The chapters most important topic was hypothalamus because it is the source for homeostasis. It for example controls the autonomic nervous system. It is the independence part of nervous system which is not conscious controlled, and it consists of two divisions. First is called sympathetic division. It is important in threating situation. It gets the physiological responses to increase, for example head rate, blood pressure and the eyes expands. The other is called parasympathetic division. After the threating situation it decreases heart rate and blood pressure. Those divisions goals are incompatible, so both can not be stimulated strongly at the same time.
Hypothalamus controls the posterior and anterior pituitary. In the posterior pituitary is the largest hypothalamic neurosecretory cells which are called magnocellular neurosecretory cells. Those cells release two chemical substances into bloodstream that are oxytocin and vasopressin (antidiuretic hormone ADH). Vasopressin controls the blood volume and salt concentration. Anterior pituitary hormones impact to the gonads, the thyroid glands, the adrenal glands and the mammary glands by bloodstream. Parvocellular neurosecretory cells control the anterior lobe.
One example of the function of the hypothalamus can be seen in the communication between the kidneys and the brain. After a several different chains of activity hypothalamus receives a stimulus which causes an increase in ADH production which in turn make us feel thirst.
One interesting topic from the topis is the enteric division of the autonomic nervous system. It is weird to think that there is a system in our middle body which consists of two networks and controls our transportation and digestion of food with millions of neurons. However, even thought the enteric division is mostly autonomous, it also receives messages from the brain via axons.
