Lesson 7: Nervous System

Brain, spinal cord, nerves, sensory receptors, neurons, neuronal support cells

1) receiving sensory input2) integrating information3) controlling muscles and glands4) maintaining homeostasis5) establishing and maintaining mental activity

Brain & spinal cord (interneurons)

Sensory receptors and nerves (outside the CNS)main function is to connect the CNS to the limbs and organs (afferent & efferent neurons)

A cordlike structure that contains many axons (or 'fibres'); provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons

Supplies triceps brachii muscle of the arm and all 12 muscles in the posterior osteofascial compartment of the forearm, as well as the associated joints and overlying skin

Originate from the brain; 12 pairs

Originate from spinal cord; 31 pairs

Ending of neurons or separate, specialized cells that detect such things as temperature, pain, touch, pressure, light, sound, odors

Sensory neurons; pick up stimulus via sensory receptors; transmit this info to interneurons (usually) in CNS (transmit signals TO CNS)

Integrate the information, formulate a response

Carry the response signal to the muscles, glands so that response can be carried out (transmit signals FROM CNS)

Type of efferent neuron that carries signals to the skeletal muscle

Mostly voluntarycontrols body movements that are CONSCIOUS (mostly)Note: some contractions of skeletal muscle are involuntary: shivering, reflexes, muscles that control postureutilizes motor neuronscarries efferent signals from CNS to the skeletal muscles

Functions BELOW the level of consciousness (involuntary)controls visceral (organs of the gut) functionsANS affects: heart rate, digestion, respiration rate, salivation, perspiration, diameter of pupils, micturition (urination), sexual arousal, smooth muscle contractionsmost of its actions are involuntary, but some, such as breathing, work in tandem with the conscious mind