Psychology 2521 Midterm 1 - Structure of the Nervous System (Neuroanatomy)

Nerves

The central nervous system communicates to rest of body via __________________

Neuraxis

goes from the bottom of the spinal cord to the front of the forebrain. In humans, the neuraxis rotates 90 degrees at the head

Medial

toward midline

Lateral

toward side

Ipsilateral

same side

Contralateral

opposite side

Dorsal

Top (think dorsal fin)

Superior

Dorsal is also known as ______________________

Ventral

Bottom (think ventre)

Inferior

Ventral is also known as ______________________

Anterior

Front

Rostral

Anterior is also known as ____________________

Posterior

Back

Caudal

Posterior is also known as _____________________

Planes of View

1. Coronal/Cross Section
2. Sagittal Section
3. Horizontal Section

Coronal (cross) Section

View from front

Sagittal Section

View from side

Horizontal Section

View from top

Meninges

Protective layers of tissues surrounding the brain and spinal cord

Layers of the meninges

1. Dura mater
2. Arachnoid mater
3. Pia mater

Dura mater

The outer layer (hard mother)

Arachnoid

The middle layer (spider-web)

Pia mater

Closest to brain (delicate mother)

Subarachnoid space

area between arachnoid and pia mater, filled with cerebrospinal fluid (CSF)
- brain "floats" in CSF

Ventricular System

A series of fluid-filled interconnected chambers within the brain

Functions of the ventricular system

CSF flows between ventricles via aqueducts and down into spinal canal. Also flows out into subarachnoid space surrounding brain. As pressure increases, CSF reabsorbed into veins and general blood circulation. Carries waste by-products from brain such as neurotransmitter metabolites

Lateral ventricles

Fluid-filled chambers, one on each side of brain (numbered I and II)

Third ventricle

Fluid-filled chamber in middle of brain near hypothalamus. Separates the right and left sides of the hypothalamus

Fourth Ventricles

Fluid-filled chamber in hindbrain (between cerebellum and pons

Choroid plexus

CSF is produced continuously by cells ____________________ in ventricles

Divisions of the brain/central nervous system

1. Forebrain
2. Midbrain
3. Hindbrain

Divisions of the Forebrain

1. Telencephalon
2. Diencephalon

Division of the Midbrain

1. Mesencephalon

Divisions of the Hindbrain

1. Metencephalon
2. Myelencephalon

Structures of the Forebrain

1. Cerebral cortex
2. Basal ganglia
3. Limbic system
4. Thalamus
5. Hypothalamus

Structures of the Midbrain

1. Tectum
2. Tegmentum

Structures of the Hindbrain

1. Cerebellum
2. Pons
3. Medulla oblongata

Structures in the Telencephalon

1. Cerebral cortex
2. Basal ganglia
3. Limbic system

Structures in the Diencephalon

1. Thalamus
2. Hypothalamus

Structures in the Mesencephalon

1. Tectum
2. Tegmentum

Structures of the Metencephalon

1. Cerebellum
2. Pons

Structures of the Myelencephalon

1. Medulla oblongata

Forebrain

Most anterior division of the brain

Telencephalon

- Cerebral Cortex
- two cerebral hemispheres (corpus callosum); four lobes
- subcortical structures: cingulate gyrus, limbic system, basal ganglia

Four Lobes of the Cerebral Cortex

1. Frontal Lobe

2. Temporal Lobe

3. Parietal Lobe

4. Occipital Lobe

Frontal Lobe

• primary motor cortex

• premotor cortex

• prefrontal cortex

Functions:

-language production
- regulates emotion
- olfaction

Movement and cognition

Primary Motor Cortex

controls voluntary movement

Premotor Cortex

planning of movement (motor association cortex)

Prefrontal Cortex

executive function attention, short term memory

Temporal Lobe

• primary auditory cortex

• auditory association cortex

• visual association cortex (forms)

Hearing

Primary Auditory Cortex

the first relay station for auditory information in the cortex

Parietal Lobe

• primary somatosensory cortex

• somatosensory association cortex

• vision (movement)

Sensation

Primary Somatosensory Cortex

receives touch related information from the body

Occipital Lobe

primary visual cortex

Vision

Primary Visual Cortex

receive, segment, and integrate visual information

Left hemisphere

analyzes information (serial)

Right hemisphere

synthesizes information (holistic)

Corpus callosum

a large fiber bundle that crosses the midline and carries information between the left and right cerebral hemispheres

Limbic System

Ring of structures including the hippocampus and the amygdala. Involved in learning, memory, and emotions

Basal Ganglia

Group of subcortical nuclei in the forebrain. Involved in the control of movement

Diencephalon

Second major division of the forebrain

- Pineal gland (epithalamus)
- Thalamus
- Hypothalamus

Thalamus

Projects sensory information to specific regions of cerebral cortex and receives information from it

Hypothalamus

Controls autonomic nervous system and endocrine system. Regulates behaviors related to basic survival (eating, drinking, sex/bonding, thermoregulation). Controls pituitary gland (regulation of hormones). Important for homeostasis

Pituitary Gland

regulates growth, metabolism, and reproduction through the hormones that it produces

Mesencephalon

division of the midbrain. Includes the tectum and tegmentum

Tectum

“roof”
– Superior colliculus (vision)
– Inferior colliculus (hearing)

Superior colliculus

processing optical stimuli, orienting attention, and coordinating eye and head movements (vision)

Inferior colliculus

signal integration, frequency recognition, and pitch discrimination (hearing)

Tegmentum

“Floor”
– Substantia nigra
– Ventral Tegmental Area
– Red nucleus
– Periaqueductal gray matter
– Some reticular formation

Substantia nigra

Neurons in this region produce the neurotransmitter dopamine (DA). Involved in movement. Neurons selectively die off in Parkinson’s disease

Ventral Tegmental Area (VTA)

Neurons in this region produce the neurotransmitter dopamine (DA). Regulates motivated behaviour and is studied extensively in addiction research

Red nucleus

a structure in the rostral midbrain involved in motor coordination

Periaqueductal gray matter

the gray matter located around the cerebral aqueduct within the tegmentum of the midbrain

Reticular formation

Located in the pons. made up of a net-like structure of various brainstem nuclei and neurons and covers an expansive portion of the brainstem. Main functions are modulatory and premotor, involving somatic motor control, cardiovascular control, pain modulation, sleep and consciousness, and habituation

Metencephalon

division of the hindbrain that includes the cerebellum and the pons

Cerebellum

Receives visual, auditory, vestibular, and somatosensory information and information about individual muscle movements. Modifies motor outflow, exerting a coordinating and
smoothing effect on movements

Pons

large bulge in the brain stem, relays information from the cerebral cortex to the cerebellum. Contains reticular formation

Myelencephalon

division of the hindbrain that includes the medulla

Medulla Oblongata

Contains nuclei of cranial nerves (e.g. vagus nerve) which regulate vital functions (breathing and heart rate)

Spinal cord

Long, tubelike structure runs through spinal column
- subdivided (e.g., cervical, thoracic, lumbar, sacral, coccyx)
- spinal canal in centre (CSF) and surrounded by meninges (CSF)

White matter

Descending motor tracts to muscles and ascending somatosensory tracts to brain

Gray matter

somas and interneurons

Spinal Nerves

One pair (left-right) for each vertebrae
- Dorsal root (sensory information)
- Ventral Root (motor)

Dorsal root

sensory information

Ventral root

motor information

Cranial Nerves

– twelve pairs
– attached to the ventral surface of the brain
– Most serve sensory and motor functions of the head and neck region

Vagus nerve

regulates the functions of organs in the thoracic and abdominal cavities

Autonomic Nervous System

Functional branch of PNS - concerned with regulation of organs of body

Divisions of the Autonomic Nervous System

1. Sympathetic

2. Parasympathetic

Sympathetic

responsible for your body activate its “fight-or-flight” response (think speed)

Functions of Sympathetic

• dilates pupils

• inhibits salivation

• accelerates heart

• facilitates breathing

• inhibits digestion

• stimulates release of glucose

• secretes epinephrine and norepinephrine

• relaxes bladder

• inhibits sex organs

Parasympathetic

responsible for relaxing or reducing your body's activities (think parachute)

Functions of Parasympathetic

• constricts pupils

• stimulates salivation

• slows heart

• constricts breathing

• stimulates digestion

• stimulates gallbladder

• contracts bladder

• stimulates sex organs