Unit 5 Review Lesson 1: Nervous Tissue

Unit 5 Review: Lesson 1: Nervous Tissue ● Compare and contrast the anatomical and physiological subdivisions of the nervous system. ○ Anatomical divisions ■ Central nervous system (CNA) ■ Peripheral nervous system (PNS) ● Somatic nervous system ● Autonomic nervous system ○ Sympathetic ○ Parasympathetic ○ Functional divisions ■ Afferent → to the CNS ■ Efferent → to the effectors ● What is the difference between neuroglia and neurons? List and describe the different types of neuroglia and their functions ○ Neurons are the functional units of the nervous system, they are responsible for the transfer and processing of information ○ Neuroglia are supporting cells that separate and protect neurons ○ Astrocytes: maintains blood brain barrier (BBB) ○ Oligodendrocytes: forms myelin sheath in CNS ○ Microglia: phagocytic neuroglia ○ Ependymal cells: produces CSF ○ Satellite cells: surrounds neuron cell bodies in ganglia, regulates interstitial fluid around neurons ○ Schwann cells: forms myelin sheath in PNS ● Describe the structure of a typical neuron and explain the significance of its principal regions. ○ nah ● Describe the different types of neurons. ○ Anaxonic: cell body with lots of projections, hard to tell which are dendrites and which are axons ○ Bipolar: cell body with dendrite on one end, and axon on other ○ Unipolar: one long projection with cell body on one side (most common in PNS) ○ Multipolar: more than two processes, many dendrites on soma and long axon (most common in CNS) ● Describe how the resting membrane potential is established. What is the role of Na+/K+ pumps in the maintenance of the resting membrane potentials? ○ I honestly have no idea and I hope it's not important ● Describe the sequence of events that occur during the production of an action potential. 1. Depolarization to threshold 2. Activation of voltage-gated sodium ion channels (rapid depolarization) 3. Inactivation of voltage-gated sodium ion channels and activation of potassium ● ● ● ● ● ion channels (beginning of repolarization) 4. Closing of voltage-gated potassium ion channels (brief hyperpolarization) and a return to resting membrane potential What is the significance of the all-or-none law and the refractory periods? ○ All or none - it either happens or it doesn’t. It must reach threshold potential to start and action potential ○ Refractory period - in absolute refractory period you are unable to have another action potential take place, but in relative refractory you can have another action potential, but it requires a strong signal because the cell has not yet repolarized to resting membrane potential Review the different types of synapses. ○ Electrical: through the use of neurons ○ Chemical: through neurotransmitters List and describe the structural components of a synapse. Describe the steps that occur when a neurotransmitter carries a signal across a synapse. 1. Action potential passes along axons and over synaptic knob/terminal 2. Synaptic terminals become more permeable to calcium ions, which diffuse inward 3. Synaptic vesicles fuse to terminal membranes 4. Synaptic vesicles release neurotransmitters into the synaptic cleft 5. Synaptic vesicles re-enter the axon’s cytoplasm to pick up more neurotransmitters List the common neurotransmitters and their primary roles/functions. ○ Norepinephrine: excitatory effect ○ Acetylcholine: excitatory - muscle contraction and cognitive function ○ Dopamine: excitatory or inhibitory - reward and motivation ○ Serotonin: inhibitory - mood and sleep ○ Epinephrine: excitatory ○ GABA: inhibitory ○ Endorphins: pain relief, inhibitory ○ Nitric oxide (NO): inhibitory What is EPSP? IPSP? Differentiate between the two and explain their significance. ○ EPSP (excitatory postsynaptic potential) ■ Causes depolarization ■ Promotes generation of action potentials ○ IPSP (inhibitory postsynaptic potential) ■ Causes hyperpolarization ■ Suppresses the generation of action potentials Lesson 2: CNS ● Discuss the structure and functions of the spinal cord. ○ The gray matter in center is made of neuron cell bodies and the white matter around it is made of myelinated axons ○ Central canal contains CSF ○ Information enters through the dorsal root and leave through the anterior root ● Describe the protective structures (hard bony skull, vertebral column, and meninges) of the brain and spinal cord. ○ Epidural space contains adipose tissue for protection ○ 3 spinal meninges: ■ Pia mater ■ Arachnoid mater ● Subarachnoid space contains CSF ■ Dura mater ○ Bones of the skull: parietal, frontal, occipital, and temporal bones ○ Blood brain barrier (BBB) ● Describe the peripheral distribution of spinal nerves. Differentiate between sensory, motor, and mixed nerves. ○ Spinal nerves are part of the peripheral nervous system and are responsible for connecting the spinal cord to multiple part of the body, and are named after the region of the body they go to ○ Sensory nerves: sensory info from the spinal cord to the brain ○ Motor nerves: motor info from the spinal cord to the muscles and glands ○ Mixed nerves: contain both sensory and motor fibers ● Describe the structural and functional components of a reflex arc and explain the relationship of reflexes to homeostasis. ○ Reflex: an immediate involuntary motor response ○ Reflex arc: the route followed by nerve impulses 1. Activation of sensory receptor 2. Activation of sensory neuron and relays to CNS 3. Information processing in CNS 4. Activation of motor neuron 5. Response by peripheral effector ● Identify the major regions of the brain and describe their functions. ○ Cerebrum: covered by the cerebral cortex for processing sensory and motor info ○ Cerebellum: adjusting postural muscles for balance ○ Diencephalon ■ Thalamus: final relay point for sensory information, filters conscious awareness ■ Hypothalamus: secretes oxytocin and ADH, regulates the pituitary gland hormones and controls all those parts of the body (which is a LOT) ○ Brainstem ■ Midbrain: visual and auditory info, reflexes, consciousness and alertness ■ Pons: relay station between cerebellum and thalamus ● ● ● ● ● ● ● ■ Medulla: critical autonomic functions Describe the cortex, gyri, fissures, and sulci of the cerebrum ○ Gyri: the noodle looking part of the brain ○ Sulcus: the curves if the noodles ○ Fissures: the lines separating the brain like the longitudinal fissure Identify and describe the ventricles of the brain including the formation circulation and functions of CSF. ○ Each cerebral hemisphere contains a lateral ventricle that is line with ependymal cells that create the CSF and deliver the CSF through the cerebral aqueduct Describe the functions of the basal ganglion and the limbic system ○ Limbic system is also called the motivational system and is important for establishing mental states and memory storage/retrieval ○ Basal nuclei are masses of gray matter in the white matter that handle subconscious control of skeletal muscle for learned movements Identify the major arteries that supply blood to the brain and explain the importance of blood-brain barrier. ○ Receives blood through the internal carotid artery ○ The BBB is important for selective transport to protect the brain and CSF from harmful substances, the only entrance is through fenestrated capillaries in circumventricular organs Describe the locations and functions of the sensory, association and motor areas of the cerebral cortex ○ Primary motor cortex and the primary sensory cortex are separated by the central sulcus Define the term “cranial nerve” and identify the twelve pairs of cranial nerves by name, number, and functions. I. Olfactory → smell II. Optic → visual acuity III. Oculomotor → eye movement/pupils IV. Trochlear → vertical eye movements V. Trigeminal → facial expression/sensation VI. Abducens → lateral eye movements VII. Facial → taste + facial expression VIII. Vestibulotrochlear → hearing + balance IX. Glossopharyngeal → taste + swallowing X. Vagus → sensation in throat + visceral muscles XI. Accessory → head + shoulder movements XII. Hypoglossal → tongue movements List and describe the sensory and motor tracts of the spinal cord. ○ Spinothalamic: pain, temperature, crude touch ○ Posterior column pathway: fine touch, pressure, vibration, proprioception ○ Spinocerebellar pathway: proprioceptive information from muscles, tendons, and joints to the cerebral cortex ○ Corticospinal pathway: conscious voluntary control over skeletal muscles ○ Medial and lateral pathways: motor commands to the cerebrum, diencephalon, and brainstem ○ Can you explain how the anatomical name of a spinal tract tells you where the tract begins and ends within the CNS? ■ Tbh no ● Describe the route by which afferent and efferent information enters the spinal cord. ○ Afferent info enters the spinal cord through the back ○ Efferent info leaves the spinal cord through the front ● List the ascending and descending tracts found in the white matter of the spinal cord. ○ Can you explain how ascending and descending tracts are named and the significance of the tracts? ■ One goes up and one goes down Lesson 3: Sensory Pathways & Somatic NS ● Define sensation and perception ○ Sensation: when a stimulus arrives to a sensor ○ Perception: the conscious sensation of a stimulus once it reaches the somatosensory cortex ● Discuss the different categories of sensory receptors and distinguish between visceral afferent and sensory afferent pathways. ○ Sensory receptors ■ Nociceptors - pain receptors, release substance P and glutamate, free nerve endings, tonic receptors ■ Thermoreceptors - temperature receptors in the skin, phasic receptors, same pathway as pain receptors ■ Mechanoreceptors - response to physical distortion ● Tactile receptors: sense touch, pressure, vibration ● Baroreceptors: monitors change in pressure ● Proprioceptors: position sense ■ Chemoreceptors - detects small changes in concentrations of chemical or compounds, phasic receptors Lesson 4: Autonomic NS & Higher Order Functions ● Compare the structural and functional characteristics of the somatic and autonomic nervous system. ○ Autonomic: ■ Makes routine homeostatic adjustments directed by hypothalamus ■ Involuntary control ■ Directs visceral reflex responses ■ Divided into sympathetic and parasympathetic nervous systems ■ Two motor neurons (preganglionic and postganglionic) ○ Somatic: ■ Consciously perceived sensations ■ Motor neurons carry information from CNS to skeletal muscles ● ● ● ● ● ● ● ● ■ One motor neuron Identify the principal structural features of the autonomic nervous system. ○ Preganglionic neuron: cell body in brain or spinal cord ○ Postganglionic neuron: cell body outside CNS in autonomic ganglion Describe the preganglionic and postganglionic neurons of the autonomic nervous system. ○ Listed above Compare the sympathetic and parasympathetic divisions of the autonomic nervous system in terms of structure, physiology and neurotransmitters released. ○ Listed above? Describe the levels of integration and control of the autonomic nervous system. ○ Tbh idk Compare the sympathetic and parasympathetic divisions of the autonomic nervous system for similarities and differences. ○ Sympathetic ■ Fight or flight ■ Increased mental awareness, metabolic rate, respiratory rate, bronchodilation, HR, BP ■ Decreased urinary and digestive functions ■ Activation of energy reserves and sweat glands ■ Thoracolumbar division ■ Short preganglionic fibers ○ Parasympathetic ■ Rest and digest ■ Increased saliva and digestive secretions, digestive mobility, and stimulation of urination and defecation ■ Decreased metabolic rate, HR, and BP ■ Craniosacral division ■ Long preganglionic fibers Identify the autonomic neurotransmitters and receptors. Explain the physiological and clinical significance of these receptors ○ Acetylcholine: cholinergic receptors, excitatory ○ Norepinephrine: adrenergic receptors, excitatory ○ Nicotinic receptors: excitatory, Ach activates receptor (cholinergic) ○ Muscarinic receptors: excitatory or inhibitory, Ach activates receptor (cholinergic) Discuss the relationship of adrenal glands to the sympathetic nervous system. ○ The adrenal glands secrete epinephrine and norepinephrine into bloodstream (80% E) ○ Impacts metabolic activity in body Discuss briefly on autonomic reflexes. ○ Motor neurons carry information to visceral motor neurons in autonomic then from autonomic ganglia to visceral effectors ○ Two motor neurons required - preganglionic and postganglionic ● Describe the major functional areas of the cerebral cortex; explain the functions of the association areas of the cerebral cortex. ○ The major functional areas of the cerebral cortex include the motor cortex, sensory cortex, and association areas. ○ The motor cortex controls voluntary movements, while the sensory cortex receives and processes sensory information from various body parts. The association areas of the cerebral cortex are involved in higher cognitive functions such as memory, language, and problem-solving. ● Describe the location and functions of the following: diencephalon, basal nuclei, limbic system, and the reticular activating system. ○ Diencephalon ■ Thalamus: final relay point for sensory information, filters conscious awareness ■ Hypothalamus: secretes oxytocin and ADH, regulates the pituitary gland hormones and controls all those parts of the body (which is a LOT) ○ Basal nuclei ■ Basal nuclei are masses of gray matter in the white matter that handle subconscious control of skeletal muscle for learned movements ○ Limbic system ■ Limbic system is also called the motivational system and is important for establishing mental states and memory storage/retrieval ○ Reticular activating system (RAS) ■ Receives and integrates synaptic information from the cerebral cortex ■ Involved in arousal, alertness and focus (like maintaining consciousness) ■ If not active then you are unconscious ■ This is the system that wakes you up from sleep ● Explain the basis for memory (long-term vs short-term), arousal, behavior patterns developed in the brain and higher order functions discussed in the lecture. ○ Memory ■ Short term memory is only a limited capacity, whereas long term memory has a much larger capacity ■ Memory consolidation: the conversion of short term memory to long term ■ Memory engram: a single circuit that responds to a single memory ○ Arousal ■ RAS system ■ Receives and integrates synaptic information from the cerebral cortex ■ Involved in arousal, alertness and focus (like maintaining consciousness) ■ If not active then you are unconscious ■ This is the system that wakes you up from sleep