#ventral root

[hebasoffar]

Structure of the nervous system Nervous system consists central nervous system ( Brain & Spinal cord ) , peripheral nervous system ( Cranial nerves & Spinal nerves ) , Autonomic nervous system ( Sympathetic nervous system & parasympathetic nervous system ) . Central nervous system As previously mentioned the central nervous system is divided into brain and spinal cord . Brain It is the

[neuroanatomyblog]

>> Know that the roots connect the spinal nerves to a segment of the spinal cord         1. posterior (dorsal) root                 - contains only sensory axons         2. anterior (ventral) root                 - contains axons of somatic motor neurons >> Know the function of the spinal cord in the human body; there are two major    functions:         1. biological highways or "pathways" for nerve impulse conduction             (= white matter)         2. site of integration of reflexes (= gray matter) >> Know that a reflex is a very fast involuntary sequence of actions in the body in    response to a particular stimulus; some reflexes, e.g. the eye lid or patellar    knee jerk reflex, are inborn and don't have to be trained - be able to name the difference between a spinal and a cranial reflex    >> Know the different basic components and the path of nerve impulse in a typical    reflex arc; the components are:         1. Sensory receptor                 - located at distal ends of sensory neurons         2. Sensory (afferent) neuron                 - axonal conduction of nerve impulse from receptor to the gray matter of the spinal cord         3. Integrating center                 - interaction of synapse of sensory neuron with a motor neuron; sometimes                    including interneurons         4. Motor (efferent) neuron                 - axonal conduction of nerve impulse from spinal cord to responding area of                   the body, e.g. a skeletal muscle         5. Effector                 - the part of the body that responds to the (efferent) nerve impulse of the motor neuron                 - can be a skeletal muscle (= somatic reflex), or                   cardiac muscle, smooth muscle or gland (= visceral reflex) >> Know the important examples of reflexes of the human body, which are:         1. Patellar (or knee jerk) reflex             - assesses the function of the S1 and S2 spinal nerves;             - sensory receptors are in the quadriceps femoris muscle;             - effector muscle is the quadriceps femoris;           2. Plantar reflex             - another important neurological test which probes the integrity of the                corticospinal tract (= major voluntary motor tract);             - elicited by stimulating receptors in the sole of the foot;             - effector muscles are flexor muscles in the toes which flex and move closer               together;             - damage to the corticospinal tract elicits the "Babinski's sign";                 - as a consequence the toes flare and the great toe moves upward!