The Brain And Nervous System Flashcards
What two parts make up the nervous system?
• Central nervous system
• Peripheral nervous system
What makes up the CNS?
Everything inside the spine and skull
What makes up the peripheral nervous system?
Everything outside the spine and skull
What are ganglions?
Clusters of cells associated with the nerves
How can the peripheral nervous system be divided?
Efferent and afferent
What are the two systems within the efferent PNS?
• Somatic
• Autonomic
What are the two major cell types in the nervous system?
• Neurones
• Glial cells
What are neurones and what do they do?
• Electrically excitable cells
• Communicate with other cells via synapses
What are glial cells and what do they do?
• Non-neuronal cells in the nervous system
• Maintain homeostasis, form myelin and support and protect neurones
What are the 5 major types of glial cells?
• Astrocytes
• Oligodendrocytes
• Schwann cells
• Microglia
• Ependymal cells
What do astrocytes do?
• Regulate chemicals around neurones (glucose, ion concentrations and neurotransmitter uptake)
• Regulate blood flow around the brain (vasomodulation)
• Nervous system repair (following injury, astrocytes fill spaces in the nervous system creating glial scars)
What do oligodendrocytes do?
• Form the myelin sheath on axons in the CNS
• Each oligodendrocyte can myelinate up to 50 axons
What do Schwann cells do?
• Form myelin in the PNS
• Assist in regeneration and growth of axons
• Myelin allows action potentials to propagate more quickly
What do Microglia do?
• Act as the brain’s immune system
• Scavenge the CNS for plaques, damaged cells and infectious agents
What do Ependymal cells do?
• Make up a membrane called the ependyma, which is a thin membrane lining the central canal of the spinal cord and the ventricles
• Produces cerebrospinal fluid
What is white matter?
• Parts of the brain that are mainly made up of axons
• The myelin sheath surrounding the axons is made of fat and protein so is white
What is grey matter?
Areas of the brain that contain mainly the cell bodies of the neurones
What does the medulla do?
• Cardiac - central chemoreceptors sense oxygen levels in brain and alter heart rate and blood pressure
• Respiration - chemoreceptors sense changes in blood chemistry and increase breathing rate
• Reflexes - vomiting, coughing, sneezing, swallowing
What does the pons do?
• Contains nuclei that relay signals from the forebrain to the cerebellum
• Nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation and posture
What does the cerebellum do?
• Maintenance of balance and posture
• Coordination of movements (especially across multiple joints)
• Motor learning
What is the role of the midbrain?
• Tectum controls rapid orientation of the head and neck
• Also associated with sleep and wake cycles, alertness and temperature regulation
What does the thalamus do?
• Acts as a switchboard
• Takes information from the periphery and passes it to the cortex
• Hypothalamus - hormones, metabolic control
What does the basal ganglia do?
• Movement regulation
• Skill learning
• Habit formation
• Reward systems
• Selection of appropriate behaviours
• Self initiation of behaviours
What does the cerebral cortex do?
• Movement
• Attention
• Perception
• Awareness
• Thought
• Memory
• Language
• Consciousness
How many layers does the cortical sheet have?
6
Name the different parts of the brain
• Spinal cord
• Medulla
• Pons
• Cerebellum
• Midbrain
• Thalamus
• Basal ganglia
• Cerebral cortex
