Unit 3: The Brain & Neuroscience The Nervous System & The Brain

How the nervous system works… Structurally, the nervous system is divided into two parts- the central nervous system CNS (The Brain and the spinal cord) and the peripheral nervous system PNS (smaller branches of nerves that reach the other parts of the body.) Spinal Cord: nerves that run up and down the length of the back and transmit most messages between the body and the brain.

Neurons  Messages to and from the brain travel along the nerves, which are strings of long thin cells, called neurons.  Neurons: the long, thin cells of nerve tissue along which messages travel to and from the brain.  Messages to and from the brain travel along the nerves, which are strings of long thin cells, called neurons.  Neurons: the long, thin cells of nerve tissue along which messages travel to and from the brain.

The Neuron Connection  There is a space between the axon terminals of one neuron and the dendrites of another neuron. This space between neurons is called the synapse.  Synapse: the gap that exists between individual nerve cells.  The synapse is a junction or connection between the neurons. A neuron transmits its impulses or message to another neuron across the synapse by releasing certain chemicals known as neurotransmitters.  Neurotransmitters: the chemicals released by neurons, which determine the rate at which other neurons fire.

Voluntary & Involuntary Activities  Somatic Nervous System (SNS): the part of the peripheral nervous system that controls voluntary movement of skeletal muscles.  Autonomic Nervous System (ANS): the part of the peripheral nervous system that controls internal biological functions.

The three brains!!!  Hindbrain: a part of the brain located at the rear base of the skull that is involved in the basic process of life.  Midbrain: a small part of the brain above the pons that arouses the brain, integrates sensory information, and relays it upward.  Forebrain: a part of the brain that covers the brain’s central core, responsible for sensory and motor control and processing of thinking and language.

The Parts of the Brain

The Lobes of the Brain  Lobes: the different regions into which the central cortex is divided.

Right-Brain and Left-Brain?  Left: verbal, mathematic, analytic  Right: Nonverbal, spatial, holistic

How Psychologists Study the Brain… Recording:  Electrodes are wires that can be inserted into the brain to record electrical activity in the brain.  The electrical activity of whole areas of the brain can be recorded with an electroencephalograph (EEG).  Electroencephalograph (EEG): a machine used to record the electrical activity of large portions of the brain. Images:  In the 1970’s Computerized Axial tomography (CT) scans were used to pinpoint injuries and other problems in brain deterioration.  Computerized axial tomography (CT): an imaging technique used to study the brain to pinpoint injuries and brain deterioration.  Positron emission tomography (PET): an imaging technique used to see which brain areas are being activated while performing tasks.  Magnetic Resonance imaging (MRI): a measuring technique used to study brain structure and activity. Other Ways:  Stimulations  Lesions  Accidents

The Endocrine System  The endocrine system refers to the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards distant target organs. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus, gastrointestinal tract and adrenal glands.

Hormones: chemical substances that carry messages through the body in blood.  Adrenal Glands:  Anger & Fear  Epinephrine & norepinephrine  Adrenaline & noradrenaline  Sex Glands:  Testes & Ovaries  Testosterone, estrogen, progesterone

Pituitary Gland The pituitary is an important gland in the body. It's often referred to as the 'master gland'. It controls several of the other hormone glands (e.g. adrenals, thyroid). Pituitary Gland Essentials The hormones of the pituitary gland help regulate the functions of other endocrine glands. The pituitary gland has two parts—the anterior lobe and posterior lobe—that have two very separate functions. The hypothalamus sends signals to the pituitary to release or inhibit pituitary hormone production.

Thyroid Gland  The thyroid gland covers the windpipe from three sides. Two hormones of the thyroid gland, T3 (thyroxine) and T4 (triiodothyronine), help the body to produce and regulate the hormones adrenaline (also called epinephrine) and dopamine.

Hormones vs. Neurotransmitters  Both affect the nervous system  The same chemical can be used as both  Neurotransmitter, right beside the cell to excite or inhibit, immediate release  Hormone, released into blood, slow process