Class Notes (807,452)
Canada (492,628)
York University (33,498)
KINE 2031 (127)

Anatomy Nervous System Notes.docx

26 Pages
Unlock Document

York University
Kinesiology & Health Science
KINE 2031
Nicolette Bradley

Nervous System  Function  Sensory Input  Have receptors to detect changes in the environment  Detect both external/internal changes  Integration  Processes the sensory input and decides if response is required  Motor Output  Telling body what to do during a response  Sends down a motor message to respond to the stimulus  Organization  Central Nervous System (CNS): made up of Brain and Spinal Cord  They are encased in bone  Neurons are grouped into sensory, motor, and interneurons  Interneurons connect sensory with motor neurons  Peripheral Nervous System (PNS): outside of the brain and spinal cord  Has 2 divisions of neurons, Sensory (Afferent) and Motor (Efferent)  2 divisions of neurons  Neurons are the functional unit of the nervous system  Sensory Neurons  Responsible for receiving information from receptors and transmitting that to the CNS  It is subdivided into sensory Somatic (Body) – example: touch/pain/pressure  And Visceral (organs) - Example: blood vessels, digestive/respiratory organs  Visceral senses don’t reach the conscious level  Motor Neurons  Responsible for transmitting motor impulses from CNS to muscles or glands  Subdivided into Somatic (Body)  Conscious contractions of skeletal muscles  And Visceral (Organ)  Unconscious contractions of smooth/cardiac muscles  Also termed the Autonomic Nervous System  This is subdivided into sympathetic and parasympathetic  Sympathetic is flight or fight response  Parasympathetic is the function at rest  Neuron Structure  Cell Body  Dendrites  Responsible for directing information towards the body  Axon  Responsible for directing information away from the body. Non-Nervous Cells: Central Nervous System  Astrocytes  Act as a blood to brain barrier  Between the capillary and neuron  Regulate what substance comes in contact with the neuron  Oligodendrocytes  Responsible for the production of Myelin around the axons  Myelin insulates the axon and is composed of fat  Helps signal move faster by bouncing from one Myelin to the other  They skip at the Nodes of Ranvier  Axons that are myelinated are seen as whit matter  Microglial Cells  Act as white blood cells  Destroy viruses and bacteria that have invaded the CNS  Ependymal Cells  Line the ventricle of the brain  Similar function as choroid plexus (formation of cerebral-spinal fluid)  Cerebral spinal fluid is made up of cuboidal epithelial cells Non-Nervous Cells: Peripheral Nervous System  Schwann Cells: Also termed neurolemmocytes  Responsible for the formation of myelin around axon of PNS  Satellite Cells  Responsible for surrounding/separating cell bodies  Regulates the exchange of nutrients/waste between neuron & environment Brain  Forebrain  Cerebrum: Most of the forebrain is made up of the cerebrum  The cerebrum is divided into 2 hemispheres  The outer covering is the cortex  The cortex is made up non-myelinated cell bodies of the neurons  It is folded or convoluted  Grooves are sulci  Divides the cortex into lobes  Longitudinal Fissure: the groove that separates the 2 cerebral hemispheres  Central Sulcus: the groove separating the frontal lobe from parietal  Lateral Sulcus: superior border for temporal lobe  Divides frontal from the temporal  Parieto-occipital Sulcus: separates parietal from occipital lobe  Insular Lobe: deep to the temporal lobe  Hills are gyri  Pre-Central Gyrus: front of the central sulcus  Controls motor function  Post-Central Gyrus: Back of the central sulcus  Controls sensory signals  White Matter: myelinated axons of the neuron  Association Type tracts: join gyri in the same hemisphere  Arcuate Fasciculus: connect the gyri to the same lobe of the brain  Superior Longitudinal Fasciculus: connect gyri to different lobes of the brain  Commissural Tracts: join the right to the left hemisphere – example: Corpus Callosum  Helps to pass information from left to right  Projection Tracts: myelinated axons that transmit sensory information to the cortex  Or motor axons that transmit information through the cerebrum  Deeper Grey Matter: non-myelinated  Thalamus: relay center for all sensory information that goes to cerebral cortex  Hypothalamus: controller of the ANS/endocrine system  Basal Ganglia: cerebral nuclei group that receives information to regulate movement  2 of them  Midbrain: between the forebrain and the hindbrain/Superior to the pons and inferior to the thalamus  Functions: contains two cranial nerves to control eye movement  Contains motor tracts that run back to cerebellum – Superior Cerebellar Peduncles  Cerebellum to midbrain signal transfer  Contains visual and auditory centers  Hindbrain: Made up of the pons and Medulla oblongata  Pons:  contains nuclei of cranial nerve 5/6/7/8  Contains fibers that travel back to cerebellum – Middle Cerebellar Peduncles  Contains centers that regulate breathing  Medulla Oblongata  Has a connection to the cerebellum – via Inferior cerebellar Peduncles  Contains the nuclei for cranial nerves 8-12  Sensory roles on head/cranial area  Contains centers that regulate vital functions  Cardiac/respiratory center  Breathing/heart rate  Cerebellum: outer covering is cortex and convoluted  Has 2 hemispheres and a midline band called the vermis  Arbor Vitae is the myelinated axons that resemble the branching of a tree  area to co-ordinate motor movement  Meninges: are the layers that cover the brain.  The outer meningeal layer is termed the Dura Mater  Middle layer is the Arachnoid   The inner layer is the Pia Mater  Dura Mater – 2 in the brain and 1 in the spinal cord  The outermost covering  Vertical fold of Dura in the longitudinal fissure forms the Falx Cerebri  Falx Cerebri separates the left & right hemisphere  Falx Cerebelli: vertical fold between the two lobes of the Cerebellum  Tentorium Cerebelli: horizontal fold between Cerebellum and Occipital lobes  Divides cerebellum from the Cerebrum  Diaphragma Sellae: is a roof over the sella turcica (covers the pituitary gland)  Venous Sinuses: present within the edges of the Dural folds  Drains deoxygenated blood  Superior Sagittal Sinus located at top edge of Falx Cerebri  Any blood running from here is uni-directionally  Inferior Sagittal Sinus located at the bottom edge of Falx Cerebri  Moves posteriorly to meet the superior sinus via the straight sinus  Occipital Sinus located in the Falx Cerebelli *Superior sagittal sinus, straight sinus, and occipital sinus all meet at the confluence of sinuses*  Right and Left Transverse Sinuses: located outer edge of Tentorium Cerebelli  As it travels anteriorly it becomes the Sigmoid Sinus (s-shaped)  Sigmoid Sinus exits cranial cavity as Right/Left Internal Jugular Veins  After the sigmoid is sent inferiorly  Right/Left Cavernous Sinus are in the Diaphragm Sellae  Right/Left inferior and superior petrosal sinuses drain blood back to sigmoid sinus  *Path of blood*  Goes from the inferior sagittal sinus to straight sinus to confluence of sinus to the left/right transverse sinus to the sigmoid sinus and finally the jugular veins.  Arachnoid: Not attached to the spine  Follows the same contour as the Dura Mater  Connected with the Pia Mater via Trabeculae  They are connective tissue strands  The space between the arachnoid and Pia is the Subarachnoid Space  Contains cerebrospinal fluid  Extensions of arachnoid into Superior Sagittal Sinus forms Arachnoid Granulations  Projected to the sinus  Cycles cerebrospinal fluid  Pia Mater: attached to the spinal cord  Follows contours of the Cerebral Cortex  Ventricles  Cerebrospinal fluid is made here  Right and Left Lateral Ventricles are located in the Cerebrum  Communicate with midline 3 ventricle through the interventricular Foramina rd  3 ventricle is located between the thalamus  Continues in the midbrain region as the cerebral Aqueduct  Cerebral Aqueduct continues in the Pons region as 4 ventricle th  4 ventricle continues as Central Canal of spinal cord  3 apertures (openings) allow cerebrospinal fluid to get to subarachnoid space  Allows communication of Ventricle system with Subarachnoid space  Cerebrospinal Fluid formation:  Formed by the choroid Plexus  Made up of capillary networks positioned on the roof of one ventricle  Also made with Ependymal Cells that line the ventricle  Plasma is filtered through Ependymal Cells and trapped in the Ventricle  This is then termed Cerebrospinal Fluid th  It may exit ventricle system through apertures of 4 ventricle  Functions include protecting the brain from hitting the skull,  Provides buoyancy for the brain (takes pressure off muscles/bones)  Excellent tool for health of the nervous system Spinal Cord  General Structure  The outer surface has two depression (anterior/Posterior median Fissures)  The bottom of the cord is termed the Conus Medullaris  The cord is covered by same meningeal layers as the brain  Filum Terminale is the continuation of the Pia Mater from the Medullaris to the Coccyx  Internal Structure  Gray Matter: Located centrally outside and is divided into 5 parts  Posterior (Dorsal) Horn: contains axons of sensory neurons (Somatic /Visceral- Sympathetic Afferent)  Connects to an interneuron  Brings information to posterior of the cord  Anterior (Ventral) Horn: contains cell bodies of Somatic Efferent neurons  Information away from anterior of the cord  Lateral Horn: contains Sympathetic neurons in the T1-L2 region  Contains Parasympathetic Neurons in the S2-S4 region  Gray Commissural: unmyelinnated neurons that join the right/left halves of the cord  Are like interneurons  Interneurons: join posterior horn with anterior horn  Cauda Equina: bundle of nerves floating around  Covered by the meningeal layer  White matter: myelinated axons of the neuron  Takes sensory information up and motor information down  Posterior part is made up of sensory axons  Anterior part is made up of motor axons  Sensory comes from the back, motor comes out the front Spinal Nerves  General Structure of Spinal nerves  Dorsal Root: Is the afferent (Somatic/Visceral-Sympathetic) axons  Brings information into the posterior of spinal cord  Posterior Rootlets are fingerlike projections  Dorsal Root Ganglion: Bunch of cell bodies of the afferent nerves  Connection of peripheral and central nervous system  Ventral Root: Contains Efferent axons taking information away from the spinal cord  T1-L2 sympathetic  S2-S4 is parasympathetic  Axons share the same space and do not collide  Posterior Ramus: plays a distribution role  Distributes Efferent/Afferent to posterior of the body  Anterior Ramus: larger of the distribution.  Supplies Efferent/Afferent to anterior/lateral parts of the trunk  Supplies upper/lower extremities  Has cell bodies of somatic neurons Spinal Nerve Plexi  Spinal nerve plexi: control the function of different parts of the body. There are 4 of them  Cervical: formed by spinal nerves C1-C4  Associated with the neck region  Phrenic nerve innervates with the diaphragm  Nerves C3/C4/C5 keeps the diaphragm alive  Brachial: formed by spinal nerves C5-T1  Begins at the cervical enlargement  Supports entire upper limbs/some of the thorax  Nerves are both sensory/motor for upper extremity  Musculo cutaneous nerve: supplies anterior upper arm muscles.  3 nerves from the Brachial Plus are  Median: innervates with wrist/finger flexor`  Ulnar: innervates majority of intrinsic muscles of the hand  Funny bone nerve (between olecranon/medial epicondyle)  Radial: innervates muscle on the back of the arm/wrist & extensor muscles  Thoracic Nerves: Nerves coming off spinal cord in thoracic region come off and pass each rib  Lumbar: formed by spinal nerves L1-L4  Femoral Nerve is a large nerve from the plexus  Innervates the quadriceps muscle group  Obturator innervates the adductor muscle group  Sacral: formed by spinal nerves L4-S4  Supplies the hamstring  Sciatic Nerve travels down the posterior of the leg and innervates the Hamstring muscle  Splits into two parts, Common Peroneal & Posterior Tibial  Common Peroneal: supplies the lateral side of the leg  Posterior Tibial: supplies all muscles on the anterior/posterior side of leg as well as intrinsic muscles of the foot. Autonomic Nervous System  Autonomic Nervous System is responsible for  Picking up Visceral Sensory information  Controlling glands/cardiac/smooth muscles  Parasympathetic: responsible for the rest and digest activities of the body.  Example: Parasympathetic to the heart would slow the heart rate down  Exits from the CNS in the Cranial and Sacral region  No parts of parasympathetic found in the body wall or limbs  Cranial Nerves: cranial nerves 3/7/9/10 have parasympathetic function  Cranial nerve 10 (Vagus): is the most wide spread nerve  Vagus nerve innervates parasympathetically  Sacral: efferent exiting the spinal cord in the S2-S4 region supplies parasympathetic efferent for viscera in the floor of the pelvis  Includes last part of the large intestine/urinary bladder/reproductive organs  The parasympathetic nerve exits the spinal cord at ventral root and “catch a ride” on the arteries. There same nerves carry sensory information to the spinal cord through the Dorsal root.  Sympathetic: Responsible for the “fight or flight” response  Goes out the lateral horn to the anterior spinal nerve then the ganglion  Cell bodies are restricted to the thoracic and upper lumbar  Sympathetic nerves only exit from the spinal cord through the ventral root of the spinal nerves in (T1-L2) region.  Paravertebral Ganglia are located outside the spinal cord  Against the bodies of the vertebrae st  Connected to each other and stretches from 1 cervical vertebrae to sacrum  This is where the right/left Sympathetic Chain unites in one ganglia. Also called Ganglia Impar  Sympathetic/Somatic Pathways  Spinal Nerves  Thoracolumbar Region  Sympathetic nerves exit from the lateral horn through Ventral Root  Travel a short distance and leave spinal nerve forming White Ramus  The nerves present in the ramus travel to the paravertebral ganglia and synapse  The post-ganglionic nerve travels to the spinal nerve by the Gray Ramus (Location for attachment)  *Sympathetic Nerves only exit the spinal cord at thoracolumbar region where there is white rami*  Regions (C1-C8) or (L3-S5)  Must exit in the thoracolumbar region as well  Exits by white ramus  Instead of synapsing, preganglionic nerves travel up or down the chain reaching a level to synapse  Grey Ramus is where the spinal nerves will join after synapsing  *White rami are restricted*  Example: for nerves to reach C1. Nerves come off at T1 through White ramus, travel up to the C1 level and synapse at the ganglia at C1 joining through Grey Ramus.  Nerves reaching the head  There are no spinal nerves that reach the head very well  The nerves will come off in the upper thoracic region  Leaves upper thoracic spinal nerves through white ramus and travels up the sympathetic chain  Here it would reach either the top 2 or 3 ganglia in the chain and synapse  There nerves will leave the ganglion and “catch a ride” on a major artery to the head  Common/internal/external carotid artery Nerves that take either one of these routes vasoconstrict the arteries, control sweat glands/smooth muscles of body hair.  Thoracic Region  Sympathetic nerves must reach organs in the thorax  They will come off at the thoracic region and leave through white ramus  Travels up or down in the sympathetic chain and synapse at proper ganglion  They will then leave to service the thoracic organs  Different route since post autonomic ganglion don’t go to the heart  Abdominal Organs  Sympathetic nerves must reach in the abdominal cavity  They will come off at the thoracolumbar region and use white ramus to leave  It travels to the paravertebral ganglion  Instead of a connection, it passes through paravertebral ganglion and heads for sympathetic ganglion around 3 major arteries  These ganglia are Perevertebral or Collateral Ganglia  After a connection is made, the postganglionic nerves catch a ride with the major arteries Circulatory System  Functions:  The heart and blood vessels supply nutrients and oxygen to the cells (transport Function)  Removes waste generated by the cells  For example: Carbon Dioxide  If the body has to lose heat, vessels under skin dilate increasing blood flow and bringing heat to surface  If the body needs to conserve heat, vessels in the core dilate and blood will be shunted maintaining heat.  Both are Temperature maintenance function  Blood & Circulatory system assists in fluid balance (exchange of fluid between blood and interstitial fluid)  Heart  The heart is located in the mediastinum  Located at the top of the sternum  Between the lungs  Pericardial Sac is the double layered membrane that encases the heart  Outer layer of the sac is Parietal Pericardium  Has 2 layers, outer fibrous and inner serous layer  Second layer is the Visceral Pericardium  Inner layer is also Serous  It is also termed the Epicardium  Pericardial Cavity is the space between the serous parietal and visceral layer  Myocardium is the actual heart muscle  Surrounds the walls of the heart  Endocardium epithelial layer lining the inside of the chambers of the heart  Lines arteries and veins  Arteries (Blood away from the heart)  Veins (Blood towards the heart)  Blood Circulation in the Heart  Venous blood to the right atrium by superior/inferior vena cava, flowing down the right ventricle  Blood then moves to the Pulmonary Artery to get oxygenated  Oxygenated blood goes to the left atrium by the pulmonary veins  From left atrium it flows into left ventricle  Blood then flows into the left ventricles and contracts oxygenated blood out of the aorta  Heart is composed of 4 chambers  Right Atrium, Right Ventricle, Left Atrium, Left Ventricle  Right ventricle makes up most of the anterior portion.  Right Atrium is associated with the superior/inferior vena cava, and atrial septum  Superior Vena Cava  Final vein that brings venous blood above the heart  Inferior Vena Cava  Brings venous blood from areas below the heart  Atrial Septum  Wall that separates the left and right atrium  Fossas Ovale is a depression in the septum that is a remnant  Remnant allows blood flow from atria to the fetus  Cardiac Blood supply  Myocardium is supplied with arterial blood by right/left coronary arteries  They come off the aorta  Coronary Vein is responsible for bringing venous blood back to the heart  Empties into a vein called coronary sinus  This drains blood.  Right Ventricle  Right Atrioventricular Valve also termed the Tricuspid valve  Superior edge of the valve attaches around atrium/ventricle opening  Inferior edge hold the cusps are attached to collagen fibers called Chordae Tendineae  Tendineae attach to the cone shaped muscular projections called Papillary Muscles  When the ventricle contracts pushing blood out the pulmonary Artery, the pressure of the blood moves the cusps so the valves block an opening back into the atrium  The myocardium and papillary muscles are stimulated to contract as well.  Tension on the Chordae Tendineae prevents valve cusps from everting back into the atrium  Pulmonary Artery  Takes venous blood from right ventricle to the lungs  Pulmonary Semilunar Valve  Three cusp valve at the base of the pulmonary artery  Three half-moon shaped cusps attaching at the circumference of the artery  When blood flows up, valves are pushed against the wall of the artery  When it relaxes blood flows down filling the cusps and sealing the opening back to the ventricles  Interventricular Septum  Separates the right and left ventricle  Left Atrium receives oxygenated blood from lungs  Left Ventricle is the thickest muscle and gives blood to the whole body  Left Atrioventricular Valve is also termed the bicuspid valve  It is composed of two cusps  Blood from left ventricle will be pumped out the aorta  Aorta  The aortic semilunar valves has holes to go to the left and right coronary artery  The semilunar valve is located at the base of the aorta as it leaves the left ventricle  When blood passes the left ventricle, the aortic semilunar valves press against the walls of the aorta (covering the right/left coronary artery opening)  When the ventricle relaxes, blood will flow to the ventricle and the semilunar valves fill with blood.  When left ventricle relaxes blood flows back, valves are filled with blood; this blood used by the coronary arteries supple the heart  Heart Surface markings  Base is the superior border  Apex is the inferior end  Coronary Sulcus external groove around the heart  Marks the division between the two atria/ventricles  Coronary Sinus is in the Coronary Sulcus  Anterior/Posterior Interventricular Sulci  The two external grooves mark the interventricular septum  Excitability of the Heart: all involves the heart rate  Sinoatrial Node (SA Node) is the pacemaker of the heart  Located at the junction of Superior vena cava and right atrium  Electric signal at 70 times per minute  Also has autonomic nerve called Vagus Nerve to control the speed  Atrioventricular Node (AV Node) is located at the floor of the right atrium  After the signal passes the SA node causing right/left atria contraction it is picked up by the AV node  Bundle of HIS (Interventricular Bundle)  Takes signal from AV Node down the septum to the apex of the heart  Purkinje Fibers  Conduct electrical signals to the myocardium of the ventricle  Run to the papillary muscle on the inside of the ventricle  Pressure on the chamber wall is important for blood to be pumped out of the heart  Blood Vessels  Arteries: constructed of three layers (tunics)  Tunica intima is the inner layer of the vessel  Made up of simple squamous epithelial cells with areolar connective tissue  Epithelial layer with basement membrane is present at capillary level  Tunica Media: Involuntary layer located in the middle of the vessel  Stimulation causes vasoconstriction  When it relaxes it causes vasodilation.  Thickest Layer  Tunica Externa is the outer areolar connective tissue layer  Helps to anchor artery to other structures  Arterioles: Smaller diameter arteries  Have a tunica media layer and can vasoconstrict/dilate  Capillaries are the smallest and thinnest of the vessels  Consists of a tunica Intima layer of epithelial cells with a basement membrane  Exchange occurs between vascular system and interstitial fluid at this level  Venules have the similar structure as the veins  Take venous blood away from the capillaries  Veins three layers similar to the arteries but a thicker Externa layer  Have one way valves that prevent blood from back-flowing and pooling  Rely on massaging actions (pushing on the vein) to propel blood back to the heart Arteries upper torso and limbs  Aorta arterial blood out of the left ventricle passes into the aorta  Right and left coronary Artery  Come off the aorta   Supple the heart muscle with blood  Brachiocephalic Artery  Comes off the arch of the aorta  Bifurcates into the Right Common carotid artery and Right Subclavian artery (Towards the arm) nd  Left Common Carotid Artery (2 branch off the arch of the aorta)  Comes after the Brachiocephalic Artery rd  Left Subclavian Artery (3 branch off the arch of the aorta)  After the Left common carotid artery  Common Carotid Artery (right and left)  Course up the side of the neck  At the thyroid cartilage the common carotid artery bifurcates into Internal and External Carotid  Internal carotid Artery (right and left)  travels up and reaches the base of the skull  enters the cranial cavity through an opening in the base of the skull  External Carotid Artery (Right and Left)  Stays on the outer surface of the face and skull  At the ramus of mandible the artery divides into the superficial temporal artery & maxillary artery  Superficial Temporal Artery heads to the temporal bone  Maxillary Artery heads anteriorly to the maxilla  Subclavian Artery (Right and Left)  Passes under the clavicle and over the 1 rib  Gives off to a number of branches including the vertebral artery  Vertebral Artery passes in the transverse foramine of cervical vertebrae to reach Magnum  it enters the cranial cavity through the Foramen magnum  Axillary Artery is the name after the Subclavian passes under the clavicle and over the 1 rib  Lateral Thoracic Artery comes off the axillary artery  it supplies the front of the thorax  Subscapular Artery comes off the axillary artery as well  it supplies the posterior surface of the scapula  Brachial Artery (Right and Left) is the name after the axillary artery passes teres major insertion  Deep Brachial Artery is a major branch coming off the Brachial artery  It passes behind the humerus  Radial and Ulnar Artery is the name when the brachial artery bifurcates at the radial tuberosity  Radial (Right and Left)  Passes down the lateral side of the forearm  Artery becomes superficial and divides into the superficial/deep branch  Ulnar (right and Left)  Under the flexi carpi ulnaris muscle  Divides into superficial/deep branches as well at the wrist  Superficial palmar Arch (right and left) an arterial loop created mainly by the superficial branch of the ulnar artery  Deep Palmar Arch (Right and left) loop of the artery made up of the deep branch of Radial artery. Ulnar branch completes the loop. Deep in the p
More Less

Related notes for KINE 2031

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.