The Central Nervous System

Touch Neuron to review http://www.childrenshospital.org/research/_neuron/index.html http://www.childrenshospital.org/research/_neuron/index.html

The Nervous System

Central Nervous System (CNS) The brain and spinal cord The brain is the location of most information processing. The spinal cord is the main pathway to and from the brain.

Spinal Cord

Divisions of the Nervous System

Peripheral Nervous System (PNS) The sensory and motor nerves that connect the central nervous system to the rest of the body Peripheral means “outer region” The system is subdivided into the somatic and autonomic nervous systems.

Divisions of the Nervous System

Somatic Nervous System The division of the peripheral nervous system that controls the body’s skeletal muscles (remember “soma”= body) Contains the motor nerves needed for the voluntary muscles

Divisions of the Nervous System

Autonomic Nervous System The division of the peripheral nervous system that controls the glands and muscles of the internal organs Monitors the autonomic functions Controls breathing, blood pressure, and digestive processes Divided into the sympathetic and parasympathetic nervous systems

Divisions of the Nervous System

Sympathetic Nervous System The part of the autonomic nervous system that arouses the body to deal with perceived threats and stress

Divisions of the Nervous System

Parasympathetic Nervous System The part of the autonomic nervous system that calms the body Brings the body back down to a relaxed state

Divisions of the Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

The Sympathetic and Parasympathetic Nervous Systems Physical Responses

THE BRAIN

How Do We Study The Brain?

Electroencephalogram (EEG) Electrodes are placed on the scalp that amplify recordings of the waves of electrical activity across the brain’s surface

Computed Tomography (CT or CAT Scan) A series of X-ray photographs taken from different angles and combined by computer into a composite representation of the brain

Positron Emission Tomography (PET Scan) A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

PET Scans show brain activity

Magnetic Resonance Imaging (MRI) A technique that uses magnetic fields and radio waves to produce computer-generated images that allow us to see structures within the brain

Accidents Case study analysis of victims of suffer from a brain injury, resulting in variations in normal behavior IE. Phineas Gage

Lesions Lesioning is the removal or destruction of part of the brain. IE. Lobotomy

THE BRAIN AND ITS FUNCTIONS

I. The Hindbrain

The hindbrain is the oldest and innermost region of the brain

The functions of the hindbrain are mostly done outside of our awareness, and occur without any conscious effort.

The functions of the hindbrain control basic biological functions that keep the human body alive.

There are three brain areas associated with the Hindbrain: Medulla Cerebellum Pons

The point at which the spinal cord enters the skull is called the MEDULLA The MEDULLA controls heartbeat and breathing, blood pressure, and attention

Extending from the rear of the brainstem is the CEREBELLUM The CEREBELLUM coordinates voluntary movements and balance (along with the BASIL GANGLIA)

The PONS is responsible for helping to regulate breathing, to help with sleep and wake cycles, and controls facial expressions

II. The Midbrain The Midbrain is located between the hindbrain and the forebrain This area is responsible for coordinating simple muscle movements with changes in sensory information

The major area of the Midbrain is the RETICULAR FORMATION The RETICULAR FORMATION extends from the spine to the thalamus, and is responsible for arousal/wakefulness and attentiveness

The MIDBRAIN is also responsible for behaviors associated with hearing and sight Pupil dilation and eyeball movement

III. The Forebrain Areas of the forebrain control thought and reason. There are five main regions of the forebrain to study: Thalamus Hypothalamus Amygdala Hippocampus The Cerebral Cortex

On top of the hindbrain is the THALAMUS The THALAMUS receives sensory input from all of the senses except smell, and routes it to the proper area of the brain for processing The THALAMUS also helps to control the electrical currents in the brain

The HYPOTHALAMUS is responsible for several maintenance activities, including eating, drinking, body temperature, and sexual arousal

The HYPOTHALAMUS also relays communication between the brain and the endocrine system, via the pituitary gland, and then monitors the hormones released into the bloodstream

The HIPPOCAMPUS is essential to memory processing

The AMYGDALA is tied to emotions, especially those of aggression, rage, and fear

Collectively, the thalamus, hypothalamus, hippocampus, and the amygdala are known as the Limbic System as well

The CEREBRAL CORTEX is the intricate, wrinkled covering of the brain (FISSURES) (actually a bump is a gyrus and a groove is a sulcus – but that’s a bit too much info…) In addition to interneurons, it contains GLIAL CELLS, which guide neural connections, provide nutrients to myelin, and mop up neurotransmitters

The Cerebral Cortex is split into two halves, or Hemispheres: Right Hemisphere Left Hemisphere

The two hemispheres of the brain are connected by the CORPUS CALLOSUM

Hemispheres of the Brain

Each hemisphere of the brain has different functions Each hemisphere of the brain has different functions. This is called hemispheric specialization.

The Cerebral Cortex is split into four LOBES, with half of each one on the left, and half of each one on the right: The FRONTAL LOBE The PARIETAL LOBE The OCCIPITAL LOBE The TEMPORAL LOBE

The Frontal Lobes are the portions of the cortex lying just behind the forehead Mostly involved in abstract thought, speaking, muscle movements, making plans, and judgments

In the left frontal lobe specifically, there is an association area responsible for language processing called Broca’s Area

Broca’s Area controls language expression and the muscle’s involved with producing speech

Along the top of both front lobes runs the motor cortex

The motor cortex receives messages from the rest of the brain and then sends messages back to the muscles of the body in order to control voluntary movements.

The Parietal Lobes are the portion of the cortex lying at the top of the head includes the sensory (or somato-sensory) cortex

The parietal lobes play important roles in integrating sensory touch information, and in the handling and manipulation of objects.

The sensory cortex registers and processes touch sensations.

Click the homunculus to understand the homunculus! http://faculty.washington.edu/chudler/flash/hom.html

The Temporal Lobes are the portions of the cerebral cortex roughly located above the ears audio processing comprehension, naming, verbal memory and other language functions.

In the left temporal lobe specifically, there is an association area responsible for language processing called Wernike’s Area

Wernicke’s Area interprets both written and spoken language.

The Occipital Lobes are located at the back of the head The occipital lobe is responsible for processing visual information.

Brain Plasticity Module 8: The Brain

Plasticity The ability of the brain tissue to take on new functions Greatest in childhood Important if parts of the brain are damaged or destroyed Go to the next slide to see a video about brain plasticity! (may take a few seconds to load – be patient – click only once to load the video – then wait!