A Guided Tour of the Brain Minnie Greer Cassidy Boyce Deanna Hammett Diana Padilla Jessica Chappell

Table of Contents Studying of the Brain The Developing Brain Neurogenesis The Brainstem The Hindbrain The Midbrain The Forebrain Cerebral Cortex Lobes of the Brain The Limbic System Structures

Studying of the Brain One early approach to mapping brain functions involved examining the bumps on a person’s skull. Case studies of individuals with brain damage have provided valuable insights into behavior in such area as memory, speech, emotion, movement, and personality. Lesions- surgically altering, removing, or destroying specific portions of the brain In humans, lesions are produced for medical reasons, such as when part of the brain is surgically altered or removed to relieve uncontrollable seizures Electroencephalograph- allowed scientists to record the brain’s electrical activity through the use of large, disk-shaped electrodes placed harmlessly on a person’s scalp 

The Developing Brain By three weeks after conception, a sheet of primal neural cells has formed. This sheet curls to form the hollow neural tube. The neural stem cells divide and multiply, creating specific cells that eventually produce neurons and glial cells. As the neural tube expands, the cavities develop, called the ventricles. During peak periods in the brain development, new neurons are being generated rapidly. Triggered by chemical signals, the new neurons travel to specific locations. 

The Developing Brain -Neurogenesis For many years, it was thought that the mature brain could lose neurons, but not grow new ones. But new studies showed that the hippocampus, a brain structure that plays a vital role in forming new memories, has the ability to generate new neurons throughout the lifespan. Studies since this discovery have shown that stress, exercise, environmental complexity, and social status have been shown to affect the rate of neurogenesis in rats, birds, and monkeys. But it is unknown if these findings can be applied to the human brain. 

The Brainstem Includes the hindbrain and midbrain Hindbrain: Midbrain: Located at the base of the brain Hindbrain: A region at the base of the brain that contains several structures that regulate basic life functions Midbrain: The middle and smallest brain region, involved in processing auditory and visual sensory information 

The Brainstem -The Hindbrain Connected to the spinal cord with the rest of the brain Made up of three structures Medulla: Lies directly above the spinal cord; contains centers active in control of breathing, heart rate, and digestion; also controls swallowing, coughing, vomiting, and sneezing Pons: swelling of tissue; relay information from various other brain regions to the cerebellum Cerebellum: controls balance, muscle tone, and coordinated muscle movements; affected by alcohol consumption 

The Brainstem -The Midbrain Relay station that contains centers important to the processing of auditory and visual sensory information Process auditory sensations from the left and right ears Helps you visually locate objects and track their movements Substantia nigra: in midbrain; contains a large concentration of dopamine-producing neurons 

The Forebrain -Cerebral Cortex Cerebral Cortex: outer portion of forebrain Only a quarter an inch thick Mainly composed of glial cells and neuron cell bodies and axons Gray matter (in reference to color) White matter consists of myelinated axons that connect cerebral cortex to other brain regions Divided into two cerebral hemispheres connected by corpus callosum Cerebral hemispheres are then divided into four lobes Temporal, occipital, parietal and frontal lobes 

The Forebrain -The Cerebral Cortex (lobes of the brain) Temporal Lobe Contains primary auditory cortex Occipital Lobe Contains primary visual cortex Parietal Lobe Involved in somatosensory information (somatosensory cortex) Frontal lobe Largest lobe Primary motor cortex Involved in planning, initiating, and executing voluntary movements Association Areas Located on all lobes Combine sensory and motor information Coordinate interaction among different brain areas 

The Forebrain -The Limbic System Limbic System: structures that form a border around brainstem and are involved in emotion, motivation, learning, and memory. Plays a critical role in learning, memory, and emotional control 

The Forebrain -The Limbic System (structures) Hypothalamus Regulates behaviors related to survival Eating, drinking, and sexual activity Often referred to as “the brain within the brain” Controls secretion of endocrine hormones Influences anterior and posterior pituitary glands Amygdala Clump of neuron cell bodies at the base of temporal lobe Involved in emotion and memory 