1. Chapter 49 – Nervous System & Sense Organs
UNIT 5: Human Biology
Chapter 49 – Nervous System & Sense Organs

2. CH. 49.2 Structure of the Nervous System
The nervous system’s two parts work together.
The Central Nervous System (CNS) includes the brain and spinal cord.
The CNS receives, interprets, and sends signals to the Peripheral Nervous System (PNS)
The PNS is the collection of nerves that connects the CNS to all of the organ systems (digestive, muscular, etc.)

3. CH. 49.2 Structure of the Nervous System
The CNS processes information.
The brain has three major parts:
Cerebrum: controls thought, movement, and emotion.
Cerebellum: allows for balance.
Brain Stem: controls basic functions of life.

4. CH. 49.2 Structure of the Nervous System
Brain Stem

5. CH. 49.2 Structure of the Nervous System
The brain stem also has three parts.
Midbrain: controls some reflexes.
Pons: regulates breathing.
Medulla oblongata: controls heart function, swallowing, and coughing.
Midbrain
Brain Stem
Pons
Medulla
oblongata

6. CH. 49.2 Structure of the Nervous System
The Four Lobes of the Brain.
The various areas of the cerebral cortex process different types of information.
Frontal Lobe: controls personality, reasoning, voluntary movement, and speech production.
Parietal Lobe: sensory cortex; interprets & coordinates info regarding sense of touch.
Temporal Lobe: controls speech interpretation & hearing; memory.
Occipital Lobe: process visual info.

7. CH. 49.2 Structure of the Nervous System

8. CH. 49.2 Structure of the Nervous System
The Spinal Cord
The spinal cord is a ropelike bundle of neurons (located within the spinal column) that connects the brain to the nerves found throughout the body.
The brain depends on the spinal cord to deliver and receive messages from the body.

9. CH. 49.2 Structure of the Nervous System
The spinal cord controls involuntary movements called reflexes.
Reflex arcs are nerve pathways that produce a response from the spinal cord, so they occur quickly and without conscious thought.
Example: When a doctor taps your knee with a rubber mallet, tissues that connect your kneecap to your leg muscles stretch and stimulate sensory neuron in your leg. That neuron sends an impulse to the spinal cord, an interneuron there directs the impulse to the muscles to cause your leg to jerk.

10. CH. 49.2 Structure of the Nervous System