The Digestive System

The Endocrine System & The Digestive System The endocrine system is composed of glands that secrete hormones into the bloodstream. Maintains homeostasis Regulates reproduction and development

What are Hormones? Chemical messengers produced by the cell that effects specific changes in other cells (target cells) May take a long time to take effect

How do hormones travel through the body? Through the bloodstream

Endocrine Glands vs. Exocrine Glands Exocrine glands secrete substances into tube-like structures Example Digestion System Saliva Remember from Digestion Video Milk from Breasts Stomach Acid Endocrine Glands secrete substances directly into extra-cellular space. Substance moves via diffusion

Pancreas Located behind the stomach Hormone producing cells known as Islets of Langerhans Hormones Glucagon Targets the liver Increases blood glucose Kicks in after about 2 hours after eating Tells cells to release glucagon and increase blood sugar

Pancreas II Insulin Targets liver, muscle and tissue Decreases blood glucose Works after you eat a meal Tells cells to store the sugar Excess sugar changed into fat and stored in adipose cells

Diabetes Supply of insulin is insufficient for the body’s needs Type I Destruction of insulin producing cells in the pancreas Triggered by a viral infection Before the age of 25 Type II After the age of 40 Body is not making enough insulin. Obesity, the body requires larger quantities of insulin There is simply not enough

Diabetes II Muscles are deprived of fuel Sugar accumulates in the blood Sugar moves into urine and takes a lot of water with it Excessive urination, dehydration and great thirst Muscles start to waste Bleeding from eyes

Excretory System

Introduction Helps maintain homeostasis Regulates water balance Removal of harmful substances from the blood Lungs {Respiratory System} Remove CO2 Liver {Digestive System} Removes worn out Red Blood Cells Produces Urea Amino Acid Deamination

Major Parts of Urinary System Kidneys Produces urine Contains toxic substances and waste products Ureter Tube from kidney to bladder Bladder Muscular sac that stores urine Stores 200-300 ml of urine Once at that level, triggers reflex arc that stimulates spinal cord Use of the Nervous System Urethra Tube from bladder to outside world 1.5 inches long in females 6-8 inches long in males

Integumentary System

Skin/Integument Considered an organ Contains two tissues Contains accessory organ Glands Nails Hair Skin, with the accessory organs, make up the Integumentary System

Functions Protection Metabolism Excretion Thermoregulation Storage Vitamin D Excretion Salts Small amount of wastes Ammonia Urea Excreted in sweat Thermoregulation Temperature regulation Storage Blood

Accessory Organs Glands Eccrine Glands Releases watery solution Cools skin as water eveporates Ceruminous Glands Secrete cerumen (wax) Mammary Glands Produce milk secreted through the nipples of breasts Apocrine Glands Located under skin of armpits and pubic regions Releases solution in response to stress or sexual excitement beginning at puberty