A low hemoglobin count can also be due to blood loss, which can occur because of: 1  Bleeding from a wound. 2  Bleeding in your digestive tract, such as from ulcers, cancers or hemorrhoids. 3  Bleeding in your urinary tract.  Frequent blood 1  donation. Heavy menstrual bleeding.
The brain is the control centre for your body and it sits in your skull at the top of your spinal cord. The brain has three main parts. 1  The cerebellum (say se-re-bell-um). The brain stem, that controls a lot of the 'automatic' actions of your body such as breathing and heart beat, and links the brain to the spinal cord and the rest of the body.
The cerebral cortex is the part of the brain that most strongly distinguishes mammals. In non-mammalian vertebrates, the surface of the cerebrum is lined with a comparatively simple three-layered structure called the pallium.hysiologically, the function of the brain is to exert centralized control over the other organs of the body. The brain acts on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones.