Ch. 14, 15 Spinal Flashcards
The spinal cord (Structures)
Structures:
- Cervical enlargement
- Lumbar enlargement
- Cauda equina
Characteristics:
- Spans from the foramen magnum to L2
- Spinal nerves go the rest of the length of the vertebral column
- Process information (reflexes)
- Pass information up and down the cord
The Meninges
Dura mater Arachnoid mater Pia mater Subdural space Subarachnoid space Epidural space
Dura mater
Very tough outer layer of connective tissue
Continuous with dura mater of brain
Arachnoid mater
Spider web like connective tissue
Pia mater
Inner layer of connective tissue
Bound tightly to surface of spinal cord
Subdural space
Space below dura mater
Contains small amount os serous fluid
Subarachnoid space
Space between arachnoid mater and pia mater. Contains cerebrospinal fluid
Epidural space
Space between dura mater and vertebrae
Contains spinal nerve roots, blood vessels, fat
Organization of neurons
Sensory Neuron: Lateral horn and dorsal horn
Motor/Autonomic Neuron: Ventral horn
Interneuron connects sensory and motor neurons
Nerve tracts in spinal cord
There is an ascending track and a descending track. The spinal cord and the brain are very organized, with set pathways for particular purposes that are the same in just about everyone
C1 (cervical plexus)
Connects to C2?
C2 (cervical plexus)
Lesser occipital
Ansa cervicalis
C3 (cervical plexus)
Transverse cervical
Ansa cervicalis
C4 (cervical plexus)
Supraclavicular
Phrenic
C5 (cervical plexus)
Phrenic
C5 (brachial plexus)
Unique to C5
- Dorsal scapular (root)
- Subclavian (root)
C5-C6
- Thoracodorsal (post. divisions)
- Sub scapular (post. divisions)
- Supra scapular (ant. division)
- Axillary (post. divisions)
- Radial (post. divisions)
- Musculocutaneous (ant. division)
- Median (ant. division)
C6 (brachial plexus)
C5-C6
- Thoracodorsal (post. divisions)
- Sub scapular (post. divisions)
- Supra scapular (ant. division)
- Axillary (post. divisions)
- Radial (post. divisions)
- Musculocutaneous (ant. division)
- Median (ant. division)
C7 (brachial plexus)
- Axillary (post. divisions)
- Radial (post. divisions)
- Musculocutaneous (ant. division)
- Median (ant. division)
C8-T1 (brachial plexus)
- Axillary (post. divisions)
- Radial (post. divisions)
- Median (ant. division)
Unique to C8-T1
- Ulner (ant. division)
Axillary nerve
Abducts arm: Deltoid
Lateraly rotates arm: Teres minor
Radial nerve
- Extend elbow: Triceps brachii, anconeus
- Flex elbow: Brachialis, brachioradialis
- Extends, abducts wrist: Extensor carpi radialis longus and brevis
- Supinates: Supinator
- Extends fingers: Extensor digitorum
- Extends wrist: Extrnsor carpi ulnaris
- Abducts thumb: Abductor pollicis longus
- Extends thumb: Extensor pollicis longus and brevis
Musculocutaneous nerve
Flexes shoulder: Coracobrachialis
Flexes elbow: Biceps brachii, brachialis
Ulnar nerve
- Flexes wrist: Flexor carpi ulnaris
- Flexes fingers: Flexor digitorum profundus
- Adducts thumb: Adductor pollicis
- Abducts and adducts fingers
Median nerve
- Pronates hand: Pronator teres
- Flexes wrist: Flexor carpi radialis, palmeris longus
- Flexes fingers: Flexor digitorum profundus, F.d. superficialis
- Flexes thumb: Flexor pollicis longus
L2-L3
- Femoris (Ant. divisions)
- Obturator (Post. division)
L4
- Femoris (Ant. divisions)
- Obturator (Post. division)
- Superior gluteal (Ant. divisions)
- Inferior gluteal (Ant. divisions)
- Sciatic: Peronial (Ant. divisions) and Tibial (Post. division)
L5-S2
- Superior gluteal (Ant. divisions)
- Inferior gluteal (Ant. divisions)
- Sciatic: Peronial (Ant. divisions) and Tibial (Post. division)
Obturator nerve
Lateral rotation
Adducts thigh: A. magnus, A. longus, A. brevis, Gracilis
Femoral nerve
Flex hip; extend knee
Quadriceps, sartorius, iliacus
Tibial nerve
- Flexes knee: Biceps femoris, semitendinosus, semimembrinosus
- Plantar flexes foot: Gastrocnemius, plantaris, soleus
- Flexes toes: Flexor digitorum longus, Flexor hallucis longus
Peroneal nerve (fibular)
- Flexes knee: Biceps femoris
- Dorsiflexes foot: Tibialis anterior, Fibularis tertius
- Extends toes: Extensor digitorum longus and brevis Extensor hallucis longus
- Plantar flexes foot: Fibularis longus and brevis
Dermatomes
A sensory map of the body for the various spinal nerves
Spinothalamic tract
Carries information on pain, temperature, light touch, pressure, tickle and itch through the anteriolateral tracts
Dorsal column
Carries information on two point discrimination, proprioception, pressure and vibration
Posterior spinocerebellar tract
Carry proprioceptive information to the cerebellum
The current state of the muscles’ contraction is essential for coordinated movement
Direct pathway
The axons of neurons in the motor cortex go through the descending tracts and stimulate motor neurons
Indirect pathway
The axons from neurons in the motor cortex go to neurons in the basal nuclei
Feedback to the motor cortex and input and coordination with the nuclei and the cerebellum
Axon go through descending tracts and stimulate motor neurons
