Forward bends - The structural and functional physiology involved

Physically:  hips will be in dog tilt; vertebrae permit up to 90 degree flexion; Stretches entire backside of body, especially legs and lower back.  Elongate the spine outward through the crown of your head as you fold into the pose.  Movement from the hips and not the waist great movement/stronger pressure on the abdomen region, more massage effect. Allows for great extension of the spine

 
Muscles;  legs, buttocks, abdomen, thorax spine, back and neck; Stretches the hamstrings, calves, and hips; Strengthens the thighs and knees; Promote the spine to be in its natural position which in general is lost through bad posture of western life style; Extends the vertebrae allowing to separate, thus stimulating the nerves improve circulation in the spine, nourishing the cord

Physiology: Compressor and massage abdominal organs, liver, kidneys, pancreas and intestines; improved blood flow along the spine – oxygen to the brain. Improves digestion; Helps relieve the symptoms of menopause; Parasympathetic, encourages the relaxation response, lowering head and blood pressure

Organs:  Massages internal organs, tones liver, spleen, kidneys. Increases blood circulation to legs, torso, and brain; tones spinal nerves asana for compressing the pelvis and the vata region
Glands:  forward bends work on the first of the glands - the gonads or sex glands; Creativity and sex - the creative power posture – works the endocrine glands; Forward bends and twists also quiet the adrenals; the upper back, kidneys, and adrenal glands are stretched and stimulated, thus making forward bends a potentially therapeutic pose for those with respiratory or kidney problems, as well as for those who suffer from adrenal exhaustion