NREMT EMT 6 Anatomy Physiology and Pathophysiology Nervous system CNS vs PNS autonomic vs somatic brain anatomy spinal cord

What This Is: Understanding the Nervous System

The nervous system is like a superhighway of communication within our bodies. It's made up of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). Think of the CNS as the brain and spinal cord, the "highway" itself, and the PNS as the "roads" that connect the CNS to the rest of the body. When something goes wrong with the nervous system, it can affect how we think, move, and feel.

Key Steps / Core Facts:

• CNS (Central Nervous System): The brain and spinal cord work together to control our body's functions. (Think of it like a computer's CPU and motherboard.)
• PNS (Peripheral Nervous System): The PNS connects the CNS to the rest of the body, carrying messages between the brain and muscles, organs, and senses. (Like the internet connecting devices to the world.)
• Autonomic vs. Somatic: Autonomic nerves control involuntary actions (like heart rate and digestion), while somatic nerves control voluntary actions (like walking and talking). (Think of autonomic as "autopilot" and somatic as "manual control.")
• Brain Anatomy: The brain has three main parts: the cerebrum (thinking and movement), cerebellum (balance and coordination), and brainstem (life support functions). (Imagine a three-part computer system.)
• Spinal Cord: The spinal cord is a long, thin tube that connects the brain to the rest of the body, carrying messages between the CNS and PNS. (Like a super-long, thin cable.)
• Cerebral Cortex: The outer layer of the brain, responsible for processing sensory information and controlling movement. (Think of it like a computer's graphics card.)
• Cerebrospinal Fluid (CSF): A clear liquid that cushions the brain and spinal cord, helping to protect them from injury. (Like a shock absorber.)
• Spinal Cord Injury (SCI): Damage to the spinal cord can result in loss of sensation and movement below the injury site. (Think of it like a broken wire.)
• Red Flags: Sudden, severe headache, confusion, or loss of consciousness can be signs of a serious nervous system problem. (Like a warning light on a dashboard.)
• Normal Blood Pressure: 90-120 mmHg systolic and 60-80 mmHg diastolic. (Like a normal tire pressure.)
• Normal Heart Rate: 60-100 beats per minute. (Like a normal clock tick.)

What Laypeople Can Do:

• If someone has a seizure, move them to a safe area and turn them onto their side to prevent choking. (Like clearing a path for a storm.)
• If someone is having a stroke, call 911 and try to remember the time the symptoms started. (Like taking a photo of a crime scene.)
• If someone is experiencing a spinal cord injury, keep them still and call 911. (Like securing a fragile package.)

Common Mistakes:

• Mistake: Thinking that a person who is "just sleeping" is okay. Fix: Always check for breathing and pulse before assuming someone is asleep. (Why: Because "sleeping" can be a sign of a serious problem.)
• Mistake: Not recognizing the signs of a stroke (e.g., facial weakness, arm weakness, speech difficulty). Fix: Remember the acronym F.A.S.T. (Face, Arm, Speech, Time) to identify potential stroke symptoms. (Why: Because prompt treatment can make a big difference.)
• Mistake: Not calling 911 in an emergency. Fix: Call 911 immediately if someone is experiencing severe symptoms or injury. (Why: Because timely medical help can save lives.)

Quick Practice Scenarios:

• A person is lying on the ground, unresponsive, and not breathing. What should you do first?

Call 911 and start CPR.

• A person is experiencing a severe headache and is vomiting. What should you do first?

Call 911 and try to keep them calm.

• A person has fallen and is unable to move their legs. What should you do first?

Keep them still and call 911.

Last-Minute Exam Cram:

• ⚠️ Agonal breathing is NOT normal breathing – start CPR.
• Normal body temperature: 98.6°F (37°C).
• Normal blood glucose level: 70-110 mg/dL.
• AVPU: Alert, Verbal, Pain, Unresponsive (assessment sequence).
• SAMPLE: Situation, Allergies, Medications, Pertinent medical history, Last oral intake (history-taking sequence).
• OPQRSTI: Onset, Provocation, Quality, Region, Severity, Time, Insurance (pain assessment sequence).
• Normal heart rate for infants: 100-160 beats per minute.
• Normal blood pressure for children: 70-120 mmHg systolic and 40-80 mmHg diastolic.
• ⚠️ Always check for breathing and pulse before assuming someone is asleep.