Nervous System and Sensory Functions

Nervous System

• Senses and Responds to Stimuli
  • Central nervous system (CNS) - includes the brain and spinal cord.
  • Peripheral nervous system (PNS) - nerves extending to/from the CNS.

Reflexes

• Definition: A rapid response to sudden, intense, and unexpected stimulation.

  • Purpose: Provides protection and prepares the body for a fight-or-flight response.
  • Components:
  • Receptor: Detects the change.
  • Afferent/sensory neuron: Relays information.
  • Control Center (interneuron or spinal cord): Evaluates and determines an appropriate response.
  • Efferent/motor neuron: Carries information away from the control center.
  • Effector (muscle): Stimulates action at the target site.

• Types of Reflexes:

  • Simple Reflex: Involves sensory neuron and motor neuron only; quick response.
  • Complex Reflex: Involves sensory neuron, interneuron, and motor neuron; longer latency.

• Reflex Modulation:

  • Reflexes can be adaptable and flexible, varying in speed, intensity, and direction.
  • Example (Priming): When a prime stimulus is presented before the reflex stimulus, it enhances the response speed.

Respiratory System Overview

• Function: Gas exchange - obtaining oxygen and expelling carbon dioxide.
• Involved Structures:
  • Brain Control Center: Medulla.
  • Ventilation Types:
  • Ventilation: Air movement in/out of the lungs.
  • Gas Exchange: Between lungs and blood.

Mechanics of Breathing

• Inspiration:
  • Produced by the contraction of skeletal muscles (diaphragm and intercostal muscles) that create a vacuum to draw air in.
• Expiration:
  • Passive process driven by relaxation of muscles.

Lung Volumes and Capacities

• Tidal Volume (TV): Air volume during a single breath.

• Inspiratory Reserve Volume (IRV): Additional air breathed in after a normal inhalation.

• Expiratory Reserve Volume (ERV): Air remaining after a normal breath.

• Residual Volume (RV): Air that remains in the lungs.

• Capacities:

  • Inspiratory Capacity (IC) = TV + IRV.
  • Vital Capacity (VC) = TV + IRV + ERV.
  • Functional Residual Capacity (FRC) = ERV + RV.
  • Total Lung Capacity (TLC) = TV + IRV + ERV + RV.

Special Senses

• Vision and Hearing: Experiments to evaluate each sense, including identifying structures of the ear and eye.
• Gustation and Olfaction: Smell and taste interlinked.

Immunology Overview

• Function of Immune System: Disease protection involving both innate and adaptive responses.
• Types of Cells:
  • Innate Immune Cells: Phagocytes (e.g., macrophages, neutrophils).
  • Adaptive Immune Cells: T-lymphocytes and B-lymphocytes.

Cardiac and Circulatory System

• Components: Heart, vessels, and blood; roles in oxygen transport and removal of carbon dioxide.
• Heart Structure: Chambers (atria and ventricles), valves (tricuspid, mitral, pulmonary, aortic).
• Blood Flow: Overview of the circulation path through the heart chambers/valves, distinguishing between oxygen-rich and oxygen-poor blood.

Muscular System

• Functions: Produce movements, stabilize body positions, move substances, generate heat.
• Types of Muscle Tissue: Skeletal (voluntary, striated), cardiac (involuntary), smooth (involuntary).

Experiments and Assessments

• Grip Strength: Use of EMG (electromyography) to record muscle activity during grip assessments; relationship between electrical impulses and strength.
• Senses Evaluation: Various tests to investigate senses including taste, smell, vision, and hearing, with conclusions drawn based on data collected.

Safety and Procedures

• Safety Measures: Proper attire (closed-toe shoes), guidelines for lab entry and exit.