Plants and animals both show a control and coordination mechanism. In plants this done by sending chemical signals and brining about various types of movements (e.g. phototropic, chemotactic, thingmotactic, etc). Animals, specially the higher vertebrates show a gradual increase in the complexity of their control and coordination by giving both electrical and chemical singles. In this chapter now you will study about development of nervous system in different animal groups and details of the system in humans.
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
Ovarian hormones include estrogen, progesterone, relaxin, and inhibin. Functions: 1. Estrogen: • Stimulates secondary sexual characteristic development during puberty. • Regulates the menstrual cycle, promoting uterine lining growth. • Maintains bone density and cardiovascular health. 2. Progesterone: • Prepares and sustains the endometrium for potential pregnancy. • Coordinates with estrogen for menstrual cycle regulation. • Supports early pregnancy by preventing … Read more
Simple goiter: Simple goitre, also known as endemic goitre, arises from a deficiency of iodine in the diet. This deficiency leads to a reduced iodine level in the bloodstream. To compensate for this shortage, the thyroid gland attempts to extract more iodine from the blood, prompting an increase in blood supply to the gland. Consequently, … Read more
The Islets of Langerhans constitute the endocrine portion of the pancreas. There are four type of cells in islets of langerhans Alpha cell: 1. Glucagon hormone is secreted by alpha cells. 2. Alpha cells release the hormone glucagon. 3. The secretion of glucagon is carried out by alpha cells. 4. Glucagon is produced and released … Read more
1. The adrenal medulla stems from embryonic neuro-ectoderm. 2. Comprising rounded clusters of large granular cells known as chromaffin cells, it consists of modified post-ganglionic cells from the sympathetic nervous system. 3. These cells maintain connections with preganglionic fibers of the sympathetic nervous system. 4. Consequently, the adrenal medulla serves as a continuation of the … Read more
The pituitary gland is connected to the ventral surface of the brain, adjacent to the hypothalamus. The hormones secreted by anterior pituitary: 1. Growth Hormone (GH): Stimulates growth. Function: 1. Growth hormone maintains body structure, metabolism, and supports brain and organ tissue health. 2. Widely used in medicine for treating growth disorders in children and … Read more
1. Myxedema is the illness associated with this individual, characterized by a swollen look and diminished alertness. 2. It stems from thyroid gland malfunction, a consequence of severe hypothyroidism or insufficient thyroxine hormone. 3. The condition results in a puffy appearance and reduced alertness in affected patients.
site of production : secretin, Gastrin, cholecystokinin. Functions: Secretin: Promotes the release of pancreatic juice from the pancreas and bile from the liver. Gastrin: Promotes the secretion of gastric juice from gastric glands. Cholecystokinin: Encourages the pancreas and gall bladder to release pancreatic enzymes and bile, respectively.
Gustatory receptors are present on the surface of the tongue.
Excitability : Increased responsiveness or irritability characterizes the heightened sensitivity of an organ or body part, reflecting its heightened reactivity to stimulation. Conductivity: Conductivity refers to how easily electric charge or heat can move through a substance. A conductor is a material that offers minimal resistance to the flow of electric current or thermal energy. … Read more