hormones

define a hormone

A chemical messenger secreted by the endocrine glands and carried in blood plasma to target cells

describe how hormones have an effect

1. hormones are made in special cells called the endocrine gland

2. They secrete hormones into the blood stream . Its carried by blood into the plasma.

3. This is carried across the body in the blood these eventually reach target cells with receptors on there surface.

4. Receptors have specific shapes and the hormone has to be complimentary to bind to the hormone. this means it doesn’t bind to receptors on non target cells

5. the binding of a hormone to the complimentary receptor acts as a signal to trigger changes inside. This exact process depends on the the type of hormone

what is the speed and target / size of impact compared to nervous control

hormonal responses are slower and target a larger area and effect lasts longer.

1. pineal gland

2. pituitary gland

3. thyroid gland

4. adrenal gland

5. pancreas

6. ovaries

7. testes

pineal gland

1. hormone

2. function

1. melatonin

2. regulates the sleep wake cycle / biological clock

pituitary gland

1. hormone

2. function

1. growth hormone many others eg FSH LH oxytocin

2. master gland

thyroid gland

1. hormone

2. target organ

3. function

1. thyroxine

2. liver

3. controls metabolic rate

adrenal gland

1. hormone

2. function

1. adrenaline+ cortisol

2. play a role in fight or flight

pancreas

1. hormone

2. target organ

3. function

1. glucagon and insulin

2. liver

3. control glucose levels in the blood

ovaries

1. hormone

2. target organ

3. function

1. oestrogen + progesterone

2. uterus

3. controls menstrual cycle

testes

1. hormone

2. function

1. testosterone

2. male characteristics

what are the 2 lobes of the pituitary gland

anterior and posterior

which area of the brain regulates the pituitary gland

hypothalamus

Is this the anterior or posterior lobe+ fill in labels

1. hypothalamus

2. neurone secretary cell

3. portal vessel

4. endocrine cell ( releases hormone into blood stream)

5. blood vessel

anterior

Is this the anterior or posterior lobe+ fill in labels

1. hypothalamus

2. neurone secretary cell

3. blood vessel

posterior

describe how a hormone is released from the anterior lobe

The hypothalamus has a neurosensory cells these are never cells which produce and secretions from the end of there axon. One group of these neurosensory cells produces releasing factor which are released into the portal blood vessel. This causes the endocrine with in the cells to release specific hormones into the blood stream

describe how a hormone is released from the posterior lobe

The posterior lobe releases the hormones that have been produced by the hypothalamus itself. Neurosensory cells extend from the hypothalamus into the posterior lobe. There stores here before being released into the blood stream.

is this insoluble and soluble

1. hormone

2. hormone receptor complex

3. adenylate cyclase

4. ATP

5. cAMP

6. secondary messenger

7. active enzyme

8. glycogen

9. glucose

describe how insoluble hormones impact a cell

most hormone do not enter the cell but bind to a receptor protein on the cell membrane to form a hormone receptor complex. This complex then activates the enzyme adenylate cyclase which catalyses the production of chemicals cyclic AMP cAMP from ATP in the cytoplasm . The cAMP in turn activates a cascade of enzymes resulting in the breakdown of glycogen to glucose. The cAMP is called a second messenger.

1. hormone

2. hormone receptor complex

3. nuclear membrane

4. DNA

5. RNA polymerase

6. transcription

describe how soluble hormones impact a cell

The hormone is lipid soluble so can easily pass through the cell membrane by lipid diffusion. They bind to receptor proteins to form a hormone receptor complex in the cytoplasm which enters the nucleus and stimulates protein synthesis by binding to DNA and acting as a transcription factor. For example the steroid hormone oestrogen stimulates the growth of the uterus lining by being a transcription factor.

what is another name for a soluble hormone

steroid