The Nervous System Task 01
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Schwann cells
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Tasks 1. Label this diagram of a neuron. 2. Outline the function of the Schwann cells. 3. Describe the action of the sympathetic and parasympathetic systems on the Heart and Digestive system. 1. 2. 3. 4. 5. 6. 7. Cell body Dendrites Axon hillock Terminal boutons Axon terminals Axon Nodes of Ranvier
The Schwann cells wrap themselves around the axon and increase the speed of nervous conduction The sympathetic system stimulates the heart and increases cardiac output. It depresses digestive activity. The parasympathetic system has the opposite effect, it slows the heart and reduces cardiac output whilst stimulating digestive activity
Task 02 Briefly describe the major functions of the Central, Peripheral and Autonomic nervous systems Briefly describe the major functions of the Central, Peripheral and Autonomic nervous systems CNS Brain Receives sensory input from the spinal cord as well as from its own nerves. Devotes most of its volume to processing its various sensory inputs and initiating appropriate - and coordinated - motor outputs. Spinal Cord It connects a large part of the peripheral nervous system to the brain. The spinal cord also acts as a minor coordinating centre responsible for some simple reflexes.
PNS and the ANS Carry information between the CNS and other parts of the body. Afferent division of the PNS sends information about the internal and external environment to the CNS. The efferent division of the PNS is the communication link by which the CNS controls the activities of the muscles and glands. The voluntary division of the PNS (Somatic nervous system) controls skeletal muscle movements. The involuntary division of the PNS is knows as the ANS. ANS controls the cardiac muscle, smooth muscle, most exocrine glands and some endocrine glands.
Task 03 Name the four bones of the skull that cover the anterior, superior, lateral and posterior surface of the brain. Anteriorly = Frontal Bone Superiorly = Parietal Bone Laterally = Temporal Bone Posteriorly = Occipital Bone Briefly describe the three layers that make up the meninges, between which two of these layers would you normally find Cerebro-Spinal Fluid (CSF)? The Meninges of the Brain are made up of the following layers: Dura Mater - consist of dense fibrous tissue, it is double layered around the Brain. The outer layer takes the place of the Periosteum on the inside of the Skull. The inner layer protects the Brain and helps to anchor it in place by the use of the following folds: Falx Cerebri, Falx Cerebelli within these folds you have Superior Sagittal Sinus and the Straight and Transverse Sinuses respectively. Another fold is the Tentotrium Cerebelli, Arachnoid Mater - consist of serous membrane. It is the middle layer of the Meninges and is separated from the Dura mater by the Sub Dural space. Beneath this is the wider Sub Arachnoid space that contains CSF. The Arachnoid Mater is held against the layer below by spider like projections. Pia Mater - consist of delicate connective tissue that adheres closely to the Brain and holds many minute blood vessels.
Task 04 The Brain is described as being made up of the following parts,the: Cerebrum Midbrain Thalamus Pons Hypothalamus Medulla Oblongata Cerebellum Identify Parts of the Brain- Task and give a brief outline of their these areas on the diagram below 4 functions.
Cerebrum Thalamus
Hypothalamus Pons Cerebellum Medulla Oblongata
Tortora, G. J. and Grabowski, S. (2000) Principles of Anatomy and Physiology
Midbrain
Cerebrum - Higher functions such as cognition, sensory perception and voluntary muscle control. Thalamus - Relay centre that receives information from the skin and organs of the body, including the special sences before sending these messages on to the Cerebrum. Hypothalamus -This is closely related to the Pituitary gland and is concerned with the Maintenance of Homeostasis of the ANS, Body Temperature, Hunger and Thirst etc. Cerebellum - Coordination of intended muscle contraction, posture and balance. Midbrain - Relay zone for nerve Ascending and Descending Nerve fibres. Coordinates movement of the eyeball in response to stimuli. Pons - Transmits signals from one side of the Cerebellum to the other and betweenthe Midbrain and the Medulla Oblongata. Medulla Oblongata -This contains the vital functions of the following: Cardiac centre, this is responsible for the rate and force of Cardiac contractions. Respiratory centre, which controls the rate and depth of respiration. Vasomtor centre, that controls the diameter of blood vessels. Reflex centres which may initiate sneezing, coughing and vomiting.
Task 05 Draw a diagram to demonstrate the Central, Lateral and Parieto-occiptal sulci and then identify the lobes of the Cerebrum. Identify the location of the following areas: Motor area Sensory area Broca’s area Auditory area Visual area
www.smc.edu
Task 06 On the Coronal Diagram below identify the Grey and White matter, the Thalamus, Hypothalamus and the Basal Ganglia, Corpus Callosum,. Draw on some Association fibres and Projection fibres.
Task 6 Grey/ White
Association Fibres
Corpus Callosum Commissural Fibres
Projection Fibres Thalamus Grey Basal Ganglia White Hypothalamus
Tortora, G. J. and Grabowski, S. (2000) Principles of Anatomy and Physiology
Task 07
Make brief notes on the number, names and major functions of the cranial nerves. No. I Name Olfactory Origin in CNS From olfactory mucosa to bulb to olfactory areas within cortex. From retina of eye via optic chiasm and thalamus to visual cortex. Sensory: fibres from musculature of the eye to midbrain Motor: from midbrain to muscles of the eye. Sensory: fibres from superior oblique muscles of the eye to midbrain Motor: from midbrain to superior oblique muscles of the eye. Opthalmic, Maxillary and Mandibular branches, ending at the pons. Ends in the pons Function Sence of smell, loss of which is termed anosmia.
II
Optic
Sence of vision, loss of which may be termed anopia.
III
Oculomotor
Sensation from the eye and movement of the muscles for the eye, eyeball and iris
IV
Trochlear
Sensation and movement of the superior oblique muscles of the eye.
V
Trigeminal
Sensory and motor of facial area.
VI
Abducens
VII
VIII
IX
From taste buds, tongue and face, from pons to face, scalp and neck. Vestibulocochlear Fibres end in the pons and cerebellum and auditory area of the cortex. Glossopharyngeal To and from the medulla.
Facial
Sensory and motor of function of the Lateral rectus musclues of the eye. Sence of taste and motor facial expression
Sensory and motor. Hearing, posture and balance.
Sensory and motor. For taste and swallowing. Monitors blood pressure , oxygen and
X
Vagus
To and from the medulla and pons
XI
Accessory
XII
Hypoglossal
To and from sensory and motor cortex. Has cranial and spinal portion To and from sensory and motor cortex.
carbon dioxide levels within the blood, allows feedback for changes in rate and depth of breathing. Stimulation of saliva Sensory and motor. For taste swallowing and visceral organs of thorax and abdomen. Monitors blood pressure , oxygen and carbon dioxide levels within the blood, allows feedback for changes in rate and depth of breathing, coughing. Control of ANS of cardiac muscle and GI tract. Sensory and motor functions of the muscles of the neck.
Sensory and motor functions of the tongue for swallowing and speech
Task 08 Make brief notes on which areas of the body are supplied by these plexuses.
Area= Neck,Phrenic nerve branches from this to supply the diaphragm.
Area= shoulders and Upper limbs.
Area= Anterolateral abdominal wall and part of lower limbs.
Area= Perineum Lower limb via sciatic nerve.
Wilson, K.J.W. (1999) Ross and Wilson Anatomy and Physiology in Health and illness. (8 Edition). Edinburgh, Churchill Livingstone.
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