The Nervous and Endocrine system by Mariam https://padlet.com/maz24/cp4gv11i6578 Control and coordination of the human body en-us 2018-05-13 14:08:04 UTC 2024-05-25 19:30:16 UTC hello@padlet.com The nervous system maz24 https://padlet.com/maz24/cp4gv11i6578/wish/269616774  
The nervous system is structured groups of cells which conducts electrochemical stimuli from the sensory receptors to the area in which the response occurs. 

Every living organism can detect when there is a change inside themselves and within their environments. The changes within the external environment are temperature, motion, light, odour and sound. Whilst the changes in the internal environment are internal organs and the position of your limbs and head. When the external and internal changes are detected, they are analysed and acted upon, so they can survive. Since the earth has evolved and the environment has become very complex, the organisms try to survive by how well they adapt towards the changes in the surroundings. A rapid reaction and response is essential for survival. A system evolved which allowed a quicker reaction from one cell to another since the communication between cells was chemically far too slow. The system is known as the nervous system, which is based upon the almost instantaneous transmission of electrical impulses from one region of the body to another along specialized nerve cells called neurons.  

Resting potential is the electrical potential across the plasma membrane of a cell that is not conducting an impulse. Resting potential is maintained by active transport (antiport) 


Active potential is the reversal (depolarisation) and restoration (repolarisation) of the electrical potential across a plasma membrane as a nerve impulse passes along a neuron: 
1. Resting potential is maintained by active transport: Na+/K+ pumps Na+ out and K+ in. 
2. Arrival of an Action Potential (AP) causes depolarization of adjacent sections of the neuron.
-this causes local Na+ diffusion and a current.
-if the current is enough to rise above the threshold, voltage-gated Na+ channels open and Na+ rushes in. Internal potential is reversed} it is more positive than the outside (depolarization)
3. K+ channels are opened and K+ diffuses out. internal charge is negative again (repolarization) 
4. Refractory period is when the channels rest between openings. This ensures one-way impulse flow. resting potential is then returned by active transport. 

]]> 2018-07-07 13:55:52 UTC https://padlet.com/maz24/cp4gv11i6578/wish/269616774 The function of the nervous system maz24 https://padlet.com/maz24/cp4gv11i6578/wish/269616828 The nervous system primary function is to get information( simple or complex) and to create a response towards that stimulus. For example, if you were to touch a hot item, the temperature is conveyed rapidly to the CNS and there is a quick response by the hand being removed, from the action of the skeletal muscles. Incidents such like that could possibly lead to the formation of long-term memory and learning which is encoded as a series of neural connections. On the other hand it could be a sensation of the touch of a cold drink on a hot day in which the response of the body feels pleasure. This is expressed through neuronal activity in different areas of the body which depends on the individual and not depending on any effector cell. 

]]> 2018-07-07 13:57:47 UTC https://padlet.com/maz24/cp4gv11i6578/wish/269616828 The endocrine system maz24 https://padlet.com/maz24/cp4gv11i6578/wish/269616937 The endocrine system produces and secrete hormones which is made up of gland. There are chemical substances which is produced in the body, they regulate the activity of organs and cells. Sexual development, metabolism and the body’s growth is regulating by these hormones. One or many organs can be affected once the hormones are released into the bloodstream.   

To co-ordinate the functions of different parts of the body, hormones (also known as chemical messengers) transfer information from a group of cells to another. 

The seven most important glands in the endocrine system is; the reproductive system organs, adrenals, thyroid, hypothalamus, pineal body, para-thyroids and the pituitary, (the pancreas is another gland and it plays a role in the digestion and the hormone production).

There are hormones which are regulated by the pituitary gland and the hypothalamus sends a signal to the pituitary gland (also referred to as the “releasing hormone”), which then the stimulating hormone is secreted in the pituitary, by the stimulation of the “releasing hormone”, into the circulation. A signal sent from the stimulating hormone makes the target gland secrete its hormone.    As the level of this hormone rises in the circulation, the hypothalamus and the pituitary gland shut down secretion of the releasing hormone and the stimulating hormone, which in turn slows the secretion by the target gland. This system results in stable blood concentrations of the hormones that are regulated by the pituitary gland.

]]> 2018-07-07 14:01:00 UTC https://padlet.com/maz24/cp4gv11i6578/wish/269616937 the function of the endocrine system maz24 https://padlet.com/maz24/cp4gv11i6578/wish/269617909 The function of the endocrine system is to secrete hormones directly into the bloodstream. Hormones are chemical messengers which control and co-ordinate the activities through the whole body.

 When the hormones reach the site targeted, a receptor and a hormone bind together, just like the lock and key mechanism. When the receptor has been locked by the hormone, a message is transmitted which causes the site targeted to take a specific action. Hormone receptors can be on the surface of a cell or inside a nucleus.

 The function of every organ is controlled by hormones which affect many processes such as the reproductive system, sexual characteristics and growth and development. The amount of fluid inside the body, the levels of glucose and salt and the way the body stores energy is all influenced by hormones. A huge amount of responses throughout the body can be triggered by a small number of hormones. 

Each type of hormone influences a certain type of organ or tissue even though the hormones circulate throughout the whole body. Some hormones influence many organs through the body however some hormones only affect one or two organs. An example is: A thyroid hormone which is produces in the thyroid gland affects cells throughout the whole body (regulating growth of cells, affecting the speed of calories burned and controlling the heart rate, on the other hand, a thyroid stimulating hormone produced in the pituitary gland only affects the thyroid gland. 

]]> 2018-07-07 14:32:10 UTC https://padlet.com/maz24/cp4gv11i6578/wish/269617909 The nervous system and the endocrine maz24 https://padlet.com/maz24/cp4gv11i6578/wish/269619310  | NERVOUS SYSTEM
| Works by nerve impulses
| Response is short lived
| Impulses act on individual cells
| Travels fast and has instant effect

 | ENDOCRINE SYSTEM
 | Works by hormones transmitted in the bloodstream
 | Response is longer lasting
 | Widespread effect on different organs
 | Travels slowly and had a slower effect]]> 2018-07-07 15:10:50 UTC https://padlet.com/maz24/cp4gv11i6578/wish/269619310