nervous system Flashcards
(27 cards)
What is the flexor reflex?
Muscles that detect injury and contract in response, also called withdrawal reflex
What are spinal nerves?
Mixed nerves that carry both sensory and motor information
How are spinal nerves formed?
By the lateral fusion of the dorsal (sensory) and ventral (motor) roots
How many pairs of spinal nerves are there?
31 pairs
What are the types of spinal nerves based on their location?
- Cervical nerves C1-C8
- Thoracic nerves T1-T12
- Lumbar nerves L1-L5
- Sacral nerves S1-S5
- Coccygeal nerve C0
What is a dermatome?
Area of skin supplied by a single spinal nerve
Define a plexus.
A collection of ventral rami forming an interwoven network
List the four major plexuses.
- Cervical plexus
- Brachial plexus
- Lumbar plexus
- Sacral plexus
What is the purpose of the knee-jerk reflex?
An automatic response when the patellar tendon is struck
What is a somatic reflex?
A reflex where the effector organ is skeletal muscle
What is a visceral reflex?
A reflex where the effector organ is smooth muscle, cardiac muscle, or a gland
What are the five components of a reflex arc?
- Receptor
- Sensory neuron
- Integration center
- Motor neuron
- Effector organ
What is the definition of a reflex?
An automatic reaction to a stimulus that is rapid, predictable, and involuntary
What is the role of the phrenic nerve?
Supplies the diaphragm
What does the median nerve supply?
Supplies forearm and wrist flexors
What is the function of the femoral nerve?
Supplies the thigh region
What nerve supplies the posterior thigh?
Sciatic nerve
What is the function of the olfactory nerve (Cranial nerve I)?
Sensory for smell
What is the function of the optic nerve (Cranial nerve II)?
Sensory for vision
What does the oculomotor nerve (Cranial nerve III) control?
Motor to muscles that move the eye; constricts pupil
What is the role of the trigeminal nerve (Cranial nerve V)?
Sensory to the face, motor to muscles of mastication
How many pairs of cranial nerves are there?
12 pairs
What is the vagus nerve (Cranial nerve X) responsible for?
Sensory and motor to internal organs in thoracic and abdominal cavities
What is the reflex arc?
Nerve pathway of a reflex
