Parts of the Brain

1. Parts of the Brain By: Derrick Yeagle

2. Subdivided into six main regions: • Midbrain • Pons • Medulla • Diencephalon • Cerebrum • Cerebellum Brainstem

3. Brainstem • Midbrain, Pons, and Medulla make up the brainstem • Brainstem connects to the spinal cord • Brainstem contains neurons that relay signals from the spinal cord to the cerebrum and cerebellum

4. Midbrain Within the midbrain, there are cell bodies containing red nucleus which is for controlling muscle coordination and maintains posture

5. Pons • Contains neurons that relay signals for: • Chewing • sensations to the head and face • Certain respiratory functions • Eye movement • Taste • Salivation • Facial expressions • equilibrium

6. Medulla • Contains tracts that travel in both directions between the brain and spinal cord • Various nuclei of the medulla transmits nerve impulses that control: • Heart rate • Constriction • Dilation of blood vessels • Blood pressure • Swallowing • sneezing

7. Diencephalon • Composed of two major compartments: • Thalamus • Complex of nuclei that facilitate hearing, taste, vision, sensation, wakefulness, voluntary motor control • Hypothalamus • Collection of nuclei that controls the autonomic nervous system, secretion from various glands, heart rate, movement of food in the intestines, rage, aggression, body temperature, hunger, thirst, sleep

8. Cerebrum CEREBRUM • Accounts for approximately 80% of total mass of the brain • Uppermost 2-to 4-mm layer of the cerebrum is crammed with cell bodies and neuroglia, called the cerebral cortex Two Hemispheres

9. Cerebral Cortex • Functions: • Human consciousness • Motor skills • Awareness of subtle variations in the external environment • Language • Reasoning • Imaginations • Composed of regions with specific neuronal responsibilities

10. Beneath the cerebral cortex • Number of different nuclei • Basal ganglia contain a number of different nuclei and subdivisions within some of these nuclei: • Caudate nucleus • Putamen • Globus pallidus • Subthalamic nucleus • Nuclei interconnect with neurons of the cerebral cortex, thalamus, and hypothalamus and control involuntary skeletal muscle movements

11. Other neuronal structures • Limbic system • Lies deep within the cerebrum near the diencephalon and midbrain • Hipocampus • Component of the limbic system • Contributes to emotional states, such as fear, anger, rage, pleasure, and sorrow. • Also with learning and memory capabilities

12. Cerebellum • Located in lower posterior portion of the brain • Responsible for responding to signals from muscles, tendons, joints, and sense organs • Controls skeletal muscle contractions, coordination, muscle tone, balance and posture

13. References • Pasternak,Jack. An Introduction to Human Genetics. pg. 400-401.