Function of Hormones Essay examples

Submitted By XMartiine1
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Pages: 14

Chapter 3a (IV)

Function of hormones
Endocrine glands (made of secretory cells) produce hormones.
POSTERIOR Pituitary gland * Antidiuretic (ADH) promotes water absorbtion * Oxytocin (OT) stimulates milk ejection, stimulates uterine contractions
ANTERIOR Pituitary gland * Growth (GH) stimulates growth & breakdown fat * Prolactin(PRL) stim breasts produce milk * Thyroid Stimulating (TSH) synthesis & release of thyroid hormones * Adrenocorticotropic (ACTH) synthesis & release of hormones from adrenal glands * Follicle-stimulating (FSH) gamete production, secretion of estrogen by ovaries * Luteinizing (LH) causes ovulation, stimulates secretion of estrogen & progesterone, testes to synthesize &secrete testosterone
Pineal Gland * Melatonin sleep
Parathyroid Glands * Parathyroid (PH) blood level calcium
Thymus Gland * Thymo maturation of white blood cells
Adrenal Gland * gluCORTI glucose synthesis * mineralCORTI Na reabsorption, K+ excretion * gonaCORTI secretion by gonads
Adrenal medulla * Epinephrine fight or flight
Thyroid Gland * Thyroid (TH) metabolism & heart production, development & function of nerves, muscles, muscular, skeletal systems * Calcitonin (CT) blood levels of Ca & P
Pancrease
* Glucagon blood Glucose levels * Insulin  blood glucose levels
Testis
* Androgen develop male sex parts
Ovary
* Estrogen & Progesterone develop female parts

Mechanisms of hormones
Lipid soluble hormones – STIMULATES PROTEIN SYNTHESIS * Steroid hormones (ovaries,testies & adrenal) * Move easily through PM as lipid bilayer * Binds to receptor in Cytoplasm * Hormone & receptor enters nucleus & binds to DNA * Certain genes are activated * Proteins & enzymes synthesized in rougher * Enzymes alter activity of cell
Water-soluble hormones – ACTIVATE PROTEINS ALREADY PRESENT IN CELL * Protein or peptide chain (epinephrine) * Hormone (1st messenger) binds to receptor on PM * Activates 2nd messenger (cAMP) which activates an enzyme * Enzyme cascade, enzyme 3 activates breakdown of glycogen to glucose

Positive feedback loops * The outcome of the system feeds back to system & stimulates the process to continue

Negative feedback * Regulate the secretion of some hormones * Too high levels inhibit further release * Secrete another hormone2 which prompts other hormone1 to be stored & lower the too high levels, if hormone 1 gets too low, stop secreting hormone2

Hypothalamus * Regulates physiological responses

Plasma Calcium Homeostasis * Mechanism how the body maintains adequate calcium levels * INSERT IMAGE Plasma Glucose Homeostasis INSERT Image

Pineal Gland/Melatonin Function * Sleep, Rhythms, slow aging process Oxytocin: (pituitary gland) Produced in Hypothalamus, quick-childbirth, stimulates childbirth, example of positive feedback Fight or Flight: (Adrenal medulla, Epinephrine) The reaction by body’s sympathetic nervous system to emergencies. Insulin Shock: severe depletion of blood glucose levels Chapter 3a (V) Three lines of defence 1. Keep foreign organisms or molecules out of the body * Chemical & physical barriers 2. Attack ANY foreign organism, molecule or cancer cell inside the body * Internal cellular & chemical defenses 3. Destroy a specific type of foreign organism, molecule or cancer cell inside the body * Immune response, usually disease causing organisms & remembers target so quick response 1st Physical barrier * Skin * dead cells filled with keratin (waterproofs) & flake off taking any microbes * Mucous membrane * Line digestive tract & respiratory passages, sticky mucus traps microbes * Cilia Chemical Barrier…