University:
High School
Course:
High School Biochemistry
Academic year:

2022
Views:

306

Pages:

11
Author:

larbiwxcvbn

Divisions of the Nervous System Maintains homeostasis by controlling all of the systems of the body. Main Divisions • Central Nervous System (CNS) * Brain & Spinal Cord • Peripheral Nervous System (PNS) * Nerves that extend out from CNS Central Nervous System • The Brain = Control center of nervous system • Regions of the Brain: – Forebrain – Brain Stem: • Midbrain • Hindbrain The Forebrain • Cerebrum – involved in memory, learning, speech, emotions & controls complex behaviors – Divided into “hemispheres” • Left hemisphere controls movement on the right side of the body & vise versa • Thalamus – sorts sensory data & motor output • Hypothalamus – controls homeostasis The Brainstem • Midbrain – relays auditory & visual data to other brain centers • Hindbrain: – Pons – controls breathing – Medulla oblongata – controls breathing, circulation, swallowing & digestions – Cerebellum – coordinates body movement and balance Spinal Cord • Column of nerve tissue (interneurons) from hindbrain through vertebral column • Carries signals from the body to the brain & vise versa • Reflex – involuntary response to a stimulus. – Stimulus is processed through the interneuron in the spinal cord – not the brain!!! – Ex: Patellar reflex Peripheral Nervous System (PNS) • Somatic Division of the Nervous System – motor neurons that you have control over. • Voluntary movement – skeletal muscle control • Autonomic Division of the Nervous System – motor neurons that you do NOT have control over. (heart rate, breath rate, etc.) • This controls all systems of the body • Smooth muscle (heart etc) control Autonomic Division • Sympathetic Division – stimulates activity of the autonomic system. “fight –or-flight” – Adrenaline released, heart beats faster, breathe faster, muscles tense • Parasympathetic Division – decreases activity of the autonomic system – Adrenaline cleared out, heart slows, breathing back to normal, muscles relax How It’s all Connected • Information about a stimulus is brought in by the sensory receptors – PNS – Sensory division • Information is processed & interpreted by the interneurons – CNS – brain (or spinal cord) • Action is caused by the motor neurons in response to the stimulus – PNS – Somatic division Divisions of the Human Nervous System The Nervous System Central Nervous System (Interneurons) Peripheral Nervous System Sensory Division Brain Spinal Cord (Sensory Neurons) Motor Division (Motor Neurons) Autonomic Nervous System Somatic Nervous System Sympathetic Division Parasympathetic Division Essential Questions 1. Describe the function of each of the regions of the brain. 2. Where are the neurons that make up the main two divisions of the nervous system located? 3. How is the PNS divided? 4. What are the divisions of the autonomic nervous system