What are the chemical messengers of the nervous

What are the chemical messengers of the nervous system called? Who makes them?

Endocrine system is made of glands that make hormones

Ductless Glands • Endocrine glands make hormones • These are ductless glands • Hormones are always secreted into the blood stream • Hormones are secreted in very small amounts • Work over a long period of time…they work slowly

Is salivary gland an endocrine gland? Why not an endocrine gland? It doesn’t make hormones and has DUCTS It is an exocrine gland…

How do glands know when and how much hormones to make? • They are regulated by negative feedback mechanism • Who tells these glands to make their hormones?

Pituitary Gland is the master gland… PITUITARY GLAND WHY? HYPOTHALAMUS It controls all other glands. .

Pituitary Gland Controls Growth • Has a big JOB>>> • to produce and release different HORMONES • These hormones then give messages to other glands to make their hormones

Endocrine system

Lets talk about pancreas…

Islets of langerhan cells of pancreas make insulin and glucagon

Insulin lowers blood sugar. How? It gives message to cells to uptake glucose from blood. HOW?

Insulin lowers blood sugar. How?

What happens to the extra glucose in BLOOD GOES BACK TO LIVER blood? Asks for glucose back!!!! • What happens if you don’t eat and blood glucose goes down …and cells need more glucose? Or, how can we bring up blood glucose levels? Who is the messenger now? INSULIN Request the liver to store it as… Give sugar back please

• What happens to the extra glucose? • How does liver take up this glucose? • What happens if you don’t eat and blood glucose goes down …and cells need more glucose? Or, how can we bring up blood glucose levels? Insulin Please store glucose as…

Insulin in blood signals the cells to uptake glucose • How does signaling work? • How do cells receive the message? • Cells have Receptors to receive messages • How do receptors work? • The signal, INSULIN, binds to the receptors on the cell surface and the cells UNLOCK to absorb glucose. • What makes insulin bind to the receptor molecules? • The signal (insulin) and the receptor on the cell’s surface fits because of its shape

Insulin in blood signals the cells to uptake glucose • How does the signaling work? • How do cells receive the message? • Receptors • How?

How does insulin work? Hormones are always released in blood…

Glucagon does the opposite…it increases the blood sugar…

What happens if cells don’t respond to insulin? They fail to absorb glucose and blood glucose level increases DIABETES

How Pancreas regulates blood sugar? • What is this mechanism called? • Negative feedback regulation

Ok, I’ll hold it…store it as GLYCOGEN

Ok, I’ll hold it…store it as GLYCOGEN

Hypothalamus senses it and tells pituitary to stop making TSH… When enough thyroxin is there in blood… Thyroid makes thyroxin Low thyroxin levels detected by hypothalamus - It tells pituitary gland Pituitary makes TSH +

Liver, small intestine

Pancreas

Pituitary Gland Controls Growth • If your clothes from last year are too small, it's because your pituitary gland released special hormones that made you grow. • This gland is a big player in puberty too. This is the time when boys' and girls' bodies go through major changes as they slowly become men and women, all thanks to hormones released by the pituitary gland… • Will talk about other hormones later….

Pituitary- dehydration response • http: //highered. mheducation. com/sites/0072 495855/student_view 0/chapter 20/animation __hormonal_communication. html