Hormonal Communication
Endocrine System- communication system using hormones as cell Pituitary- master gland secretes growth hormone, antidiuretic
signalling molecules. hormone, and gonadotrophins.
Hormones- chemical messengers that carry info from one part of the Pineal- secretes melatonin which affects reproductive
body to another. development.
Types of hormones: Thyroid- secretes thyroxine which controls rate of
Peptide Hormones metabolism.
Steroid Hormones Thymus- secretes thymosin which promotes production of
white blood cells.
Adrenal- secretes adrenaline/noradrenaline.
Pancreas- secretes insulin/glucagon.
Testes- secretes testosterone which controls sperm
production and secondary sexual characteristics.
Ovary- secretes oestrogen and progesterone which
controls ovulation, secondary sexual characteristics and
prepares body for an embryo.
Adrenal Glands
Adrenal Cortex – uses cholesterol to produce a range of hormones. It
is steroid based so cells can directly enter the nucleus to DNA.
Layers of cortex: Regulation of blood glucose
Glucocorticoids- cortisol which regulates metabolism and blood Factors increasing blood glucose concentration:
pressure and corticosterone which regulates immune response. Diet- high amounts of carbs digested.
Mineralocorticoids- aldosterone which helps control blood pressure Glycogenolysis- glycogen that’s stored in the liver and muscle
by maintaining salt and water concentrations. cells is broken down into glucose and carried in blood.
Androgens- female and male sex hormones for secondary sexual Gluconeogenesis- production of glucose from a non carb such
characteristics. as lipids and amino acids
Adrenal Medulla- hormones are released when the sympathetic Factors decreasing blood glucose concentration:
nervous system is stimulated. Respiration- some of glucose is used by cells to release energy
Adrenaline: increases heart rate quick sending of blood to brain and required for bodily functions and during exercise more is
muscles, increases blood glucose conc and rate at which glycogen is needed.
converted to glucose. Adrenaline must be detected by receptors to Glycogenesis- production of glycogen, when blood glucose is
enter cell as it’s a polar molecule. too high excess is taken and converted into glycogen stored in
Noradrenaline: works with adrenaline in response to stress, increases the liver.
heart rate, dilates pupils and air passages, narrows arteries etc
Pancreas
Small organ below stomach has both endocrine and exocrine
functions
Exocrine- secretes substances into a duct to synthesise and release
enzymes. Enzymes are then contained in pancreatic juices which are
then secreted into small intestine. Acini are small groups of exocrine
cells which surround tubules, these join to form the pancreatic duct.
Endocrine- islet of Langerhans secrete hormones. These are
dispersed in small sections of lobules of acini. They contain alpha cells
which secrete glucagon and beta cells which secrete insulin.
Endocrine System- communication system using hormones as cell Pituitary- master gland secretes growth hormone, antidiuretic
signalling molecules. hormone, and gonadotrophins.
Hormones- chemical messengers that carry info from one part of the Pineal- secretes melatonin which affects reproductive
body to another. development.
Types of hormones: Thyroid- secretes thyroxine which controls rate of
Peptide Hormones metabolism.
Steroid Hormones Thymus- secretes thymosin which promotes production of
white blood cells.
Adrenal- secretes adrenaline/noradrenaline.
Pancreas- secretes insulin/glucagon.
Testes- secretes testosterone which controls sperm
production and secondary sexual characteristics.
Ovary- secretes oestrogen and progesterone which
controls ovulation, secondary sexual characteristics and
prepares body for an embryo.
Adrenal Glands
Adrenal Cortex – uses cholesterol to produce a range of hormones. It
is steroid based so cells can directly enter the nucleus to DNA.
Layers of cortex: Regulation of blood glucose
Glucocorticoids- cortisol which regulates metabolism and blood Factors increasing blood glucose concentration:
pressure and corticosterone which regulates immune response. Diet- high amounts of carbs digested.
Mineralocorticoids- aldosterone which helps control blood pressure Glycogenolysis- glycogen that’s stored in the liver and muscle
by maintaining salt and water concentrations. cells is broken down into glucose and carried in blood.
Androgens- female and male sex hormones for secondary sexual Gluconeogenesis- production of glucose from a non carb such
characteristics. as lipids and amino acids
Adrenal Medulla- hormones are released when the sympathetic Factors decreasing blood glucose concentration:
nervous system is stimulated. Respiration- some of glucose is used by cells to release energy
Adrenaline: increases heart rate quick sending of blood to brain and required for bodily functions and during exercise more is
muscles, increases blood glucose conc and rate at which glycogen is needed.
converted to glucose. Adrenaline must be detected by receptors to Glycogenesis- production of glycogen, when blood glucose is
enter cell as it’s a polar molecule. too high excess is taken and converted into glycogen stored in
Noradrenaline: works with adrenaline in response to stress, increases the liver.
heart rate, dilates pupils and air passages, narrows arteries etc
Pancreas
Small organ below stomach has both endocrine and exocrine
functions
Exocrine- secretes substances into a duct to synthesise and release
enzymes. Enzymes are then contained in pancreatic juices which are
then secreted into small intestine. Acini are small groups of exocrine
cells which surround tubules, these join to form the pancreatic duct.
Endocrine- islet of Langerhans secrete hormones. These are
dispersed in small sections of lobules of acini. They contain alpha cells
which secrete glucagon and beta cells which secrete insulin.
