Structure and Functioning of the Brain Flashcards
Define biological psychology
The study of thinking and behaving from a biological point of view: everything is related to the CNS
What does the CNS do?
Central Nervous System - processes information
How many neurons are in the brain?
860,000,000
How many possible connections are in the brain?
70,000
What is the Brain made up of?
the cerebellum, the cerebrum, and the brain stem
What does the brain control?
thoughts, memory, speech, movement and organ function
How many different parts of the brain are there?
Frontal lobe, Parietal Lobe, Occipital Lobe, Temporal Lobe
What is the CNS made up of?
What is the CNS made up of?
What is the PNS made up of?
the spinal and cranial nerves
What is the cerebrum?
The largest part of the brain, divided into two hemispheres
What is the cerebrum in control of ?
All higher functions e.g. interpreting touch, hearing and vision, as well as speech, reasoning, emotions, learning and movement
How are the hemispheres joined?
through the corpus callosum (fibres) who transmit messages to either side
What does the left hemisphere control?
The right side of the body, speech, comprehension, arithmetic and writing
What is the left hemisphere known as?
the ‘dominant’ in hand use and languages in 92% of people
What does the right hemisphere control?
creativity, spatial, musical and artistic ability
What is found in the right hemisphere?
Speech in 1/3 of people
Where is the cerebellum found?
Under the cerebrum
What does the cerebellum control?
coordinates muscle movement, maintains balance and posture
what is the function of the brainstem?
automatic function e.g. breathing and maintaining heart rate
Why is the brain stem known as a relay centre?
it connects the cerebellum and the cerebrum to the spinal cord
What are the four lobes of each hemisphere?
temporal, occipital, frontal and parietal
What is the function of the frontal lobe?
it controls:
personality, behaviour and emotions
Judgement, planning and problem-solving
Speech- speaking and writing (Broca’s Area)
Intelligence, concentration and self awareness
What is the function of the temporal lobe?
understanding language (Wernicke’s area)
Memory
Hearing
Sequencing and organisation
What is the function of the occipital lobe?
Interprets vision (colour, light, movement)
What is the function of the parietal lobe?
Interprets language and word
Senses of touch, pain and temperature (sensory strip)
Interprets signals from vision, hearing, motor, sensory and memory
Spatial and visual perception
What is asphasia?
A disorder that causes a disturbance in language, speech production, comprehension, reading and writing due to brain injuries
What is Broca’s Area?
Found in the frontal lobe, makes it hard to move facial muscles and tongue to produce coherent speech (difficulty speaking and writing)
What can someone with an injury in Broca’s area do, despite their injury?
No difficulty understanding speech and reading
What is Wernicke’s area?
Found in the left, temporal lobe, speaks long sentence (creating or adding unnecessary words) with no meaning
What makes a Wernicke’s area sufferer different to a Broca’s Area sufferer?
Wernicke’s find it difficult to understand speech and therefore making them unaware of mistakes they make - unlike Broca’s sufferers
What is the surface of the cerebrum known as?
the cortex (grey matter)
What is the appearance of the cortex?
Folded to allow for a larger surface area (16 billion neurons to enable higher functions in specific area)
What is under the cortex?
Axons connecting different matter
What are folds within the cortex known as?
gyrus
What is the groove between the folds in the cortex known as?
sulcus
Where is the hypothalamus?
Situated on the floor of the third ventricle
What is the hypothalamus known for?
master of the automatic system: controls hunger, thirst, sleep, sexual desire, regulation of blood pressure, body temperature, emotions and hormone secretion
Where is pituitary gland situated?
In a small pocket of bone known as the sella turcia
How the pituitary gland connected to the hypothalamus?
Through the pituitary stalk
What is the function of the pituitary gland?
Master Gland: controls all other endocrine glands, secreting hormones for sex development, promotes muscle growth and stress response
Where is the pineal gland?
Behind the third ventricle
What is the function of the pineal gland?
regulates the internal clock and circadian rhythms through melatonin secretion - has also some role in sexual development
What is the thalamus?
Relay centre for nearly all information given to the cortex
What is the role of the thalamus?
Pain sensation, attention, alertness and memory
What is within the basal ganglia?
the caudate, putamen and globus pallidus
What is the function of the basal ganglia?
to work together with the cerebellum to coordinate fine movements e.g fingertip movement
What is the function of the limbic system?
Centre of all emotions, learning and memory
What is within the limbic system?
cingulate gyrus, hypothalamus, amygdala (emotions) and the hippocampus (memory)
What are the three phases of memory?
Encoding, storing and re-coding
Where is the short-term memory?
Stored in prefrontal cortex
What is the short term memory?
limited to 7 items a minute, intervenes during reading to memorise the previous sentence so the next one makes sense
Where is the long term memory?
stored in the hippocampus, in the temporal lobe
What is the long term memory?
Unlimited content capacity, containing personal memories + facts and figures
Where is skill memory?
stored in the cerebellum to reach information based within the basal ganglia
What is the role of skill memory?
stores procedural memories e.g. tying shoelaces or riding a bike
Why do we have C.S.F.?
Cerebrospinal fluid cushions the brain against injury and so it is constantly absorbed and replenished
What makes C.S.F.?
Brain has hollow cavities, known as ventricles with ribbon-like structures inside (choroid plexus) which makes CSF
How does CSF get from the choroid plexus to the brain to cushion it against injury?
Two ventricles in the cerebral hemisphere (lateral ventricles) connect to the third ventricle through a seperate opening (freman of Monroe). The third ventricle connects to the fourth ventricle through a narrow tube (aqueduct of Sylvius). CSF goes from the fourth ventricle to cushion the brain
How is CSF absorbed?
Absorbed by structures in the superior sagittal sinus called the arachnoid villi
What will happen if CSF is not carefully managed?
If there’s a blockage, there’ll either be an enlargement of a ventricle (hydrocephalus) or fluid collection in the spine (syringomyelia).
What is the purpose of the skull?
to protect the brain from injury
How is the skull formed?
formed from eight bones fused along the suture lines
What are the skull bones called?
2 x pariortal
2 x temporal
Sphenoid occipital
Ethmoid
How is the face formed?
14 paired bones
What are the face bones called?
maxilla, zygoma, nasan, palatine, lacrimal, inferior nasal conchae, mandible and vomer
What are the three distinct areas within the skull?
Anterior, middle, and posterior fossa
What is within the anterior fossa?
Olfactory, Optic
What is within the middle fossa?
Trigeminal
What is within the posterior fossa?
Oculomotor, Trochlear, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory and Hypoglossal
Where does everything exit?
Through the base of the skill (foramina), from the big hole (foramen magnum)
How does the brain communicate with the body?
Through the spinal cord and 12 pairs of cranial nerves
What do the cranial nerves control?
10 control hearing, eye movement, facial sensations, tasting, swallowing
The cranial nerves for smell and vision originate in the cerebrum.
What originates in the brain stem?
Face, neck, shoulder and tongue muscles
What are meninges?
They cover the brain and spinal cord - are three layers of tissue
What are the types of meninges called?
Dura, arachnoid and pia mater
What is dura mater?
Strong, thick tissue lining the inside of the skull with two layers (periosteal and meningeal dura) which are fused and only separate to form venous sinuses.
The dura form small compartments of which there are two special ones: the falx and the tentorium
Why are the falx and the tentorium special in dura mater?
Falx separates to the right and left hemispheres whilsts tentorium separates the cerebrum from the cerebellum.
What is Arachnoid mater?
Thin, web-like structured, elasticated tissue that covers the entire brain
What is the name for the space between the dura and the arachnoid mater?
Subdural space
What is pia mater?
Hugs the brain, following its folds and grooves with many blood vessels reaching deep into the brain
What is the space between the arachnoid and pia mater?
the subarachnoid space (where CSF comes in to cushion the brain)
Why is Phineas Gage important to understanding the structure and functioning of the brain?
Phineas Gage was a railway worker who received a substantial brain injury when an explosion caused a metal bar to be shot through his head. He survived, but suffered damage to the right frontal lobes of his brain. Gage’s personality changed following the injury. He became more impulsive and there was some memory impairment. This led later researchers to conclude that specific brain areas were responsible for specific psychological functions, an idea we now know as ‘localisation of function’.
Why is Broca (1861) important to understanding the structure and functioning of the brain?
Broca (1861) studied a patient (‘Tan’) who was unable to speak. ‘Tan’ died, and during post-mortem examination, Broca discovered that Tan had an area of brain damage in his left frontal lobe. He concluded that the ability to speak is linked to that specific region, adding weight to the idea that function is localised in the brain. This region is still referred to as ‘Broca’s area’ and patients who understand language but cannot speak are said to have ‘Broca’s aphasia’
What research methods are used within ‘structures and functioning of the brain’?
Brain scanning
Studies using animal models
define neuron
one of the cells that make up the nervous system.
define nervous system
the network of signalling cells throughout the body, responsible for organising behaviour.
define central nervous system
the brain and the spinal cord.
define hind brain
a set of brain structures at the top of the spinal cord, mainly dealing with survival functions like breathing, heartbeat and consciousness.
define midbrain
a set of brain structures above the hindbrain, mainly responsible for movement and for homeostasis (keeping the internal environment stable).
define limbic system
a set of brain structures linking the midbrain and the forebrain, mainly responsible for emotional responses including fear and anger. It plays an important role in aggression.
define forebrain
a set of brain structures in the upper and outermost parts of the brain. It includes areas important for ‘higher’ mental functions like thinking, language and memory.
