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.
1. Parkinson’s disease causes this condition. 2. It results from the degeneration of dopamine-producing neurons in the central nervous system. 3. 80% of patients experience this condition alongside stiffness, walking difficulties, and challenges in balance and coordination.
Heart beat: The sympathetic nervous system speeds up the heart rate, while the parasympathetic nervous system slows it down. Urinary bladder: The sympathetic nervous system suppresses bladder contractions, while the parasympathetic nervous system promotes bladder contraction.
1. Rakesh’s fall from the motorbike involved the protective brain membranes: dura mater, arachnoid membrane, and pia mater, shielding against injury. 2. The cerebrospinal fluid (CSF) also served as a shock absorber during the accident, enhancing protective measures.
Excessive thirst (polydipsia) and frequent urination (polyuria) result from insufficient secretion of ADH in the associated disease.
The function of testosterone: 1. Testosterone facilitates the development of genital tracts. 2. Inadequate secretion or failure of testosterone leads to eunuchoidism, affecting the formation of secondary sexual characteristics.
The pancreas contains clusters of endocrine cells known as Islets of Langerhans, and these islets comprise four distinct types of hormone-secreting cells 1. Alpha (α) cells: constituting 20%, release glucagon—a hyperglycemic hormone that promotes glucogenolysis in the liver, elevating blood glucose levels. 2. Beta (β) cells: comprising 70%, produce insulin—a hypoglycemic hormone triggering glycogenesis in … Read more
1.Melatonin. 2.The pineal gland, a small endocrine organ located in the brain, generates and releases melatonin, a hormone crucial for regulating biological rhythms like sleep and wake cycles. Light inhibits melatonin secretion, while darkness triggers it.
Excessive release of growth hormones in adults results in the abnormal lengthening of the bones in the arms, legs, and lower jaw, leading to a condition known as acromegaly.
Hormones derived from steroids.