Help Me to Raise Money for Children's Charity, Cerebra

Because my site has attracted a worldwide audience I thought that it would be an excellent opportunity to ask you for money to support children's charity, Cerebra ...

Cerebra are trying to raise £4,000,000 to support brain injured children and young people. They provide parental support and fund research projects into the prevention of brain injury and neurological conditions.

Cerebra are currently part-funding an ongoing study which began in 1979 at University College Hospital in London of infants born prematurely. It examines the effects of being born prematurely and low birth weight on subsequent health, development and brain structure. It includes a new fMRI brain study of tasks for cognitive functions which have been found to be affected in those born preterm which is due to be completed by March 2010.

"Despite the increase in the survival rate and the increase in the occurrence of premature births, little is known about the effect of prematurity on the child’s development throughout childhood, adolescence and into adulthood." (Institute of Psychology, Kings College London).

Since this study began, more than 1,500 children have taken part, and it is now arguably the most detailed long term study of premature babies to be carried out anywhere in the world.

Please donate ...

References
Cerebra Research, Cerebra | Research. Available at: http://www.cerebra.org.uk/Research/ [Accessed May 9, 2009].

Follow-up Study of Infants Born Prematurely, IoP: General Psychiatry. Available at: http://www.iop.kcl.ac.uk/departments/?locator=398&context=1001#item05 [Accessed May 9, 2009].

The Role of the Nervous System in Generating a Normal Breathing Rhythm

In order to understand the role of the nervous system in generating a normal breathing rhythm, it is beneficial to have a basic understanding of the nervous system:

The nervous system comprises of three interrelated components, which may be considered by functionality and anatomical distinction: (1) the central nervous system, or CNS, consists of the brain and the spinal cord which runs inside the vertebral column branching 43 pairs of nerves, 31 from the spinal cord and 12 from the brain. Subdivisions of these nerves pass throughout the body to form (2), the peripheral nervous system, or PNS. The CNS processes and coordinates most voluntary movements using the PNS to send sensory input and receive motor instructions to muscles. And finally, (3) the autonomic nervous system, or ANS, although having some origins with the CNS, and sharing some nerves with the PNS, has its own nerve chains that run along the spinal cord. Its roles are to automatically, and subconsciously, facilitate functionalities such as heart rate, blood pressure and a normal breathing rhythm ...

Key structures involved in breathing rhythm

• Within the brainstem, respiratory centres of the medulla oblongata provide autonomic control over breathing; they control the rate and depth of breathing by sending nerve impulses to the diaphragm and intercostal muscles to make them contract;
  

• brainstem continued: the pons pneumotaxic centre provides fine adjustment of respiratory rate, and its apneustic centre appears to encourage inspiration by stimulating neurons in the medulla;
  

• stretch receptors within the diaphragm and intercostal muscles are stimulated as the lungs inflate. They are supplied with nerves from the spinal cord and, with conscious effort, are able to alter the basic breathing rhythm by sending nerve impulses back to the medulla. The medulla's expiratory centre then sends impulses back to these muscles, causing them to relax;

• and, the cerebral cortex is consciously able to control breathing because the cortex receives sensory information from, for example, the diaphragm; it can modify the rate at which neurons fire. When conscious control over breathing is exerted, breathing centres in the brainstem are overridden, therefore, breathing speeds up, or slows down.

• Further reading …

The initial autonomic pathways for motor actions are along spinal nerve tracts inside the spinal cord to the autonomic regions of the brain. Once analysed and processed, the information received passes along autonomic pathways, sending instructions as impulses, to involuntary muscles. There are two types of contrasting response which exist within two divisions of the ANS: the parasympathetic response that restores a resting state to conserve energy, and the sympathetic response that prepares the body for action.

BREATHING	PARASYMPATHETIC RESPONSE	SYMPATHETIC RESPONSE
Bronchial tubes	constrict	dialate

The two ganglion chains of the sympathetic ANS division are located either side of the vertebral column, and the ganglia of the parasympathetic ANS are within the body's organs.

References
CG Partnership, 2009. 'Nervous System and Respiration, and 'The Respiratory System'. Course hand-outs.
Breathing
Control of Respiration
The Human Respiratory System
The Autonomic Nervous System ( for kids :)

Question: How do chemoreceptors in the medulla and stretch receptors in _____ affect the regulation of respiration?

The Constituents and Functions of Plasma

Plasma is an aqueous solution that forms approximately half of the blood volume and is nine-tenths water. Its colour is pale straw yellow. Plasma contains substances such as:

• Glucose (blood sugar);

• hormones (sex hormones, insulin and glucagon regulate blood-glucose levels, and thyroid controls metabolism);

• electrolytes (once dissolved mineral salts form ions, such as sodium, potassium, chloride and calcium);

• wastes (carbon dioxide (CO2));

• digested food (nutrients, glucose, amino acids, and lipids such as cholesterol);

• and, proteins e.g., albumins (prevent leakage of water into tissues), fibrinogen (blood clotting agent) and globulins (antibodies).

Copied from CG Partnership's 2009 Plasma Table

Substance	Origin	Destination
Carbon Dioxide	Body	Lungs
Digested Food	Gut	Liver and the rest of the body
Wastes e.g., urea	Liver	Kidneys
Hormones	Endocrine Glands	'Where needed' and the rest of the body
Plasma proteins normally remain in the blood
Albumin	Liver	Keeps blood osmotic pressure & pH constant, and assists in the transport and release of other soluble components
Fibrinogen	Liver	Complex reaction when a wound occurs, resulting in the formation of insoluble fibrinogen. The basis of a clot, which seals a wound
Globulins (or antibodies)	Lymphatic System	When an infection occurs: sticks to invading organisms and inactivates them

Blood Plasma and the Lymphatic System

The body's fluid components consist of the intracellular fluid (cytoplasm within cells) and extracellular fluid (all other bodily fluids) – referred to as the two fluid compartments.

Interstitial fluid is a subcomponent of extracellular fluid, it fills the spaces between cells, lymph and blood plasma. Blood and lymph circulate closely and constantly exchange fluids. Blood cells, such as red blood cells, are suspended in plasma, they carry oxygen and remove carbon dioxide. Plasma passes from capillaries into surrounding cells and becomes interstitial fluid. It is reabsorbed into the bloodstream, but some leak into capillaries of the lymphatic system to be used as lymph fluid to convey, antibody producing, white blood cells to fight infections and disease. The lymphatic system then drains lymph back into the blood to be used as plasma once it has completed a full lymphatic cycle.

References

Human Circulatory System - Heart, Blood, Red blood cells, White blood cells, Lymphatic system. Available at: http://articles.directorym.co.uk/Human_Circulatory_System-a1077620.html [Accessed April 14, 2009].

Extracellular fluid - Wikipedia, the free encyclopedia. Available at: http://en.wikipedia.org/wiki/Extracellular_fluid [Accessed April 14, 2009].

Fluid Compartments, Fluid Physiology: 2.1. Available at: http://www.anaesthesiamcq.com/FluidBook/fl2_1.php [Accessed April 14, 2009].

Lymph and immunity. Available at: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookIMMUN.html [Accessed April 14, 2009].

Joints

The site by which two bones are linked is called a joint or articulation. Synovial joints being the most common are encapsulated in a protective covering, inside of which, is a lubricating membrane which produces an oil like substance called synovial fluid. This fluid keeps the joint well lubricated ensuring minimal friction and wear.

Types of synovial joint include:

• hinge joint: allows mainly to-and-fro movement in a single plane e.g., elbow joint;
  
• ball-and-socket joint: the ball fits into the socket e.g., the shoulder and hip;
• and, the ellipsoidal joint: an ovoid shaped bone fits within the ellipsoidal cavity e.g., where the forearm's radius bone meets the wrist's scaphoid bone allowing side-to-side movement.

Non-synovial joints include fixed joints and slightly moveable joints:

• fixed fibrous joints

tooth socket, ankle, and skull (cranium) e.g., the craniums' joints allow for growth of the developing brain. Its bone plates are loosely fixed until growth is complete, when fibrous tissue, consisting of the protein, collagen, secures its interlocking plates.

• cartilaginous and partly flexible semimovable joints

In females, the pubic symphysis is slightly moveable to accommodate childbirth.

References
CG Partnership, 2009. 'The Musculo-skeletal System' and 'Skeletal System - joint types'.
Synovial Joints

Respiration and the Respiratory Tract

Respiration, or breathing, is the process by which oxygen (O₂) in the air is taken into the lungs, and is absorbed into the bloodstream to be transported around the body. The blood also carries away carbon dioxide (CO₂) from cells to the lungs for expiration.

• Sinuses regulate temperature and humidity of air;

• the nasal cavity, which is lined with fine filtering hairs, carries air into the respiratory system;

• the mouth can be used for breathing in, if a person has a cold which obstructs the nose (the preferred intake of air);

• the pharynx receives air from the nose and mouth, and passes it to the trachea;

• the epiglottis, a flap of tissue, when closed, prevents food going into the trachea and lungs;

• when breathing in and out air passing through the larynx/voicebox produces vocalisation sounds;

• the trachea, or windpipe, connects from the pharynx to the lungs;

• the ribcage protects the thoracic cavity;

• the trachea divides into two bronchial tubes, one for each lung. Subsequent subdivisions form the “bronchial tree”;

• the smallest of the bronchial tree subdivisions are the bronchioles, which terminate into alveoli, the lung's surface area for gaseous exchange to take place;

• in each lung, there are approximately 300,000,000 tiny air sacs, or alveoli. They have extremely thin membrane walls. Capillaries are embedded into alveolus walls. Pulmonary arteries transport blood towards the capillaries, and it is taken away by pulmonary veins. Carbon dioxide is passed into the alveoli from blood in the capillaries for expiration by the lungs, and oxygen is passed from the alveoli through the capillaries into the bloodstream for transportation to the body's cells;

• Cilla, or fine hairs, line the bronchial tubes to capture phlegm, or mucus. These hairs convey these foreign substances in a wave-like motion, to the throat to be coughed up or swallowed.

• the lymph nodes of the lungs are located against the trachea and the bronchial tubes;

• the pleura membranes surround the lobes of the lungs providing separation from the chest wall;

• the right lung has three lobes, and the left lung two. Each lobe is filled with sponge-like tissue;

• and, the diaphragm provides separation between the thoracic cavity and the abdominal cavity creating suction to draw in air by moving downward and expanding the lungs.

Average volumes of air and breathing rates for an adult man.

• The total intake of air when completely breathed in: 6 litres;

• the remaining air in lungs after breathing out: 1.2 litres;

• air between breathing in normally and breathing out forcefully and completely : 1.0 litre;

• air breathed in and out at rest: 0.5 litres;

• extra air when breathing in very forcefully: 3.3 litres;

• normal breathing rate at rest: 15 in-and-out per minute;

• breathing rate after exercise: 50 per minute;

• amount of air breathed in and out after exercise: 3 litres;

• therefore, the amount of air going in and out of the lungs varies from 7.5 litres at rest to 150 litres after exercise.

References
Exercise Physiology
Respiratory Functions
Respiratory System
Lung Function Fundamentals
Lung Volumes
The Tidal Volume Response to Exercise: The Exercise Tidal-Flow Volume Loop