Anatomy - Week 2 - Major Peripheal Nerves Flashcards
What is the somatic nervous system?
It’s provides motor and sensory innervation to all parts of the body except the viscera, smooth muscle and glands. It’s transmits the sensations of pain, touch, temperature and position from sensory receptors
Where does the somatic nervous system innervate?
Only skeletal muscle, stimulating voluntary and reflexes movements by causing the muscle to contract as in the example of the reflex arc.
What is the autonomic nervous system?
It is the division of the nervous system concerned with the involuntary regulation of smooth muscle, cardiac muscle and glands.
It’s motor component controls the smooth muscle contractions of the viscera, heart and glands, whilst it’s sensory component provides feedback to the CNS for the fine control of the motor component playing a role in the regulation of visceral function.
What are nerve plexuses?
In certain regions of the spinal cord anterior rami join and divide in complex patterns (when the branches of the nerves join forming a network)
What is the cervical plexus?
Is formed from the anterior rami of the spinal nerves C1 - C4, it supplies structures in the anterior and lateral regions of the neck.
What is the brachial plexus?
It is formed from the anterior rami of the spinal nerves C5 - T1. It supplies all the structures of the upper limb.
What is the lumbar plexus?
It is formed by the anterior rami of the spinal nerves L1 - L4 and supplies the pelvis and entire lower limb.
What is the sacral plexus?
Is formed by the anterior rami of the spinal nerves L4 - S4 and supplies and the perineum and lower limb. As some nerves from the lumbar and sacral plexuses join to form the roots of some nerves it is referred to as the lumbosacral plexus
What is the coccygeal plexus?
It is formed by the anterior rami of spinal nerves S4 - C1 and supplies and the skin of the coccygeal area. (Always place anterior rami before naming the numbers)
What are the two subdivision of the ANS?
Parasympathetic nervous system
Sympathetic nervous system
What is the parasympathetic nervous system?
It regulates the functional activities of the viscera and glands.
It slows down the heart, increases peristalsis and glandular secretions and opens gut sphincters. Generally this system acts to conserve energy and promote digestion.
What is the Sympathetic nervous system?
It tends to prepare the body for stressful situations and its effects are obvious during times of stress.
What is the major anatomical difference between the parasympathetic and sympathetic divisions of the ANS?
The location of their central connections.
The neurones that connect the parasympathetic nervous system to CNS originate in the cranial or sacral nerves so the parasympathetic divisions has craniosacral “outflow”. It’s neurons begin at the cranial nerves and sacral spinal cord segment.
The sympathetic trunk travels in a downward direction from the skull, just lateral to the vertebral bodies.
What are the 4 main lobes of the brain?
The parietal lobe
Occipital lobe
Temporal lobe
Frontal lobe
