Brain anatomy 101 Flashcards
What does the CNS include?
The brain and the spinal cord
What does the Peripheral Nervous system include?
Somatic and autonomic nervous system
What does somatic nervous system do?
Links the spinal cord and organs and controls voluntary behaviours
What does the autonomic nervous system do?
serves internal organs and glands, controls involuntary functions
What involuntary functions does the autonomic nervous system control?
Heart rate, blood pressure, respiration rate
What else does the autonomic nervous system control?
The flight or fight response
What nervous system in the autonomic nervous system controls the fight or flight response?
The sympathetic nervous system
What is the sympathetic response?
Arouses the body, it stimulates, organises and mobilises energy resources, spends energy
What neurotransmitters are involved in the sympathetic response?
Acetylcholine -> activates sympathetic adrenal-medullary system which released -> Epinephrine (adrenalin) which metabolised glucose -> Norepinephrine (noradrenaline) which increases heart rate and blood pressure
What does the Neurotransmitter acetylcholine do?
It activates and stimulates the sympathetic adrenal-medullary system
What does the stimulation of the adrenal medulla cause?
The release of Epinephrine and Norepinephrine
What is Epinephrine?
Adrenalin
What is Norepinephrine?
Noradrenaline
What is the parasympathetic response?
Relaxes the body, most active after an emotional event, conserves energy
What is the parasympathetic system known as?
Rest and digest
What part of the peripheral nervous system controls the sympathetic and the parasympathetic states?
Autonomic
What is the other component of the peripheral nervous system?
The somatic nervous system
What does the somatic nervous system control?
Controls voluntary actions and movements
What is the somatic nervous system responsible for?
Allows for sensory input and movement control and processes sensory information from external stimuli and reflex movements
How does the somatic nervous system manage reflex reactions?
A sensory receptor senses a stimulus this then transmits signal to the PNS via nerve fibres, the spinal cord then decodes the signal, the signal then travels to the efferent nerve fibres to the effectors, the effector muscles then respond by contracting
What areas of the spine are involved in the reflex motions and at what point?
The Dorsal Horn - decodes the signal after the sensory neuron transmits it via the nerve fibres
The Ventral Horn - the signal travels down the ventral horn after the signal is decoded
Summarise the roles of the Autonomic Nervous system
Regulates involuntary responses, controls the function of internal organs such as the heart, stomach, lungs and intestines
Summaries the roles of the Somatic Nervous system
Regulates voluntary systems and movements, connects the brain to the motor neurons such as those found in the skeletal muscles
What is another component of the nervous system outside of the PNS?
The CNS - central nervous system
What does the CNS include?
The brain and Spinal Cord
What are the three main functions of the spinal cord?
Conduit for motor information, conduit for sensory information, a centre for coordinating certain reflexes
What is the anatomy of the spinal cord?
The inner layer is grey matter, the outer layer is white matter, the dorsal horn a site where afferent nerve fibre meet, ventral horn is a site where efferent nerve fibre synapse
What is the result of an injury to the upper spinal cord?
Can cause paralysis in most of the body and can affect all of the limbs (called tetraplegia or quadriplegia)
What is the result of an injury to the lower spinal cord?
May cause paralysis affecting the legs and lower body, called paraplegia
What does lateral mean?
Towards the side, away from the brain
What does Medial mean?
Towards the middle away from the side
What does Ipsilateral mean?
On the same side
What does contralateral mean?
On the opposite side
What does anterior/rostral mean?
In front of; towards the front of the brain but the top of the spinal cord
What does posterior/caudal mean?
Behind; towards the back of the brain and the bottom of the spinal cord
What does the superior/dorsal mean?
Above; towards the top of the brain but the back of the spinal cord
What does inferior/ventral mean?
Below; towards towards the bottom of the brain but the front of the spinal cord
How much of the body weight is the brain?
2%
How much of the blood supply does the brain receive?
16%
What is grey matter?
Neuronal cell bodies
What is white matter?
Neuronal axons
What develops first?
Build up from grey matter and white matter
What are the three gross divisions?
Cerebellum, Brain stem and Cerebral cortex
Within the fine divisions what are the major divisions?
Forebrain, Midbrain and Hindbrain
What are the four corresponding ventricles to the major divisions?
Lateral, Third, Cerebral aqueduct, fourth
What are the corresponding five subdivisions?
Telencephalon, Diencephalon, Mesencephalon, Metencephalon, Myelencephalon
What are the principal structures of the forebrain, lateral?
Cerebral cortex, basal ganglia and the limbic system
What are the principal structures of the third forebrain?
Thalamus and Hypothalamus
What are the principal structure of the Mid brain
Tectum, Tegmentum
What are the principal structures of the Metencephalon hindbrain?
Cerebellum and Pons
What are the principal structures of the myelencephalon
Medulla Oblongata
Where is the Medulla oblongata?
In the lower part of the brain stem
What does the Medulla Oblongata do?
Controls functions such as heart rate, breathing, blood pressure and vomiting
Where is the pons?
The upper part of the brain stem
What is the location of the pons?
Connects the rest of the brain to the cerebellum, bridges the spinal cord and the brain
What is the function of the pons?
Controls muscle movement and carries sensory-motor information from the PNS, arousal and automatic functions and is also involved in the sleep/wake cycle
What does the tectum contain?
The Superior Colliculi
What is the superior colliculi a part of?
It forms a part of the visual system
What does the superior colliculi control?
Eye movements such as fixations, saccades and smooth pursuits
What else does the tectum contain?
The inferior colliculi
What does the inferior colliculi form a part of?
The auditory pathway
What does the inferior colliculi control?
Pitch perceptions and startle response
What does the tegmentum contain?
The periaqueductal grey, the reticular formation, the red nuclei an the substantia Nigra
Where is the cerebellum located?
The back of the brain
What is the function of the cerebellum?
Controls motor movements coordination, balance and equilibrium, automated movement sequences, fine movement and muscle tone. Also involved in automatic language processing
Where is the thalamus located?
At the top of the brain stem
What is the thalamus comprised of?
Thalamic nuclei
What are the functions of the Thalamus?
Takes part in sensory pathways, motor pathways and cortico-cortical loops; fundamental role in attention an is involved in alertness/consciences
Where is the Hypothalamus located?
Below the thalamus
What does the hypothalamus contain?
Mamillary bodies and connect to the pituitary gland
What are the four functions of the hypothalamus?
Controls the autonomic nervous system, role in maintaining homeostasis, central for regulation of hormones via control of pituitary gland, regulates basic behaviours such as fight or flight, hunger and sexual behaviours
What does the Limbic system include?
The hippocampus, amygdala, fornix, cingulum, mamillary bodies and olfactory bulb
What are not included in the limbic system but have a lot of influence in the function of it?
Thalamus and hypothalamus
What shape is the amygdala?
Almond shape
What are the three main functions of the Amygdala?
Central for emotional responses, Involved in fear conditioning and responds to emotionally salient stimuli and attaches emotional content to memories which reinforces their storage
What the main 2 functions of the hippocampus?
Responsible for learning and long term memory storage and consolidation and can produce new brain cells
What are the three main structures within the basal ganglia?
Globus Palidus, Caudate nucleus and Putamen
What is the basal ganglia connected to?
The brain stem, thalamus and cortex
What is the function of the basal ganglia?
Controls the higher order motor movement, habit learning and eye movement
What is the cerebral cortex?
Is the outer layer of neural tissues of the cerebrum of the brain, it is folded providing a greater surface are in the confined volume of the cranium
What functions is the occipital lobes responsible for?
Controls the processing of visual information, the calcarine fissure is the centre point of the primary visual cortex and higher order vision is further processed in the visual associations cortices
What is the temporal lobe composed of?
The superior temporal cortex (Heschel’s gryus) which is the seat of the primary auditory cortex
Wernicke’s area- lateralised to the left hemisphere
What is Heschel’s gryus responsible for?
Auditory perceptions and higher order hearing
What is the Wernicke’s area responsible for?
Language control and speech comphrension
What are the inferior temporal lobes responsible for?
Organising and integrating visual-sensory input
What does the temporal lobe pay a key role in?
Semantic memory and cognition
What is the last brain region to evolve?
The frontal lobes
What does the posterior proportion of the frontal lobe control?
Controls pre-motor and motor cortices that control motor function
What functions is the pre-frontal cortex involved in?
Executive function, attention, social cognition and emotional regulation, language production (Broca’s area) and semantic control
What falls under the umbrella term of ‘executive functions’?
Planning, reasoning, decision making, response inhibition, working memory, problem solving and initiations
What are the notable structure of the cerebral cortex?
The anterior cingulate cortex and the corpus collosum
What function does the anterior cingulate cortex serve?
It is involved in emotional processing and self-referential processing
What purpose does the corpus collosum serve?
It is a white matter bundle which joins the two hemispheres and allows for communication between them
How many ventricles of the brain are there?
4
What are the four ventricles of the brain?
Lateral, third, fourth, and cerebral aqueduct
What is the function of the the brain ventricles?
Serves as protection for the brain, supports the brain against gravity, enables chemical stability and provisions of nutrients
What are the Meninges of the brain?
A protective sheet wrapping around the whole CNS
What are the three layers of the Meninges of the brain?
Dura matter, Arachnoid and Pia matter
What are the functions of the three layers of Meninges?
Dura matter - holds it together
Arachnoid - cushions it
Pia matter- allow for nourishment
What is a sublayer of the arachnoid layer and what is it’s function?
The subarachnoid space is filled with cerebro-spinal fluid (CSF)
