1/15/15 – Lecture 2 – Anatomy of the Nervous System- Nervous System: the organs, tissues, and cellular structures that coordinate the actions of an organism that transmits signals (through electrical shocks) between parts of its body (Made up of Peripheral NS and CentralNS)o Peripheral Nervous System: components of the NS outside of the skull and spine (nerves extending out into the body and limbs) Peripheral NS Components- Nerves: bundles of cable-like 2 way highways that transmit electrical impulses from the body structures and the brain- Ganglia: clusters of nerve cell bodies that are associated with nerveso Very close to the spinal chord Peripheral NS Branches- Somatic (Body) NS: nerves carrying sensory information to the brain/ CNS and motorcommands to the body from the brain/ CNSo Cranial Nerves: carry information to and from the brain and the head, neck, and trunko Spinal Nerves: carry information to and from the CNS and the rest of the body- Autonomic (Automatic) NS: nerves that regulate automatic processes of the internal organs and other natural bodily functionso Digestion, breathing, swallowing, dilation of pupils, ect Breathing is the only one that we can actually take control ofo Parasympathetic NS: regulates day to day functions Mainly happens when were relaxed and keeps us at this homogenous levelo Sympathetic NS: manages the “fight or flight” response to threats or stressors Happens when were agitated and need to survive, bodily functions increase or decrease depending on needo Central Nervous System: components of the NS inside of the skull and spine (the brain and the spinalcord) Central NS Components- Spinal Cord: functions mainly to transmit signals to and from the body and the brain,can react independent of the brain with local reflexes and neural connections (takes too long to go to the brain)o Brain -> spinal cord = motor commandso Spinal cord -> brain = sensory information Dorsal Roots: bring sensory information into the CNS from the body- Afferent (affective) Neuron: back of the spine channel that goes up to the brain Ventral Roots: take motor commands from CNS to muscles and the parts of the body- Efferent (effective) Neuron: front of the spine channel that goes out to the bodyo Spinal Cord and Neck Injury Physical trauma to the spine can sever communication between the brain and the rest of the body- Depends of severity of the severing and how high the injury is on the spinal chord- The Brain: 2 hemispheres separated by a longitudinal fissure, and yet connected by the corpus callosum allowing communication between the hemisphereso The cells of the brain are organized into different structures Cortex: layers of cells on the outer part of the brain, wrinkles and folds are used to increase surface area- Gyri (2+)/ Gyrus (1): bulges/ ridges on brain’s surface- Sulci (2+)/ Sulcus (1): groves/ indentations in the brain’s surface Nuclei: clusters of nerve cells/ neurons deep inside the brain (thalamus, amygdala, hippocampus, ect)o The 2 Hemispheres of the brain are both SYMMETRICAL and ASYMMETRICAL Symmetrical: both have sensory and motor areas that are very similar Asymmetrical: the language center in the left is more dominant thanin the right for right handed people and swapped for left handed people, spatial navigation is more dominate on the right for right handed people and swapped for left handed people Contrateral: messages are sent and received from opposite sides of the brain and body- Left brain controls the right side of the body- Right brain controls the left side of the bodyo 3 Subdivisions of the Brain Hind Brain: regulates functions that are basic and critical for life (Pons, Reticular Formation, Medulla, Cerebellum)- Regulation of heart rate, breathing, blood pressure, and swallowing- Control over sleep and arousal/ wakefulness- Regulation of posture, movement, and balance Mid Brain: controls movement, reward centers, and arousal/ alertness- As well as auditory and visual reflexes Fore Brain: the part of the brain that makes us human through conscious thoughts, memory, emotion, ect- Controls body temp, hunger, thirst, and sleep patterns- Relays and processes sensory information- Initiates and changes of movement behaviors- Creation of emotion in the limbic system- Memory storage- COGNITION: thoughts, impulse control, and planningo Lobes of the Cerebral Cortex Occipital Lobe: located at the back of the head Temporal Lobe: ears to the lower back of the head Parietal Lobe: ears to the top back of the head Frontal Lobe: front of the head to middle of the heado Other Parts of the Brain Meninges: membranes surrounding and protecting the jelly like brain- Dura Mater (hard mother): outer most layer, very tough like leather- Arachnoid Membrane (medium): spider web like middle layer- Pia Mater (soft mother): adheres to the brain and spinal cordo Can get infected = Meningitis = infection/ inflammation of the membranes surrounding the brain Viral (can’t be cured) and bacterial (can be cured) Symptoms = headache, neck stiffness, fever,confusion/ altered consciousness, vomiting, photophobia (inability to tolerate light), andphonophobia (inability to tolerate loud noises) Ventricles: 4 large fluid filled chambers in the brain that contain Cerebrospinal Fluid/ CSF- CSF produced by Choroid Plexuses and trickles out of the ventricles and washes through the brain into the blood fromthe Glymphatic System (most active at night)- The Ventricles are like liquid cushions to protect the brain from impacts- Hydrocephalus: disease that can happen if the liquid does not drain, comes from the blockage of the draining of CSF and causes them to swello Symptoms = obvious swelling to the head, “sun downing” or pressure causing the eyes to look down Cerebral Vasculature: blood vessels supplying the brain with oxygen and nutrients Blood Brain Barrier: tight seals and other barriers around blood vessels that restrict movement from the blood into the brain and vise versa- Brain depends on the deliverance of oxygen because it cannot store them itself very well- Endothelia cells: ensures the blood brain barrier is tight so very little gets througho Stroke: interruption of blood and oxygen supply to the brain, neurons down stream die and are damaged from lack of oxygen Can happen from a leak in the blood streamor a clogging Usually happen unilaterally (on one side of the brain)