{"id":1756,"date":"2020-07-11T09:07:11","date_gmt":"2020-07-11T09:07:11","guid":{"rendered":"https:\/\/murreeroad.org\/Biology10\/?p=1756"},"modified":"2020-07-12T14:27:50","modified_gmt":"2020-07-12T14:27:50","slug":"q-5-explain-central-nervous-system-c-n-s-in-detail","status":"publish","type":"post","link":"https:\/\/murreeroad.org\/Biology10\/q-5-explain-central-nervous-system-c-n-s-in-detail\/","title":{"rendered":"Q.5 Explain Central Nervous System (C.N.S) in detail."},"content":{"rendered":"

Q.5 Explain Central Nervous System (C.N.S) in detail. <\/strong>Parts of CNS<\/strong>
\nCNS consists of two parts:
\n (i) Brain” (ii) Spinal cord<\/strong>
\n(i) Brain<\/strong>
\nIntroduction<\/strong>
\nIn animals, all life activities are under the control of brain. The structure of brain is suitable to perform this function. ”
\nLocation<\/strong>
\nBrain is situated inside a bony cranium i.e. a part of skull.
\nMeninges<\/strong>
\nInside cranium, brain is covered by three layers called meninges.
\nFunction of meninges<\/strong>
\nMeninges protect brain and also provide nutrients and oxygen to brain tissues through their capillaries. Ventricles<\/strong>
\nThe brain contains fluid filled ventricles that are continuous with the central canal of spinal cord.Cerebrospinal fluid (CSF)<\/strong>
\nFluid within ventricles and central canal is called cerebrospinal fluid (CSF).
\nFunction of CSF<\/strong>
\nIt provides cushioning and ions to brain and spinal cord.
\nDivision of Brain<\/strong>
\nThere are three main regions in the brain of humans and other vertebrates. These are forebrain, midbrain, and hindbrain.
\n(a) Forebrain\u00a0<\/strong>
\n Introduction<\/strong>
\nForebrain is the largest area of brain. It is most highly developed in humans.
\nParts of Forebrain
\n(i) Thalamus <\/strong>
\nLocation<\/strong>
\nIt lies just below the cerebrum.
\nFunctions<\/strong>
\nIt serves as a relay center between various parts of brain and spinal cord. It also receives and modifies sensory impulses (except from nose) before they travel to cerebrum. Thalamus is also involved in pain perception and consciousness i.e. sleep and awakening.
\n(ii) Hypothalamus <\/strong>
\nLocation<\/strong>
\nIt lies above midbrain and just below thalamus.
\nSize <\/strong>
\nIn humans, it is about the size of an almond.
\nFunction <\/strong>
\n(a)<\/strong> The most important function of hypothalamus is to link nervous system and endocrine
\nsystem.
\n(b)<\/strong> It controls the secretions of pituitary gland.
\n(c)<\/strong> It controls feelings such as rage, pain, pleasure and sorrow.
\n(iii) Cerebrum <\/strong>
\nIt is the largest part of forebrain.
\nFunction<\/strong>
\nIt controls skeletal muscles, thinking, intelligence and emotions.
\nCerebral hemispheres <\/strong>
\n\u00c7erebrum is divided into two cerebral hemispheres.
\nOlfactory Bulbs <\/strong>
\nThe anterior parts of cerebral hemispheres are called olfactory bulbs which receive impulses from olfactory nerves and create the sensation of smell.
\nCerebral cortex <\/strong>
\nThe upper layer of cerebral hemisphere i.e. cerebral cortex consists of grey matter.
\nGrey matter <\/strong>
\nThe grey matter of nervous system consists of cell bodies and non-myelinated axons.
\nWhite matter <\/strong>
\nBeneath this layer is present the white matter. The white matter of nervous system consists of myelinated axons. Cerebral cortex has a large surface area and is folded in order to fit in skull.
\nLobes of cerebral cortex
\nIt is divided into four lobes:<\/p>\n\n\n\n\n\n\n\n
Lobe<\/strong><\/td>\nFunctions<\/strong><\/td>\n<\/tr>\n
Frontal<\/td>\nControls motor functions, permits conscious control of skeletal
\nmuscles and coordinates movements involved in speech<\/td>\n<\/tr>\n
Parietal<\/td>\nContains sensory areas that receive impulses from skin<\/td>\n<\/tr>\n
Occipital<\/td>\n\u00a0Receives and analyzes visual information<\/td>\n<\/tr>\n
Temporal<\/td>\nConcerned with hearing and smell<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Hippocampus<\/strong>
\nIt is a structure that is deep in the cerebrum. It functions for the formation of new memories. People with a damaged hippocampus cannot remember things that occurred after that but can remember things that occurred before damage.
\n(b) MIDBRAIN<\/strong>
\nLocation: <\/strong>
\nMidbrain lies between hindbrain and forebrain and it connects the two.
\nFunctions:<\/strong>
\n1.<\/strong> It receives sensory information and sends it to the appropriate parts of fore brain.
\n2.<\/strong> Midbrain also controls some auditory reflexes and posture.
\n(c) HINDBRAIN \/ What are parts of hind brain and how they perform their function? Parts of hindbrain<\/strong>
\nHindbrain consists of three major parts:
\n1. Medulla Oblongata<\/strong>
\nLocation<\/strong>
\nIt lies on the top of spinal cord.
\nFunctions <\/strong>
\n(i)<\/strong> It controls breathing, heart rate and blood pressure.
\n(ii)<\/strong> It also controls many reflexes such as vomiting, coughing, sneezing etc.
\nInformation that passes between spinal cord and the rest of brain pass through medulla.
\n2. Cerebellum Location <\/strong>
\nIt is behind the medulla oblongata.
\nFunction <\/strong>
\nIt coordinates muscle movements.
\n3. Pons Location <\/strong>
\nIt is present on the top of medulla oblongata.
\nFunction<\/strong>
\n(i)<\/strong> It assists medulla in controlling breathing.
\n(ii)<\/strong> It also serves as a connection between cerebellum and spinal cord.
\n\"human
\n(ii) SPINAL CORD<\/strong>
\nDefinition<\/strong>
\nIt is a continuation of medulla oblongata. .
\nLocation<\/strong>
\nIt starts from brain stem and extends to lower back
\nSTRUCTURE<\/strong>
\nThe spinal cord is infact a tubular bundle of nerves. It is the continuation of medulla. oblongata.
\nLength<\/strong>
\nIt is roughly 40 cm long.
\nWidth<\/strong>
\nIt is about as wide as our thumb for most of its length.
\nMeninges<\/strong>
\nLike brain, spinal cord is also covered by meninges.
\nProtection of spinal cord <\/strong>
\nThe vertebral column surrounds and protects spinal cord.
\nOuter Region <\/strong>
\nThe outer region of spinal cord is made of white matter containing myelinated axons.
\nCentral Region <\/strong>
\nThe central region is butterfly-shaped that surrounds the central canal…. Composition
\nIt is made of grey matter containing neuron cell bodies.
\nSPINAL NERVES <\/strong>
\n31 pairs of spinal nerves arise along spinal cord. These are \u201cmixed” nerves because each contains axons of both sensory and motor neurons.
\nROOTS OF SPINAL NERVES <\/strong>
\nAt the point where a spinal nerve arises from spinal cord, there are two roots of spinal nerves. Both roots unite and form one mixed spinal nerve.
\nDorsal root <\/strong>
\nThe dorsal root contains sensory axons and a ganglion where cell bodies are located.
\nVentral root<\/strong>
\nThe ventral root contains axons of motor neurons.
\n\"spinal\"
\nFunctions of Spinal Cord<\/strong>
\n1.<\/strong> It serves as link between body parts and brain. Spinal cord transmits nerve impulses from body parts to brain and from brain to the body parts.
\n2.<\/strong> Spinal cord also acts as a coordinator, responsible for some simple reflexes.
\n\"\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Q.5 Explain Central Nervous System (C.N.S) in detail. Parts of CNS CNS consists of two parts: (i) Brain” (ii) Spinal cord (i) Brain Introduction In animals, all life activities are under the control of brain. The structure of brain is suitable to perform this function. ” Location Brain is situated inside a bony cranium i.e.… Read More »Q.5 Explain Central Nervous System (C.N.S) in detail.<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[23],"tags":[],"_links":{"self":[{"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/posts\/1756"}],"collection":[{"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/comments?post=1756"}],"version-history":[{"count":4,"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/posts\/1756\/revisions"}],"predecessor-version":[{"id":1777,"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/posts\/1756\/revisions\/1777"}],"wp:attachment":[{"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/media?parent=1756"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/categories?post=1756"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/murreeroad.org\/Biology10\/wp-json\/wp\/v2\/tags?post=1756"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}