Biological 6-10 Flashcards
(113 cards)
Hormones
Enable communication between cells through the blood (endocrine system)
Similarities between neural and endocrine systems
- production of chemicals stored for later release
- some chemicals are hormones and neurotransmitters
- stimulated to release chemicals
- each react with specific receptors
Differences between neural and endocrine systems
- Neural communication is fixed between channels to precise locations; hormonal signalling is more generalised
- Neural messages are very rapid; hormonal communication is slower and more prolonged
- Neural messages either fire or dont; hormones require more for greater effect
- Some neural communication is under voluntary control; hormone release is not
Hormonal Classification and action
- PROTEIN hormones made up of amino acids- BIG so bind with receptors on membrane
- STEROID hormones made up of cholesterol-SMALLER so pass through membrane and bind with receptors on the cytoplasm
Location of Major Endocrine Glands (7)
- Hypothalamus
- Pituitary Gland
- Pineal gland
- Thyroid Gland
- Thymus
- Adrenal Gland
- Pancreas
- Ovary (women)
- Testis (men)
What does the Pineal gland produce?
Melatonin
affects sleep and light
Job of the hypothalamus in relation to pituitary gland
Makes Hypothalamic Releasing Hormones that stimulate or inhibit release from the pituitary gland
Job of the pituitary gland
releases tropic hormones which influences release of hormones from other glands
What controls the Anterior Pituitary Gland?
Hypothalamic Releasing Hormones
What controls the Posterior Pituitary Gland?
Nerve stimulation from hypothalamus
What does the Posterior Pituitary Gland produce?
Anti-diuretic hormone (ADH/Vaporessin)
Oxytocin
What is the job of Anti-diuretic hormone? (secreted by the pituitary gland)
- stimulates the re-absorption of water by kidneys
- stimulates vasoconstriction
What is the job of oxytocin? (secreted by the posterior pituitary gland)
- causes muscle contraction in uterus (childbirth)
- stimulates ejection of breast milk
Why is oxytocin known as the tend and befriend
- levels respond to social stimulation (inhibits stress)
- elevated levels during sexual arousal and orgasm
What does the Anterior Pituitary Gland produce?
- growth hormones
- thyroid stimulating hormones
- gonadotrophins (sex hormone release)
- Adrenocorticotropic Hormone (ACTH)
- Prolactin
What is the job of the growth hormones? (Anterior pituitary glands)
-regulates GROWTH rates (not enough growth hormones causes pituitary dwarfism; too much causes gigantism)
What is the job of thyroid stimulating hormones? (Anterior pituitary glands)
-stimulates THYROXINE by the thyroid gland. if thyroid can’t produce enough thyroxine, it swells up
What is the job of Gonadotrophins? (Anterior Pituitary Glands)
- Luteinizing Hormone- production of PROGESTERONE and TESTOSTERONE (ovaries and testes and adrenal cortex
- Follicle Stimulating Hormone- production of ESTROGEN ad SPERM (ovaries and testes)
What is the job of PROLACTIN?
- tissue development in breasts during pregnancy
- stimulates milk production after birth
- sexual desire: more prolactin after orgasms reducing sexual desire)
Structure of the Adrenal Gland
- Sits on top of the kidneys
- Made up of Medulla (inside),NERVE IMPLUSES and Cortex (outside), ACTH from anterior pituitary
Job of the Adrenal Medulla (Fight, Flight, F**k Hormones
-Secretes Adrenaline and Noradrenaline which regulates heart rate, glucose release and peripheral blood vessels
Job of the Adrenal Cortex
- SEX HORMONES (Adrogens and Estrogens(testes/ovaries)
- MINERALOCORTICOIDS (Aldosterone-kidneys retain sodium and excrete potassium, maintains blood pressure, maintains salt and water in the body
- CORTICOSTEROIDS (stress hormones-Cortisol)
Job of the Pancreas
-secretes insulin (takes up excess glucose) and glucagon (releases glucose)
Job of the testes
-secretes androgens–> Testosterone (begins in prenatal development to determining sex, then bursts in puberty)