specifically the medulla (activate the sympathetic nervous system, the left is a crescent shape, the right is a triangle shape) located on top of and behind the kidneys.
Epinephrine and norepinephrine
fight or flight response
aldosterone = increase Na+ and water retention, raises blood pressure.
cortisol = stress hormone = increase blood sugar.
located across the back of the abdomen, behind the stomach, connected to the duodenum by the pancreatic duct, mostly on the left side.
The study of the relationship between nervous system and the endocrine system.Endocrine system is little slower than nervous system because it requires hormones to travel throughout the body in the bloodstream.Two systems work closely together to regulate physiological processes in the human body
increases blood sugar (break down glycogen, stimulate gluconeogenesis).
lower blood sugar (stimulates glucose uptake by cells).
make estrogen (and a small amount of testosterone).
no insulin made, or no insulin receptors, glucose can't enter cells, high blood sugar. cell starved of sugar, leading to fatty acid metabolism, which leads to production of ketone bodies, which lead to ketoacidosis (more acidic blood). sugar in urine, leading to more water in urine due to osmosis.
can be water soluble or lipid soluble. Water soluble hormones can not enter the cell and need a receptor; lipid soluble hormones directly activate genes within the cell.
Water soluble hormones
bind to a receptor on the cell membrane and a secondary messenger relays the signal inside the cell.
Lipid soluble hormones
cross the membrane and activate genes inside the cell.
bind to receptors inside the cell inside or outside the nucleus, affecting the amount of mRNA and proteins produced.
amino acid hormones bind to receptors in the membrane, the G protein is activated, adenylate cyclase is activated, cAMP is made causeing a protein kinase cascade.
amino acid hormone binds to membrane receptor, a G protein is activated, phospholipase C is activated, membrane phospholipids split into DAG and IP3, DAG triggers a protein kinase cascade, IP3 releases Ca 2+ from ER.
Transport of Hormones (Bloodstream)
Hormones can travel long distances in the bloodstream to affect far parts of the body.
Specificity of Hormones (Target Tissue)
Hormones only have receptors on cells they affect. The cells can reduce or increase the amount of receptors they have on their membrane.
Integration with Nervous System (Feedback Control)
The nervous system can regulate hormones being produced in the hypothalamus that in turn regulate other hormones.
glands directly respond to chemical levels in the blood (parathyroid respond to low blood calcium).
glands release hormones when stimulated by nerves (fight or flight response).
glands release hormones when stimulated by other hormones (tropic hormones).