An endogenous pacemaker – ‘free-running’ internal rhythm, allows organisms to control their internal rhythms and helps animals to anticipate cyclical events. They are innate. The SCN maintains the link between light and melatonin production. In humans the pineal gland is regulated by the SCN and leads to changes in levels of melatonin. The SCN (Suprachiasmatic nucleus) is a small group of cells in the hypothalamus located behind the eyes in the brain.
The main function of the pituitary gland is to regulate the human growth hormone (HGH) and weight; main controller along with the genes of final height of a person. A malfunction in the pituitary gland can cause hypersecretion which results in gigantism or acromegaly and hypo secretion can result in dwarfism. The Thyroid Gland: The Thyroid gland is a very small vascular organ that is located in the neck. It consists of two lobes, one on each side of the trachea, just below the larynx or the voice box. The two lobes are
Endogenous pacemakers are body clocks that are internal to our biological systems, the most important being the superchiasmatic nucleus (SCN) which is sensitive to light and receives information via the optic nerve and send this info to the pineal gland, which controls the production of melatonin. Melatonin is vital to the sleep-wake cycle because the hormone induces sleep by inhibiting the brain mechanisms that promote wakefulness. Circadian rhythms are also controlled by exogenous zeitgebers, which are external factors that give an indication of time e.g. daylight, therefore controlling the biological rhythm to be in time with the world. Research has been conducted into the role of endogenous pacemakers by removing external cues from participants by using temporal isolation methods and allowing the free-running biological clock to run unaffected.
During blood feeding, the damage caused to the host blood vessels usually results in vasoconstriction that may increase insect feeding time due to restricted blood flow to their mouth parts. Blood-sucking insect saliva usually contains components promoting vasodilation. Vasodilators such as, a peptide tachykinin has been characterized in Aedes aegypti that facilitate efficient blood feeding. Tachykinins also act as pharmacological
Central Core: The central core is called primitive because it has been evident in even the most primitive vertabrates. It is considered to be the earliest part of the brain to begin evolving. It becomes the hindbrain at the juncture of the spinal cord and the skull. The central core consists of the hindbrain, cerebellum, midbrain, thalamus/hypothalamus and the reticular formation. The hindbrain consists of the medulla which controls your breathing, heart rate and blood pressure and the pons which produces chemicals that are responsible for the sleeping and waking cycles of the body.
The endocrine system is an information signal system like the nervous system, yet its effects and mechanism are classifiably different. The endocrine system's effects are slow to initiate, and prolonged in their response, lasting from a few hours up to weeks. The nervous system sends information very quickly, and responses are generally short lived. Hormones are substances (chemical mediators) released from endocrine tissue into the bloodstream where they travel to target tissue and generate a response. Hormones regulate various human functions, including metabolism, growth and development, tissue function, sleep, and mood.
Hormones are produced by the glands and a few organs spread in different places of the body. According to Morris and Maisto (2002) the glands engaged in hormone production are thyroid, parathyroids, pineal, pituitary, gonads, and adrenal glands. Pancreas and some parts of the digestive tract also play role in the production of certain hormones which working together with glands has an effect of many other areas of the human body. Genes are which give us different hereditary characteristics. They do have an effect on behavior; but, not single genes.
Without melatonin, we would have severe insomnia and various negatives effects in behavior can be seen. The suprachiasmatic nucleus (SCN) of the hypothalamus is ultimately responsible for regulating sleep patterns as it sends signals to the pineal glands for the production of melatonin according to our body clock. However, our endogenous pacemaker can be disrupted by the abnormal light rhythm to some extent. The presence of light will be detected by the SCN through the retina and
The limbic system regulates body temperature, blood pressure, blood sugar level, and other housekeeping activites. The limbic system contains the Hippocampus, the amygdala and the hypothalamus. Some researchers of memory focus their studies on the limbic system. Memory function is partly organized by the hippocampus which collects and relays memory information to other layers of the brain. Memory-impairing conditions like Alzheimer’s
The autonomic system mainly controls functions that we have less conscious control over. These include the digestion of food, the blood pressure and the heart rate; these are split into two branches called the sympathetic and the parasympathetic branches. The sympathetic branch activates the glands and organs that defend the body against attack, when faced with a stressor the body releases more adrenaline and cortisol into the bloodstream drawing blood away from the stomach and extremities of the body and dilating the pupils of the eyes which initiates a 'fight' or 'flight' reaction, this prepares the body to deal with the stressor before returning to normal. When stress occurs regularly the body maintains this state instead of returning to normal causing