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 is like a computer that controls the body's functions, and the nervous system is like a network that relays messages to parts of the body. Click through this slideshow to learn more about the brain and nervous system. The largest part of the brain, the cerebrum has two hemispheres (or halves). The cerebrum controls voluntary movement, speech, intelligence, memory, emotion, and sensory processing. At the base of the brain, the brain stem connects to the spinal cord and is made up of the midbrain, pons, and medulla oblongata. The midbrain acts like a complex switchboard, allowing the brain to communicate with the rest of the nervous system.