ENDOCRINE SYSTEM AND THE HUMAN EYE Rayvin Ewers Savana Canary Emily Haimes

THE ENDOCRINE SYSTEM  The endocrine system is sometimes at fault for osteoporosis.  Hormones produced by the endocrine system are released directly into the blood stream.  The nervous system stimulates organs that need hormones to be released.  The endocrine system is responsible for sexual characteristics and development.  The hypothalamus is the gland that makes you feel hungry and thirsty. It also helps regulate body temperature.  The digestive system contains the stomach, which is what is fed.  An early endocrinologist attempted hormone replacement therapy on himself.

THE ENDOCRINE SYSTEM IS SOMETIMES AT FAULT FOR OSTEOPOROSIS  Secondary System:  Skeletal- Osteoporosis is the density-loss of bones as they grow older.  Organ- bones  When women reach menopause, their estrogen levels drop, and because estrogen is important to new bone production, the bones become weak and susceptible to fractures.  The same thing happens in men when their testosterone levels drop, leading to bone-density loss.

HORMONES PRODUCED BY THE ENDOCRINE SYSTEM ARE RELEASED DIRECTLY INTO THE BLOOD STREAM  Secondary System:  Circulatory- Hormones are released directly into the bloodstream  Organs- Veins, arteries  Hormones travel throughout the body, either in the blood stream or in the fluid around cells, looking for target cells.

THE ENDOCRINE SYSTEM IS RESPONSIBLE FOR SEXUAL CHARACTERISTICS AND DEVELOPMENT  Secondary System:  Reproductive- The endocrine system is responsible for the development of testes (males) and ovaries (females), which are major organs of the reproductive system  Organs- ovaries and testes

THE ENDOCRINE SYSTEM

THE HUMAN EYE  Seeing requires about half of the brain.  The nervous system includes the brain.  The muscular system is a secondary system to sight because it controls movement of the eye.  Newborns don’t produce tears. They start flowing tears when they are about 4-13 weeks old.  The entire length of all the eyelashes shed by a human in their life is over 98 feet, with each eyelash having a life span of approximately 5 months.  The nervous system controls the act of blinking, in which eyelashes are shed.  Corneas are the only tissues that don’t have blood.  Some people are born with two different colored eyes. This condition is called heterochromia.

SEEING REQUIRES ABOUT HALF OF THE BRAIN  Secondary System:  Nervous: The eye’s two optic nerves meet at the optic chaism, the split again to go to each halves of the brain to process what is seen.  Organs- brain

CORNEAS ARE THE ONLY TISSUES THAT DON’T HAVE BLOOD  Secondary System:  Circulatory- Blood vessels to not travel to the cornea  Organs- Veins, arteries  “It is the clarity of the cornea that allows light to pass onto the retina and from there to the brain for interpretation. When the cornea is clouded by injury, infection or abnormal blood vessel growth, vision is severely impaired, if not destroyed.” Read more: Scientists Learn Why Cornea Is Clear, without Blood Vessels | health.am blood-vessels/#ixzz3jD64pLXFScientists Learn Why Cornea Is Clear, without Blood Vessels | health.amhttp:// blood-vessels/#ixzz3jD64pLXF

THE HUMAN EYE