Neuroanatomy II

Autonomic Nervous System (4.1)

Neuroanatomical Divisions of the Brain (4.1)• hindbrain• midbrain• forebrain• ventricles

Review

Autoreceptors

A) are located on the presynaptic membraneB) are located on the postsynaptic membraneC) decrease the amount of neurotransmitter in the

synaptic cleftD) two of the above

Sensory information from the foot enters the spinal cord through

A) central canalB) dorsal rootC) dorsal hornD) all of the above

The Autonomic Nervous System

SNS: facilitates energy expenditure

PNS: facilitates energy conservation

Major Neuroanatomical Divisions of the Brain

Hindbrain: pons, medulla, cerebellum

Midbrain: tectum, superior/inferior colliculus, substantia nigra

Forebrain: thalamus, hypothalamus, cerebral cortex, hippocampus, basal ganglia

Fish Brain

Medulla: • just above the spinal cord• important for vital reflexes• damage is often fatal

Pons: • lies anterior and ventral to the medulla• contains lots of axons

Cerebellum: • lies dorsal to the medulla• controls movement, attention

The Hindbrain

The Human Brainstem

Tectum: • “roof” of the midbrain• receives information from the eyes and the ears

Superior and Inferior Colliculi: • SC: visual sensation• IC: auditory sensation• orientation (motor)

Substantia Nigra: • important dopaminergic circuit involved in the control of movement• cell death: Parkinson’s disease

The MidbrainThe Human Brainstem

• several interlinked structures comprise the limbic system • important for motivated/emotional behaviors (eating, drinking, sexual activity, aggressive behavior)

The Forebrain: Limbic System

• receives and processes sensory information (except olfaction)• sends the output to the cerebral cortex

The Forebrain: Thalamus

• contains several distinct nuclei; widespread connections• communicates with the pituitary gland to regulate the release of several hormones• regulates motivated behavior

The Forebrain: Hypothalamus

• three major structures: caudate nucleus, putamen, globus pallidus• highly conserved across evolution (amphibians - mammals)• important for sequences of behavior & certain aspects of memory and emotional expression• deteriorates in Parkinson’s and Huntington’s diseases

The Forebrain: Basal Ganglia

The Ventricles

• contain cerebral spinal fluid (CSF); similar to blood plasma• formed by the choroid plexus; reabsorbed into the blood vessels• protective function; provides a reservoir for hormones and nutrients

The Cranial Nerves: Location

1 - olfactory nerve (s)2 - optic nerve (s)3 - oculomotor nerve (s/m)4 - trochlear nerve (s/m)5 - trigeminal nerve (s/m)6 - abducens (s/m)7 - facial nerve (s/m)8 - statoacoustic nerve (s)9 - glosophayyngeal nerve (s/m)10 - vagus nerve (s/m)11 - accessary nerve (m)12 - hypoglossal nerve (s/m)

The Cranial Nerves: Function

Meningitis & Encephalitis

Meningitis: infection of the meninges• adults: usually begins with a severe headache and a stiff neck• children: convulsions are common• inflammation around the brain causes pressure points on the brainstem/SC

Encephilitis: infection of the brain• symptoms vary depending upon the site of infection

Meninges: membrane lining the brain