Ch. 19 Endocrine System Flashcards
Functions of the Endocrine System
Regulation:
Development and tissue maturation Ion regulation Water balance Immune system Heart rate and blood pressure Blood glucose Reproduction Uterine contraction Milk production and release
Types of Hormones
Peptide (oxytocin) From fatty acids (prostaglandin) Steroids Modified amino acids (T3 and T4) Protein (insulin)
Basic Characteristic of Hormones
They travel through the blood
Hypothalamic hormones
Growth Hormone Releasing Hormone (GHRH): Peptide
Growth Hormone Inhibiting Hormone (GHIH): Peptide
Thyrotripin Releasing Hormone (TRH): Peptide
Corticotropin Releasing Hormone (CRH): Peptide
Gonadotropin Releasing Hormone (GnRH): Peptide
Prolactin Releasing Hormone (PRH): ??
Prolactin Inhibiting Hormone (PIH): ??
Pituitary Gland (Structures
Mammillary body
Posterior pituitary
Anterior pituitary (Don’t need to know substructures)
Pituitary hormones (posterior)
Antidiuretic hormone: Peptide Increased water reabsorption in the kidneys Oxytocin: Peptide Uterine contractions, milk expulsion Males ???
Pituitary hormones (anterior)
Growth Hormone (GH): Protein Most tissues; Growth Lipotropins: Peptides Increased fat breakdown Adrenocorticotropic Hormone (ACTH): Peptide Stimulate glucocorticoids Thyroid Stimulating Hormone (TSH): Glycoprotein Stimulate thyroid hormones Lutinizing Hormone (LH): Glycoprotein Ovulation; Sperm production Follicular Stimulating Hormone (FSH): Glycoprotein Follicles; Sperm production Prolactin: Protein Milk production
Functions of growth hormone
Determines height
Metabolism Movement of amino acids into cells Slows protein breakdown Increases fat breakdown Increased glucose neogenesis
Thyroid hormones
Triiodothyronine (T3) and Tetraiodothyronine (T4)
Amino acid derivative
Stored in follicles
Transported by thyroxine-binding globulin (protein)
Diffuse into cytoplasm and bind with receptors
Regulates metabolism
Normal growth of hair, bone, connective tissue,
nervous tissue
TSH regulates the release of T3 and T4
Hyperthyroidism
Too much thyroid hormone
Increased metabolic rate and appetite, weight loss
Sweating and warm skin
Protruding eyes
Increased heart rate, high blood pressure
Hyperactivity, weak skeletal muscles
Hypothyroidism
Not enough thyroid hormone Decreased metabolic rate and appetite, weight gain Dry cold skin Swelling of face and body Slow heart rate, low blood pressure Apathy
i.e. Grave’s disease
Goiter
Caused by a lack of iodine
Parathyroid Glands
Located on the sides of the thyroid Parathyroid hormone (PTH)
Polypeptide hormone
Reculates Ca++ levels
Stimulates osteoclasts
Stimulates Ca++ reabsorption in the kidneys
Increased Vitamin D synthesis
Hypocalcemia
Inactive glands
Opening of Na+ channels in plasma membrane
Flacid heart muscles
Hypercalcemia
Abnormal function, diet Calcification of tissues (kidney stones) Weak bones Weak muscles Increased force of heart contraction
Adrenal gland (Structure)
Cortex: (surface to deep) Zona glomerulosa, Zona fasciculata, Zona reticularis
Medulla
Zona Glomerulosa:
Adrenal Cortex
- Aldosterone: Steroid
- Increased Na+ reabsorption
Zona fasciculata:
Adrenal Cortex
- Cortisol: Steroid
- Increase fat breakdown, protein breakdown glucose neogenesis
Zona reticularis:
Adrenal Cortex
- Androgens: Steroid
- Pubic hair and sex drive in females
Cushing’s disease
High glucocorticoid levels cause fat to accumulate in cheeks and on neck
Adrenal medulla
Secretes:
- Epinephrine and norepinephrine (amino acid derivatives)
Effects:
- Increase heart rate and blood pressure
- Increased blood glucose levels
- Reduced digestive activity
- Fight or flight response
The pancreas (Structures)
Pancreatic duct
Alpha (effects glucagon) and beta (effects insulin) cells
Insulin (effects)
- Liver: Glycogen synthesis from glucose
- Adipose: Glycogen and fat synthesis from glucose
- Skeletal muscle: Glycogen synthesis from glucose
- Hypothalamus: Control of appetite
Glucagon
- Liver: Breakdown of glycogen to free glucose
- Adipose: Breakdown of fats (high concentrations)
- Skeletal muscle: Little effect
- Hypothalamus: No effect
Pineal Gland
Secretes: Melatonin
Light inhibits
Dark stimulates
Sleep cycles?
