PRACTICE QUIZ UNIT 9 Flashcards
Dendrite
Receives input from other neurons
Cell body
Part of neuron with most cytoplasm
Cause of white appearance on white matter
Presence of myelin
Cervical, lumbar, sacral, coccygeal, thoracic: which is not part of a spinal cord
Coccygeal
What are groups of cell bodies in PNS called
Ganglia
Cerebrum function
Memory, emotion, consciousness
Diencephalon function
Regulate homeostasis
Midbrain of brain stem function
Visual space, auditory space, somatosensory space
Hindbrain of brain stem function
Heart contraction and rate of breathing
Cerebellum function
Coordination and motor activity precision
Order of brain meninges and structures from deepest to superficial
Cerebral cortex -> pia mater -> arachonoid trabeculae -> arachnoid mater -> subdural space -> dura mater -> cranial bone
What stimulus opens the ligand gated
Neurotransmitter
What stimulus opens the leakage
No specific event
What stimulus opens mechanically gated
Pressure or touch
What stimulus opens voltage gated
Action potential
What is myelin, what cells produce it and why is it important in nervous system function
- Myelin is a lipid rich sheath surrounding axon
- Produced by oligodendrocytes in CNS and schwann cells in PNS
- Important for facilitating transmission of electrical signals across axon
Relative to PNS, what’s the difference between nerve and ganglion
- Nerve is the term for a bundle of axons (white matter)
- Ganglion is a term for a group of neuron cell bodies (Gray matter)
Steps involved in proves of generalized reflex arc
- Sensory neuron triggered and sends nerve impulse to spinal cord
- Motor neuron stimulated to send nerve impulse to skeletal muscle
- Voluntary skeletal muscle reaction occurs as a response to sensory input
3 factors contributing to resting membrane potential of neuron
- Sodium ions concentrated outside cell
- Potassium ion concentrated inside cell
- Cytosol contains many anions and negatively charged proteins
Resting potential
The sodium/potassium pump maintains potential; sodium and potassium channels are closed
Depolarization
Sodium ion channels open and sodium ions diffuse into neuron; potassium channels closed
Repolarization
Potassium channels open and potassium ions diffuse out of neuron; sodium channels closed
Hyperpolarization
Potassium channels stay open below resting membrane potential; slight delay in closing; sodium channels closed
Describe the events occurring after an action potential reaches axon terminal that leads to stimulation of another neuron (7)
- Action potential reaches axon terminal
- Voltage gated Ca2+ channels in membrane of synaptic end bulb opens
- Ca2+ ions facilitate the merging of synaptic vesicles with presynaptic membrane
- NT released through exocytosis into synaptic cleft
- NT diffuses to postsynaptic membrane interacting with NT receptors
- Result in depolarization or hyperpolarization leading to excitation or inhibition
- NT removed from synaptic cleft by diffusion or from action of enzymes that break it down chemically or by transporters in presynaptic cell membrane
Roles of activation and inactivation gates in resting neuron and during action potential (4)
- Activation gates closed and inactivation gates open during resting potential
- Once threshold is reached, activation gates open and sodium diffuses into neuron
- At peak depolarization, inactivation gates close and sodium ions dont diffuse
- When the potential passes threshold again, inactivation gates open and activation gates close; sodium ions dont diffuse
Difference between the 2 anatomical divisions of nervous system
- CNS: Composed of brain and spinal cord
- PNS: Everything outside of CNS
Difference between tract and nerve
- Tract: Bundle of axons (white matter) in CNS
- Nerve: Bundle of axons (white matter) in PNS
3 basic process involved in functioning of nervous system
- Sensation: senses register presence of an event in environment
- Integration: Senses communicate presence of stimulus through system where that information is proceeded; combining higher cognitive functions such as learning, memory and emotion
- Response: Contraction of skeletal muscle (voluntary) or contraction of smooth muscle, regulation of cardiac muscle, activation of glands (involuntary)
Difference between somatic and autonomic divisions in nervous system
- SNS: Controls conscious perception and voluntary motor responses
- ANS: Responsible for involuntary control of the organ system of body
Dendrite function
Receive information from other neurons
Cell membrane function
Separates cytoplasm from extracellular environment and regulates passage in and out cell
Cell body function
Main part of neuron containing nucleus and most of major organelles
Axon function
Fiber emerging from cell body and projects to target cells
Oligodendrocyte function
Glial cell that produces myelin in CNS
Myelin function
Layers or insulating lipids surrounding portions of axons
Nodes of ranvier function
Periodic gaps in myelin
