14119042
Description
Flashcards by Angus Cooper, updated more than 1 year ago
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Created by Angus Cooper
almost 6 years ago
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| Question | Answer |
| Name the two main divisions of the nervous system and their components? | Central Nervous system - brain, spinal cord Peripheral Nervous system - Spinal Nerves, Cranial nerves |
| What is the main function of the nervous system? | To detect change in the internal and external environment and respond by providing input to the muscles or glands. |
| How can the main function be divided? Three ways... | Sensory input - external stimulus is taken in from receptors Integration - processing of stimulus and deciding a response Motor output - response enacted through muscular or glandular response. |
| Neurons are composed of which main cell structures? | Some (cell body) - contains Nucleus, E.R., golgi, mitochondria etc. Axon - long body of cell that may or may not be myelinated. Dendrites - long projections that receive stimulus from other cells. |
| What are neuroglia? | Non-neuronal nervous system cells. Have a variety of functions such as physical and metabolic support, immuno-defence, production of myelin. |
| Name the main types of neuroglia. | Astrocytes, Microglial, Ependymal cells, Oligodendrocytes, Schwann cells, satellite cells. |
| Main functions of Astrocytes? | The most abundant neuroglia, provide physical support for neurons, establishment of blood brain barrier. |
| Main functions of Microglia? | Serve an immunity role in the CNS. Are immobile until activated by pathogen, engage in phagocytosis. |
| Main functions of Oligodendrocytes? | Production of myelin around neurons in CNS, serve as insulator. ** FULL myelination, not nodes. |
| Main functions of Ependymal cells? | Line the fluid-filled parts of the CNS. Produce Cerebrospinal Fluid, and cilia aid in the movement of the fluid. Can act as neuronal stem cells. |
| Main functions of Schwann cells? | Aid in the production of myelin around neurons in PNS. Create nodes of Ranvier. speed up the conduction of the electrical impulses. |
| A stimulus will always trigger an action potential in a neuron. True or False? | False. The stimulus needs to be sufficiently powerful enough in order to trigger an action potential. |
| What are main ion involved in an action potential and how do they influence the conduction of the electrical impulse? | Sodium and Potassium. Sodium has a more negative charge compared to potassium and the electrical charge differential is what moves the particles through the axon. |
| Resting membrane potential requires energy. True or false? | True. The resting membrane potential is maintained by the Na+/K+ pump, requiring ATP, and thus ENERGY. |
| What are the 5 step of the formation of an action potential? | 1. Input from sensory cells cause initial depolarisation. 2. If excitation continues until the threshold is reached, then all Na+ channels open, and the cell becomes fully depolarised. Sodium rushes into cell. 3. At the peak of the action potential, the K+ channels start to open and K starts to LEAVE the cell, Na+ channels close. 4. As K+ continues leaves the cell, hyper-polarisation occurs, and the cell is in a refractory period. It cannot be stimulated. 5. After the refractory period, K+ channels close and the Na+/K+ pump brings the cell back to a resting potential. |
| The action potential moves in bi-directionally. True or False? | False. Due to the refractory period of the action potential, the impulse can only move in ONE direction. |
| Difference between continuous and saltatory conduction? | Continuous conduction is not in the presence of nodes. Takes longer. Saltatory conduction is in the presence of nodes. It is much quicker. |
| What are the two main types of synapses? | Electrical and chemical |
| How do electrical synapses work? Some examples around the body? | The electrical impulse is fed through a gap junction and directly into the next cell. E.g., cardiac muscle cells, some smooth muscle cells. |
| How do chemical synapses work? Some examples around the body? | Electrical impulse is fed to a synaptic knob. Neurotransmitters in vesicles are transmitted across the synaptic cleft to the postsynaptic cell. E.g., muscle cells. |
| How many different classes of neurotransmitters are there? | 4 Classes. Class I = acetylcholine Class II = amine (dopamine, serotonin, epinephrine, histamine). Class III = amino acids (GABA, glutamate). Class IV = other small molecules. |
| What are dermatomes? | Each area of skin is supplied is specific set of sensory fibres of a spinal nerves. A dermatome describes the area of skin. |
| What are myotomes? | A groups of muscles that is supplied is specific set of motor fibres of a spinal nerves. A myotome describes the group of muscles. |
| What are the four divisions of the PNS? | Somatic sensory system. - hearing, touch, pain, proprioception. Somatic motor system. - voluntary skeletal muscle contractions. Visceral sensory system - involuntary senses, stretch, pain, hunger. Visceral motor system - involuntary motor functions, smooth & cardiac muscle, GIT function etc. (contains ANS - SNS). |
| What are the 12 cranial nerves? | 1. Olfactory. 2. Optic. 3. Oculomotor 4. Trochlear 5. Trigeminal 6.Aduccens 7. Facial 8. Vestibulocochlear 9. Glossopharyngeal 10. Vagus. 11. Accessory 12. Hypoglossal |
| What do each of the 12 cranial nerves do? | 1. Sense of smell (S) 2. Eye sight/aperture (S) 3. Most eye movement (M) 4. Down eye movement (M) 5. Facial sensation and chewing (B) 6. Lateral eye movement (M) 7. Facial sensation/expression, taste. (B) 8. Hearing and balance(S) 9. Tongue swallow, PaO&PaCO2 sensors(B) 10. Thoracic, abdominal and laryngeal innervation (B) 11. Movement of shoulders, head. (M) 12. Movement of tongue and throat. (M) |
| Describe the flow of cerebrospinal fluid through the brain | Starts at the 1st & 2nd ventricle (lateral), then moves past the 3rd (middle) and 4th (inferior) ventricles. Moves from in an ascending manner towards the top of the brain, and then is absorbed in the arachnoid villi. |
| Which type of molecules penetrate the BBB easily? | Lipid-soluble molecules easily pass through the endothelial cells' membrane. |
| Describe the three layers of the meninges | The dura mater - is white, fibrous and tough. Inelastic covering. The arachnoid layer - many projections (spider-like), delicate, vascular, has CSF moving through it. The pia mater - most delicate. highly vascular. Closely adhered to the brain. |
| How is the ICF maintained? | The intracranial pressure is maintained through the 20% that is changeable, blood volume and CSF. Blood volume can be changed and CSF pressure can also be regulated. |
| What structures are housed in the brainstem? | Medulla oblongata, pons, midbrain. Contains all the life-sustaining processes: cardiac centre, respiratory centre, emetic reflex, coughing, etc. |
| What structures belong in the diencephalon? | Thalamus and hypothalamus. Thalamus is responsible for pain, touch, reaction to pleasant/unpleasant stimuli and is a relay centre for most sensory information. |
| What is the cerebellum responsible for? | Posture, balance, planning and coordinating motor activity |
| How is the cerebral cortex divided? | It is divided in four lobes and the insula. Insula is the deeper matter underneath the frontal, parietal and temporal lobes. |
| What does the frontal lobe do? | Voluntary motor responses, thought, speaking, personality, complex problem-solving. |
| What does the parietal lobe do? | Processing of sensation information, proprioception. |
| What does the temporal lobe do? | Auditory processing, language. Wernicke's area - can't understand words. |
| What does the occipital lobe do? | processing visual stimulus, integration of sensory information. |
| Name the three parts of the limbic system. | Hippocampus, amygdala, and the cingulate gyrus. Hippocampus (memories), amygdala (emotion), C.G. (emotion, sensory integration). |
| What age do neuron numbers start declining? | In your 30s. |
| What age does your brain start shrinking? | In your 50s. |
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