The Nervous System Flashcards
The nervous system divides into:
The peripheral and central nervous system
The central nervous system consists of:
the brain and the spinal cord
The peripheral nervous system consists of
- Somatic Nervous System
- Autonomic Nervous System
The autonomic nervous system consists of
- Sympathetic nervous system
- Parasympathetic nervous system
3 main parts of the brain
- Cerebrum
- Cerebellum
- Brain stem
Subparts of the cerebrum (2)
- Telencephalon
- Diencephalon
Subparts of the brain stem (3)
- Mid brain
- Pons
- Medulla oblongata
The brain boasts three poles:
- Frontal pole
- Temporal pole
- Occipital pole
Telencephalon
- largest and most recently evolved area of the brain
- shaped like a boxing glove
- divided into left and right hemisphere by sagittal fissure
Horizontal fissure
- separates the telencephalon from the cerebellum
- has a lateral fissure which separates the temporal lobe from the upper part of the cerebrum
Frontal lobe
Parietal lobe
Occipital lobe
Occipital lobe
Temporal lobe
The cortex
- the outer covering of the hemisphere
- has many folds
Pre-central sulcus
Central sulcus
Post-central sulcus
Pre-central gyrus
Post-centrl gyrus
Lateral sulcus
Components of the diencephalon (4)
- thalamus
- hypothalamus
- subthalamus
- epithalamus
Thalamus
a large nucleus located on both sides of the third ventricle; it is the main sensory nucleus of the brain handling every sense apart from smell
Hypothalamus
situated below the thalamus and connected directly to the pituitary gland, which hangs from it
Subthalamus
a small nucleus located below the thalamus
Epithalamus
another small nucleus located below the thalamus
Cerebrum
Midbrain
Diencephalon
Pons
Medulla
Spinal cord
Cerebellum
Lateral ventricles
Caudate nucleus of the basal ganglia
Lentiform nucleus of the basal ganglia
3rd ventricle
Internal capsule
Thalamus
Corpus callosum
Grey matter of the cerebrum contains:
the cell bodies of the neurons (nerve cells)
Basal ganglia (3)
- Lentiform nucleus
- Caudate nucleus
- Amygdala
Spinal cord
Medulla
Pons
Midbrain
3rd ventricle
Corpus callosum
Parieto-occipital sulcus
Calcarine sulcus
4th ventricle
3 types of fibers of white matter
- Association fibers
- Commissural fibers
- Projection fibers
Association fibers
are for communication within one hemisphere and can be long, short, or intermediate
Commissural fibers
are for communication between the hemispheres
3 sets of commisural fibers in the brain
- the small anterior commissure
- the tiny posterior commissure
- the huge corpus callosum
Projection fibers
- communicate between different levels of the nervous system
- pass from one level of the nervous system to another
Describe the pathway fibers of the Pyramidal tract take
fibers pass from the motor cortex, down through the internal capsule, through the cerebral peduncles, through the pons and medulla to the spinal cord and eventually to the spinal level of their target tissue
The midbrain has two large fiber bundles
- anteriorly the cerebral peduncles
- posteriorly the paired superior and inferior colliculi
Pons
bridges the cerebellar hemispheres
Medulla oblangata
- continuous with the spinal cord
- on the anterior sureface are the paired pyramids medially and the olives laterally
Cerebellum
- responsible for coordination
- its main connection to the brain stem is via the large middle cerebellar peduncles
Cerebellum
Inferior colliculus
Superior colliculus
Midbrain
Mammillary body
Oculomotor nerve
Pons
4th ventricle
Central canal
Medulla
Spinal cord
Cervical enlargement
Lumbar enlargement
Conus medullaris
Filum terminale
Cauda equina
The spinal cord extends in the ___________ from the __________ down to _____
- vertebral canal
- foramen magnum
- L 1/2
Ventral root
Spinal nerve
Dorsal root ganglion
Dorsal root
Posterior horn
Intermediate horn (T1-L2)
Anterior horn
Dorsal funiculus
Ventral funiculus
Lateral funiculus
The anterior horns are responsible for:
motor function
The posterior horns are responsible for:
sensory function
The ventricular system
The CNS contains a fluid-filled system of chambers known as ventricles and ducts
Lateral ventricles
- numerically: ventricles 1 and 2
- anterior horn (in the frontal lobe)
- posterior horn (in the occipital lobe)
- inferior horn (in the temporal lobe)
- body (in the parietal lobe)
Atrium of the ventricles
- the wide posterior part of the body joining the posterior and inferior horns
- contain choroid plexuses
- filled with cerebrospinal fluid (CSF)
- connect to the third ventricle via the paired foramina of monro
Third ventricle
- thin, sagittally oriented space located between the two halves of the thalamus
- joined to the fourth ventricle by the aqueduct of sylvius which passes through the midbrain
Fourth ventricle
- diamond-shaped space between the pons and medulla in front and the cerebellum behind
- is continuous with the central canal of the spinal cord
In the fourth ventricle, CSF travels from the ____________ and _________ into the _____________.
Foramina of luschka; foramen of magendie; subarachnoid space
Anterior horn
Body
Posterior horn
Inferior horn
3rd ventricle
Foramen of munro
Aqueduct
4th ventricle
Central canal
Foramen of Monro
Lateral ventricle
4th ventricle
Central canal
Foramina of Luschka
Aqueduct
3rd Ventricle
Meninges
specialized connective tissue that encases the CNS
From outermost to innermost, they three layers of meninges are:
- Dura mater
- Arachnoid mater
- Pia mater
Dura mater
- closest to surrounding bone
- invaginates into the sagittal fissure to form the falx cerebri
- invaginates into the horizontal fissure as the tentorium cerebelli
- contains channels: the dural venous sinuses
- covers the brain and extends down the vertebral canal as far as the sacrum
- has a fat-filled space between it and the vertrebral column called the epidural space
Arachnoid mater
- contains blood vessels
- invaginates into the fissures and extends a short way into the sulci
- attaches to the pia mater in the cranial vault, creating the subarachnoid space for CSF to circulate
- is firmly attached to the dura in the vertebral column
- is connected to the pia in the verterbal column by the denticulate ligaments
Pia matter
- attached to the superficial cortex and to the outer surface of the spinal cord
- is the outer layer of the CNS
Skull
Pia
Arachnoid
Dura
Pia
Denticulate ligaments
Arachnoid
Dura
Dura
Falx cerebri
Arachnoid
Pia
Tentorium cerebelli
Skull
Epidural space
Vertebrae
Denticulate ligaments
Dural & arachnoid