Exercise 21: Human Reflex Flashcards
A neural pathway
Reflex arc
- A rapid predictable response that occurs in response to a stimulus
- Involuntary
- Happens over a reflex arc (a neural pathway)
Reflex
What are the 5 components of a reflex arc?
- Receptor
- Sensory neuron
- Integration center
- Motor neuron
- Effector
Site of stimulus action
Receptor
Brings afferent impulses towards CNS
Sensory neuron
Consists of one or more neurons in the CNS
Integration center
Conducts efferent impulses from integration center to an effector organ
Motor neuron
Muscle fibers or glands; responds to efferent impulses (contracting or secreting)
Effector
A type of reflex that has a single synapse between the afferent and efferent neurons
Monosynaptic reflex
A type of reflex that has two or more synapses
Polysynaptic reflex
Reflexes that involve stimulation of skeletal muscles by somatic division of the nervous system
(Ex: moving your hand from a hot pot)
Somatic reflexes
3 types of somatic reflexes
- Stretch reflex
- Crossed-extensor reflex
- Superficial cord reflex
Important postural reflexes to maintain posture, balance, and movement
Stretch reflex
A stretch reflex is initiated by tapping a ____ which stretches the ____ to which it’s attached.
- Tendon
2. Muscle
Stretch reflexes are absent in ____ ____ and ____.
- Deep sedation
2. Coma
2 types of stretch reflexes
- Patellar reflex
2. Achilles reflex
Consists of a flexor, or withdrawal, reflex followed by extension of the opposite limb
(Ex: when you flex one leg and the other leg extends and becomes firm while standing)
Crossed-extensor reflex
Reflexes that result from pain and temperature changes
Superficial cord reflexes
3 types of superficial cord reflexes
- Abdominal
- Cremaster
- Plantar
Superficial cord reflexes are initiated by stimulation of receptors in the ____ and ____.
- Skin
2. Mucosae
Superficial cord reflexes depend both on these 2 things
- Functional upper-motor pathways
2. Cord-level reflex arc
Tested by looking for Babinski’s sign by stimulation of the foot
Plantar reflex
2 types of cranial nerve reflex tests
- Corneal reflex
2. Gag reflex
A reflex tested by using a cotton tip applicator and touching the cornea with it to notice blinking
Corneal reflex
The corneal reflex is done through the ____ nerve, also known as cranial nerve ____.
- Trigeminal
2. V
The absence of the corneal reflex correlates to ____ ____ damage due to ____ ____ or ____.
- Brain stem
- Brain compression
- Trauma
In this reflex, when the uvula is stroked, each side of the mucosa should rise equally
Gag reflex
The gag reflex tests cranial nerves ____ and ____.
- IX
2. X
Reflexes that occur through the ANS; we are not usually aware of them
Autonomic reflexes
3 parts of the body that autonomic reflexes activate
- Smooth muscles
- Cardiac muscle
- Glands of the body
Autonomic reflexes also help with regulating ____ ____.
Body functions
A reflex that allows the iris to constrict when light is shined into the eye
Pupillary reflex
Pupillary reflexes involve these cranial nerves
II and III
In a pupillary reflex, if you shine a light into one eye, the other eye also constricts. This is called a ____ ____.
Contralateral response
A reflex which involves gently stroking or pinching the skin (or just the hairs) on the left side of the back of the subject’s neck close to the hairline
Ciliospinal reflex
In a ciliospinal reflex, you should see ____ ____ on the ____ eye. This is due to a ____ nervous system stimulation.
- Pupillary dilation
- Left
- Sympathetic
2 types of autonomic reflexes
- Pupillary reflex
2. Ciliospinal reflex
