Anatomy and Physiology

• The nervous system works with the endocrine system to regulate and maintain body homeostasis

  
• The endocrine system produces hormones that are released into the blood, acting in a more leisurely way compared to the rapid electrical nerve impulses of the nervous system
• The nervous system has three main functions: sensory input, integration, and motor output
• Sensory input involves monitoring changes inside and outside the body, integration processes and interprets this input, and motor output causes a response by activating muscles or glands
• The nervous system is the master control and communication system of the body, communicating with body cells using electrical impulses that cause almost immediate responses
• The structural classification of the nervous system includes the central nervous system (CNS) - brain and spinal cord, and the peripheral nervous system (PNS) - all parts outside the CNS
• The functional classification of the nervous system divides the PNS into the sensory division (afferent) - conveying impulses to the CNS, and the motor division (efferent) - carrying impulses from the CNS to effector organs, the muscles and glands
• The motor division of the nervous system has two subdivisions: the somatic nervous system (voluntary control of skeletal muscles) and the autonomic nervous system (involuntary control of smooth muscle, cardiac muscle, and glands)
• Neurons are the basic functional unit of the nervous system, transmitting signals to different parts of the body

  
• Neurons have a cell body containing the nucleus and processes extending from it
• Neuron processes conveying incoming messages toward the cell body are dendrites, while those generating nerve impulses away from the cell body are axons
• Axons transmit nerve impulses away from the cell body and release neurotransmitters at their terminals to communicate with other neurons or target cells
• Myelin sheaths, produced by Schwann cells in the PNS and oligodendrocytes in the CNS, protect and insulate nerve fibers, increasing the speed of nerve impulse transmission
• Neurons are the basic functional unit of the nervous system, receiving and transmitting signals to different parts of the body

  
• Neurons can be classified based on their function or structure
• Functional Classification of Neurons:

  • Sensory neurons (afferent neurons) carry impulses from sensory receptors to the CNS
  • Motor neurons (efferent neurons) transmit impulses from the CNS to effectors in the body periphery
  • Association neurons (interneurons) connect motor and sensory neurons in neural pathways
• Structural Classification of Neurons:

  • Multipolar neurons have several processes extending from the cell body
  • Bipolar neurons have one axon and one dendrite
  • Unipolar neurons have a single process emerging from the cell body, dividing into proximal and distal processes
• Neurons have two major functional properties: irritability (responding to a stimulus by producing a nerve impulse) and conductivity (transmitting the impulse to other neurons, muscles, or glands)
• Electrical Conditions of a Resting Neuron's Membrane:

  • Resting neuron's membrane is polarized, with fewer positive ions inside compared to outside
  • Potassium ions exit the cell, maintaining a negative inside compared to outside
• Action Potential Initiation and Generation:

  • Different stimuli excite neurons to become active and generate an impulse
  • Permeability properties of the cell's plasma membrane change briefly, allowing ions to diffuse through
• Attachment is a strong reciprocal emotional bond between an infant and a primary caregiver

  
• Schaffer and Emerson's 1964 study on attachment:

  • Aim: identify stages of attachment / find a pattern in the development of an attachment between infants and parents
  • Participants: 60 babies from Glasgow
  • Procedure: analysed interactions between infants and carers
  • Findings: babies of parents/carers with 'sensitive responsiveness' were more likely to have formed an attachment
• A neuron is composed of a cell body, dendrites, and an axon
• Neurons can be classified into different types based on their structure, such as multipolar, bipolar, and unipolar neurons
• The human nervous system is composed of neurons, which are the building blocks of the nervous system
• The human nervous system is responsible for receiving and transmitting signals to different parts of the body
• The human nervous system is composed of the central nervous system (CNS) and the peripheral nervous system (PNS)
• The CNS includes the brain and spinal cord, while the PNS includes nerves outside the CNS
• The human brain is responsible for various functions such as thinking, memory, and coordination of movement
• The brain is divided into different regions, each responsible for specific functions
• The four lobes of the human brain are the frontal lobe, parietal lobe, temporal lobe, and occipital lobe, each with distinct functions
• The frontal lobe is responsible for higher-level cognitive functions such as planning, decision-making, and judgment
• The parietal lobe processes sensory information from the skin, muscles, and joints
• The temporal lobe processes auditory information and memory
• The occipital lobe processes visual information
• The motor cortex is responsible for controlling voluntary movements, while the somatosensory cortex processes sensory information
• The transmission of nerve impulses involves depolarization, generation of an action potential, propagation of the action potential, repolarization, and restoration of initial ionic conditions
• The transmission of nerve impulses along unmyelinated fibers is slower compared to myelinated fibers, where the impulse jumps from node to node
• Factors like sedatives, anesthetics, cold, and pressure can impair the conduction of nerve impulses
• Synaptic transmission involves the release of neurotransmitters that bind to receptors on the membrane of the next neuron, influencing its activity