Adrenal Cortex Prof K Sivapalan Structure of Adrenal
- Slides: 30
Adrenal Cortex Prof. K. Sivapalan
Structure of Adrenal Cortex. • • Histologyzona glomerulosa. zona faciculata zona reticulata. 08 -01 -14 Adrenal Cortex. 2
Structure of Steroid Hormones. 08 -01 -14 Adrenal Cortex. 3
Structure of Steroid Hormones. 08 -01 -14 Adrenal Cortex. 4
Classification of steroids • Mineralocorticoids- aldesteron • Glucocorticoids- cortizol • Sex hormones • androgens • estrogens 08 -01 -14 Adrenal Cortex. 5
Mechanism of Action of Steroids. • Transport- bound to globulin- Transcortin. • Binds to receptors in cytozol, transported to Nucleus and act on transcription. • Direct action on membrane and enzymes. 08 -01 -14 Adrenal Cortex. 6
Glucocorticoids. • Half-life- 60 -90 minutes 08 -01 -14 Adrenal Cortex. 7
Effects on Carbohydrarte Metabolism. • In Liver, increases gluconeogenesis. – Increase transport of AA into cells of liver. – Gluconeogenic enzymes increased in liver. – Entry of AA into other tissues prevented. • Reduces glucose utilization by cells. • The above changes are not seen in Heart, Brain, and red cells. • Increases blood glucose level. 08 -01 -14 Adrenal Cortex. 8
Effects on Protein Metabolism. • Reduce protein synthesis. • Increase catabolism of cellular protein. • Reduce RNA in muscles and lymphoid tissue. • Increase blood Amino acids. • Increase protein synthesis in liver, plasma proteins. 08 -01 -14 Adrenal Cortex. 9
Effects on Fat Metabolism. • Increased lypolysis from adipose tissue in limbs. • Fat storage increased in face and trunk. • Increased plasma FFA. 08 -01 -14 Adrenal Cortex. 10
Other Effects of Glucocorticoids. • Permissive action: – Catacholamines- calorigenesis, lypolytic action, pressure responses, bronchodilation. – Glucagon- same as above. • Vascular reactivity: – Smooth muscle tone requires steroids. – Capillaries require steroids for normal permeability [absence increases permeability] • Essential for life. 08 -01 -14 Adrenal Cortex. 11
Other Effects of Glucocorticoids • Nervous system: – Reduction results in personality changes- irritability, apprehension and inability to concentrate. – Electroencephalogram changes: slower than normal A rhythm. – Increase results in reduced threshold for convulsions. • Water Metabolism: – Deficiency leads to inability to excrete water. Increased ADH and reduced GFR observed which are repaired by glucocorticoids only. 08 -01 -14 Adrenal Cortex. 12
Other Effects of Glucocorticoids • Bone- reduce protein matrix and causes osteoporosis. • Blood and Immunity: – Increased RBC, nutrophils, platelets. – Reduced eosinophils, basophils, lympho cytes and all immune responses at high doses. – Use as anti-inflammatory drug. • Resistance to stress: – High levels of corticoids needed to cope with stressful conditions. [Essential for life] 08 -01 -14 Adrenal Cortex. 13
Effects of Mineralocorticoids. • Half life- 20 minutes. • Distal tubule of kidney- sodium absorption in exchange of potassium and hydrogen. Blood volume cannot be maintained without this action. • *Essential for life. • Similar action seen in sweat glands, salivary glands and gastric glands. 08 -01 -14 Adrenal Cortex. 14
Effects of Sex Hormones • Secretion increases at puberty. • Androgens are responsible for acne in males and females. • All other actions done by sex hormones secreted by testis and ovary. 08 -01 -14 Adrenal Cortex. 15
Regulation of secretion. • Corticotrophin Releasing hormone [CRH] stimulates ACTH which stimulates glucorticoids. • Renin- angeotensin system regulates aldesteron secretion. 08 -01 -14 Adrenal Cortex. 16
Effect of Hypophysectomy • Zona glomeruloza is not affected. • Other two zines atrophic. 08 -01 -14 Adrenal Cortex. 17
Diurnal Variation of Secretion. 08 -01 -14 Adrenal Cortex. 18
Other factors that stimulate CRH • Trauma- nociceptive pathways • Emotion- lymbic system – Emotional stresses, fear, anxiety, apprehension • Baro receptors throw Nucleus Tractus Solitarius inhibit. 08 -01 -14 Adrenal Cortex. 19
Stimuli that increase aldesteron secretion. • Glucorticoid also increased, – – Surgery. Anxiety. Physical trauma. Haemorrhage. • Glucocorticoid unaffected: – – – 08 -01 -14 High potassium intake. Low sodium intake. Inferior vena cava constriction in throax. Standing. Secondary to congestic cardiac failure, cirrhosis, nephrosis. Adrenal Cortex. 20
Adreno Cortical Insufficiency. • Acute- adrenal crisis: – Head ache, lassitude, confusion, restlessness, vomiting, abdominal or costo-vertibral pain, circulatory collapse, unconsciousness, death. • Chronic- Addison’s disease. – Mineralocorticoid insufficiency alone is rare. – Mixed insufficiency is common. 08 -01 -14 Adrenal Cortex. 21
Addison’s disease. • Weakness and fatigability. • Weight loss and dehydration. – Increased sodium excretion, water diuresis, reduced appetite and GIT function. • Hypotension and small heart- dizziness, syncopal attacks. • GIT- reduced acid secretion, reduced motility. • Nervousness and mental symptoms. • Precipitation of crisis in stress. • Pigmentation- depends on the cause. 08 -01 -14 Adrenal Cortex. 22
Pigmentation due to ACTH. 08 -01 -14 Adrenal Cortex. 23
Hyper Aldesteronism. • Primary hyper aldesteronism– tumor- Conn’s Syndrom. • Secondary Aldesteronism– Cardiac failure, renal disease, cirrhosis. • • Hypokalaemia. Slight increase in ECF and blood volume. Slight increase in plasma sodium. Hypertension. 08 -01 -14 Adrenal Cortex. 24
Hyper Adrenalism- Cushings Disease. • • Redistribution of fat. Moon face. Fat pads of neck. Pendulous abdomen. Buffalo hump. Striae in skin. Thin extremities. 08 -01 -14 Adrenal Cortex. 25
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MOON Face. Same Twinperson sisters before with and without after treatment. moon face. 08 -01 -14 Adrenal Cortex. 27
Other Features of Increased Glucocorticoids. • Red face- polycythaemia. • Thin skin, wasting of muscles, osteoporosisweakness and backache. • Poorly healing wounds. • Systolic hypertension- sodium retention, angeotensin increase or direct effect. • Diabetes mellitus. • Mood changes- increased appetite, insomnia, euphoria, toxic psychosis. • Hypokalaemia- mineralocorticoid action. • Hirsutism- increased androgens. 08 -01 -14 Adrenal Cortex. 28
Effects if increased Androgens. • Female fetus- male type of genitalia. • Male fetus- facilitated development of genitalia. • In childhood- stimulation of growth but early closure of epiphysis and short stature. • Prepubertal boys- precautious puberty without testicular development. • Adult male- no significant changes. • Pubertal and adult females- male features. 08 -01 -14 Adrenal Cortex. 29
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- Rekha sivapalan
- Glucocorticoids
- Adrenal cortex develops from
- Adrenal medulla cortex
- Adrenal cortex and medulla
- Motor cortex sensory cortex
- Parasympathetic and sympathetic
- Adrenal bez histolojisi
- Arritimias
- Dr dawn lim
- Estadiamento de tanner
- 21 alfa hidroksilaz eksikliği
- Nerve supply of adrenal gland
- Medulla
- Adrenal kriz acilci
- Congenital adrenal hyperplasia characteristics
- Menopause and mania
- Summary of adrenal gland
- Thyroid
- Ectocrine
- 17 hydroxyprogesterone level
- Virilisation in females
- Acth
- Psödo cushing sendromu
- Adrenal cushing
- Congenital adrenal hyperplasia genitalia
- Adrenal sympathetic pathway
- Adenoma
- Guyton
- Adrenal gland regions
- Psammoma bodies