key component of this system. It's a gland located in the brain and it's responsible for producing some of our most important hormones. It's actually made of two parts: the anterior, which is a fancy way of saying the front, and the posterior, which is a fancy way of saying the back. A lot of what the pituitary gland does contributes to the smooth functioning of other glands in the endocrine system. This includes controlling the function of the thyroid gland and adrenal gland.The pituitary gland regulates a number of important hormones related to stress, growth, the production of breast milk in women, and hormones in the ovaries and testes related to reproduction and sex drive. Right near the pituitary gland we find the pineal gland, a very small gland that is primarily responsible for regulating our circadian rhythm, which is basically our body's biological clock. It helps us sleep and wake on a regular schedule. The pituitary gland secretes melatonin, which is the hormone that helps to keep our circadian rhythms functioning normally. The adrenal glands are key for something known as the fight or flight response. Have you ever been in a very stressful situation and made a snap decision to act, without much time to think about it? Your adrenal glands were responsible for helping you out here. When we perceive that we might be in a dangerous or highly stressful situation, our adrenal glands are involved in a physiological response that helps us make a quick decision to get to safety. The thyroid gland is also a part of the endocrine system. This gland is responsible for many things related to our metabolism, which is basically what our body does with energy. So, our body temperature and our weight are regulated by the thyroid. Problems with the thyroid can lead to issues like being overweight or underweight. Finally, the hypothalamus is another key component of the endocrine system. Think of the hypothalamus as in charge of either stimulating or inhibiting a number of different hormones that occur in the anterior part of the pituitary gland. So, in some ways, the hypothalamus is in charge of the pituitary gland. The hypothalamus lets the pituitary gland know when it's time to release hormones that let us know if we're tired, stressed, or hungry. NOTES- The endocrine system consists of a series of glands that produce chemical substances known as hormones (Figure 1). Like neurotransmitters, hormones are chemical messengers that must bind to a receptor in order to send their signal. However, unlike neurotransmitters, which are released in close proximity to cells with their receptors, hormones are secreted into the bloodstream and travel throughout the body, affecting any cells that contain receptors for them. Thus, whereas neurotransmitters’ effects are localized, the effects of hormones are widespread. Also, hormones are slower to take effect, and tend to be longer lasting. The study of psychology and the endocrine system is called behavioral endocrinology, which is the scientific study of the interaction between hormones and behavior. This interaction is bidirectional: hormones can influence behavior, and behavior can sometimes influence hormone concentrations. Hormones regulate behaviors such as aggression, mating, and parenting of individuals. Hormones are involved in regulating all sorts of bodily functions, and they are ultimately controlled through interactions between the hypothalamus (in the central nervous system) and the pituitary gland (in the endocrine system). Imbalances in hormones are related to a number of disorders. This section explores some of the major glands that make up the endocrine system and the hormones secreted by these glands. Major Glands The pituitary gland descends from the hypothalamus at the base of the brain, and acts in close association with it. The pituitary is often referred to as the “master gland” because its messenger hormones control all the other glands in the endocrine system, although it mostly carries out instructions from the hypothalamus. In addition to messenger hormones, the pituitary also secretes growth hormone, endorphins for pain relief, and a number of key hormones that regulate fluid levels in the body. Located in the neck, the thyroid gland releases hormones that regulate growth, metabolism, and appetite. In hyperthyroidism, or Grave’s disease, the thyroid secretes too much of the hormone thyroxine, causing agitation, bulging eyes, and weight loss. In hypothyroidism, reduced hormone levels cause sufferers to experience tiredness, and they often complain of feeling cold. Fortunately, thyroid disorders are often treatable with medications that help reestablish a balance in the hormones secreted by the thyroid. The adrenal glands sit atop our kidneys and secrete hormones involved in the stress response, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). The pancreas is an internal organ that secretes hormones that regulate blood sugar levels: insulin and glucagon. These pancreatic hormones are essential for maintaining stable levels of blood sugar throughout the day by lowering blood glucose levels (insulin) or raising them (glucagon). People who suffer from diabetes do not produce enough insulin; therefore, they must take medications that stimulate or replace insulin production, and they must closely control the amount of sugars and carbohydrates they consume. Luteinizing hormone (LH). Prolactin. Thyroid-stimulating hormone (TSH). The posterior pituitary releases the following hormones: Antidiuretic hormone (ADH, or vasopressin). Oxytocin. Pineal gland Your pineal gland is a tiny gland in your brain that’s located beneath the back part of the corpus callosum (nerve fibers that connect the two parts of your brain). It releases the hormone melatonin, which helps control your sleep-wake cycle. Thyroid gland Your thyroid is a small, butterfly-shaped gland located at the front of your neck under your skin. Your thyroid’s main job is to control the speed of your metabolism (metabolic rate), which is the process of how your body transforms the food you consume into energy. Your thyroid releases the following hormones: Thyroxine (T4). Triiodothyronine (T3). Reverse triiodothyronine (RT3). Calcitonin. Thyroxine and triiodothyronine are often collectively called “thyroid hormone.” Parathyroid glands Most people have four pea-sized parathyroid glands located behind their thyroid gland (the butterfly-shaped gland in your neck). Sometimes, your parathyroid glands are located along your esophagus or in your chest. These are known as ectopic (in an abnormal place) parathyroid glands. The main job of your parathyroid glands is to release parathyroid hormone (PTH), which is responsible for the calcium balance in your blood and bone health. Adrenal glands Your adrenal glands, also known as suprarenal glands, are small, triangle-shaped glands that are located on top of each of your two kidneys. Your adrenal glands make the following hormones: Cortisol. Aldosterone. DHEA and androgens. Adrenaline (epinephrine). Noradrenaline (norepinephrine). Pancreas Your pancreas is an organ in the back of your abdomen (belly). It’s part of your digestive system and endocrine system. The islet cells (endocrine cells) in your pancreas make the following hormones: Insulin. Glucagon. Ovaries People assigned female at birth (AFAB) have two ovaries — each located on both sides of their uterus below the opening of the fallopian tubes. In addition to containing the egg cells necessary for reproduction, the ovaries produce the following hormones: Estrogen. Progesterone. Testosterone. Testes People assigned male at birth (AMAB) have two testes that hang in a pouch outside of their body below their penis. The testes are part of the male reproductive system and produce sperm and the hormone testosterone. Adipose tissue (fat tissue) Adipose tissue is commonly known as body fat. It’s located all over your body, including under your skin, around internal organs, between muscles, in bone marrow and breast tissue. Adipose tissue makes and releases the following hormones: Leptin. Adiponectin. Plasminogen activator inhibitor-1. Estrogen. Angiotensin. Kidneys Your kidneys are two bean-shaped organs that filter your blood. They’re part of your urinary system, but they also produce hormones, including: Erythropoietin. Renin. The active form of vitamin D (vitamin D isn’t actually a vitamin — it’s a prohormone, which is a substance that your body converts into a hormone). Liver Your liver is an essential organ and gland, performing hundreds of functions necessary to sustain life. It’s considered part of your digestive system, but also produces hormones, including: Insulin-like growth factor 1 (IGF-1). Angiotensinogen. Gut (gastrointestinal tract) Your gut (gastrointestinal tract) is the long, connected tube that starts at your mouth and ends at your anus. It’s responsible for digestion. Scientists are currently studying the hormones that your gut makes and their effects. These hormones include: Ghrelin. Somatostatin. Glucagon-like peptide 1 (GLP-1). Placenta The placenta is a temporary organ that develops in your uterus during pregnancy. It provides oxygen and nutrients to your unborn baby. The placenta produces the hormones estrogen and progesterone to maintain the pregnancy. Types of Hormones To regulate various functions, different types of hormones are produced in the body. They are classified as follows: Peptide Hormones Steroid Hormones Peptide Hormones Peptide hormones are composed of amino acids and are soluble in water. Peptide hormones are unable to pass through the cell membrane as it contains a phospholipid bilayer that stops any fat-insoluble molecules from diffusing into the cell. Insulin is an important peptide hormone produced by the pancreas. Steroid Hormones Unlike peptide hormones, steroid hormones are fat-soluble and are able to pass through a cell membrane. Sex hormones such as testosterone, estrogen and progesterone are examples of steroid hormones.