If you cut your finger off, do not worry about the until bleeding has stopped! Then pack it in ice and get to hospital!
Balance is an internal sense and relies on sensory receptors that monitor the position of the head and body. Whether we are still or moving, balance is essential for maintaining our posture and stopping us falling over. The vestibule and semicircular canals of the inner ear provide information on the position and movements of the head. Combined with signals from the eyes, this helps us balance.
Turning movements of the head are picked up by sensory hair cells embedded in structures called cupulae in the semicircular canals. Tilting movements of the head, and its position, are monitored by hair cells within structures in the vestibule.
As well as the pubic and armpit hair that appears in girls and boys at puberty, boys develop hair on the face and often the chest. This new hair growth is caused by an increase in the male hormone testosterone. In addition, a boy’s voice deepens as his voice box gets bigger and the vocal cords lengthen.