10. Nervous System Flashcards
Brain disorder marked by deterioration of mental capacity.
Alzheimer’s disease
Damage to the blood vessels of the cerebrum, leading to loss of blood supply to brain tissue; a stroke
Cerebrovascular accident
Blunt injury to the brain severe enough to cause loss of consciousness
Concussion
Chronic brain disorder characterized by recurrent seizure activity
Epilepsy
Malignant brain tumour arising from glial cells.
Glioblastoma
Paralysis that affects the right or left half of the body
Hemiplasia
Inflammation of the membranes surrounding the brain and spinal cord
Meningitis
Destruction of the myelin sheat on the nerve cells in the central nervous system (brain and spinal cord), with replacement by plaques of sclerotic (hard) tissue
Multiple Sclerosis
Paralysis that affects the lower portion of the body
Paraplegia
Fainting; sudden and temporary loss of consciousness as a result of inadequate flow of blood to the brain
Syncope
Pressure of CSF is measured and contrast may be injected for imaging after removal of CSF from a space between the lumbar vertebrae. This also provides a sample of CSF for analysis.
Lumbar Puncture
Chemical tests (for Na, Cl, Protein and glucose), cell counts, cultures and bacterial smears on CSF samples to detect diseases of the brain or meninges.
Cerebrospinal Fluid Analysis
Cerebral Angiography
X-ray imaging of the blood vessels in the brain after injection of contrast material in an artery
PET scan
Positron emission tomography.
Radioactive material into the brain shows how the brain uses glucose and gives information about brain function
AD
Alzheimer disease
CNS
Central nervous system
CVA
Cerebrovascular accident
stroke
CSF
Cerebrospinal fluid
EEG
Elecroencephalography
LP
Lumbar puncture
MS
Multiple Sclerosis
TIA
Transient Ischemic Attack (temporary interference with blood supply to the brain)
Two major divisions of the nervous system
Central nervous system
Peripheral nervous system
Two components of the CNS
brain
spinal cord
the components of the PNS
cranial nerves, spinal nerves, plexuses and the peripheral nerves throughout the body
Vagus nerve
Tenth cranial nerve that carries messages to and from the neck, chest and abdomen.
Plexus
A large network of nerves in the peripheral nervous system.
Sensory (afferent) nerves
Carry messages toward the spinal cord and brain
Motor (efferent) nerves
travel from the spinal cord and brain to the muscles of the body, telling them how to respond.
Autonomic nervous system
Nerves that control involuntary body functions of muscles, glands and internal organs.
Acetylcholine
Neurotransmitter chemical released at the ends of nerve cells.
arachnoid membrane
Middle layer of the three membranes (meninges) that surround the brain and spinal cord.
Astrocyte
Type of glial (neuroglial) cell that transports water and salts from the capillaries in the nervous system
Axon
Microscopic fibre that is part of a neuron and carries nervous impulses along a nerve cell
Blood-brain barrier
Protective separation between the blood and brain cells. This makes it difficult for substances (such as anticancer drugs) to penetrate capillary walls and enter the brain
Brainstem
Posterior portion of the brain that coordinates muscle movements and maintains balance
Cauda euqina
Collection of spinal nerves below the end of the spinal cord
Cell body
part of a nerve cell that contains the nucleus
Central nervous system (CNS)
Brain and spinal cord
Cerebellum
Posterior part of the brain that coordinates muscle movements and maintains balancew
Cerebral cortex
Outer region of the cerebrum, containing sheets of nerve cells: gray matter of the brain.
Cerebral spinal fluid (CSF)
Circulates throughout the brain and spinal cord
Cerebrum
Largest part of the brain; responsible for voluntary muscular activity, vision, speech, taste, hearing, thought and memory.
Cranial nerves
Nerves carry messages to and from the brain to all parts of head and neck and also (in the case of the vagus nerve) to other parts of the body. There are 12 pairs of cranial nerves.
Dendrite
Microscopic branching fibre of a nerve cell (neuron) that is the first part to receive the nervous impulse.
Dura mater
Thick, outermost layer of the meninges, surrounding and protecting the brain and spinal cord.
Efferent nerves
Carries messages away from the brain and spinal cord; motor nerves.
Ependymal cell
Glial cell that lines membranes within the brain and spinal cord and helps form CSF
Ganglion
Collection of nerve cell bodies in the peripheral nervous system.
Glial cell
Supportive and connective nerve cell that does not carry nervous impulses.
Examples are astrocytes, microglial cells, ependymal cells and oligodendrocytes. Glial cells can reproduce by themselves, as opposed to neurons.
Gyrus
Sheet of nerve cells that produces a rounded ridge on the surface of the cerebral cortex; convolutions.
Hypothalamus
Portion of the brain beneath the thalamus; controls sleep, appetite, body temperature, and secretions from the pituitary gland.
Medulla oblongata
Part of the brain just above the spinal cord; controls breathing, heartbeat and the size of blood vessels; nerve fibres cross over here.
Meninges
Three protective membranes that surround the brain and spinal cord.
Microglial cell
Phagocytic glial cell that removes waste products from the nervous system
Midbrain
Uppermost portion of the brainstem
Motor nerve
Carries messages away from the brain and spinal cord to muscles and organs; efferent nerve
Myelin sheath
Covering of white fatty tissue that surrounds and insulates the axon of a nerve cell. Myelin speeds impulse conduction along axons
Nerve
Macroscopic cord-like collection of fibres (axons) that carry electrical impulses
Neuron
Nerve cell that is necessary for impulses to be carried throughout the nervous system; parenchyma of the nervous system
Neurotransmitter
Chemical messenger released at the end of a nerve cell. It stimulates or inhibits another cell, which can be a nerve cell, muscle cell, or gland cell.
Examples are acetylcholine, norepinephrine, dopamine and seritonin.
Oligodendroglial cell
Glial cell that forms the myelin sheath covering axons. Also called oligodendrocytes.
Parasympathetic nerves
Involuntary autonomic nerves that regulate normal body functions such as heart rate, breathing, and muscles of the gastrointestinal tract.
Parenchyma
Essential, distinguishing tissue of any organ or system. The parenchyma of the nervous system includes the neurons and nerves that carry nervous impulses. Parenchymal cells of the liver are hepatocytes, and ones of the kidney include nephrons, where urine is formed.
Peripheral nervous system (PNS)
Nerves outside the brain and spinal cord; cranial, spinal and autonomic nerves.
Pia mater
Thin delicate inner membrane of the meninges.
Pons
Part of the brain anterior to the cerebellum and between the medulla and the rest of the midbrain. It is a bridge connecting various parts of the brain.
Receptor
Organ that receives and transmits a stimulus to sensory nerves. The skin, ears, eyes and taste buds are receptors.
Sciatic nerve
Nerve extending from the base of the spine down the thigh, lower leg and foot. Sciatica is pain or inflammation along the course of the nerve.
Stimulus
Agent of change in the internal or external environment that evokes a response. It may be light, sound, touch, pressure or pain.
Stroma
Connective and supporting tissue of an organ. Glial cells make up the stromal tissue of the brain
Sulcus
Depression or groove in the surface of the cerebral cortex; fissure
Sympathetic nerves
Autonomic nerves that influence bodily functions involuntarily in times of stress.
Synapses
Space through which a nervous impulse travels between nerve cells or between nerve and muscle or glandular cells.
Thalamus
Main relay centre of the brain. It conducts impulses between the spinal cord and the cerebrum; incoming sensory messages are relayed through the thalamus to appropriate centres in the cerebrum.
Ventricles of the brain
Canals in the brain that contain cerebrospinal fluid. Ventricles are also found in the heart–they are the two lower chambers in the heart.