Endocrine system (endo) within; as apposed to outside the body (crine) – separate; separating from the secreting cell Endocrine system

Two systems coordinate communication throughout the body: the endocrine system and the nervous system The endocrine system secretes hormones that coordinate slower but longer-acting responses including reproduction, development, energy metabolism, growth, and behavior The nervous system conveys high-speed electrical signals along specialized cells called

How insulin signals the body to lower blood Glucose Steps of the endocrine system How insulin signals the body to lower blood Glucose

Signal is given You eat a meal with carbohydrates… Yum! Your body senses a rise in blood glucose (specifically in the pancreas) Signals that stimulate other hormones include: high or low blood pressure, increase or decrease in body temperature, sensing danger, baby suckling, decreased oxygen to blood, etc.

Hormones released from an endocrine gland or cells Insulin is released from the pancreas Other hormones could be released from any of these endocrine cells

But wait… what are hormones Insulin is a protein … but others can be lipids or amines

Once released, Hormones travel through the blood The insulin is sent off throughout the body… it is not directed to any specific tissue All hormones travel through the blood unless they are a localized signal

How do certain hormones only target specific tissues Insulin stimulates almost all cells in the body… but not all hormones do

Ex. Epinephrine (AKA fight or flight hormone)

The hormone causes a response in the cell Insulin stimulates cells to take in glucose and to stop breaking down glycogen in the liver Glycogen is just a big sugar storage molecule (mainly found in liver) Signals from other hormones can cause an increase in a certain enzyme, stop transcription of some genes, constriction or dilation in muscle cells, etc.

How does the endocrine gland/cells know when to stop making the hormones? Negative Feedback!!!

Negative Feedback Ex. Insulin and Glucagon Insulin lowers blood glucose by slowing the breakdown of glycogen Glucagon heightens blood glucose by increasing breakdown of glycogen

Insulin Beta cells of pancreas release insulin into the blood. Fig. 45-12-1 Insulin Beta cells of pancreas release insulin into the blood. STIMULUS: Blood glucose level rises. Figure 45.12 Maintenance of glucose homeostasis by insulin and glucagon Homeostasis: Blood glucose level (about 90 mg/100 mL)

Body cells take up more glucose. Insulin Beta cells of pancreas Fig. 45-12-2 Body cells take up more glucose. Insulin Beta cells of pancreas release insulin into the blood. Liver takes up glucose and stores it as glycogen. STIMULUS: Blood glucose level rises. Blood glucose level declines. Figure 45.12 Maintenance of glucose homeostasis by insulin and glucagon Homeostasis: Blood glucose level (about 90 mg/100 mL)

Alpha cells of pancreas release glucagon. Fig. 45-12-3 Homeostasis: Blood glucose level (about 90 mg/100 mL) STIMULUS: Blood glucose level falls. Figure 45.12 Maintenance of glucose homeostasis by insulin and glucagon Alpha cells of pancreas release glucagon. Glucagon

Blood glucose level rises. Fig. 45-12-4 Homeostasis: Blood glucose level (about 90 mg/100 mL) STIMULUS: Blood glucose level falls. Blood glucose level rises. Alpha cells of pancreas release glucagon. Figure 45.12 Maintenance of glucose homeostasis by insulin and glucagon Liver breaks down glycogen and releases glucose. Glucagon

Fig. 45-12-5 Body cells take up more glucose. Insulin Beta cells of pancreas release insulin into the blood. Liver takes up glucose and stores it as glycogen. STIMULUS: Blood glucose level rises. Blood glucose level declines. Homeostasis: Blood glucose level (about 90 mg/100 mL) Figure 45.12 Maintenance of glucose homeostasis by insulin and glucagon STIMULUS: Blood glucose level falls. Blood glucose level rises. Alpha cells of pancreas release glucagon. Liver breaks down glycogen and releases glucose. Glucagon

Diabetes Deficiency of insulin or decreased response to insulin, so blood glucose is high Type I diabetes mellitus (insulin-dependent) is an autoimmune disorder in which the immune system destroys pancreatic beta cells (the ones that make insulin) Type II diabetes mellitus (non-insulin-dependent) involves insulin deficiency or reduced response of target cells due to change in insulin receptors

Follow the path of 1 of these ADH Growth Hormone (GH) Oxytocin Triiodothyronine (T3) and thyroxine (T4) Epinephrine

Use play dough to describe it to another group Include What is it stimulated by Where is it released from What type of hormone it is (chemical class) What tissues it acts on What it does in the cell or tissue How is it regulated Disorders for non-regulation