MIDTERM 1 Flashcards
Includes all the spinal and cranial nerves carrying sensory information to the CNS from the muscles, joints, and skins. Also transmits outgoing motor instructions that produce movement.
Somatic Nervous System (SNS)
Balances the body’s internal organs by producing the rest-and-digest response through the parasympathetic nerves or the fight-or-flight response through the sympathetic nerves
Autonomic Nervous System (ANS)
Mesh of neurons embedded in the linings of the gut, running from the esophagus through the colons; controls the gut
Enteric Nervous System (ENS)
Conducting towards a CNS structure
Afferent
Conducting away from a CNS structure
Efferent
Tough triple-layered protective covering of the brain
Meninges
Three layers of the meninges
Dura mater (tough double layer of fibrous tissue) Arachnoid layer (ultra thin sheet of delicate connective tissue) Pia mater (inner moderately tough membrane of connective fibres that clings on brain surface)
Thin folded film of nerve tissue composed of neurons that is t he outer layer of the forebrain
Cerebral cortex
Found between the arachnoid layer and pia mater which is a colourless solution of sodium chloride and other salts. Cushions the brain so that it can move or expand slightly without pressing on the skull
Cerebrospinal fluid (CSF)
Part of the cerebral cortex that functions in connection with hearing, language, and musical abilities; lies below the lateral fissure, beneath the temporal bone at the side of the skull
Temporal lobe
Generally characterized as performing the brain’s executive functions (decision making)
Lies anterior to the central sulcus and beneath frontal bone of the skull
Frontal lobe
Direct movements toward a goal or to perform a task such as grasping an object;
Lies posterior to the central sulcus and beneath the parietal bone at the top of the skull
Parietal lobe
Where visual processing begins; lies at the back of the brain and beneath the occipital bone
Occipital lobe
Bumps on the brain are called…
Gyrus/gyri
Cracks found on the surface of the brain are called
Sulcus (sulci)
Sudden appearance of neurological symptoms as a result of a severely interrupted blood flow in the brain
Stroke
Darker regions of the nervous system composed predominantly of cell bodies and capillary blood vessels that either collect and modify information or support this activity
Grey matter
Lighter regions of the brain which are rich in fat-sheathed neural axons that form the connection between brain cells
White matter
Two-winged cavities that contain CSF and is one of the four cavities in the brain;
Play a role in maintaining brain metabolism
Ventricle
A canal that runs down the length of the spinal cord where CSF flow into
Cerebral aqueduct
Band of white matter containing about 200 million nerve fibres that connects the two cerebral hemisphere to provide a route for the direct communication between them
Corpus callosum
Two main types of cell in the brain
Neurons (carry out the brain’s main functions) Glial cells (modulate the neuron’s activities)
Differentiate a never from a tract
Nerve = large collections of axons outside of the CNS Tract = large collection of axons coursing together in the CNS
Three parts of a brain of a fish or amphibian
Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
The mammalian brain further develops into five parts namely…
Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon
Responsible for most of our unconscious behaviour
Brainstem
Three regions of the brainstem
Diencephalon
Midbrain
Hindbrain
The hindbrain is most important in what kind of functions?
Motor functions
The midbrain is especially important in what kind of functions?
Sensory functions
The diencephalon is especially important in what kind of functions?
Integrative sensory functions
Part of the hindbrain responsible for controlling complex movement;
correlated with increased capacity for planning and executing complex behavioural sequences and increased tool use and language
Cerebellum
Net-like mixture of neurons (gray matter) and nerve fibres (white matter) which is associated with sleep-wake behaviour and behavioural arousal
Reticular formation
Receives input from the cerebellum and actually forms a bridge from it to the rest of the brain
Pons
Found at the rostral tip of the spinal cord;
Regulates vital functions such as breathing and cardio-vascular system
Medulla
Central part of the brain;
Contains neural circuits for hearing, seeing and orienting movements
Midbrain
Located at the roof of the midbrain;
Functions are sensory processing, particularly visual and auditory, and the production of orienting movement
Tectum
Part of the tectum where optic nerves send a large bundle of fibres
Superior culliculus
Part of the tectum which receives much of its input from the auditory pathways
Inferior colliculus
Floor (area above the ventricle) of the midbrain;
A collection of nuclei with movement-related, species-specific and pain perception functions
Tegmentum
Part of the tegmentum which controls limb movements
Red nucleus
Part of the tegmentum which connects forebrain and important in initiating movement
Substantia nigra
Made up of cell bodies that surround the aqueduct joining the third and fourth ventricles;
Contains circuits controlling species typical behaviours
Pariaqueductal gray matter
The between brain which integrates sensory and motor information on its way to the cerebral cortex
Diencephalon
Lies along the brain’s midline which contains many nuclei (22) associated with temperature regulation, eating, drinking and sexual behaviour
Hypothalamus
Critical function of the hypothalamus
Hormone production
Much larger structure than the hypothalamus;
Diencephalon structure through which information from all sensory systems is integrated and projected into the appropriate region of the neocortex
Thalamus
Large fibre bundle in the thalamic region where the optic tract sends information
Lateral geniculate nucleus (LGN)
Evolutionary the newest part of the brain;
Coordinates advanced cognitive functions such as thinking, planning, and language;
Contains the limbic system, basal ganglia and neocortex
Forebrain
Most recently evolved outer layer (new bark) of the forebrain;
Composed of about six layers of grey matter;
Construct our reality
Neocortex (cerebral cortex)
The older, more primitive three- or four-layered cortex which lies adjacent to the cerebral cortex;
Plays a role in controlling motivational and emotional states, as well as in certain form of memory
Allocortex
Distinct characteristics of the six layers of the neocortex
1) different layers have different types of cells
2) cell density varies from layer to layer, ranging from virtually no cells in layer I to the very dense cell packing in layer IV
3) other difference in appearance are both regional and functional
Map of the neocortex based on the organization, structure and distribution of the cells
Cytoarchitectonic map
A kind of cortical activity where the cortex influences how the information os processed in lower regions of the hierarchy
Top-down process
A collection of nuclei that lie in the forebrain just below the white matter of the cortex;
Coordinates voluntary movements of the limbs and body;
Connected to the thalamus and to the midbrain
Basal ganglia
Three principal structures of the basal ganglia
Caudate nucleus
Putamen
Globus pallidus
A motor system disorder characterized by severe tremors, muscular rigidity and a reduction in voluntary movement
Parkinson disease
Another disorder of the basal ganglia which characterized by tics, involuntary vocalizations (incl curse words and animal sounds) and odd involuntary movements of the body, esp of the face and the head
Tourette syndrome
Disparate forebrain structures lying between the neocortex and the brainstem that form a functional system controlling affective and motivated behaviours and certain forms of memory
Limbic system
Believed to contribute to the rewarding properties of psychoactive drugs snd other potentially addictive substances and behaviour
Amygdala
Lies at the base of the forebrain, connects to the receptor cells that lei in the nasal cavity, and sends most of the input to the pyriform cortex en route to the amygdala and thalamus
Olfactory bulb
One of the set of 12 nerve pairs that control sensory and motor functions of the head, neck and internal organs
Cranial nerve
Bones that form the spinal column
Vertebrae
Lies inside the bony spinal column ,which is made up of series of small bones called vertebrae
Spinal cord
Body segment corresponding to segment of the spinal cord
Dermatome
The principle that sensory fibres are dorsal and the motor fibres are ventral
Law of Bell and Magendie
Part of the autonomic nervous system;
Arouses the body for action such as mediating the involuntary fight or flight response to alarm by increasing heart rate and blood pressure
Sympathetic division
Part of the ANS which acts in opposition to the sympathetic division;
Prepares body to rest and digest by reversing the alarm response or stimulating digestion
Parasympathetic division
States that neurons are the functional unit of the nervous system
Neuron theory
Core region of the cell containing the nucleus and other organelles for making proteins
Cell body (soma)
Branching extension of a neuron’s cell membrane; greatly increased the cell’s surface area; collects information from other cells
Dendrite
Root, or single fibre, of a neuron that carries message to other neurons
Axons
Functional group of neurons that connects wide areas of the brain and the spinal cord
Neural network
Comprehensive map of the all structural connectivity (the physical wiring) in an organism’s nervous system
Connectome
Protrusion that greatly increased the dendrites surface area;
Typical point of dendritic contact with the axons of other cells
Dendritic spine
Juncture of soma and axon
Axon hillock
Branch of an axon is called
Axon collateral
Knob at the tip of an axon that conveys information to other neurons
Terminal button (end foot)
Spatial junction between one neuron and another;
Forms the information transfer site between neurons
Synapse
Cells that detects or carries sensory information into the spinal cord and the brain;
Simplest structurally
Sensory neurons
Sensory neuron with one axon and one dendrite
Bipolar neuron
Brain cell that bring sensory information from the body to the spinal cord (long distance)
Somatosensory neuron
Associated cell that interposed between a sensory neuron and a motor neuron;
In mammals, interneurons constitute most of the brain’s neurons
Interneuron
Distinctively shaped interneuron found on the cerebral cortex
Pyramid cell
Distinctively shaped (extremely branched forming a fan shape) interneuron found in the cerebellum
Purkinje cell
Cells that have extensive dendritic networks that carries efferent information from the brain and spinal cord to make muscle contract’
Reside in the lower brain stem and spinal cord
Motor neurons
Glial cell that makes and secretes CSF; found on the walls of the brain ventricles
Ependymal cells
Buildup of fluid pressure in the brain, and in infants, swelling of the head, if the flow of CSF is blocked;
Can result in intellectual impairment
Hydrocephalus
Mass of new tissue that grows uncontrolled and independent of surrounding structures
Tumor
Also called astroglia, these cells provide structural support to the CNS. Their extensions attach to blood vessels and to the brain’s lining, forming a scaffolding that holds neuron in place. May also serve as pathways for certain nutrients to move between blood vessel and neurons. Also contribute to healing damaged brain tissue.
Astrocytes
Tight junctions between the cells that compose blood vessels in the brain providing a barrier to the entry of an array of substances, including toxins into the brain
Blood-brain barrier
Originate in the blood as an offshoot of the immune system and migrate throughout the nervous system, where they make up 20% of all glial cells. Engulf any foreign tissue and dead brain cells through phagocytosis.
Microglia
Glial coating that surrounds axons in central and peripheral nervous system;
Preventing adjacent neurons from short circuiting
Myelin
Glial cells in the CNS that myelinate axons by sending out large, flat branches that enclose and separate adjacent axons
Oligodendroglia
Glial cells in the PNS that myelinate sensory and motor axons by wrapping itself repeatedly around a part of an axon, forming a structure somewhat like a bead on string
Schwann cells
