The whole brain Flashcards
How many neurons in the brain?
85 billion
How many glia in the brain?
At least 85 billion
How many synapses per neuron?
1-10 thousand
The brain along with the spinal cord makes up which part of the nervous system?
Central nervous system (CNS)
What part of the nervous system makes up all nerves outside the brain and spinal cord?
Peripheral nervous system (PNS)
What are the three primary brain divisions?
Forebrain (prosencephalon)
Midbrain (mesencephalon)
Hindbrain (rhombencephalon)
What do we call the structure connecting the two hemispheres?
Corpus callosum
What are some functions associated with the hindbrain?
- connects brain to spinal cord
- deep nuclei for vital functions
- control head and neck muscles
- reticular formation for arousal
What are the three major levels of the brainstem?
- myencephalon (hindbrain)
- metencephalon (hindbrain)
- mesencephalon (midbrain)
True/false the cerebellum has more neurons than the rest of the brain combined.
How much weight of the brain does the cerebellum take up?
True
10%
Name some functions associated with the cerebellum.
- Coordination of voluntary movement
- balance
- motor learning
Name some functions associated with the cerebrum?
- Voluntary motor control
- Sensory and motor processing
- executive function
- learning
- planning
- emotion
What are the small structures visible on the medulla?
Cranial nerves
How many cranial nerves are there?
12
What major endocrine glands are located in the diencephalon?
Pineal gland
Pituitary gland
What is the function of the pineal gland?
Melatonin production,
Sleep cycle,
What is the structure and function of the pituitary gland?
Structure: neural portion(posterior) and glandular portion (anterior), midline structure under hypothalamus, in sella turcica
Function: controls other glands, lactation, stress, growth & reproduction, blood pressure
What is the structure and function of the thalamus?
Structure: lobed, comprised of interconnected nuclei.
Function: relay station for sensory info
Which thalamic nucleus processes visual info?
Lateral geniculate nucleus
Which thalamic nucleus processes audio info?
Medial geniculate nucleus
Which thalamic nucleus processes somatosensory info?
Ventroposterior nucleus
What is the myencephalon?
- Primarily axon tracts carrying info between body and brain
- Part of the hindbrain - medulla oblongata
- Controls vital functions e.g. heart rate, breathing
- contains portion of reticular formation
What is the metencephalon?
- Tracts of nerves that form part of reticular formation
- Pons-vital functions relay centre
- Cerebellum-voluntary motor control
What is the mesencephalon?
- Midbrain
- Contains tectum and tegmentum
What is the tectum and where is it located? What does it contain?
- contains superior and inferior colliculi (visual and audio orienting of attention respectively)
- Located in mesencephalon, anterior to tegmentum
What is the tegmentum and where is it located?
- periaqueductal grey matter and substantia nigra
- located in mesencephalon posterior to tectum
What is the diencephalon?
-contains thalamus and hypothalamus, limbic system, epithalamus
What is the lateral geniculate nucleus and where is it located?
- First synapse after the optic nerve leaves the eye
- in the thalamus
- visual sensory processing
What is the function of the hypothalamus?
Controls pituitary gland
What is the limbic system
- The four f’s: fighting, fleeing, feeding and reproduction
- part of the diencephalon
- seat of emotion
- Contains amygdala, hippocampus, thalamus, hypothalamus, basal ganglia and cingulate gurus
What is the tencephalon
It is the cerebrum (see cerebrum card)
What are the basal ganglia?
- group of nuclei lying deep in the subcortical white matter of the frontal lobes
- organising motor behaviour and coordinated, rule based habit learning
What is grey matter?
Most of the brain’s neural cell bodies
What is white matter?
Most of the brain’s axons
What disease is linked to basal ganglia damage
Parkinson’s disease
What are sulci and gyri?
Sulci-valleys in cortex (LATERAL)
Gyri-mountains in cortex
What are fissures, commisures and ventricles?
Fissures-valleys in brain (CORONAL)
Commisures - groups of axons that connect the two hemispheres
Ventricles
What is the role of the oligodendrocyte/schwann cell?
Facilitate saltatory conduction, myelination, regeneration
What is the function of the substantia nigra? Where is it located?
Reward and movement, ventral to the amygdala inside the mesencephalon
What is the function of the superior and inferior colliculi and where are they located?
Sup - Converting visual signals to plan movement - orienting the animal’s position to best pick up signals.
Inf- same except with audio
Location: midbrain
What happens when you split the brain (commisurotomy/callosotomy)
Principle 1: in callosotomy, information from one hemisphere does not flow to the other
Principle 2: The two hemispheres process information in different ways. Left is language hemisphere therefore information presented to the right hemisphere does not get translated into language but still is known what it is.
What happens when myelin/glia are damaged? What are its symptoms?
Multiple Sclerosis. Symptoms:
Visual: blurred and double vision, flashes
Motor: muscle weakness, slurred speech, muscle wastage, poor posture, tics
Sensory: numbness, tingling, pain
Coordination and balance: not good
Cognitive: short and long term memory loss, forgetfulness, slowed recall
What are 2 types of glial tumors?
Astrocytoma, glioblastoma multiforme, acoustic schwannoma (gliomas)
