Physiology of Pituitary gland Pituitary gland is divided into two distinct portions, the anterior pituitary or adenohypophysis and posterior pituitary or neurohypophysis or pars nervosa. The pituitary is connected to the brain by means of the pituitary stalk. The adenohypophysis consists of three portions, viz., the pars distalis, pars tuberalis and the pars intermedia. The […]
Hormones of Hypothalamus Prolactin, Gonadotropic, Corticotropin, Thyroid Stimulating Hormone and Growth Hormone are hormones of Hypothalamus. It release and regulate functions of Pituitary gland, that’s why it is known as headmaster gland. The hypothalamus is located adjacent to the third ventricle in the forebrain and is connected by the hypophyseal stalk to the pituitary gland (hypophysis
Regulation of Hormone secretion Regulation of Hormone secretion is placed by three mechanism By metabolite concentration, Feed back control (or) Servo mechanism and Synergism and antagonism. By metabolite concentration Mechanism Feed back control (or) Servo mechanism Synergism and antagonism mechanism Metabolite concentration Mechanism Regulation of Hormone secretion– Metabolite concentration Mechanism of hormone regulation is one
Mechanism of action of Hormone Mechanism of action of Hormone is majorly classified into two categories – Mechanism of protein (Hydrophilic) hormone and Mechanism of steroid (Lipophilic) hormone. Mechanism of action of Hormone is described for both hormone types- Mechanism of protein (Hydrophilic) hormone The first step in protein or peptide hormone action, the hormone
Hormone Receptor properties All receptors are proteins and have these properties- Each cell may have receptors for more than one hormone and therefore is a target for several hormones Specificity spill over – hormones with similar structure may bind to one another’s receptors usually with lower affinity and ability to activate the receptors. Activation of
Target organ and receptor types Different Hormone have different Target organ and receptor types for their functioning. Target Cell is the cells that contain specific receptors for a hormone. Although all cells are exposed to all hormones, only few cells or organs can respond to all specific hormone, termed as target cells or target organ. This is
Transportation of hormone in blood Most water soluble hormone molecules circulate in the blood in the free from (not attached to a protein) and Most lipid soluble hormones bind to transport proteins to transportation of hormone in blood. Binding of hormones to proteins are loose and reversible. Transport proteins are albumin and globulins synthesized by
Pattern of hormone secretion in animals Fluctuations of frequency and amplitude of hormone secretion is described as hormone peaks, pulses, spikes or bursts these are called Pattern of hormone secretion in animals. The rhythm of hormone secretion may be one the following- Ultradian- Ultradian pattern of hormone secretion have many short pulses occurring every few
Classification of hormones Classification of hormones is based on chemical nature, Based on Physiological Functions. these are detailed described below- Classification of hormone based on chemical nature- Peptides and proteins Hormones Peptides and proteins consist of chains of amino acids. Examples of small peptide hormones are TRH and vasopressin . Peptides composed of numerous amino
Functions of Endocrine System Functions of Endocrine System are vast in animals and human body, these are like – Maintain homeostasis, Control chemical and water balance in body, Control growth and metabolism, Control embryonic development and preparation for nurturing a newborn, Influence sexual behavior, stimulate growth and maturation of the genitalia, Feedback to the nervous
