Grafilon, Jonathan Fuller, Shiitj B.
The nervous system enables humans to react to their surroundings and to coordinate their behaviour. Information from receptors passes along cells neurones as electrical impulses to the central nervous system CNS. The CNS is the brain and spinal cord.
The CNS coordinates the response of effectors which may be muscles contracting or glands secreting hormones. Reflex actions are automatic and rapid; they do not involve the conscious part of the brain.
In a simple reflex action such as a pain withdrawal reflex: You should understand why reflex actions are important. You should be able to extract and interpret data from graphs, charts and tables, about the functioning of the nervous system. You should be able to translate information about reaction times between numerical and graphical forms.
Revise required practical 5: Investigating the effect of a factor on human reaction time. It is made of billions of interconnected neurones and has different regions that carry out different functions. The cerebral cortex is concerned with consciousness, intelligence, memory and language.
The cerebellum is concerned mainly with the coordination of muscular activity. The medulla is concerned with unconscious activities such as heartbeat and breathing. You should be able to identify the structures listed above on a diagram of the brain and describe their functions.
HT only You should be able to explain some of the difficulties of investigating brain function and treating brain damage and disease. HT only Neuroscientists have been able to map the regions of the brain to particular functions by studying patients with brain damage, electrically stimulating different parts of the brain and using MRI scanning techniques.
The complexity and delicacy of the brain makes investigating and treating brain disorders very difficult.
HT only Be able to evaluate the benefits and risks of procedures carried out on the brain and nervous system. The eye is a sense organ containing receptors sensitive to light intensity and colour.
In the eye you should be able to identify the following structures on a diagram of the eye and explain how their structure is related to their function: Know that accommodation is the process of changing the shape of the lens to focus on near or distant objects.
To focus on a near object the ciliary muscles contract, the suspensory ligaments loosen, the lens is then thicker and refracts light rays more strongly.
To focus on a distant object the ciliary muscles relax, the suspensory ligaments are pulled tight, the lens is then pulled thin and only slightly refracts light rays.
Two common defects of the eyes are myopia short sightedness and hyperopia long sightedness in which rays of light do not focus on the retina. Generally these defects are treated with spectacle lenses which refract the light rays so that they do focus on the retina.
New technologies now include hard and soft contact lenses, laser surgery to change the shape of the cornea and a replacement lens in the eye. You should be able to interpret ray diagrams, showing these two common defects of the eye and demonstrate how spectacle lenses correct them.
The thermoregulatory centre contains receptors sensitive to the temperature of the blood.
The skin contains temperature receptors and sends nervous impulses to the thermoregulatory centre. If the body temperature is too high, blood vessels dilate vasodilation and sweat is produced from the sweat glands. Both these mechanisms cause a transfer of energy from the skin to the environment.
If the body temperature is too low, blood vessels constrict vasoconstrictionsweating stops and skeletal muscles contract shiver. HT only You should be able to explain how these mechanisms lower or raise body temperature in a given context. The endocrine system is composed of glands which secrete chemicals called hormones directly into the bloodstream.
The blood carries the hormone to a target organ where it produces an effect. Compared to the nervous system, the effects are slower, but, act for longer. These hormones in turn act on other glands to stimulate other hormones to be released to bring about effects.
You should be able to identify the position of the following on a diagram of the human body: If the blood glucose concentration is too high, the pancreas produces the hormone insulin that causes glucose to move from the blood into the cells.
In liver and muscle cells excess glucose is converted to glycogen for storage. You should be able to explain how insulin controls blood glucose sugar levels in the body. Type 1 diabetes is a disorder in which the pancreas fails to produce sufficient insulin.
It is characterised by uncontrolled high blood glucose levels and is normally treated with insulin injections.9 May, hrs – see updates at end of post Once again media reports have emerged claiming that genetically modified pest-resistant Bt brinjal (eggplant) has failed in the field and that farmers in Bangladesh are regretting that they have begun to grow it.
Journal of Environmental Biology January, O n l i n e C o p y Acid rain and its ecological consequences Such changes in the soil chemical characteristics reduce the soil fertility, which ultimately causes the negative Acid rain and its ecological consequences-.
DAY – Insights Self Study Guide for Prelims + Mains – 10 June Following Questions are Based on this TIMETABLE. ARCHIVES. 1) Explain circumstances leading to acid rain. International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research. Risk is the possibility of losing something of value. Values (such as physical health, social status, emotional well-being, or financial wealth) can be gained or lost when taking risk resulting from a given action or inaction, foreseen or unforeseen (planned or not planned).Risk can also be defined as the intentional interaction with uncertainty.
When acid rain and dry acidic particles fall to earth, the nitric and sulfuric acid that make the particles acidic can land on statues, buildings, and other manmade structures, and damage their surfaces.
The effects of acid rain, combined with other environmental stressors, leave trees and plants less able to withstand cold temperatures, insects, and disease. Acid rain has a long term can directly effect on the aquatic life, as the high amount of sulphuric acid and nitric acid levels in acid rains are directly consumed by aquatic animals and plants.
The harmful acids affect the ability of fish to take in nutrients, salt, and oxygen. Pure and simple, if you put acid up into the atmosphere, not just carbon dioxide as you hear about today, but sulfuric acid and nitric acid, from the burning of fossil fuels and smelting, the acid.