 Chemicals that dissolves in water and dissociates into positive and negative ions  Most are inorganic salts, acids and bases  Positive ions = cations (Na+, K+, Ca+, Ca++, Mg++ and H+)  Negative ions = anions [Cl -, HCO 3 -, SO 4 -2 (sulfate), HPO 4 -2 ( phosphate) & protein]  Electrolytes help osmolarity of body fluid  Regulate osmosis of water between different compartments

 Mixture of carbonic acid (H 2 CO 3 ) = weak acid sodium bicarbonate (NaHCO 3 ) = weak base  If there is pH change due to presence of strong acids ◦ Bicarbonate ions (HCO 3 – ) react with strong acids to change them to weak acids HCl + NaHCO 3  H 2 CO 3 + NaCl strong acid weak base weak acid salt

 If there is pH change due to presence of strong base ◦ Carbonic acid dissociates in the presence of a strong base to form a weak base and water NaOH + H 2 CO 3  NaHCO 3 + H 2 O strong base weak acid weak base water

 Resp. system controls the amount of CO 2 in body fluid  Carbon dioxide in the blood is converted to bicarbonate ion and transported in the plasma  Increases in hydrogen ion concentration produces more carbonic acid  Excess hydrogen ion can be blown off with the release of carbon dioxide from the lungs  Respiratory rate can rise and fall depending on changing blood pH

 Excrete or conserve H + ions  Excrete or reabsorb Na + and HCO3 - (bicarbonate ions)  generate new bicarbonate ions if needed

 When blood pH rises ◦ Sodium and Bicarbonate ions are excreted ◦ Hydrogen ions are retained by kidney tubules  When blood pH falls ◦ Sodium and Bicarbonate ions are reabsorbed ◦ Hydrogen ions are secreted  Urine pH varies from 4.5 to 8.0

1. Nephron numbers in Kidney decreased by half by year old 2. Concentrating ability of urine by tubules cells decreased 3. Glomerular filtration rate decreased due to reduced renal blood flow as a result of arthrosclerosis 4. Detrusor muscle tone reduced & the bladder shrinks –need to void more frequently 5. Enlarged prostate in older male results in urinary retention

 Female: male = 100:1  As you get older, your risk increases. Assuming you live to age 90, your risk of getting breast cancer over your lifetime is about 12%.  Smoking is associated with an increased risk of breast cancer  Family history - risk increases with number of first degree relatives affected. (1-.5 to 4 times increased risk)  inherited cases of breast cancer have been associated with two genes: BRCA1,, and BRCA2  Hormone replacement therapy, ? Contraceptive pills  Risk increases with earlier menarche and late menopause  Age at first live birth (If aged 30 years or older, relative risk is 2 times that of patients who gave birth when younger than 20 )years.

 Recommended for > 20 years at least once a month

 Look for changes in your breasts in front of the mirror  while holding your arms at your side. Then, raise your arms above your head, clasp your hands behind your neck, and check again.

Press your hands on your hips to flex your chest muscles. Look for changes in the appearance of your breasts.

 Squeeze your nipple between your thumb and forefinger to check for discharge. (A drop or two of clear or whitish fluid is normal.)

 Lie down and place a pillow under the shoulder of the breast you're examining. Keep the arm on that side raised as shown.  Mentally divide the breast area into strips or circles. The area should include your collar bone to your bra line and your breast bone to your underarm

 Feel with the sensitive pads of your three middle fingers held flat  Use small circular motions to cover each area of the strip or circle. Go over each area three times using varying degrees of pressure as shown.

 Use light pressure to feel for changes below the skin.  Use deeper pressure to feel for changes in breast tissue.

 12 months has passed without menstruation ◦ Ovaries stop functioning as endocrine organs ◦ Childbearing ability ends  yrs (Malaysian average age is 47 years )  Preceded by declining ovarian function over time resulting in scanty and shorter menses - perimenopause  Symptoms due to deficiency of estrogen ◦ Atrophy of reproductive organs and breasts ◦ Mood changes, depression ◦ Hot flushes ◦ Loss of bone mass – osteoporosis Risk of bone fractures ◦ Increased risk of cardiovascular diseases due to arthrosclerosis and increased cholesterol level