Hormones exert their effects by acting on specific target organs or tissues with designated binding sites, known as hormone receptors. The mechanisms vary between steroid hormones and protein hormones. Steroid Hormones: 1. Lipid-soluble steroid hormones easily traverse the lipoproteinaceous plasma membrane. 2. Receptors for steroid hormones are located in the cytoplasm or nucleus. 3. The … Read more
Adrenal cortical secretion disorders result from both insufficient and excessive production of adrenal cortex hormones. Addison’s diseases: Addison’s disease manifests through symptoms such as hypoglycemia, reduced body temperature, weakened heart function, low blood pressure, acidosis, decreased concentrations of sodium and potassium in the plasma, increased urinary loss of sodium and water, impaired kidney function, and … Read more
1. The adenohypophysis constitutes the prominent anterior segment of the pituitary gland. 2. Originating from the embryonic ectoderm, it emerges as Rathke’s pouch, a small protrusion from the roof of the embryonic stomodaeum. 3. Comprising secretory cells with an epitheloid structure, the adenohypophysis carries out hormonal functions. 4. Rathke’s pouch undergoes development to form this … Read more
1. Homeostasis maintains a constant internal body environment, with negative feedback mechanisms playing a crucial role. 2. Excessive hormone secretion triggers inhibiting factors from the hypothalamus, leading to negative feedback that halts pituitary stimulating hormone production. 3. Hormone deficits prompt the release of specific factors, signaling the respective gland to maintain hormonal balance and homeostasis. … Read more
(a) Adenohypophysis releases TSH. (b) The degenerating corpus luteum of the ovary produces Relaxin. (c) Duodenal mucosa secretes Secretin. (d) Thyroid releases Calcitonin (hypocalcemic hormone), and parathyroid glands produce Parathormone(hypercalcemic hormone). (e) Hypothalamus releases ADH. (f) Atrial natriuretic factor is produced by the atria of the heart. (g) Aldosterone is synthesized by the adrenal cortex. … Read more
The thyroid gland’s atrophy causes a reduction in thyroid hormone secretion, leading to the development of hypothyroidism. Hyposecretion of thyroid hormone: Hypothyroidism occurs when the thyroid gland fails to produce and release an adequate amount of thyroid hormone into the body. a. Cretinism: Hypothyroidism, characterized by a deficiency in the production of the thyroid hormone … Read more
Krishna’s symptoms were a result of the sympathetic nervous system activation during an emergency. The adrenal medulla cells release adrenaline and noradrenaline, directly affecting the heart’s pacemaker, leading to increased heart rate and associated symptoms—a typical fright reaction triggered by the sympathetic nervous system.
1. Receptor organs, such as the skin, eyes, tongue, nose, and ears, specialize in converting stimuli into impulses. 2. Sensory neurons transport these impulses from the receptors to the central nervous system, with their cell bodies in the dorsal root ganglion. 3. Motor neurons, located in the ventral horn of the spinal cord, convey motor … Read more
Polarisation and Depolarisation along a nerve i. A nerve impulse signifies a wave of bioelectrical or electrochemical disruptions coursing through a neuron. ii. Neurons possess a polarized cellular membrane with distinct voltages on its outer and inner sides. The plasma membrane separates these solutions of differing chemical compounds, despite having approximately the same total number … Read more