The endocrine system Flashcards
what is The endocrine system
it’s composed of ductless glands which produce hormones
* Hormones control and affect many body functions and organs as well as behavior
* Each gland produces specific hormones
what are Hormones
- Hormones are chemical messengers
- Secreted into the blood by a particular gland
types of hormones
- Some hormones are made of protein (insulin)
- Some hormones are steroids (adrenocorticoid hormones)
- Others are glycoproteins (FSH, LH, TSH)
- Or derivatives of single amino acids (T4 and T3)
why hormone affect only some cell
because They affect only the cells which
have receptors for that
hormone
what is Endocrine glands
- Ductless gland
- Produces hormones
- Hormones travel straight to the bloodstream from the gland
Role of hormones
Affect the behaviour and function of different areas of the body E.g.
* Correct growth
* Changes during puberty
* Menstrual cycle
* Pregnancy
* The menopause
* Response to stress and danger
* Proper functioning of the kidneys and digestive system
Hormone release
- The release of a hormone in response to another hormone or chemical being present in the blood is controlled by a negative feedback loop
- A decrease in the amount of metabolite results in the secretion of less hormone and vice versa
what is the Pituitary gland
- Located at the base of the brain
- Closely connected to the hypothalamus
- Anterior and posterior lobes
what are the hormones controlled by Anterior pituitary
1-Human growth hormone (HGH)
2-Melanocyte-stimulating hormone (MSH)
3-Thyrotrophin (TSH)
4-Adrenocorticotrophin (ACTH)
5-Prolactin/lactogenic hormone
6-Lutenising hormone (LH)/Interstitial cellstimulating hormone (ICSH)
7-Follicle stimulating hormone (FSH)
what is Human growth hormone (HGH) responsible for
Regulates height and growth
Hypersecretion = gigantishm
Hyposecretion = dwarfism
what is Melanocyte-stimulating hormone (MSH) responsible for
Stimulates production of melanin in basal layer of the skin
what is Thyrotrophin (TSH) responsible for
Controls thyroid gland
what is Adrenocorticotrophin (ACTH) responsible for
Controls adrenal cortex
what is Prolactin/lactogenic hormone responsible for
Production of milk during lactation
what is Lutenising hormone (LH)/Interstitial cellstimulating hormone (ICSH) responsible for
1-Stimulates ovaries to produce the corpus luteum and progesterone
2-Stimulates sperm production
what is Follicle stimulating hormone (FSH) responsible for
Stimulates the ovaries to produce oestrogen and stimulates sperm production
what does Posterior pituitary secret
1-Antidiuretic hormone/vasopressin (ADH)
2-Oxytocin