6.6 Flashcards
What is homeostasis?
Homeostasis is the ability to maintain a stable internal environment
How is homeostasis maintained?
The body has several negative feedback, loops or mechanisms that bring a value back to a sept point
What is the endocrine system?
A series of glands that produce hormones that circulate in the bloodstream to targeted tissues
How do the endocrine glands know to release hormones?
Sensory neurons send messages to the brain. The brain interprets the message and send a message to the glands to release hormones.
What is a hormone?
A lipid based or protein molecule that is secreted into the bloodstream by the endocrine gland, only affects targeted tissues
What is thyroxine?
Thyroxine is a hormone secreted by the thyroid gland controls, metabolic rate and body temperature
What does two little into much thyroxine lead to
Hyperthyroidism, which is too much and hypothyroidism, which is two little
What is leptin?
Leptin is a hormone secreted by adipose (body fat tissues) in the body and its function is to decrease appetite
What is one problem encountered with leptin
You can become desensitised to leptin, meaning it does not control your appetite
What is melatonin?
Melatonin is a hormone secreted by the pineal gland in the brain regulates the day and night circle levels are highest in night
What type of gland is the pancreas?
The pancreas is both endocrine and exocrine
What is the role of the exocrine glands?
To send secretions to a specific location via a duct
What is the role of endocrine gland?
To secrete hormones that travel through the bloodstream to target tissues
Which two hormones are produced by the endocrine cells of the pancreas
Insulin and glucagon
What cells in the pancreas produce glucogen?
Alpha cells
What cells in the pancreas produce insulin?
Beta cells
What are two functions of insulin
1: causes liver cells to absorb the glucose from the blood, turning into glycogen, and to store it.
2: causes the glucose protein channels in body cells to open, so that some of the glucose goes into the cell
What are the functions of glucagon?
Stimulates the liver cells to turn some stored, glucagon into glucose and release it into the bloodstream
Describe type, one diabetes
-The beta cells of the pancreas do not produce enough insulin
-It can be controlled by injections
-It’s around 10% of diabetes cases
-It is an auto immune disease where the body attacks its own beta cells
Describe type two diabetes
-Body cell receptors do not respond properly to insulin
-Controlled by diet and exercise
-Around 90% of diabetic cases
-Associated with obesity, lack of exercise, age, ethnicity, and genetic’s
What is testosterone responsible for?
-Development of male genitalia during embryonic development
-Development of secondary sex characteristics in puberty
-Sperm production, and sex drive in adulthood
How does a person become male or female?
If there are 2X chromosomes the alleles, interact to produce oestrogen and progesterone which result in female development
If there is a Y chromosome present, testosterone is produced and the male reproductive organs form
Embryos don’t show sexual development until eight weeks
What is the role of testosterone during puberty?
The growth of facial underarm, chest and pubic hair
-Deepening of the voice
-Increase muscle mass
-Enlargement of penis
What are Estridge and and progesterone responsible for during puberty
The enlargement of breasts
-Growth of pubic and underarm hair
-Widening of the hips
