Aim: How does the endocrine system control activities of the body?

What system might have caused this?

Endocrine System The endocrine and nervous system act together to regulate the functions of the body (homeostasis). *Allows for cell to cell communication.

Consists of a series of glands Glands secrete HORMONES into the bloodstream (chemical regulation). Endocrine System

Hormones Chemical messages that affect a target tissue.

Example…… GSH (growth stimulating hormone) will affect only the bones (target tissue) Cell A Cell BCell C If GSH is hormone B, what cell represents its target tissue? How do you know?

Receptors RECEPTORS Proteins found on the cell membrane. Messengers(hormones) from other cells bind to these receptors (based on shape) and transfer information.

Receptor Cells must have a RECEPTOR with the matching shape to receive the message. Hormone Target Tissue Receptor

Aim: How does the endocrine system use negative feedback to maintain homeostasis?

1. The thermostat is set to a certain temperature….Homeostasis. 2.The heater will turn on until it reaches the temperature 3.The heater will turn off. 4.As the heat decreases, the heater will turn on until it the desired temp is reached. The cycle repeats!!!!! How does a thermostat work?

Example of Negative feedback Thermostat senses temperature change and switches off heating system Room temperature decreases Thermostat senses temperature change and switches on heating system Room temperature increases

Negative Feedback Pancreas Releases Blood sugar drops Pancreas stops releasing insulin Blood sugar rises High Blood Sugar INSULIN

Feedback Feedback Mechanism – A response that allows your body to maintain homeostasis. Negative Feedback The initial response is to increase the release of a hormone, then once the desired effect is reached, the initial response is turned off! The OPPOSITE from the ORIGINAL RESPONSE!!!!!!!

Feedback Positive Feedback: A change prompts a response, which leads to a greater change and greater response. Uterine Contractions Baby’s head hits Base of uterus Stronger Contractions Increase in pressure of baby’s head against base of uterus

Homeostasis/Dynamic Equilibrium There are constant small corrections that normally keep the internal environment within the limits needed for survival.

Nervous vs. Endocrine Nervous System Neuron Regulation Cell-Cell Communication FAST Endocrine System Hormones Regulation Cell-Cell Communication SLOW Hypersecretion – Over secretion Hyposecretion - Under secretion

Endocrine Glands Hypothalamus Pituitary Gland Thyroid Gland Adrenal Gland Pancreas Gonads

Hypothalamus Location: In the center of the brain, it connects the brain to the pituitary gland. Function: Controls the release of hormones from the pituitary gland.

Pituitary Gland Location: base of the brain. Function: called the “MASTER GLAND” Secretes: (GSH) Growth Stimulating Hormone Hypersecretion: Giantism Hyposecretion: Dwarfism

Thyroid Gland Location: Neck, in front of your trachea. Function: regulates metabolism (WEIGHT) depending on iodine intake. Hyposecretion: Weight Gain Goiter (due to an iodine deficiency)

Aim: How can the endocrine malfunction?

Aim: What are some diseases of the Endocrine System? Hypersecretion – Over secretion –Too much hormone is released Hyposecretion - Under secretion –Too little of the horomone is released

Giantism Over secretion of GROWTH HORMONE

Dwarfism Hyposecretion of GROWTH HORMONE

Goiter A goiter is an ENLARGEMENT of the thyroid gland. Caused by a hyposecretion of thyroxin. Iodine deficiency TREATMENT: Medication Iodized Salt

Diabetes Caused by an insulin deficiency or cell do not respond to insulin Results in an Increased blood glucose level. Treatment: insulin and diet

Diabetes Mellitus Pancreas cannot make enough insulin What happens to the blood glucose level if you have no insulin? It remains high, & cells can’t use it for energy. If you were a doctor, how would you test someone for diabetes? High glucose levels in blood and urine.

Adrenal Gland Location: Top of the kidneys Function: Secretes: Adrenaline – “Fight or Flight” response

Islets of Langerhans (Pancreas) Location: Pancreas Function: Secretes: Insulin – increases the amount of glucose taken up by body cells from the blood (decreases glucose in the blood). Glucagon – stimulates release of glucose from body cells into the blood (increases glucose in the blood). Together they regulate the amount of glucose in the blood (homeostasis)

What are the effects of Insulin & Glucagon? What is glycogen? Polysaccharide

Gonads Location: testes and ovaries Function: Ovaries: (secrete) estrogen – female sex characteristics Testes: (secrete) testosterone – male sex characteristics