Neurosensory (2) Flashcards
What are the cells of the Central nervous system?
Ependymal cells
Oligodendrocytes
Astrocyte
Microglia
What are ependymal cells?
- Line ventricles in the brain and the central canal in the spinal cord
- Assist in producing, circulating and monitoring of the CSF
What are Oligodendrocytes?
- Myelination of central nervous system axons (equivalent of schwann cells in PNS)
- Provide structural framework
What are Astrocytes?
Maintain the blood-brain barrier and provide structural support
- Regulate ion, nutrient and dissolved gas concentrations as well as absorbing and recycling neurotransmitters
- Form scar tissue after injury
What are Microglia?
- Removes cell debris, wastes and pathogens by phagocytosis
Functions of the frontal lobe?
- Movement of the body
- Personality
- Concentration & planning
- Problem solving
- Meaning of words
- Emotional reactions
- Speech
- Smell
Functions of the parietal lobe?
- Touch and pressure
- Taste
- Body awareness
- Visual
- Spatial processing
Functions of the occipital lobe?
- Vision
Functions of the cerebellum?
- ‘Little brain’
- Fine motor control
- Balance
- Coordination
Functions of the temporal lobe?
- Hearing
- Recognizing faces
- Emotions
- Long term memory
- Visual analysis
What is broca’s area?
- Production of speech
- Frontal lobe of the left hemisphere
- Responsible for precise control of the mouth and laryngeal muscles
- If damaged, the patient is still fully able to understand language.
- However they cannot form words properly and speech may be slow or slurred
- Patients often get frustrated with this
What is Wernicke’s area?
- Understand speech
- Left temporal lobe
- Responsible for understanding of written and spoken language
- If damage, the patient may not be aware of their own or other peoples speech
- Or they may put words together that don’t make sense
What is the Motor association area/Pre-motor cortex?
- Occupies Brodmann’s area 6
- Located immediately anterior to the primary motor cortex
- Plays a role in planning and anticipating specific motor acts
- ‘Mental rehearsal of movements’ before performing a complex function
What is the Primary motor cortex?
- Highest level of motor function
- Function is the action of precise, skillful and intentional movements
- The regions of the motor cortex mirror the regions of the body (homunculus)
- The regions of the body that require more precise control occupy larger regions of the motor cortex
What is the Sensory association area?
- Lies immediately posterior to the primary somatosensory cortex
- Functions to integrate different sensory inputs (eg: touch and pressure)
- Draws upon stored memories of past sensory experiences
What is the Primary sensory cortex?
Located on the postcentral gyrus
- Receives information about the body sensation (ie: touch)
- The area of the cortex relates to the sensitivity of the body part (homunculus)
What is the Visual cortex?
- Located in the occipital lobe
- Highly specialized for processing information about static and moving
objects - Excellent at pattern recognition
- Further divided into special regions to process colour, space, depth, texture and motion
What is homunculus?
- A cortical homunculus is a distorted representation of the human body
- The homunculus allows us to say ‘how much’ of the cortex relates to each body part
Names of the things that can go wrong in the brain?
Aphasia Agnosia Alexia Agraphia Ataxia Apraxia
What is Aphasia?
Impairment of the language affecting the production or comprehension of speech, reading and writing (several types – Broca’s, Wernicke’s, Conduction)
What is Agnosia?
Inability to interpret sensations and hence the inability to recognise things
What is Alexia?
Disorder of reading
What is Agraphia?
Disorder of writing
What is Ataxia?
Lack of voluntary coordination of muscle movements including a gait abnormality
What is Apraxia?
Difficulty with motor planning and performance of a task/movement
What roles does the midbrain have?
Vision, hearing, eye movement and body movement
What roles does the pons have?
Involved in motor control and sensory analysis
What roles does medulla oblongata?
Vital body functions such as heart rate and respiratory rate
What s the diencephalon made up of?
Hypothalamus
Thalamus
Hormones in the hypothalamus:
The hormones from the hypothalamus govern physiologic functions such as temperature regulation, thirst, hunger, sleep, mood, sex drive, and the release of other hormones within the body
What is the thalamus?
The thalamus is a small structure within the brain located just above the brain stem between the cerebral cortex and the midbrain and has extensive nerve connections to both. The main function of the thalamus is to relay motor and sensory signals to
the cerebral cortex.
What is the Limbic system?
- Set of brain structures located on both sides of the thalamus, inferior to the cerebrum
- Made up of the hippocampus, amygdala, fornix, cingulate gyrus,
anterior thalamic nuclei, olfactory bulbs and mammillary body
What is the limbic system involved in?
motivation, memory, learning and emotion
What is the hippocampus?
- Hippocampus allows us to lay down new memories
What is the amygdala?
- Located deep in the medial temporal lobe
- Receives highly processed information
- Responsible for emotional
membrane - Produces instinctive emotional output
Your working memory is……
prefrontal cortex (short term, few seconds)
Your long term memory is……
Explicit memory (declarative = episodic and semantic) + implicit (skills = cerebellum) (conditioned reflexes = cerebellum) (emotion - amygdale)
Episodic =
things we know day to day (how was your first day at work)
Semantic =
things we just know (ie: what is a city)
Consciousness =
The state of being aware of and responsive to one’s surroundings
What is the Blood Brain Barrier made up of?
Astrocyte foot processes and tight junctions
What is the Blood Brain Barrier?
- A semipermeable membrane separating the blood from the cerebrospinal fluid,
and constituting a barrier to the passage of cells, particles and large molecules - The BBB prevents many harmful substances passing to the brain, but it is useless
against: Alcohol, nicotine, anaesthesia, fat soluble molecules - Overall, it aims to maintain a constant environment for the brain
What is cauda regions?
Bundles of nerves the spinal cord terminates in.
Grey matter:
Unmyelinated, cell bodies and dendrites, synapses
White matter:
Myelinated, divided into columns and tracts
Both the brain and spinal cord are heavily protected by :
the bone, adipose
tissue, meninges and liquid cushion (CSF)
The 3 layers of meninges
are:
- Dura mater
- Arachnoid mater
- Pia mater
CSF is also present in____
brain ventricles and the central canal of the spinal cord
What are the cells in the peripheral nervous system?
Satellite cells
Schwann cells
Satellite cells:
- Surround neuron cell bodies in the ganglia
- Regulate O2, CO2, nutrient and neurotransmitter levels around neurons in
the ganglia
Schwann cells:
- Surround axons in the PNS, and are responsible for myelination of peripheral nerves (equivalent of oligodendrocytes in the CNS)
- Participate in repair process after injury