Structure of the Nervous System (Cranial nerves) Flashcards
Afferent
Nerves that are conducting information to a location
Anterior
Nearer the front
Arachnoid membrane
A fine, delicate membrane, the middle one of the three membranes or meninges that surround the brain and spinal cord, situated between the dura mater and the pia mater.
Brain
An organ of soft nervous tissue contained in the skull of vertebrates, functioning as the coordinating centre of sensation and intellectual and nervous activity.
Brain stem
The central trunk of the mammalian brain, consisting of the medulla oblongata, pons, and midbrain, and continuing downwards to form the spinal cord.
Caudal
At or near the tail or the posterior part of the body
Central nervous system
The complex of nerve tissues that control the activities of the body. In vertebrates, it comprises the brain and spinal cord.
Cerebellum
The part of the brain at the back of the skull in vertebrates, which coordinates and regulates muscular activity.
Cerebrospinal fluid
The clear watery fluid which fills the brains ventricles and the space between the arachnoid membrane and the pia mater.
Cerebrum
The principal and most anterior part of the brain in vertebrates, located in the front area of the skull and consisting of two hemispheres, left and right, separated by a fissure.
Choroid plexus
A network of blood vessels in each ventricle of the brain, producing the cerebrospinal fluid
Contralateral
Relating to or denoting the side of the body opposite to that on which a particular structure or condition occurs.
Coronal
Relating to the crown of the head
Cranial nerve
Each of twelve pairs of nerves which arise directly from the brain, not from the spinal cord, and pass through separate apertures in the skull.
Dorsal
On or relating to the upper side or back of an animal, plant, or organ.
Dura mater
The tough outermost membrane enveloping the brain and spinal cord.
Efferent
Nerves that are conducting information from a location
Ipsilateral
Belonging to or occurring on the same side of the body
Lateral
Of, at, towards, or from the side
Lymphatic system
The network of vessels through which lymph drains from the tissues into the blood.
Medial
Situated in the middle
Meninges
The three membranes (the dura mater, arachnoid, and pia mater) that line the skull and vertebral canal and enclose the brain and spinal cord.
Midline
A median line or plane of bilateral symmetry, especially that of the body.
Midsagittal plane
The median vertical longitudinal plane that divides a bilaterally symmetrical animal into right and left halves — called also median plane.
Pia mater
The delicate innermost membrane enveloping the brain and spinal cord.
Posterior
Further back in position
Rostral
Situated or occurring near the front end of the body, especially in the region of the nose and mouth
Sagittal
Relating to the suture on top of the skull which runs between the parietal bones in a front to back direction.
Spinal cord
The cylindrical bundle of nerve fibres and associated tissue which is enclosed in the spine and connects nearly all parts of the body to the brain, with which it forms the central nervous system
Ventral
On or relating to the underside of an animal or plant; abdominal
Ventricular system
A set of four interconnected cavities (ventricles) in the brain
Human nervous system
CNS and PNS
Peripheral nervous system
- Somatic nervous system
- Autonomic nervous system
Fundamental life processes
- Breathing
- Organ function
- Movement
Complex processes
- Thought
- Behaviour and emotion
- Creating memories
Forebrain
o Telencephalon (or cerebrum) o Diencephalon
Brainstem
o Midbrain
o Pons
o Medulla oblongata
Major brain regions
Forebrain
Brainstem
Cerebellum
Anterior-posterior
o Anterior = Front
o Posterior = behind
Rostral - caudal
o Rostral = ‘Nose’
o Caudal = ‘Tail’
Dorsal-ventral
o Dorsal = top
o Ventral = bottom
Superior-inferior
o Superior = above
o Inferior = below
Coronal
o Divide the brain into a front (anterior) and a back (posterior) section
Horizontal
o Divide the brain into an upper (superior) and lower (inferior) section
Sagittal
o Divide the brain into two hemispheres
o Further characterized as midsagittal (midline) or parasagittal (more lateral)
Hippocampus
The hippocampus (derived from the Greek for “seahorse”) is a region of the cerebral cortex embedded deep within the temporal lobe.
Function of hippocampus
- Learning
- Memory formation and retrieval
- Regulation of hypothalamus-pituitary-adrenal (HPA) axis
Coronal sections
Coronal sections can reveal important regions within the forebrain, including various sub-cortical structures (e.g. the hippocampus
Horizontal sections
Horizontal sections can reveal important regions within the forebrain, including various sub-cortical structures (e.g. the hippocampus)
Sagittal sections
Sagittal sections can reveal important regions within the forebrain, including various sub-cortical structures (e.g. the hippocampus)
Cranial nerves 1
Olfactory
Special sensory – the sensation of smell
Cranial nerves 2
Optic
Special sensory – the sensation of vision
Cranial nerves 3
Oculomotor
Somatic motor – eye and eyelid movement
Visceral (autonomic) motor – parasympathetic control of pupil size
Cranial nerves 4
Trochlear
Somatic motor – eye movement
Cranial nerves 5
Trigeminal
Somatic sensory – the sensation of touch to the face
Somatic motor – a movement of muscles of mastication (chewing)
Cranial nerves 6
Abducens
Somatic motor – eye movement
Cranial nerves 7
Facial
Somatic sensory – movement of muscles of facial expressions
Special sensory – the sensation of taste in the anterior tongue
Cranial nerves 8
Vestibulocochlear
Auditory – vestibular (vestibulocochlear) nerve
Special sensory – hearing and balance
Cranial nerves 9
Glossopharyngeal
Special sensory – the sensation of taste in posterior tongue
Visceral sensory – detection of blood pressure changes in the aorta
Somatic motor – the movement of muscles in the throat
Visceral motor – parasympathetic control of salivary glands
Cranial nerves 10
Vagus
Visceral sensory – the sensation of pain associated with viscera (internal organs)
Somatic motor – the movement of muscles in the throat
Visceral motor – parasympathetic control of heart, lungs and abdominal organs
Cranial nerves 11
Spinal accessory
Somatic motor – the movement of muscles in the throat and neck
Cranial nerves 12
Hypoglossal
Somatic motor – movement of the tongue (e.g. swallowing and speech)
3 protections/ support for the brain
Meninges
Ventricular system
Vasculature system
Meninges
The meninges describe the three membranous layers that cover the brain (and spinal cord).
Function of meninges
- Primary function is in the protection of the brain and spinal cord
- Passage of cerebrospinal fluid (CSF) – ventricular system
- Support of cerebral and spinal blood vessels – vasculature system
From superficial to deep the meninges comprises of?
- Dura mater
- Arachnoid mater
- Pia mater
Ventricular system
The ventricular system comprises a series of interconnected, cerebrospinal fluid (CSF)-filled spaces that lie at the core of forebrain and brain stem.
What makes up the ventricular system?
- Lateral ventricles
- Third ventricle
- Fourth ventricle
What is the choroid plexus?
Responsible for producing the cerebrospinal fluid (CSF) that fills these ventricular spaces
The function of Ventricular system?
- Protection of the brain (e.g. cushion for physical shocks)
- Transport (e.g. nutrients, waste products)
- Other functions include regulation of buoyancy
Vasculature of the brain
Two pairs of arteries supply blood to the brain: the internal carotid arteries and the vertebral arteries.
Anterior circulation
Derived from the internal carotid arteries – supplies the forebrain (cerebrum and diencephalon)
Posterior circulation
Derived from the vertebral arteries – supplies the brainstem, cerebellum and upper spinal cord
Vertebral arteries
Vertebral arteries converge near the base of the pons to form the basilar artery
Basilar artery
Basilar artery splits into the right and left superior cerebellar arteries and the posterior cerebral arteries at the level of the midbrain
Posterior cerevral arteries
Posterior cerebral arteries send branches – posterior communicating arteries – that connect to the internal carotid arteries
Internal carotid arteries
- Internal carotid arteries branch to form middle cerebral arteries and the anterior cerebral arteries
- Anterior cerebral arteries are connected by the anterior communicating artery
- Ring of connected arteries form the circle of Willis at the base of the brain
The function of the vasculature stem
- Delivery of oxygen (O2)
- Removal of carbon dioxide (CO2)
- Transport (e.g. nutrients, waste products)
