Salivary Amylase PepsinPancreatic Lipase Source salivary glandsstomach cellspancreas cells Substrate amylose (starch)proteins (polypeptides) lipids Products.

Salivary Amylase

Pepsin Pancreatic Lipase

Source salivary glands stomach cells pancreas cells

Substrate amylose (starch) proteins (polypeptides)

lipids

Products maltose and glucose

amino acids glycerol and fatty acids

Optimum pH

neutral (pH 7) acidic (pH 3) neutral (pH 7)

http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_pumping.html

Myogenic muscle contraction: heart muscle can contract and relax without nervous system

SA node: tissue sends an electrical signal to stimulate atrial contraction (nearly every second)

AV node: tissue responds to SA node sending an electrical signal to stimulate ventrical contraction 0.1 seconds after it gets SA node signal

These act as the heart’s pacemaker to keep it “in time”

When you exercise, CO2 levels in your blood increase

This increase is sensed by the medulla in your brain which sends a nerve signal through your cardiac nerve to the SA node which increases your heart rate

When you stop exercising, CO2 levels fall, and the medulla sends another signal to the SA node through the vagus nerve to return rate control to the SA node, slowing down the rate.

Resting potential: the condition of a nerve axon when it is ready to send a signal, or impulse Characterized by Na+ ions outside the

membrane, and K- ions inside Action potential: the condition of a

nerve axon when it is sending a signal, or impulse Characterized by K- ions outside the

membrane, and Na+ ions outside

ccccc

Cell membrane (axon)

Key:

Sodium ion

Potassium ion

Resting Potential

cytoplasmAction Potential(depolarized area)

polarized area

Human body kept within normal limits for: Blood pH CO2 concentration Blood glucose concentration Body temperature Water balance

Affected by your nervous (mostly autonomic), endocrine, and circulatory systems primarily.

Thermostat in the hypothalamus If thermoreceptors detect an increase in

temp: Increase activity of sweat glands (persperation,

evaporative cooling) Skin arterioles dilate filling capillaries with blood

(works really well in elephant ears) If thermoreceptors detect a decrease in

temp: Skin arterioles constrict Skeletal muscle activation (shivering)

Cellular respiration always takes glucose out

Digestion always adds more glucose From the villi in the intestines, glucose enters

capillaries which eventually lead to the hepatic portal vein into the liver

Hepatocytes are liver cells that are directed by 2 important hormones for controlling blood glucose (antagonistic) Insulin Glucagon

Pancreatic β (beta) cells produce & secrete the hormone insulin

Insulin communicates to body cells the need for opening protein channels to absorb more glucose (facilitated diffusion)

Insulin also causes hepatocytes in the liver to convert glucose into glycogen

Pancreatic α (alpha) cells produce & secrete the hormone glucagon

Glucagon stimulates the hydrolysis of glycogen in hepatocytes and muscle cells

By breaking glycogen down into glucose, blood sugar will go back up

Type I: caused when β cells of the pancreas do not produce enough insulin and is autoimmune (often called “juvenile onset”) ~10%

Type II: caused when body cell receptors do not respond properly to insulin (insulin resistance)~90%

Can cause: blindness, kidney failure, nerve damage, higher risk of cardiovascular disease, decreased healing capacity