hormones
HORMONES
Hormones are a class of regulatory biochemicals produced in all multicellular organisms by glands, and transported by the circulatory system to a distant target organ to coordinate its physiology and behavior. They serve as a major form of communication between different organs and tissues. Hormones regulate a variety of physiological and behavioral activities, including digestion, metabolism, respiration, tissue function, sensory perception, sleep,excretion, lactation, stress, growth and development, movement, reproduction, and mood. Generally, only a small amount of hormone is required to alter cell metabolism.
CLASSIFICATION OF HORMONES BY CHEMICAL
COMPOSITION
PITUITARY GLAND:
The human pituitary gland or hypophysis is an endocrine gland about the size of pea and weighing 0.5g. It is situated in a small cavity in the sphenoid bone at the base of the skull and is attached to the base of the brain by a short stalk. Pituitary is from Latin pituita, meaning slime or mucus. Pathologies include hypopituitarism and hyperpituitarism. The pituitary body is in reality two glands by origin and function:
Anterior Pituitary Gland (Adenohypophysis)
The anterior lobe is ectodermal in origin, derived from an out pouching from the primitive pharynx.
Posterior Pituitary Gland (Neurohypophysis)
The posterior lobe is neural in origin,derived from the out pouching of the base of the brain.
Posterior Pituitary Gland Effects:
Extracts of the posterior pituitary lobe exhibit the following effects:-
1. A pressor effect, owing to arteriolar and capillary vasoconstriction
2. Direct stimulation of smooth muscle, seen in the intact animal or in preparations of isolated muscles 3. An antidiuretic action, effected by increasing the tubular and collecting duct resorption of water in the kidney.
OXYTOCIN (hypophamine)
Physiological Function
Oxytocin is the uterine- stimulating fraction, and it is relatively free from
Hormones are a class of regulatory biochemicals produced in all multicellular organisms by glands, and transported by the circulatory system to a distant target organ to coordinate its physiology and behavior. They serve as a major form of communication between different organs and tissues. Hormones regulate a variety of physiological and behavioral activities, including digestion, metabolism, respiration, tissue function, sensory perception, sleep,excretion, lactation, stress, growth and development, movement, reproduction, and mood. Generally, only a small amount of hormone is required to alter cell metabolism.
CLASSIFICATION OF HORMONES BY CHEMICAL
COMPOSITION
PITUITARY GLAND:
The human pituitary gland or hypophysis is an endocrine gland about the size of pea and weighing 0.5g. It is situated in a small cavity in the sphenoid bone at the base of the skull and is attached to the base of the brain by a short stalk. Pituitary is from Latin pituita, meaning slime or mucus. Pathologies include hypopituitarism and hyperpituitarism. The pituitary body is in reality two glands by origin and function:
Anterior Pituitary Gland (Adenohypophysis)
The anterior lobe is ectodermal in origin, derived from an out pouching from the primitive pharynx.
Posterior Pituitary Gland (Neurohypophysis)
The posterior lobe is neural in origin,derived from the out pouching of the base of the brain.
Posterior Pituitary Gland Effects:
Extracts of the posterior pituitary lobe exhibit the following effects:-
1. A pressor effect, owing to arteriolar and capillary vasoconstriction
2. Direct stimulation of smooth muscle, seen in the intact animal or in preparations of isolated muscles 3. An antidiuretic action, effected by increasing the tubular and collecting duct resorption of water in the kidney.
OXYTOCIN (hypophamine)
Physiological Function
Oxytocin is the uterine- stimulating fraction, and it is relatively free from