The Brain - RGU University Aberdeen - PDF

The Brain 21 November 1 2024  The Neuron (nerve cell) Neurons, also known as nerve cells, they are the fundamental units of the brain and nervous system. They are specialised cells responsible for transmitting information throughout th...

The Brain 21 November 1 2024  The Neuron (nerve cell) Neurons, also known as nerve cells, they are the fundamental units of the brain and nervous system. They are specialised cells responsible for transmitting information throughout the body using electrical and chemical signals. 21 November 2 2024  Did you know? The brain contains approximately 86 billion neurons Each neuron has up to 15000 connections to other cells Neurons produced at a rate of 250000/min 21 November 3 2024  The Neuron (nerve cell) Key Parts of a Neuron: Cell Body – contains the nucleus and is responsible for maintain the cells’ health Axon – a long, tail-like structure that transmits signals away from the cell body to other neurons or muscles Dendrites – branch like structures that receive messages from other neurons and relay them to the cell body 21 November 4 2024  Types of Neuron Sensory Neurons – Carry signals from sensory receptors to the central nervous system (CNS) Motor Neurons - Transmit signals from the central nervous system to muscles, causing movement. Interneurons – Connect neurons within the central nervous system, communicating between sensory and motor neurons Neurons are crucial for all brain functions, from basic reflexes to complex thoughts and emotions 21 November 5 2024  The Brain Cerebrum has 2 hemispheres & is largest part of the brain 4 lobes – Frontal, temporal, parietal and occipital 2 Association areas – anterior and posterior Cerebellum Brain stem Corpus callosum - connects 2 hemispheres 21 November 6 2024  Development of nerve cells The development of nerve cells, or neurons, in the brain and nervous system is a complex and fascinating process that begins early in embryonic development. Here’s an overview: Neurons produced in one part of brain Process is NEURON often travel to other Starts in the Most neurons PROLIFERATION – parts following embryonic period present by 7th month 250000 neurons neurochemical trails. generated per min This is NEURAL MIGRATION Initial axons find Initial axons guided Once in final Myelination of their own way, but by chemical signals destination , starts neurons mostly subsequent axons and proteins building the brain’s complete by 2 years follow trails left by connect with the communication old but changes initial axons correct neuron channels occur into adulthood 21 November 7 2024  Development of the Brain Main development is increase in size: At birth = 400g, 25% of adult brain weight 6 months old = 50% of adult brain weight 2 years old brain = 75% of adult brain weight 21 November 8 2024  Areas of the Brain Cerebrum Largest part of the brain Divided into 2 hemispheres – Left and Right Thinking, Learning, Memory, Emotions, Voluntary Movements This Photo by Unknown Author is licensed under CC BY Contains 4 lobes – Frontal, Parietal, Temporal, Occipital 21 November 9 2024  Cerebrum Left & Right Temporal lobe, larger 90% brain’s cells are hemispheres on left than right, Most advanced part located in the outer anatomically distinct associated with of the brain cerebral cortex with differing language, hearing & functions smell Frontal lobe Parietal lobe is associated with Occipital lobe is associated with planning, organizing associated with processing bodily and higher mental vision sensations functions 21 November 10 2024  Areas of the Brain cont. Cerebellum Located under the Cerebrum Co-ordinates muscles movements Maintains posture and balance Brainstem Connects the brain to the spinal cord Controls automatic functions necessary for survival – beathing, heart rate, blood pressure This Photo by Unknown Author is licensed under CC BY-SA-NC 21 November 11 2024  Hemispheric Specialization Also known as laterization. Refers to the idea that the 2 halves of the brain (Right and Left) are responsible for different functions Left Hemisphere - Often associated with language, logic, and analytical thinking. It controls activities like speaking, reading, writing, and problem-solving Right Hemisphere - Typically linked to creativity, spatial ability, and visual imagery. It handles tasks like recognising faces, interpreting emotions and understanding spatial relationships 21 November 12 2024  Brain change and behavioral development Maturation – Brain growth leads to new behaviors, direct effect on developing skills OR Skill learning – Brain is developed but active learning and teaching is required to acquire skills and behaviors Or Interactive specialization- Brain has framework for development which are influenced by interaction with the environment and how other brain areas develop and interact with each other e.g. The capacity is built into the brain, but development is dependent on the environment, development of other parts of the brain and how they all interact. 21 November 13 2024  Myelination Myelination is the process of forming a myelin sheath around the axons of neurons. The sheath is made of a fatty substance called myelin, which acts like insulation around electrical wires, allowing nerves impulses to travel quickly and effectively along nerve cells. Key points: Myelin Sheath – a protective covering which surrounds the axons of many neutrons Function – insulates nerve fibers, speeding up the transmission of electrical signals Formation – in the Central Nervous System (CNS), myelin is produced by cells called oligodendrocytes Importance: Rapid Signal Transmission – Myelination allows for faster communication between neurons, which is crucial for efficient brain and nervous system function Development – Myelination begins in the 3 rd trimester of pregnancy and continuous into young adulthood. 21 November 14 2024  Myelination cont. Neurodegenerative diseases such as Multiple Sclerosis (MS) result in demyelination of nerves and can result in speech, balance and cognitive impairment. Myelination continues into adulthood, particularly in the frontal cortex. Grey matter - the neurons decline with age As the brain refines and molds itself through pruning of neurons it develops the efficiency of transferring information through the nervous system with myelination The frontal cortex is associated with higher order thinking – required as adults for planning, organizing, attention and inhibition 21 November 15 2024  Plasticity Refers to the brain’s ability to Functional Plasticity change and adapt in response to experiences, learning and even The brain’s ability to move injury. functions from damaged areas There are two types: to non-damaged areas. This is crucial for recovery after brain Structural Plasticity injuries The brain’s ability to change it’s physical structure. This can happen when neural connections are formed, such as when learning a new skill 21 November 16 2024  Growth spurts Frontal lobe activity and an increase of synaptic connections during infancy and toddlerhood relate to grasping objects; walking; language. Surges in brain growth can relate to cognitive development 21 November 17 2024  The Ageing Brain The ageing process of the CNS involves several changes that can affect both structure and function: 1. Brain Atrophy: The brain and spinal cord lose nerve cells and overall weight, a process known as atrophy 2. Neuron Loss: There is gradual loss of neurons, which can lead to a slower communication between nerve cells 3. Accumulation of waste products: Some substances can accumulate in the brain tissue as nerve cells break down 21 November 18 2024  The Ageing Brain cont. Functional changes – 1. Slower signal transmission 2. Cognitive decline 3. Decreased blood flow 4. Increased inflammation Despite these changes the brain retains a degree of plasticity, meaning it can adapt and create new connections throughout life. This still allows older adults to continue learning new skills and forming new memories. 21 November 19 2024