homeostasis

• An example of negative feedback in homeostasis is the regulation of body temperature, where a decrease in temperature triggers mechanisms to increase heat production and decrease heat loss.
• homeostasis is the process by which internal body conditions are regulated to maintain stable conditions.


  endocrine system comprises of fluids called hormones that help to regulate conditions of the body.
• receptors are parts of the control system and they detect stimuli (changes in external or internal conditions)
• CNS (coordination center) receives impulses from receptors through a sensory neuron. they then issue a response. it includes the brain and the spinal cord.
• lastly, the effectors that issue or carry out the response.
• types of effectors are muscles and glands. muscles contract to break contact with a stimuli while glands secrete or produce hormones to regulate internal conditions for proper enzyme action
• the brain issues conscious action that need one to think about before doing for example using an umbrella when it is raining.
• the spinal cord issues reflexes which are which are automatic responses to certain stimuli for example lifting your hand from a hot surface.
• conditions that control systems regulate are water levels, blood-glucose levels and body temperature.
• synapse is a gap between two neurons. an impulse is transferred from one nerve ending to another through diffusion.
• main neurones in the control systems are sensory neuron which transfers electrical impulses from the receptor to the CNS. Next are the motor neurons which transfer electric impulses within the CNS and lastly the relay neurons which transfer response from the CNS to the receptors.
• examples of glands are; the pituitary gland(master gland) which stimulates other glands and is found in the brain.
• The thyroid gland produce thyroxine and the pancreas produces insulin. The adrenal gland secretes adrenaline while the ovaries secrete oestrogen. The testis secrete testostrone.
• When blood glucose levels are high, the pancreas secretes insulin. Insulin makes glucose bind to cells which is later turned to glycogen by the liver. So, blood sugar levels reduce to mormal.
• When blood glucose levels are low, the pancreas secretes glucagon which binds to liver cells. it then makes the liver convert glycogen to glucose. So, the blood sugar levels increase to normal levels.
• Diabetes type 1 is when the pancreas produces little or no insulin. It is from childhood and has no medication. Cause dangerously high levels of blood glucose hence leading to death or other complications. Treatment is taking insulin shots just as the normal pancreas would do every after a meal.
• Diabetes type 2 is when the body no longer responds to insulin produced by the pancreas. It is caused by long-term consumption of foods high in sugars. Glucose levels rise dangerously hence risking death. Treatment is maintaining a healthy diet and regular exercise to avoid obesity.
• Adrenaline is a hormone released in response of fear and tress. It causes increase in the heartbeat hence more supply of oxygen and glucose to the muscles and brain. Makes the body ready for a fight or flight.
• Thyroxine regulates metabolism and energy produced by the body for growth and development.
• The hypothalamus controls the pituitary gland which releases hormones that control various functions such as growth, reproduction, water balance, milk production, etc.
• Testosterone is responsible for male reproductive system
• In the menstrual cycle, on day 1, menstruation starts and the uterus lining breaks down. On day 4, the uterus lining builds up and thickens in preparation for receiving an egg. On day 14, ovulation takes place and on day 28 The wall is maintained and if no fertilized egg is produced, the cycle restarts.
• The four menstrual hormones include; FSH(follicle-stimulating hormone) which causes the maturation of the egg and stimulates production of oestrogen. Oestrogen causes growth of uterus lining and stops production of FSH
• Progesterone is the hormone that maintains the uterus lining and LH(Luteinising Hormone) stimulates ovulation and stops production of progesterone.
• Fertility drugs are used to treat infertility caused by low levels of FSH or LH. They work by increasing the amount of these hormones released from the pituitary gland.