BIO 1720 Lecture 3: The Nervous System

Central Nervous System (CNS)

Composed of the brain and spinal cord; responsible for processing and integrating information.

Peripheral Nervous System (PNS)

Connects the CNS to the rest of the body; includes sensory and motor neurons;

Transmits signals from the brain

Transmits sensory signals to the brain

Sensory-somatic Nervous System (PNS)

Transmits sensory information from skin, muscles and sensory organs to the CNS

Motor System (PNS)

Send motor commands from the CNS to the skeletal muscles

Autonomic Nervous System (PNS)

Controls bodily functions without conscious control

- Sympathetic Nervous System

- Parasympathetic Nervous Systems

- Enteric Nervous System

The autonomic nervous system controls

lungs, heart, smooth muscle, and exocrine & endocrine system

Enteric System (autonomic)

control over digestive tracts, gall bladder, pancreas

sympathetic nervous system

Arousal and energy generation. Controls fight or flight response. Prepares body for physical strain of escaping (running) or danger (fending off a predator)

parasympathetic nervous system

Calming and return to normalcy. Connection between the CNS and internal organs.

Ganglia

Clusters of neuron cell bodies in the PNS; act as mini processing centers.

Nerve Cord

Bundled axons that transmit signals; part of both simple and complex nervous systems

Decentralized Nerve Net

A simple nervous system found in organisms like cnidarians; lacks a central brain.

Cerebrum

Largest brain region (upper part of Brain); Frontal Lobe, Somatosensory, Parietal Lobe, Occipital Lobe, Temporal Lobe, Motor Cortex