sodium and its medical importance for medical students
TRANSCRIPT
sodium
Dr.M.Siva kumar Reddy MD,Department of Biochemistry
Sri Venkateswara Medical College
often touted as a nutrition villain
Sodium-chief cation of ECF
total body sodium
50% in bone
40% in ECF
10% in soft
tissues
Sodium distribution in the body
Acid base balance
Acid base balance
Muscle irritability and cell permeability
Sodium required for normal muscle irritability and cell permeability
Sodium necessary for initiating and maintaining heart beat.
Intestinal absorption of glucose & galactose
Maintenance of osmotic pressure and fluid balance
Dietary requirements
Normal individuals, the requirement of sodium is about 5-10 g/day
For persons with a family history of hypertension, the daily NaCl intake should be less than 5 g.
For patients of hypertension, around 1 g/day is recommended.
10 g of NaCl contains 4 g of sodium
Due to its flavour salt is taken more than the requirement
Sources of sodium
common salt (NaCl) is the major source of sodium.
The good sources of sodium include……
Bread
Whole grains
Leafy vegetables
Nuts
Eggs
Milk
very little of it (< 2%) is normally found in feces
In diarrhea, large quantities of sodium is lost in feces.
Absorption of sodium
Plasma sodium
Plasma
135-145mEq/L
Blood cell
35mEq/L
The mineralocorticoids, secreted by adrenal cortex, influence sodium metabolism. A decrease in plasma sodium and an increase in its urinary excretion are observed in adrenocortical insufficiency.
Excretion
Kidney is the major route of sodium excretion 800 g Na/day is filtered by the glomeruli. 99% of this is reabsorbed by the renal tubules by an active process. Controlled by aldosterone. Extreme sweating also causes considerable amount of sodium loss from the body
Diseased states due to sodium
Sodium diseased states
Hyponatremia< 135meq/L
Hypernatremia>145meq/L
Hyponatremia
Addison's diseaseAddison’s disease, also known as primary adrenal
insufficiency and hypocortisolism is a long-
term endocrine disorder in which the adrenal glands do
not produce enough steroid hormones.
Hormone replacement therapy is treatment of choice.
Oral corticosteroids or steroid injections are given
according to the need.
Addison's disease
primary secondary
autoimmune disease
Tuberculosis
Other infections of the adrenal glands
Spread of cancer to the adrenal glands
Bleeding into the adrenal glands, which may present as adrenal crisis without any preceding symptoms.
Pitutary abnormalities
Hypothalamic
abnormalities
Congenital ACTH deficiency
Hypernatremia
Hypernatremia
characterized by an elevation in the serum sodium level.
The symptoms include increase in blood volume and blood pressure.
May occur due to hyperactivity of adrenal cortex (Cushing's syndrome)
May occur due to prolonged administration of cortisone, ACTH and/or sex hormones.
Diabetes insipidus, pregnancy, steroid and placental hormones, administration of diuretic drugs .
In the patients of hypertension and congestive cardiac failure salt (Na+) restriction is advocated.
Cushing's syndromeAlso called hypercortisolism.
Cushing syndrome
Cushing syndrome• Treatments for Cushing syndrome are designed to lower the high level of
cortisol in your body. The best treatment for you depends on the cause of the
syndrome.
• Reducing corticosteroid use
• Surgery(for tumours)
• Radiation therapy
• Medications to control excessive production of cortisol at the adrenal gland
include ketoconazole (Nizoral), mitotane (Lysodren) and metyrapone
(Metopirone)
• If none of these treatment options are appropriate or effective, your doctor
may recommend surgical removal of your adrenal glands (bilateral
adrenalectomy)