EXAM 1

• Astrocytes provide blood vessel and neuronal support in the CNS.
• Astrocytes regulate the extracellular environment of the brain.
• Astrocytes can remove excess neurotransmitters from the extracellular environment in the CNS.
• Astrocytes assist in the formation of the blood-brain barrier in the brain.
• Astrocytes are capable of dividing rapidly when a brain injury occurs.
• Oligodendrocytes myelinate axons in the CNS.
• Microglia act as phagocytes in the brain, removing debris, disease-causing organisms, and dead neurons.
• Ependymal cells are ciliated cells that circulate cerebrospinal fluid and play a role in its formation.
• Oligodendrocytes, microglia, astrocytes, and ependymal cells are all found in the CNS.
• Schwann cells and satellite cells are found in the PNS.
• Schwann cells myelinate axons in the PNS. Unmyelinated axons may also be encased in Schwann cells.
• Schwann cells play a role in damaged axons within the PNS.
• Satellite cells surround and enclose cell bodies within the PNS. They also regulate the extracellular environments around neuronal body cells.
• Most neurons are amitotic.
• Multipolar neurons have one axon and multiple dendrites. They have the widest variability in size and shape.
• Bipolar neurons have one dendrite and one axon. Most of these are sensory neurons such as in the retina or olfactory epithelium of the nose.
• Pseudounipolar neurons begin developmentally as biopolar neurons, but eventually give rise to a single axon. One side brings stimuli from sensory receptors to the cell body (peripheral process or axon), and one travels away from the cell body to the spinal cord (central process or axon).
• Sensory or afferent neurons carry information from the sensory receptors to the CNS. They are generally psuedounipolar or bipolar.
• Interneurons relay messages within the CNS between sensory and motor neurons. They are multipolar as they interact with many neurons.
• Motor neurons carry stimuli away from cell bodies in the CNS to muscles and glands. They are usually multipolar.
• Pseudounipolar neurons are sensory neurons in the PNS usually associated with touch, pain, and vibrations.
• Bipolar neurons are special sensory neurons in the PNS associated with sensory receptors such as the retina and olfactory epithelium.
• Multipolar neurons make up most neurons in the CNS and motor neurons in the PNS.
• The CNS is made up of the brain and spinal cord.
• The PNS is made up of nerves.
• The brain and spinal cord merge at the foramen magnum
• The brain is made up of about 100 billion neurons.
• The spinal cord is made up of about 100 million neurons.
• All interneurons exist in the CNS.
• All sensory and motor neurons exist in the PNS.
• There are 12 pairs of nerves that leave the brain and 31 pairs that leave the spinal cord to the PNS.
• Fight or flight is the sympathetic division of the PNS.
• Rest and digest is the parasympathetic division of the PNS.
• Ribosomes, golgi, and mitochondria are abundant within the cell body for the production and secretion of neurotransmitters.
• Nerve impulses begin at the axon hillock.
• The cytoskeleton which provides structure for dendrites and axons is made up of actin, intermediate filaments (neurofibrils), and microtubules.
• The proteins involved in anterograde transport are Kinesins.
• The proteins involves in retrograde transport are Dyneins.
• Retrograde transport moves towards the cell body.
• Anterograde transport moves towards the axon terminal.