Brain Stem

Cerebral peduncles

Contain large pyramidal cortical spinal tracts

Superior cerebellar peduncles

Allow midbrain to direct some complex motor patterns at the subconscious level

Superior colliculus

Initiate reflex responses to visual stimuli

Inferior colliculus

Initiate reflex responses to auditory stimuli

Periaqueductal gray matter

Important for the detection of fear and linking it to fight or flight activation

Reticular activating system

Keeps cerebrum aroused and alert

Substantia nigra

Contains melanin and degenerates in people with Parkinson’s

Red nuclei

High in iron and plays a role in the subconscious control of upper limb positioning

Pons

Relays information between higher brain regions and lower brain regions

Decussation of pyramids

Cortical spinal tracts cross over; responsible for the contralateral control of voluntary skeletal movement

Cardiac center

helps regulate the rate and force of cardiac muscle contractions

Vasomotor center

helps regulate the diameter of blood vessels and blood pressure

Respiratory center

Autonomic reflex center that control the rate and depth of breathing