Somatic Nervous System
Which structure of the eye contains photoreceptors?
Retina
The sympathetic division is also known as the:
Thoracolumbar system
Which cranial nerve is tested by asking a patient to shrug their shoulders against resistance?
CN XI - Accessory
Which hormone increases blood calcium levels?
Parathyroid hormone
A 67-year-old male reports sudden vision loss in his left visual field and difficulty walking in a straight line. He also reports that he had a headache the day before.
Which type of stroke is most likely responsible for both symptoms?
Ischemic stroke in the posterior cerebral circulation (affecting occipital lobe and cerebellum)
Rods are more numerous than cones and are primarily used for:
Dim-light vision
Which neurotransmitter is used at parasympathetic postganglionic synapses?
Acetylcholine
Which part of the neurological exam assesses a patient’s ability to perform complex motor tasks like the finger-to-nose test?
Coordination exam
Explain the functions of oxytocin
Stimulating uterine contractions, bonding with child.
A patient presents with high blood pressure, dilated pupils, and elevated heart rate after a traumatic car accident.
Which branch of the autonomic nervous system is most active in this situation?
Which hormone might be elevated due to adrenal medulla activation?
Sympathetic nervous system
Epinephrine (and norepinephrine)
Explain the physiological cause of the blind spot.
The optic disc has no photoreceptors; it is the exit point for the optic nerve and entry/exit of blood vessels.
The receptor activated by norepinephrine in the sympathetic nervous system is the ______ receptor.
Adrenergic
Lesions above the decussation cause symptoms on the _______ side of the body.
Contralateral
A patient presents with fatigue, weight gain, and cold intolerance. What is the likely hormonal disorder?
Hypothyroidism
A patient reports irregular heartbeat, tremors, and weight loss. Lab tests show elevated T3/T4 levels and low TSH.
Which gland is most likely overactive?
What feedback mechanism explains the low TSH?
Thyroid gland
Negative feedback from high T3/T4 inhibits TRH and TSH release
How does retinal convergence enhance vision in dim light?
Multiple rods synapse onto a single bipolar and ganglion cell, increasing light sensitivity but decreasing visual acuity.
Describe how the sympathetic and parasympathetic systems affect the urinary bladder.
Sympathetic: inhibits urination (relaxes detrusor, contracts internal sphincter)
Parasympathetic: promotes urination (contracts detrusor, relaxes internal sphincter)
What is the difference between a somatic and autonomic reflex arc?
Somatic reflexes involve a single motor neuron projecting to skeletal muscle; autonomic reflexes involve two neurons (preganglionic and postganglionic) projecting to smooth muscle, cardiac muscle, or glands.
The adrenal _______ produces cortisol and aldosterone, while the adrenal _______ produces epinephrine.
Cortex; medulla
A patient complains of dull, cramping abdominal pain that radiates to the lower back. Physical exam shows minimal findings.
What phenomenon explains the pain radiating to the back?
Which part of the spinal cord integrates autonomic reflexes like digestion?
Referred pain—visceral sensory nerves converging on the same spinal segment as somatic sensory nerves
Lateral horn (origin of preganglionic autonomic neurons)
What is the order of the retinal cells from deep to superficial?
Photoreceptors --> bipolar cells --> ganglion cells, amacrine cells
What are the receptor types for ACh, ACh ganglia, and norepinephrine?
ACh = muscarinic
ACh ganglia = nicotinic
Norepinephrine = adrenergic
Describe how you would test the function of cranial nerves III, IV, and VI.
Ask the patient to follow the movement of a pen with their eyes (without moving their head); check pupillary light reflex.
T or F: ADH is released by the anterior pituitary and increases urine production.
False (released by posterior pituitary and decreases urine output)
A patient experiences sudden muscle weakness, cramping, and an abnormal heart rhythm. Labs show low blood calcium.
Which hormone is likely deficient?
What are the two primary mechanisms by which PTH raises blood calcium?
Parathyroid hormone (PTH)
Increases osteoclast activity and increases calcium reabsorption in the kidneys