1a Peripheral Nervous System + Disorders Flashcards
What is the PNS composed of?
The nerves and ganglia outside the brain and spinal cord
What are the two divisions of the PNS?
The sensory (afferent) and motor (efferent) division
What does the sensory division do?
Conducts signals from receptors to CNS
What does the motor division do?
Conducts signals from CNS to effectors
What are the two divisions of the motor peripheral nervous system?
Somatic and Autonomic
What does the autonomic nervous system do?
Controls involuntary response
What does the somatic nervous system do?
Controls voluntary response
What are the two divisions of the autonomic nervous system?
Sympathetic and parasympathetic
What does the sympathetic division do?
Mobilises body systems
Controls fight or flight responses
What does the parasympathetic division do?
Conserves energy
Controls rest and digest responses
What do sensory (afferent) nerves do?
Carry info towards the CNS
What do motor (efferent) nerves do?
Carry info away from the CNS
What are the 12 cranial nerves?
Olfactory
Oculomotor
Optic
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Hypoglossal
Vagus
Accessory
What do somatic afferent nerves do?
Convey info from skin, skeletal muscle and joints
What do somatic efferent nerves do?
Convey info TO skeletal muscles
What is a dermatome?
Area of skin that is supplied by a single spinal nerve
What is a myotome?
Group of muscles innervated by a single spinal nerve
From where do visceral afferent nerve carry information?
From the viscera: Thoracic, Abdominal and Pelvic Organs
What can visceral efferent nerves be divided into
Sympathetic and parasympathetic
What does the sympathetic system innervate?
The visceral organs and vasculature
What does the parasympathetic system innervate?
Only visceral organs
What are the sensory receptors and what do they detect?
- Chemoreceptors - Detector molecules which bind to a receptor
- Photoreceptors - Detect light in the retina
- Thermoreceptors - Detect temperature in skin
- Mechanoreceptors - Control mechanical opening of ion channels
- Nociceptors - Detect tissue damage and interpret as pain
What is a ganglion?
A collection of cell bodies outside the CNS
What is a nucleus?
A collection of cell bodies inside the CNS
What is a plexus?
A network of interconnecting nerves
Where do afferent fibers have their cell bodies?
In spinal ganglia