chapter 11

Functions of the Nervous System

• The nervous system regulates and coordinates bodily functions, ensuring normal operation.
• It maintains homeostasis, ensuring a stable internal environment for the trillions of cells in the body.
• An example is regulating heart rate to maintain sufficient blood flow.

Controlling Muscles and Glands

• Skeletal Muscle Control: Nervous system initiates muscle contractions for body movements.
• Smooth Muscle: Some smooth muscles, like those in blood vessels, contract with nervous system or hormonal stimulation.
• Cardiac Muscle: The heart's muscle contracts automatically, but the nervous system can modulate the rate of contraction.
• Glandular Secretions: The nervous system controls secretions of glands such as sweat, salivary, and digestive.

Establishing and Maintaining Mental Activity

• Brain Function: The brain acts as the center for consciousness, thoughts, memories, and emotions.
• Mental Activities: The nervous system is crucial for cognitive function and emotional health.

Receiving Sensory Input

• Sensory Receptors: The body has receptors to monitor various internal and external stimuli.
• Conscious Sensations: Examples include sight, hearing, taste, smell, touch, pain, body position, and temperature.
• Unconscious Processing: Includes processing non-conscious stimuli like blood pH, blood gases, and blood pressure.

Integrating Information

• Brain and Spinal Cord: Main centers for processing sensory information and generating responses.
• Responses: Responses can be immediate, stored as memory, or ignored, depending on the situation.

Divisions of the Nervous System

• The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS).
• Central Nervous System (CNS): Composed of the brain and spinal cord.
• Peripheral Nervous System (PNS): Includes nerves and ganglia outside the CNS, connecting the CNS to the body.
• Sensory Division (Afferent): Carries sensory information to the CNS.
• Motor Division (Efferent): Carries signals from the CNS to muscles and glands.

Motor Division of the Nervous System

• Somatic Nervous System (SNS): Controls voluntary movements of skeletal muscles.
• Pathway: CNS generates action potentials that are transmitted to skeletal muscles via somatic motor neurons.

Autonomic Nervous System (ANS)

• Involuntary Control: Controls smooth, cardiac muscle, and glands (unconscious).
• Regulates Automatic Functions: Includes heart rate, digestion, and respiration.
• Pathway: The ANS uses two sets of neurons: preganglionic and postganglionic.
• It's further divided into the sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) divisions.

Enteric Nervous System (ENS)

• Independent system located within the walls of the digestive tract.
• Controls and monitors digestion.
• It can function autonomously, but is modulated by the central nervous system.

Test your knowledge on the functions of the nervous system, including its role in regulating bodily functions, maintaining homeostasis, and controlling muscles and glands. This quiz also explores the relationship between the nervous system and mental activities.