Overview of Control Systems Clinical Sciences Applied to Nursing 29/01/2018 obrienmp@cf.ac.uk/CSAN

General Organization of the Nervous System Begins as a hollow tube First segments of the tube become the brain (Porth 2009) LWW Slide used with permission

Nervous System Functions Directs immediate responses to stimuli, usually by coordinating the activities of other organ systems. It does this via Neurones and the chemical messages between Neurones obrienmp@cf.ac.uk

The human body is made up of trillions of cells The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons, are specialized to carry "messages" through an electrochemical process. These messages are carried via Neurons and neurone to neurone. The brain has about 100 billion neurons. 29/01/2018

At the synapses messages are sent and received Electrical conduction (Saltatory) sets up chemical (Synapses) between neurones that allows them to communicate with each other 29/01/2018 http://www.brainviews.com/abFiles/AniSalt.htm

Complexity in Responsibilities/Organisation Millions of neurons may lie beneath a single square centimetre of brain surface. Each synapses with as many as 600 other neurons. Many different parts of the brain may be involved in a single task. The nervous system is divided into several distinct systems. 29/01/2018 obrienmp@cf.ac.uk

Complexity of the Nervous system Organisation to Achieve this Nervous System Responsibilities Two major divisions: Central Nervous Systems. Peripheral Nervous System. Perception of external and internal conditions and the body's response to them 29/01/2018 obrienmp@cf.ac.uk (Porth 2012) LWW image used with permission

A typical Neuron 29/01/2018 (Fox 2010) McGraw Hill image used with permission (Porth 2012) LWW image used with permission

Introduction to The brain 29/01/2018

29/01/2018 Fox McGraw Hill 2009

Cerebrum Cerebellum Motor, cognitive, hearing , language, Speech etc. Thalamus, Hypothalamus Pituitary/ Pineal gland etc Brain stem Basal Ganglia Cerebellum 29/01/2018 Fox McGraw Hill 2009

Marieb 14.6

Protection of the brain The Skull and Cerebral Spinal fluid The bony cranium is loosely jointed during early infant life and thus must be protected. 29/01/2018

The Brain Covering MENINGES Dura mater Arachnoid mater Pia Mater 29/01/2018

Dura Mater Two layers Inner layer bends over to form a fold that separates the cerebral hemispheres A second fold (tentorium) separates the cerebrum from the cerebellum

Dura Mater (cont.) Between the layers of the dura, at the base of each fold, venous blood drains out of the brain in a sinus Bridging veins carry blood from the brain across the inner layer of the dura mater to the sinus The sinus also collects cerebrospinal fluid (Porth 2012) LWW image used with permission

Arachnoid Lies just beneath the dura mater Waterproof Cerebrospinal fluid (CSF) lies under the arachnoid to cushion the brain Extensions of the arachnoid (villi) poke through the inner layer of the dura mater into the sinuses, to let CSF drain into the sinuses (Porth 2012) LWW image used with permission

Pia Mater Lies right on the surface of the brain Holds the cerebral arteries in place (Porth 2012) LWW image used with permission

Cerebrospinal Fluid Leaks out of capillaries inside the brain’s hollow ventricles Composition controlled by the blood-brain barrier Passes out an opening below the cerebellum Circulates around the brain and spinal cord in the subarachnoid space Passes through arachnoid villi into blood in the dural sinuses and is returned to the heart (Porth 2012) LWW image used with permission

Nervous System Divisions Anatomical division of Nervous system Central Nervous System (Brain, Spinal Cord) Peripheral Nervous (Nerve connections organs/tissues ) the CNS and body between System The nervous system can be anatomically divided into the Central Nervous System – the brain, spinal cord encased in the bones of the cranium and vertebral column. The peripheral nervous system which allows nerve connections between the CNS and the organs and tissues of the body i.e. the nerve trunks, plexus and nerve fibres Encased in the Cranium and vertebral column allows nerve connections between the CNS and the organs and tissues of the body i.e. the nerve trunks, plexus and nerve fibres 29/01/2018

The Parts of the Nervous System Central Nervous system Brain an Spinal Cord Peripheral Nervous system Neurones that carry information to and from the central nervous system Peripheral Autonomic Somatic Parasympathetic Enteric Central Organisation of the Nervous system 29/01/2018

Nervous System - Physiology of the nervous system Physiological division Conscious Mechanisms Voluntary and Somatic Involuntary Control Mechanisms Autonomic Sympathetic and Parasympathetic E.G Skeletal muscle and joint movement Physiologically the nervous system can be divided into a somatic part i.e. that which deals with the voluntary and concious aspect e.g. skeletal muscle movement / joint movement and the autonomic nervous system which deals with the involuntary control mechanisms e.g. regulation of heartbeat, circulation and digestive functions. There are two parts which need to be distinguished within the autonomic nervous system – the sympathetic and parasympathetic. In order to gain an understanding of these two parts it is necessary to examine the arrangement (anatomy) and the functioning (physiology) seperately. E.G regualting HR, circualtion, digestive functions 29/01/2018 obrienmp@cf.ac.uk

Comparison between Somatic and Autonomic Nervous System 29/01/2018 Marieb 14.2

Endocrine System Hormonal : androgens for men and oestradiol and progesterone for females) and neural interactions that influence and control sexual behaviour are complex but research efforts have made great progress in unfolding a fascinating story 29/01/2018 obrienmp@cf.ac.uk

Central and Peripheral communication . The other main control system of body Endocrine organs located throughout body Actions: mediate function of all tissues Control of Endocrine function is through feedback mechanisms

Endocrine Hormones Chemical messengers Secreted by endocrine gland Specific to target Activate cellular change

Testosterone – Oestrogen Hormones E.G. Ocytocin Thyroxin Cortisol Insulin Testosterone – Oestrogen Fox

References Fox SI 2009 Human Physiology McGraw-Hill: Boston. Marieb EN 2005 Essentails of Human Anatomy and Physiology, Pearson Benjamin Cummings Porth (2009/ 2012) Pathophysiology Lippincott Williams and Wilkins: Philadelphia 29/01/2018