Nervous System Part 3 PDF

Nervous System Part 3 Central Nervous System & Peripheral Nervous System Tutor Debbie Hemington Module BMS GDC Learning outcomes As for parts 1 & 2 Intended learning outcomes At the end of the session, you will be able to: Describe the 2 parts of the nervous system List the ke...

Nervous System Part 3 Central Nervous System & Peripheral Nervous System Tutor Debbie Hemington Module BMS GDC Learning outcomes As for parts 1 & 2 Intended learning outcomes At the end of the session, you will be able to: Describe the 2 parts of the nervous system List the key features of the human brain and spinal cord Describe the main areas of the brain and their func=on List the func=ons of cerebrospinal >uid List the groups of spinal nerves Assessment Forma=ve Summa=ve Short answers End of module exams MCQ  Spinal card The central nervous system - Braine Brain Weighs around 1.4kg Lies in cranial cavity Comprises of: Cerebrum Thalamus Hypothalamus Mid brain Pons Medulla oblongata Cerebellum Cerebrum oped mushroo. Largest part of the brain 3 main func=onal areas associated with; Mental Ac=vi=es-memory, intelligence, problem solving, re>ec=on, judgement, thinking, reasoning, ini=a=ve, inhibi=on, moral sense of responsibility and learning Sensory percep=on-percep=on of pain, temperature and touch Ini=a=on and control of voluntary muscle contrac=on  surface The Cerebrum Largearea. The cerebral cortex is highly wrinkled, which makes the brain more eScient, because it can increase the surface area of the brain and the amount of neurons within it. ↑ A deep furrow divides the cerebrum into two halves, known as the leT and right hemispheres. The corpus callosum is a bundle of axons which connects these two hemispheres. I hemis as comects to  & motor Thalamus - Relays Sensory information. Small structure Sensory receptors in skin & viscera send info about touch, pain & temperature Input from the special sense organs travels here too where there is percep=on but only in basic form Thought to be involved in arousal and the processing of some emo=ons and complex re>exes Hypothalamus Situated within the cerebrum AVached to the pituitary gland Controls the output of hormones Controls eHectors of the autonomic nervous system: Emo=onal reac=ons Hunger and thirst Body temperature Biological clocks Mid brain Consists of nuclei and nerve Xbres which connect the cerebrum with the lower parts of the brain and spinal cord. Nuclei act as relay sta=ons for the ascending and descending nerve Xbres and have important roles in auditory and visual re>exes. Pons Contains nerve Xbres, which form a bridge between the two hemispheres of the cerebrum Processes info from several of the cranial nerves  cord and Spinal Medulla Oblongata - connects the at the base of the Skull. Pons function. Is con=nuous with the spinal cord controlls bodily Controls eHectors: cardiovascular centre /Relays nerve signals respiratory centre re>ex centres: coughing, vomi=ng, sneezing, swallowing rebellum. Spinal Cord Nerves conveying impulses from the brain to various organs and 7ssues descend through it. Starts in the medulla oblongata and descends through the spinal column. Spinal cord Elongated, almost cylindrical part of the CNS. Suspended in the vertebral canal Surrounded by meninges & cerebro-spinal ?uid Approx the thickness of a liCle Dnger Approx 45cms long Cerebrospinal 0uid Cerebrospinal 0uid (CSF) is a clear colourless ?uid that: occupies the subarachnoid space in the brain acts as a "cushion" or buKer for the cortex is renewed 4 7mes daily contains proteins, glucose and lymphocytes Func3ons of Cerebrospinal Fluid Protec7on Buoyancy Excre7on of waste products Endocrine medium for the brain. Protec3on The CSF protects the brain by ‘buKering’ the brain. This lessens the impact when there is a blow to the head. Image sourced April 2021 Dreamstime.com Buoyancy Because the brain is immersed in ?uid, the net weight of the brain is reduced from about 1400g to about 50g, thus reducing the pressure at the base of the brain. Image sourced April 2021 Q Files Excre3on of waste products The one-way ?ow from the CSF to the blood takes poten7ally harmful metabolites, drugs and other substances away from the brain Image sourced April 2021 Depositphotos Endocrine medium for the brain The CSF serves to transport hormones to certain areas of the brain. Hormones released into the CSF can be carried to remote sites of the brain where they may act. Image sourced April 2021 SubPNG The Peripheral Nervous System Peripheral Nervous System - Involuntaryoestro - es rate heart Voluntary Image sourced April 2021 Biology Libre Texts. Autonomic Nervous System The sympathe3c nervous system ac7vates the “Cght or 0ight” response during a threat or perceived danger Needed for short term survival The parasympathe3c nervous system restores the body to a state of calm, the “rest and digest” phase Needed for long term survival.  Cranial Nerves · 12 pairs · Origin on the Interior Surface of the brain Brain Stem mainly.  Spinal Nerves · 31 Pairs Intervertebral Foramina Peripheral Nerves Useful links Autonomic Nervous System: Sympathe7c vs Parasympathe7c, Anima7on – YouTube 2-Minute Neuroscience: Divisions of the Nervous System – YouTube Thank you