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 brain stem also relays information to and from the brain to the rest of the body, so it plays an important role in the brainâs core functions, such as consciousness, awareness and movement. After brain death, it's not possible for someone to remain conscious. How brain death occurs. Brain death can occur when the blood and/or oxygen supply to the brain is stopped. This can be caused by: cardiac arrest â when the heart stops beating and the brain is starved of oxygen