Central Nervous System

• Divisions of the Brain– Brain Stem

• Mesencephalon (Midbrain): Processes visual and auditory info and reflexes triggered by these stimuli

• Pons: Connects the cerebellum to the brain stem, also involved with somatic and visceral motor control

• Medulla oblongata: The structure that connects the spinal cord to the brain, controls autonomic function like heart rate, blood pressure, and digestion

Divisions of the Brain

• Diencephalon – Hypothalamus: controls emotion, autonomic

functions, and hormone production, it rests on top of the mesencephalon

– Thalamus: relay and processing for sensory info, it rest on top of the hypothalamus

Cerebellum

• It adjusts ongoing movements on the basis of incoming sensations and sensations experienced previously, allowing you to do the same movements over and over

Cerebrum• Cerebrum: Two hemispheres divided by the longitudinal

fissure and connected by the corpus callosum, responsible for conscious thoughts and intellectual functions

• The cerebrum is divided into 4 lobes each with it’s own function

• Frontal lobe: Voluntary control of skeletal muscle• Parietal lobe: Conscious perception, touch, pressure, pain,

taste, temp • Occipital lobe: Conscious perception of visual stimuli• Temporal lobe: Conscious perception of auditory and

olfactory stimuli

Lobes of the Cerebrum

Cortex’s of the Cerebrum

Parts of the Brain

The Spinal Cord

• Enlargements

• Enlargements: thicker areas of the spinal cord, these areas have more gray matter and deal with sensory and motor control of limbs (Cervical enlargements, Lumbar enlargements)

Segments

• Each segments consists of a vertebrae with dorsal and ventral root ganglia (C3 )

• Dorsal root: Brings sensory info into the spinal cord

• Ventral root: Sends message to peripheral tissue and muscle

• Spinal nerve: The combination of dorsal and ventral roots, often called mixed nerves because they contain sensory(afferent) and motor(efferent) nerves

Spinal Meninges • Specialized membranes that protect and

cushion the spinal cord from the spinal canal and shock of daily activities

• Epidural space: Space between dura mater and the spinal canal, it contains connective tissue, blood vessels and adipose tissue (acts as padding)

• Dura Mater: A tough fibrous outer most layer of the spinal cord

Spinal Meninges

• Arachnoid: Middle meninges, made of smooth epithelium layer with collagen and elastic fibers, – Cerebrospinal fluid (CSF): Found in the subarachnoid

space (between the arachnoid fibers and the pia mater, acts as a shock absorber and a diffusion medium)

• Pia Mater: Inner most layer of the meninges, It is in direct contact with the neural tissue of the spinal cord, main function is to bind neural tissue to the spinal meninges and support blood vessels that service the spinal cord