Fundamental biology for cambridge o level free download

Kidney failure may result from an accident involving a drop in blood pressure, or from a disease of the kidneys. A dialysis machine is required to replace the function of the kidneys should the kidneys are damaged. Homeostasis Monday, November 24, PM Homeostasis is the maintenance of a constant internal environment. The regulation of blood glucose level is done by the pancreas.

Homeostatic control of blood glucose level: Fig. The two hormones, insulin and glucagon have different effects on the glucose level in the blood. They are produced by the same region of the pancreas, the islets of Langerhans, but by different cells. Their secretion into the blood is controlled by the negative feedback mechanism depicted in Figure Insulin converts glucose to glycogen which reduces the blood glucose level. Glucagon converts glycogen to glucose which increases the blood glucose level.

The regulation of blood water potential is done by the kidneys. Homeostatic control of water potential: Fig. On a cold day, if you don't sweat, you'll produce more urine which will be pale and dilute. On a hot day, you sweat a lot, your urine will be dark-coloured, concentrated and little of it.

The regulation of temperature is done by the skin. The skin: Fig. When the body is exercising vigorously or when the surrounding is hot: 1 Thermoreceptors in the skin detect an increase in environmental temperature or heat sensors in the hypothalamus detect a rise in the temperature of the blood. When the body is at rest or when the surrounding is cold: 1 Thermoreceptors in the skin detect decrease in the environmental temperature or heat sensors in the hypothalamus detect drop in temperature of blood.

The skin has three parts: 1 Epidermis: i. Cornified layer; ii. Granular layer; iii. Malphigian layer. A neurone is a nerve cell. A nerve fibre is a long protoplasmic extensions of the cell body of a neurone.

It serves to transmit impulses. A nerve is a collection of nerve fibres. A synapse is a junction between two neurones. A dendron transmits impulses towards the cell body of a neurone. An axon transmits impulses away from the cell body of a neurone. Structure and functions of the human brain: Fig. Cerebral hemisphere Intelligence, memory, voluntary actions, sensations. Cerebrum 2. Hypothalamus Regulation of body temperature and osmotic pressure in blood; appetite and emotions.

Pituitary gland Secretes a number of hormones. Optic lobes Concerned with sight and movement of eyeball. Cerebellum Muscular coordination and bodily balance. Medulla oblongata Involuntary actions, e. Reflex actions involve messages being transmitted from the sensory neurone to the motor neurone without involving the conscious part of the brain. A reflex arc is the shortest pathway by which impulses travel from the receptor to the effector in a reflex action. Structure and functions of the eye: Fig.

Parts of the eye Function s 1. Aqueous humour Refracts light; keeps eyeball firm. Vitreous humour Refracts light; keeps eyeball firm. Cornea Refracts light rays into pupil. Suspensory Attaches lens to ciliary body. Iris Controls amount of light entering the eye. Pupil Allows light to enter the eye. Lens Focuses light rays into retina. Ciliary muscle Controls curvature or thickness of the lens. Rectus muscle Movement of eyeball. Sclera Protection against mechanical injury.

Choroid Pigmented black to prevent internal reflection of light. Yellow spot fovea Region of acute vision. Optic nerve Transmits impulses from eye to brain. Blind spot No photoreceptor cells; no vision when image falls on it. Retina Light sensitive layer, contains: i. Cones concerned with colour vision in bright light. Rods concerned with vision in dim light. Accommodation is the ability to change the curvature of the lens, so that light rays continue to be focused on the retina. Hormones are chemical substances produced by a gland, carried by the blood, to the target organ s , and produce a response, and destroyed in the liver.

Since hormones are proteins, therefore they are affected by pH and temperature. The pituitary gland plays an important role as a "controller". It secretes a number of hormones, each of which controls the activity of a particular gland, hence the pituitary gland is sometimes referred to as the "master gland". Location of endocrine gland: Endocrine Secretion Effects gland 1. Thyroid Thyroxine Stimulates and maintains metabolic processes; regulates growth and development.

Adrenaline Increases blood glucose level; increases 2. Adrenal metabolic activities. Adrenal Other Increase blood glucose level; increases blood glands hormones volume and pressure.

Ovaries Oestrogen, Stimulate and regulate menstrual cycle; progesterone maintain female secondary sexual characteristics. Testes Testosterone Supports sperm formation; maintains male secondary sexual characteristics. Pancreas Insulin, Control blood glucose level. The islets of Langerhans are the special group of cells in the pancreas which secrete the hormone insulin into the bloodstream. Adrenaline: Target organ Effects of Biological advantage Effects or adrenaline sensation 1. Heart Beats faster Sends more glucose and Thumping oxygen to the muscles heart 2.

Breathing Faster and Increased oxygenation of Panting centre of the deeper the blood; rapid removal of brain breathing carbon dioxide 3. Arterioles of Constricts them Less blood for the going to Person gets the skin the skin means more is paler available to the muscles 4.

Students are encouraged to apply their knowledge through practical investigations and extensive structured and multiple-choice questions. Score: 5. It includes everything students of all abilities need to build their exam confidence.

Dedicated vocabulary exercises are included to support EAL students. Manage your own revision with step-by-step support from experienced examiner and author Mary Jones. This guide also includes a Questions and Answers section with exam-style questions, student's answers for each question, and examiner comments to ensure you're exam-ready. Score: 2. Suggestions for practical activities are included, designed to help develop the required experimental skills, with full guidance included on the CD-ROM.

This reading material covers all the Core and Supplement material and can be utilized by understudies following both the Core and Extended syllabuses. Will you be able to upload the actual Mary Jones bio olevel Textbook. Save my name, email, and website in this browser for the next time I comment. Privacy Policy About us Contact us. E books. Share on Facebook.