the endocrine system 3

• ·       The endocrine system is a second system in the body and works alongside the nervous systemthe endocrine system is made up of a network of specialist glands which release chemical messengers called hormones which transmit information through the blood stream. some of these chemicals released form glands can be both neurotransmitters and a hormone depending on the task it is performing and where it is located.
• ·       The endocrine systems function is to secrete hormones which are needed to regulate many bodily functions, growths and psychological factors and they act by relaxing chemical messages called hormones into the blood stream.
• ·       The endocrine system is regulated by the hypothalamus which exerts its influence through its effect on the pituitary gland.
• ·       The endocrine system and the nervous system work very closely together to regulate the physiological processes in the body but instead of using nerves like the nervous system to transmit information the endocrine system uses blood vessels to deliver hormones to their target sites in the body.
• Endocrine glands

  ·       Endocrine glands produce and secrete hormones which are chemical substances that regulate the activity of cells or organs in the body
• Endocrine glands

  ·       the major glands of the endocrine system include the pituitary gland, the adrenal glands and the reproductive organs
• Endocrine glands

  ·       each gland in the endocrine system produces different hormones which regulate the activity or organs and tissue in the bodythe endocrine system is also regulated by feedback.
• example of system= A signal sent from the hypothalamus to the pituitary gland by releasing hormones causes the pituitary gland to secrete a stimulating hormone into the bloodstream and this hormone would then signal the target gland for example could be the adrenal glands to secret the hormones they have into the bloodstream too.
• example of system= .b)as levels of hormones rise in the blood stream the hypothalamus shuts down secretion of the releasing hormone and then the pituitary gland also shuts down its secretion of the stimulating hormone which then causes secretion of the target glands hormone which results in stable concentrations of hormones circulating in the bloodstream
• Hormones

  ·       Hormones are chemicals that circulate in the bloodstream and are carried to target sites throughout the body
• Hormones

  ·       hormones come into contact with most cells in the body but particular hormones usually only effect only a limited number of cells which are known as target cellstarget cells respond to a particular hormone because they have receptors for that hormone and cells that do not have such receptors cannot be influenced directly by that hormonewhen enough receptor sites are stimulated by hormones it results in physiological reactions in the target cell
• Hormones

  ·       timing of hormone release and the levels of hormone release are both  critical for normal functioning , if the release hormones is too much or too little at the wrong time it can result in dysfunction bodily systems , for example if levels of cortisol are too high it can lead to cushing’s syndrome which causes high blood pressure and depression – and the most coon cause of excess cortisol is a tumour in the pituitary gland which makes too much of a hormone called adrenocorticotrophic hormone which stimulates the adrenal glands to make too much cortisol.
• 8 major glands

  -          Pituitary gland – is located in the brain and its hormonal secretions influence the release of hormones from other gland in the body (main function) which will help regulate the bodies functions.

  for example a hormone it does release is adrenocorticotropic hormone which is released during the flight or fight response which also results in the stress hormone cortisol in the adrenal glands
• 8 major glands

  -           Hypothalamus - the pituitary gland is controlled by the hypothalamus which is a region of the brain just above the pituitary gland and it receives information form a number of sources about basic functions of the body and it then used this information to help regulate bodily functions and one of the ways it does this is by controlling the pituitary gland
• 8 major glands

  -          pituitary gland - produces hormones that travel in the blood stream to their specific targets and the hormones form the pituitary gland either directly cause changes in physiological processes in the body or stimulates other glands to produce other hormonesand high levels of hormones produced in other endocrine glands can stop the hypothalamus and pituitary releasing more of their own hormones and this is called negative feedback which prevents hormone levels from rising too high
• hormones produced by the pituitary gland

  -          pituitary gland has 2 main parts the anterior (front) pituitary and they posterior (back) pituitary and these two different parts release different hormones which target different parts of the body and which act on different target glands or cells
• hormones produced by the pituitary gland

  -          the anterior pituitary releases ACTH  as a response to stress which stimulates adrenal glands to the produce cortisol
• hormones produced by the pituitary gland

  -          the anterior pituitary also produced 2 important hormones which are important in controlling reproductive functioning and sexual characterises called lutenising / LH and follicle- stimulating hormone /FSH and in females these hormones stimulate the ovaries to produce oestrogen and progesterone and in males they stimulate testes to produce testosterone and sperm
• hormones produced by the pituitary gland

  -          the posterior pituitary releases oxytocin which stimulates contractions for a mother in childbirth and it is an important hormone to be release to help either mother and baby bonding
• hormones produced by the pituitary gland

  -          the hypothalamus It also has a range of functions like maintaining homeostats which is the balance of the bodies processes like heart rateone of the hormones it releases for example is CRH which is detected then by the pituitary gland in the fight or flight response.
• hormones produced by the pituitary gland

  -          Penial gland – also lies on the brain and this gland modulates your sleep pattern keeping you to a day to night circuit rhythm and it does this by releasing the hormone melatonin.
• hormones produced by the pituitary gland

  -          The thyroid gland – is located in the front of the neck and its main role is to influence metabolic rate and it does this by relaxing thyroid hormones such as thyroxine.
• hormones produced by the pituitary gland

  -          Thymus – is located in the chest and is only active until puberty stimulating the development of T cells that help work in the immune response.
• hormones produced by the pituitary gland

  -          Pancreases – is located just behind the stomach and its function is to regulated blood sugar levels by releasing hormones including insulin and glucose – (this system can lead to the disease diabetes
• hormones produced by the pituitary gland

  -          Adrenal glands – are located on the top of each of the kidneys and their main function is the release of cortisol and adrenaline which place the body in a flight or fight response under stress
• hormones produced by the pituitary gland

  -     there is 2 adrenal glands one on the top of each kidney and each of them is made up of 2 distinct parts. the outer part of each gland is called the adrenal cortex and the inner region is known as the adrenal medulla and each have different functions and one of the main distinctions between them is that the hormones released form the adrenal cortex are necessary for life and the hormones released by the adrenal medulla are not.
• Hormones released by the adrenal glands.

  • Adrenal medulla -  mainly releases adrenaline and noradrenaline and  the main effect of these hormones being released is an increase in heart rate and blood flow to the brain as it prepares the body for the flight and fight response as well as  also helping the conversion of glycogen to glucose to provide energy used in the flight or fight responseso the adrenal medulla when releasing adrenaline helps the body respond to stressful situationsnoradrenaline also constricts blood vessels causing blood pressure to increase
• Hormones released by the adrenal glands.Adrenal cortex – produces cortisol which regulates or supports a variety of important bodily functions including cardiovascular and anti-inflammatory functionsthe production of cortisol is increased in response to stressso if an individual has low levels of cortisol they would be experiencing low blood pressure , poor immune function and an inability to deal with stress
• Hormones released by the adrenal glands.

  The adrenal cortex also produces aldosterone which is responsible for maintain blood volume and blood pressurealso releases hormones called gulcocorticoids which results in the further release of stored glucose and fats for energy expenditure. and it is also responsible for the immune system and the inflammatory response.
• Hormones released by the adrenal glands.

  -          Testicles and ovaries – are reproductive glandstestis produce a male sex hormone called testosterone ich is known as an androgen and this results in the development of distinctively male secondary sexual characteristics
• Hormones released by the adrenal glands.the pituitary gland and the hypothalamus control the production of testosterone by the hypothalamus instructing the pituitary gland on how much testosterone to produce followed by the pituitary gland then passing this message onto the testes.

  and ovaries produce estrogenic which results in distinctively female secondary sexual characteristics.

  -          Pineal - is located in the brain and the main hormone it releases is melatonin and its main function is to regulate arousal, biological rhythms and the sleep wake cycle
• hormones released by adrenal glands  

         the pituitary gland and the hypothalamus control the production of testosterone by the hypothalamus instructing the pituitary gland on how much testosterone to produce followed by the pituitary gland then passing this message onto the testes.

  and ovaries produce estrogenic which results in distinctively female secondary sexual characteristics.
• hormones released by adrenal glands

  -          Pineal - is located in the brain and the main hormone it releases is melatonin and its main function is to regulate arousal, biological rhythms and the sleep wake cycle