Principles of neuroanatomy Flashcards
What are the 3 principal planes?
Sagittal, coronal, transverse
What are the different positional and directional terms?
Rostral - towards the head Caudal - towards the tail Anterior - front Posterior - back Lateral - side Medial - middle Dorsal - back Ventral - belly
What does the central nervous system consists of?
Brain and spinal cord, lying within the cranium and vertebral column.
What does the peripheral nervous system consist of?
Nerves joined to the brain and spine - cranial and spinal nerves
What are spinal nerves to the lower limbs called?
Lumbar plexus
What are spinal nerves to the upper limbs called?
Brachial plexus
What are nerve cell bodies located peripherally called?
Ganglia
What is the function of the autonomic nervous system?
Detect changes in and control the activity of internal organs, smooth muscle, cardiac muscle, glands etc…
What is the function of the somatic nervous system?
Detects changes in the environment and controls movement
What are the two functionally and anatomically distinct parts of the autonomic nervous system?
Sympathetic and parasympathetic.
What are afferent neurones?
Neurones that carry signals from peripheral receptors to the CNS.
What are sensory neurones?
If the information carried by afferent neurones reaches consciousness then it is also a sensory neurone.
What are efferent neurones?
Neurones that carry impulses aay from the CNS.
What are motor neurones?
Efferent neurones that innervate skeletal muscle to cause movement.
What are interneurones?
Neurones located entirely within the CNS.
How are afferent and efferent used within the CNS?
Afferent and efferent mean entering and leaving structures within the CNS. They denote the polarity of projections from structure in the CNS. Projections entering the cerebral cortex for example are cortical afferents.
What are the bony coverings of the CNS called?
Skull (brain) and vertebral column (spine)
What are the three concentric layers of membranes covering the CNS called?
The meninges
What are the 3 layers of the meninges from outside to in?
Outermost layer is the dura mater.
Middle layer is the arachnoid mater.
Innermost layer is the pia mater.
What is the dura mater?
The outermost membrane of the meninges, It is a tough fibrous coat that surrounds the brain and spinal cord.
What are the two sheets of dura that divide the cranial cavity into compartments called?
The falx celebri which lies in the sagittal plane between the two cerebral hemispheres.
The tentorium cerebelli lying beneat the occipital lobes of the cerebral hemispheres and above the cerebellum.
The tentorium cerebelli is continuous with the posterior part of the falx cerebri.
Where does venous drainage of the brain occur?
The cranial dura mater contains dural venous sinuses where the two layers of the dura mater are sepearated.
What are important locations of the dural venous sinuses?
On the floor of the crainial cavity.
Along the lines of attachment of the falx cerebri and tenotorium cerebelli to the interior of the skull and to each other.
What is the arachnoid mater?
Layer of meniges just below the dura separated by a thing dubdural space. It is a translucent, collagenous membrane that loosely envelops the brain and spinal cord.
What is the pia mater?
The pia mater is a delicate membrane of microscopic thickness that is firmly stuck to the surface of the brain and spinal cord, closely following their surface contours.
What is between the arachnoid and pia mater?
The subarachnoid space through which cerebrospinal fluid circiulates.
How is the brain supplied with arterial blood?
Supplied by the internal carotid and vertebral arteries which link to the form the circle of Willis on the base of the brain.
How is the spinal cord supplied with arterial blood?
Supplied by blood vessel that arise from the vertebral arteries reinforced by radicular arteries.
What are the ventricles of the brain?
A communicating network of cavities filled with cerebrospinal fluid.
What is the ventricular system composed of?
2 lateral ventricles
The third ventricle
The cerebral aqueduct
The fourth ventricle
What secretes cerobrospinal fluid?
The choroid plexus
What are the main features and landmarks in the brain?
- The cerebral cortex - outer mantle of grey matter
- Inner core of white matter
- The great longitudinal fissure which is a deep cleft that separates the cerebral hemispheres.
- The corpus callosum that lies within the great longitudinal fissure and contains comissural nerve fibres that run between the two hemipsheres.
- The brainstem which is the origin of 10 of the 12 pairs of cranial nerves (nerves 3-12).
- Behind the brainstem is the cerebellum
Cranial nerve 1
Olfactory (smell)
Cranial nerve 2
Optic (vision and pupil light reflex)
Cranial nerve 3
Oculomotor (eyelid movement, elevation and abduction of eye, depression during abduction of eye)
Cranial nerve 4
Trochlear (intorsion and depression of eye during adduction of eye)
Cranial nerve 5
Trigeminal (masticiation and sensations from face, teeth and sinuses)
Cranial nerve 6
Abducens - abduction of eye
Cranial nerve 7
Facial - movement of muscles associated with facial expression, and taste
Cranial nerve 8
Vestibulococholear (Sense of hearing and balance)
Cranial nerve 9
Glossopharnygeal - Movement of the stylopharyngeus muscle and sense of taste
Cranial nerve 10
Vagus - Movement of vocal muscles, sensory from pharynx and larynx, parasympathetic innervation of GI tract, heart and lungs.
Crainial nerve 11
Accessory - Movement of sternocleidomastoid and trapezoid
Cranial nerve 12
Movement of tongue muscle
