Chemical Coordination Flashcards
What is a gland?
A gland is an organ that secretes a substance
How are hormones specific?
Hormones only affect particular tissues or organs if the cells or tissues of that organ have special chemical receptors for the particular hormone
These receptors are located in the cell membrane/ cytoplasm/ nucleus of the cell
Points of differences between the nervous system and the endocrine system:
- Works by
- Transmitted through
- Time taken to act
- Lasting of the response
- Area affected
Hormones released by the pituitary gland and their functions:
- FSH: Stimulates the development of gametes and secretion of estrogen
- LH: Stimulates ovulation and testosterone production
- ADH: Osmoregulation
- GH: stimulates growth, cell division, and regeneration of cells
The functions of thyroxine, insulin, glucagon, and progesterone:
Thyroxine: controls the body’s metabolic system
Insulin: lowers blood glucose
Glucagon: raises blood glucose
Progesterone: regulates the menstrual cycle
Effect of lack of iodine in the diet:
It causes the thyroid gland to enlarge, called goitre
What is BMR?
Basal Metabolic Rate: rate of oxygen consumption at rest
Two effects of thyroxine on the body (at cellular level):
- Increase the BMR
- Increases protein synthesis
- Increases the production of GH
What is negative feedback?
A control mechanism in the body where any change from the set-point is detected and starts a process to return conditions to normal
Discuss the negative feedback loop which controls metabolic rate
Drop in BMR
⬇
The hypothalamus releases MORE T(thyrotropin)RH
⬇
Stimulates the pituitary gland to release MORE TSH
⬇
The thyroid gland releases MORE thyroxine
⬇
Rise in BMR
⬇
The hypothalamus releases LESS TRH
⬇
Stimulates the pituitary gland to release LESS TSH
⬇
The thyroid gland releases LESS thyroxine
⬇
Drop in BMR
Changes that occur due to adrenaline release:
- Breathing rate increases
- Heart beats faster
- The blood is diverted from the intestine to the muscles
- The liver breaks down glycogen into glucose
- Pupils dilate
- Increase in mental awareness
(- Body hair stand up to make the animal look larger)
A group of cells in the pancreatic tissue known as ______________ that contains two types of cells ______ and _______
Islets of Langerhans
Alpha and beta
Larger alpha cells secrete ________
Glucagon
Smaller beta cells secrete ________
Insulin
Discuss the two types of diabetes
TYPE 1:
- Body not producing enough insulin
- High blood glucose levels
-common in chidren
SYMPTOMS:
- High glucose levels in urine
- Constant thirst
EFFECT:
- If left untreated, the person loses weight, becomes weak, falls into a coma, and dies
TREATMENT:
- Reducing carbohydrates in the diet
- Taking daily insulin injections
TYPE 2:
- Body becomes insulin resistant so the insulin is going to have minimum effect
- Common in people who are overweight, eat a poor diet
- Common in middle-aged and older people
PREVENTION:
- Regular exercise
- Eating a good diet
