M2 Topic 6: Central Nervous System Flashcards
(37 cards)
What is the CNS composed of?
Brain and spinal cord
What is the main role of the CNS?
Receive, integrate, and send information using neurons
What are the two types of matter that make up the CNS?
- Grey matter
- White matter
Grey matter
Cortex (outer layer, cell bodies)
- Nuclei and cell bodies of neurons
- Processing area
White matter
Subcortex (inner layer, axons)
- Axons (myelin)
- Transmission area
What is a sulcus?
Grooves in the brain
What is a gyrus?
Ridges in the brain
What are the four main structures in the brain?
- Cerebrum
- Cerebellum
- Diencephalon
- Brainstem
Cerebrum
Located on outer surface of brain, responsible for thinking, motor/sensory functions, executive functions
Cerebellum
Located at back of brain, responsible for balance, motor coordination (e.g. smooth movement)
Diencephalon
Located in middle of brain, responsible for relaying sensory information, autonomic & endocrine control
Consists of 4 main parts…
- Thalamus = relays sensory info to cortex
- Hypothalamus = controls ANS and hormone secretion
- Epithalamus = connects emotions to other parts of brain
- Pineal gland = regulates sleep cycle
Brain stem
Located at bottom of brain, responsible for keeping you alive, autonomic functions (e.g. breathing)
3 main parts…
- Midbrain = eye movement, relay signals for hearing, seeing reflexes
- Pons - relay station, coordinates control for breathing
- Medulla = controls involuntary functions, breathing, blood pressure, swallowing, vomiting
The cortex
Uppermost part of brain is called cerebrum, outer layer of cerebrum is called the cortex
- Brain ‘controls’ opposite side of body (with some exceptions)
- Right brain gets info and sends to left side
- Complex with visual system
4 main parts (lobes) of the cortex
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
Named after bones of cranium that overlie them
Frontal lobe
Primary motor cortex
- Motor function, executive functions
Parietal lobe
Primary sensory cortex
- Integration of sensory information
Temporal lobe
Primary auditory cortex
- Integration of auditory information, hearing, memory
Occipital lobe
Primary visual cortex
- Integration of visual information, sight
What protects the CNS and brain tissue?
- Meninges (membranes)
- Cerebrospinal fluid (CSF)
- Blood-brain barrier (BBB)
Meninges (membranes)
3 membranes that surround the brain…
- Dura matter (hard, outer layer)
- Arachnoid matter (spider-web like, middle layer)
- Pia matter (delicate, tender, inner layer
Ventricles of the brain
Ventricles in the brain is a fluid filled space filled with cerebrospinal fluid
- Lateral ventricles (1 and 2)
- 3rd and 4th ventricles extend through brain stem and connect to central canal that runs through spinal cord
Cerebrospinal fluid (CSF)
Clear, watery fluid that flows in and around brain and spinal cord
- Cushions and nourishes brain
- Secreted into ventricles and flows in subarachnoid space
- Contain modified ependymal cells called the choroid plexus, makes CSF by transporting water, ions, vitamins and nutrients from blood
- CSF reabsorbed into blood at projections called the arachnoid villi
Glial cells (neuroglia/nerve glue) in the CNS
Do more than glue neurons, have other important functions
- Outnumber neurons almost 10 to 1
- 6 types, 4 in CNS, 2 in PNS
Types of glial cells in the CNS
- Astrocytes
- Microglial cells
- Oligodendrocytes
- Ependymal cells
