Intro to the Nervous System Flashcards
What are the 4 components of the human nervous system?
- Brain
- Spinal Chord
- Nerves
- Ganglia
What do the Glia cells do?
They are support cells that transfer nutrients to neurons.
What are the three main parts of the neuron?
- Dendritric tree
- Cell body
- Axon
What is the Axon?
The appendage of the cells along which information is carried.
What are sensory neurons?
Neurons that bring information to the CNS.
What are interneurons?
Neurons that associate info within the nervous system.
What are motor neurons?
Neurons that send info from the brain and spinal chord to the muscles.
What are the 4 main jobs of glia cells?
- They transfer nutrients to the neurons.
- They help repair damage to the nervous system, removing dead neurons.
- They guide neurons from production site to final position.
- They maintain the blood brain barrier.
What are the anatomical names for the front of the brain?
Anterior/Rostral
What are the anatomical names for the back of the brain?
Posterior/Caudal
What are the anatomical names for the top of the brain?
Superior/Dorsal
What are the anatomical names for the bottom of the brain?
Inferior/Ventral
Coronal View:
When the brain is sliced from ear to ear - separating front from back.
Horizontal View:
When the brain is sliced, separating top and bottom.
Sagittal View:
When the brain is sliced into left and right hemispheres.
What does cerebrospinal fluid do?
It cushions the brain. The fluid is found in ventricles along the spine and the skull. Nutrients from the blood reach nerve cells through CSF.
What do the cells in the dorsal section of the spine do?
They receive sensory info - from the body to the brain.
What do the cells in the ventral section of the spine do?
They convey motor info - from the brain to the body.
Where is the medulla?
It’s directly superior to the spinal chord.
4 main functions of the medulla:
- It contains cell bodies of the 12 cranial nerves, meaning it receives sensory info and motor control of the head and organs.
- It is the point where the motor fibres cross contralaterally.
- It controls vital functions such as respiration and heart rate.
- It is home to the Reticular Activating System, which is important in arousal, attention and sleeping cycles.
What does the Cerebellum do?
It controls fluid movement.
Where is the Pons?
Superior to the medulla and anterior to the cerebellum. It is the main connective bridge between the cerebellum and the rest of the brain.
What does the Pons do?
It is a point of synapse for some cranial nerves, acting as a centre for control for certain eye movements and balance.
Where is the Superior Olive and what does it do?
It’s in the pons, and it processes auditory information, allowing for comparison of info received from both ears.
Where is the midbrain?
Superior to the pons.
What is in the midbrain?
The inferior and superior colliculi.
What does the inferior colliculus do?
It controls the reflexive movements of the head and eye in response to sound.
What does the superior colliculus do?
It controls perception and orientation toward large moving objects in the periphery of our vision.
What is Foveation?
When our eyes are guided to a large object so that it lies in the centre of our vision.
What does the Hypothalamus do?
It maintains homeostasis - influencing target organs and secreting hormones.
What does the Thalamus do?
It’s essentially a relay centre for the brain - it takes in sensory info and sends it off to the part of the brain it needs to be in.
What’s the name for the Thalamus and the Hypothalamus?
The Diencephalon.
What does the Basal Ganglia do?
It controls motor movement and involuntary movement.
What does the Basal Ganglia consist of?
Caudate nucleus, putamne and globus pallidus.
What does the limbic system consist of? (6 parts)
- The amygdala
- The hypothalamus
- The hippocampus
- The cingulate cortex
- The anterior thalamus
- The mammillary body
What are gyri?
Convolutions packing more brain tissue into smaller space.
What are the valleys between gyri called?
Sulci, or if they’re deep they’re called fissures.
What does the central fissure do?
It separates the left and right hemisphere.
What section of the brain, in relation to the central fissure, controls motor processing?
The area in front of the central fissure.
What does the area behind the central fissure do?
Sensory processing.
What does the Sylvian fissure do?
It separates the dorsal and ventral sections of the brain.
What is the area below the Sylvian fissure?
The Temporal Lobe.
Which area is first to receive info about a sensory modality?
Primary sensory cortex.
What is the final exit point for neurons responsible for fine motor control?
Primary motor cortex.
In what manner is the body mapped on the brain?
Upside down and backward.
Where is the primary motor cortex?
Directly in front of the central fissure.
What happens if you damage your motor cortex?
Muscle weakness on the contralateral side of the body and loss of independent muscle movement.
What is Hemiplegia?
Massive unilateral destruction to the motor strip along with damage to the basal ganglia - leading to paralysis on the contralateral side of the body.
Where is the primary somatosensory cortex?
Directly posterior to the central fissure.
What three functions does the somatosensory cortex have?
- It receives info about tactile stimulation.
- It controls proprioception.
- It receives pressure and pain sensations from internal organs and muscles.
What is proprioception?
The perception of the body parts and their movements.
How is the body mapped onto the primary somatosensory cortex?
Left to right and bottom to top.
What happens when the somatosensory cortex is damaged?
It impairs discrimination of touch on the opposite side and phantom limb pain.
What 3 parts make up the frontal lobe?
Primary motor region, premotor region and prefrontal region.
What 3 regions make up the prefrontal region? And what are each of these regions responsible for?
- Dorsolateral - memory and attentional processing.
- Orbital - emotional processing.
- Medial - judgement, decision making and detection of errors.
What does the Parietal lobe do?
It integrates information from various sensory modalities.
What is Apraxia?
The inability to link skilled motor movement to ideas and representations.
What does the Temporal lobe do? (4 functions)
- Memory
- Visual item recognition
- Auditory processing
- Emotion
