Changes

*Produces fine movements associated with skill, e.g. writing and playing a musical instrument.

*Produces fine movements associated with skill, e.g. writing and playing a musical instrument.

*Most developed in primates, although may exist in other species such as the cat, where it aids in grooming.

*Most developed in primates, although may exist in other species such as the cat, where it aids in grooming.

*Nerve fibres of the pyramidal system originate in the [[Hindbrain - Anatomy & Physiology#Cerebellum|cerebellum]], and then pass to the [[Forebrain - Anatomy & Physiology#Thalamus|thalamus]], and [[Hindbrain - Anatomy & Physiology#Medulla Oblongata|medulla oblongata]].

*Nerve fibres of the pyramidal system originate in the cerebral cortex and then pass to the [[Forebrain - Anatomy & Physiology#Thalamus|thalamus]], and [[Hindbrain - Anatomy & Physiology#Medulla Oblongata|medulla oblongata]].

*Some fibres decussate in the [[Hindbrain - Anatomy & Physiology#Medulla Oblongata|medulla oblongata]], whilst others remain ipsilateral until they leave the [[Spinal Cord - Anatomy & Physiology|spinal cord]] where they cross the midline of the body.

*Some fibres decussate in the [[Hindbrain - Anatomy & Physiology#Medulla Oblongata|medulla oblongata]], whilst others remain ipsilateral until they leave the [[Spinal Cord - Anatomy & Physiology|spinal cord]] where they cross the midline of the body.

**Nevertheless, all fibres cross the midline at some point, so that the left side of the brain controls the right side of the body and vice versa.

**Nevertheless, all fibres cross the midline at some point, so that the left side of the brain controls the right side of the body and vice versa.