Nervous Kleenex
What two kinds of cells make up neural tissue?
Neurons and neuroglia (glial cells).
Which lobe of the cerebrum is associated with visual processing?
The occipital lobe.
Which nerve plexus innervates the entire upper extremity?
Brachial plexus
The sympathetic nervous system is called “fight or flight.” What is the parasympathetic nervous system called?
Rest and digest.
What are the three main classes of muscle tissue?
Skeletal, smooth, and cardiac.
Which division of the nervous system carries information from the periphery to the CNS?
The afferent (sensory) division.
Which part of the brain coordinates skeletal muscle contractions and maintains muscle tone, posture, and balance?
The cerebellum.
Which nerve from the cervical plexus innervates the diaphragm?
The phrenic nerve.
Which photoreceptors let you see in dim light, and which produce color vision?
Rods for dim light, cones for color vision.
Which connective tissue layer surrounds fascicles?
The perimysium.
Which glial cells form the myelin sheath in the CNS, and which form it in the PNS?
Oligodendrocytes in the CNS, Schwann cells in the PNS.
What does the blood-brain barrier protect the brain from, and what’s one way it can work against us?
It protects brain cells from harmful substances and pathogens. It can also block therapeutic drugs from entering the brain
What serves as the integrating center for spinal reflexes, and in what part of it does integration take place?
The spinal cord. Integration takes place in the gray matter.
Which ANS division makes the pupil smaller, and which makes it larger? Name the muscle that contracts in each.
The parasympathetic division makes the pupil smaller, and the pupillary sphincter muscle contracts. The sympathetic division makes the pupil larger, and the pupillary dilator muscle contracts.
What’s the difference between an isometric contraction and an isotonic contraction? Then explain the difference between concentric and eccentric isotonic contractions.
In an isometric contraction, the muscle develops tension but doesn’t shorten.
In an isotonic contraction, movement occurs. In a concentric contraction the muscle shortens, like lifting a weight.
In an eccentric contraction the muscle lengthens, like putting the weight down.
What are the two methods of propagating action potentials? Say which type of axon uses each, which is faster, and where the voltage-gated Na⁺ channels are in myelinated axons.
Continuous propagation happens in unmyelinated axons and is slower. Saltatory propagation happens in myelinated axons and is very fast. In myelinated axons, the voltage-gated Na⁺ channels are at the Nodes of Ranvier.
Which limbic system structure converts short-term memory into long-term memory, and which is involved in emotion, especially fear?
The hippocampus converts short-term memory into long-term memory. The amygdala is involved in fear.
Name the connective tissue layer around each nerve fiber, around each fascicle, and around the whole nerve.
The endoneurium surrounds each nerve fiber, the perineurium surrounds fascicles, and the epineurium surrounds the whole nerve.
Trace the taste pathway. Name the three cranial nerves involved, where they terminate, where the signal goes next, and where taste is interpreted.
The facial (CN VII), glossopharyngeal (CN IX), and vagus (CN X) nerves terminate in the solitary nucleus in the medulla oblongata. The signal goes to the thalamus and then to the primary gustatory cortex in the insula.
What is the Cori cycle? Explain what the liver does with lactic acid.
The Cori cycle is the removal and recycling of lactic acid by the liver. The liver converts lactic acid to pyruvic acid and then to glucose. The glucose is released to recharge muscle glycogen reserves.
Walk through the phases of an action potential, from resting potential back to rest. Include the membrane potentials and which channels open or close.
List every layer from the skin down to the brain, in order from superficial to deep, including the spaces.
Skin, periosteum, bone, epidural space, dura mater, subdural space, arachnoid mater, subarachnoid space, pia mater.
If you hold your breath until you pass out, why do you start breathing again? Explain how central chemoreceptors differ from peripheral chemoreceptors.
CO₂ builds up in the brain, and central chemoreceptors respond only to CO₂. Peripheral chemoreceptors are in the carotid and aortic bodies and sense changes in H⁺, CO₂, and O₂.
Trace the full path of light, from the moment it enters the eye until it’s perceived in the brain.
Cornea, anterior chamber, pupil, posterior chamber, lens, retina. Then rods and cones, bipolar cells, ganglion cells, optic nerve (CN II), optic chiasm, optic tract, thalamus, optic radiations, and finally the primary visual areas of the occipital lobes.
Compare muscle spindles and Golgi tendon organs. What does each respond to, and what response does each lead to?
Muscle spindles respond to changes in stretch, length, and position, and they lead to muscle contraction. Golgi tendon organs are in the tendon, respond to force, and lead to muscle relaxation.