Nervous System and the Brain

What are the two parts of the nervous system? -CNS (central) -PNS (peripheral) -Somatic (Muscle contraction - Somatic What are the two types of output from the motor) nervous system? -Autonomic (Internal organs - subconscious - Visceral) What are the four regions of the spinal cord? -Cervical -Thoracic -Lumbar -Sacral What are mechanoreceptors? Respond to touch, pressure, vibrations, or stretch. What are nociceptors? Pain receptors What are thermoreceptors? Temperature receptors What are Chemocepters? Chemical receptors Is the dorsal root, at the front or back of the spine? Back Where does the signal come into the spinal cord? Dorsal root Where is the cell body for the dorsal root? The dorsal root ganglion Where does the signal output from the CNS? Ventral root What sort of reflex is the knee-jerk reflex? Monosynaptic reflex Does the afferent fibre bring the input or take the output? Input What part of the CNS is not involved in the monosynaptic reflex? Brain What is the effect of increasing axon di- Larger the axon the faster the transmisameter on transmission speed? sion speed What is the role of cranial nerves? Input from the rest of the body passes through cranial nerves 1/6 What is the role of oligodendrocytes? Production of myelination What is the role of astrocytes? -Equalises concentrations of Potassium ions, in order to aid re-polarisation -Regulate blood diffusion important in the blood-brain barrier What is inside the subarachnoid space? Cerebrospinal fluid (CSF) What gland produces the cerebrospinal fluid? Choroid plexus What are the main components of the cerebrospinal fluid? -High conc of NaCL and Glucose -Low conc of K+ and Ca2+ How does CSF protect the brain? Cushioning What is the method for sampling CSF for diagnosis of conditions? Lumbar puncture What is hydrocephalus? -Fluid accumulates on the brain -Lack of drainage of the CSF -Also called fluid on the brain -Protects the brain from chemicals and What is the role of the blood brain barripathogens in the blood er? -Reduces diffusion What part of the brain is attached to the spinal cord? brain stem What part of the brain is at the back and the bottom? Cerebellum What is the cerebral cortex responsible for? consciousness, intelligence, memory and language What part of the brain is largest in humans? Cerebral cortex What are the 5 parts of the cerebral cortex? -Frontal -Central -Parietal -Temporal -Occipital 2/6 What is the role of the somatosensory cortex? Processing and perception of sensation What is the role of the prefrontal cortex? Personality and mood What is the role of the cerebellum? coordinates voluntary movement and balance What region of the brain is responsible for the primary visual cortex? Occipital lobe Name two fast-acting brain neurotransmitters -Glutamate -GABA What sort of receptor to Glutamate and GABA activate? Ligand-gated ion channels Name some slow-acting brain neurotransmitters? -Dopamine -Acetylcholine -Noradrenaline -5-hydroxytryptamine (5HT) (serotonin) What sort of receptors do slow-acting neurotransmitters activate? G-protein-coupled (GPCR) The various sizes of the body on the homunculus represent of the amount of What does the homunculus represent? cerebral tissue dedicated to that particular body part Output from the brain to the periphery, What is the autonomic nervous system? not under voluntary control (e.g. heart muscle and smooth muscle) What are the two subsections of the autonomic nervous system? -Sympathetic (fight or flight) -Parasympathetic (rest and digest) -Pupil dilates -Blood vessels constrict (vasoconstriction) 3/6 Name same things that happen when your sympathetic system is activated? -Inhibits salvation -Heartrate accelerates -Airways relax (bronchodilation) What happens to the liver during the sympathetic division? Converts stored glycogen into glucose for the fighting or the flighting What is the vagus nerve? Cranial nerve (X) that causes the parasympathetic effect -pupils constrict Name same things that happen when -saliva production your parasympathetic system is activat- -Slows heartrate -digestion stimulated and enzyme proed? duction from the pancreas (e.g. insulin) -Stimulated vagus nerve (parasympathetic) in a frog heart -Heart slows -Removed fluid around the nerve What was Otto Loewi's experiment? -Inserted fluid into a second heart -Heart rate slowed What did the Otto Loewi experiment prove? Neurotransmitters and chemical transmission in nerves What sort of receptors are the musGPCR and they are activated by acetylcarinic and nicotinic receptors and what choline is their ligand (neurotransmitter)? What are the 3 most important subtypes of adrenoreceptors? -Alpha 1 -Beta 1 -Beta 2 What is the importance of the alpha 1 adrenoreceptor? -Vasoconstriction -Relaxation of the GI tract What is the importance of the beta 1 adrenoreceptor? Increase of heart rate (B1 on the heart) What is the importance of the beta 2 receptor? Bronchodilation (B2 on the lungs) What are the 3 subtypes of muscarinic receptors? M1, M2, M3 4/6 What section of the autonomic nervous system are muscarinic receptors involved in? Parasympathetic What is the importance of the M2 receptor? Decrease in heart rate -Causes constriction of the smooth musWhat is the importance of the M3 recepcle in the lungs tor? -Relaxation of the pupil Why do we not consider M1 receptors for They are related to the CNS and not the the autonomic nervous system? PNS What are the role of inhibitory neurons? To relax some muscles when others contract What is the main inhibitory neurotransmitter? GABA Name a type of reflex that doesn't involve the brain? -Light -Focus (distance dependent) What muscles change the the thickness of the lens? Ciliary muscles What are the two types cells in the eye that convert light energy into electrical impulses? Rods and cones What are rods sensitive to? Light and dark (brightness) What are cones sensitive to? Red green and blue light (RGB) What is the pretectal nucleus responsible for? Pupil size reflex changes What is the part of the cortex responsible for the interpretation of sight? Occipital lobe association area What are the 5 types of taste receptors? -Sweet -Salty -Sour -Bitter -Umami 5/6 What are the 4 nerve endings involved in mechanoreception? -Merkel's disk -Meissner corpuscle -Pacinian corpuscle -Ruffini's ending How does the sense of taste roughly work? -Each type of receptor responds to its complementary chemical -Causing depolarisation and an impulse to be generated -Sense of taste is also complemented by the sense of smell What is the main difference between the There are far more types of receptors for sense of taste and the sense of smell? the sense of smell What are the three bones responsible for amplification of sound in the ear so it can be converted to an impulse? -Malleus -Incas -Stapes -Vibrate in response to the mechanical energy of sound waves -They are attached to nerve cells What are the role of hair cells in the ear? which fire impulses in different strengths (greater depolarisation) depending on the sound waves -They are the agonist for the nerve What is the area of the brain that is responsible for interpretation of sound? Temporal lobe association area 6/6