Anatomy, Physiology And Neuroanatomy Flashcards
What is the space between neurons in which information is passed?
Synapses
What is the basic structural and functional unit of the nervous system?
The neurons.
The neuron is a single cell body from which a variable number of branching processes emerge. What are these called and what is their function?
Dendrites.
They generally receive messages.
What is the function of an axon?
The axon carries away information from the cell body of the neuron.
What is the resting membrane potential across the membrane neuron?
60 - 70 millivolts.
And what way does transmission of information between neurons almost always occur?
Transmission of information is almost always chemical rather than electrical.
Other than Neurons what other type of cell composes the other major cellular component of the nervous system?
Neuroglia / glia cells
What three main types of neuroglia are recognized?
- Oligodendrocytes
- Astrocytes
- Microglia
What is he function of Oligodendrocytes?
They form the myelin sheath which surrounds many neural axons.
What is the function of Astrocytes?
They form a selectively permeable barrier between the circulatory system and neuron of the brain and spinal cord.
What is the function of Microglia?
They play a phagocytic role in response to damage within the nervous system.
What type of neural cell forms the protective blood-brain barrier?
Astrocytes
What are the two main subdivisions of the nervous system?
Central nervous system (CNS) and the Peripheral nervous system (PNS)
The CNS is composed of what?
The brain, spinal cord, and the majority of nerve cell bodies and synaptic connections.
What does the PNS consist of?
Nerves joined to the brain, spinal cord, and their other ramifications within the body.
What is the autonomic nervous system?
The system that detects and controls change within the body.
Where is the autonomic nervous system located?
It’s components are found throughout the CNS and PNS.
What are the two main divisions of the autonomic nervous system?
- Sympathetic
2. Parasympathetic
What are afferent neurons?
They carry information from peripheral receptors to the CNS.
What are sensory neurons?
They are that carry information which will reach a conscious level.
What are efferent neurons?
They carry away impulses from the CNS.
What are the areas of the brain that are enriched with nerve cell bodies?
Grey matter
What are the regions of the brain that are primarily composed of nerve processes that are often myelinated called?
White matter
During embryonic development what cell layer give rise to the nervous system?
The ectoderm
During embryonic development what does the mesoderm form?
Skeletal, muscle and connective tissue.
In regards the the nervous system, what happens during the third week of embryonic development?
The dorsal midline of the ectoderm undergoes thickening to form the neural plate. The lateral margins of the neural plate become elevated, forming the neural folds and along the midline depression the neural groove forms. The neural folds fuse together forming the neural tube.
During the 5th week of embryonic development what three primary brain vesicles can be distinguished?
- Prosencephalon (forebrain)
- Mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
During embryoni development when does the first bend occur in the developing CNS?
The first bend occurs in the 5th week in between the mid rain nd forebrain.
During the 7th week of embryonic development what further differentiation occurs during neural development?
The prosencephalon develops into the telencephalon and diencephalon.
The rhombencephalon develops into the metencephalon and myelecephalon.
During embryonic development the telencephalon gives rise to what structure in the mature brain?
The cerebral hemispheres.
During embryonic development the diencephalon gives rise to what structure in the mature brain?
The Thalamus.
During embryonic development the mesencephalon gives rise to what structure in the mature brain?
The Midbrain.
During embryonic development the metencephalon gives rise to what structure in the mature brain?
The Pons and Cerebellum.
During embryonic development the myelecephalon gives rise to what structure in the mature brain?
The Medulla Oblongata.
What structures surround the brain?
The skull and the 3 meninges.
Name and discribe the layers that surround the brain.
The outer most layer is called the dura matter. It is a tough fibrous coat that surrounds the brain like a loose fitting bag.
The dura is separated from the next meninge by the subdural space.
The middle layer is called the arachnoid mater. It is a translucent, collagenous membrane that loosely surrounds the brain and spinal cord.
The arachnoid mater is separated from the next meninge by the subarachnoid space though which the cerebral spinal fluid (CSF) circulates.
The inner most layer is called the pia mater. It is a delicate membrane of microscopic thickness that is firmly adherent to the surface of the brain and spinal cord.
Define anastomose.
It is when two structures split and then rejoin together.
What arteries supply the brain with blood?
The internal carotid and vertebral arteries.
Which two arteries anastomose to form the circle of Willis?
The cardioid and vertebral arteries.
What is the most significant intracranial artery?
The middle meningeal artery.
Where is the spinal cord located?
Within the vertebral canal of the spinal column.
How many pairs of spinal nerves are there?
31 pairs.
Discribe the function of the spinal cord.
It receives information from and controls the trunk and limbs of the body.
In psychophysics what does the term threshold refer to?
The amount of stimulus that is needed for the sensory system to elicit a behavior response.
What factors affect perception and sensitivity to a stimulus?
- Prior stimulation can decrease the sensitivity to a sensory system because of ADAPTATION or FATIGUE.
- Simultaneous presentation of stimuli can also increase the threshold to stimulation known as MASKING.
- Threshold of detection decreases as the duration of the stimulus is increased- known as TEMPORAL INTEGRATION.
- stimulation of a large number of receptors may decrease the threshold because of SPATIAL INTEGRATION.
- Faint stimuli detection depends on CRITERIA FOR DETECTION and HOW and WHERE the stimulus is measured.
The dependence of the threshold of sensory systems on prior stimulation is known as what?
adaptation
What is the body’s most complex bony structure?
Skull
How many bones does the skull contain?
22
Name the 4 major sutures of the skull.
- Coronal
- Sagittal
- Squamous
- Lambdoid
