Central Nervous System Flashcards
Layers of the scalp
Skin Connective tissue Aponeurosis Loose areolar tissue Periosteum
Divisions of nervous system
PNS and CNS
PNS
→ Cranial nerves
→ Spinal nerves
CNS
→ Brain
→ Spinal cord
(Processing sensory data and sending motor commands
Higher functions such as intelligence, memory, learning and emotion)
Divisions of PNS
PNS
→ Somatic nervous system
→ Autonomic nervous system
→ Parasympathetic/Enteric/Sympathetic
Parasympathetic vs Sympathetic
What connects the 2 cerebral hemispheres?
Corpus callosum
What increases surface area on the brain surface?
Highly convoluted: to increase surface area
Gyri (gyrus, singular): convolutions
Sulci (sulcus, singular): Creases
Location of grey and white matter in the brain
What are the different lobes of the brain and their function?
Temporal Frontal Parietal Cerebellum Occipital
Longitudinal fissure (between the two cerebral hemispheres)
Cerebellum
The cerebellum is concerned with balance, muscular co-ordination and dexterity
- Outer layer of grey matter
- Inner layer of white matter
- Highly convoluted
Brainstem
The brain stem is critical for normal conscious awareness and basic “life support” functions (e.g. control of breathing and blood pressure).
Contains ascending and descending nerve fibre tracts linking brain to spinal cord
Receives sensory and motor information from trunk and limbs
Spinal cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column.
It terminates approximately at the level of L1, from there a series of spinal nerves branch off to form a structure called “cauda equina”, which means “horse’s tail”
Describe the meninges
The meninges form a protective barrier that safeguards the sensitive organs of the central nervous system. They contain blood vessels that deliver blood to the brain and they produce cerebrospinal fluid. This fluid protects and nourishes the brain tissue by acting as a shock absorber, by circulating nutrients, and by getting rid of waste products.
Dura Mater
The dura mater is the outermost layer. Located between the periosteal and meningeal dura mater are channels called dura venous sinuses. These venous sinuses drain blood from the brain to the internal jugular veins, where it is returned to the heart.
Arachnoid Mater
The arachnoid mater is the layer underneath the dura. The subarachnoid space contains arachnoid trabeculae, which connect the pia with the arachnoid. In between the trabeculae there are blood vessels and nerves that supply the brain. The subarachnoid space also contains cerebrospinal fluid (CSF). Arachnoid granulations are extensions of the arachnoid mater into the dura mater. The CSF flows from the granulations into the dura, to be reabsorbed in the dural sinuses.
Pia mater
The pia mater is the inner layer that cover the brain. The pia mater has a rich supply of blood vessels, which provide nutrients to nervous tissue.