THE STRUCTURE AND
FUNCTION OF BRAIN AREAS
The brain is described as having three distinct
areas.
Hindbrain
Midbrain
Forebrain
Each has specific mental processes and behaviour.
The more basic functions of our existence are
located in the deepest part of the brain and
develop first.
The largest part of our brain is the most highly
developed.
THE STRUCTURE AND
FUNCTION OF BRAIN AREAS
From early in gestation, the three brain
areas develop.
The neural tube closes around 28 days
after conception. (Some research
suggests as early as 3 weeks after
conception).
Shortly after, bulges form and begin to
develop into the three brain regions.
THE ROLES OF THE HINDBRAIN, MIDBRAIN AND
FOREBRAIN, INCLUDING THE CEREBRAL CORTEX, IN
BEHAVIOUR AND MENTAL PROCESSES
HINDBRAIN
Located at the base of the
brain around the brainstem.
Consists of the:
Cerebellum
Medulla
Pons
These control vital functions
such as breathing and heart
rate, but also movements and
memory.
HINDBRAIN: CEREBELLUM
Looks like a mini brain attached to the brain stem.
Roughly tennis ball shaped in adults.
Contains 10% of the brain’s mass but around 80% of the brain’s
neurons.
Functions controlled by the cerebellum:
Fine muscle movements
Posture and balance
Controls movements that are quick and precise (speaking)
Involved in learning new movements
Learning and memory associated with movements (walking,
playing an instrument, sport, etc.)
Some research suggests that it my be involved in other
processes such as spatial learning, navigation and spatial
memory.
HINDBRAIN: CEREBELLUM
Although the cerebellum controls fine movements, posture and balance, these movements are initiated higher up in
the forebrain.
The cerebellum organises and adjusts this so your movements are smooth and precise.
It makes quick adjustments in movements and calculates which muscles to move and how much to move them.
(Think about the movements needed to pick up a hot cup of tea, or to surf, or balance on a high wire)
It is believed to process and temporarily store the information when learning a new physical skill before that
information is sent to the cerebral cortex for permanent storage.
Damage results in:
difficulty coordinating muscle control in everyday activities (reaching, walking, riding a bike)
balance problems
speech difficulties (speech involves a large number of fine muscle movements and precise control)
HINDBRAIN: MEDULLA
Also known as the medulla oblongata.
The lowest part of the brain, it connects to the spinal cord.
Functions (all involuntary):
Breathing
Swallowing
Heart rate
Blood pressure
Vomiting
Salivating
Coughing
Sneezing (it detects histamine, thanks hayfever!)
Sensations (touch, pressure, vibration)
A severe blow to this area can result in death.
HINDBRAIN: PONS
2.5cm bundle of neural tissue.
Functions include:
Sleep
Waking from sleep
Dreaming
Controlling breathing
Some movements
Messenger/relay system (between the cerebral cortex
and cerebellum, and the medulla and midbrain)
Auditory information from the ear first enters the pons
before being relayed elsewhere
THE ROLES OF THE HINDBRAIN, MIDBRAIN AND
FOREBRAIN, INCLUDING THE CEREBRAL CORTEX, IN
BEHAVIOUR AND MENTAL PROCESSES
MIDBRAIN
Central part of the brain,
roughly 2.5cm long.
Neural pathways connect
upper and lower brain areas.
Consists of the:
Reticular formation
Movement, arousal and
attention.
MIDBRAIN
Central part of the brain, roughly 2.5cm long.
Neural pathways connect upper and lower brain areas.
Functions include:
Movement
Processing of information (auditory, visual and tactile)
Sleep and arousal
Orients our movements around what is being received from the
ears and eyes
For example, if you are walking and hear a car braking suddenly and
loudly, the sound registers in your midbrain, which then triggers
muscles in your neck and for eye movements to enable you to turn
your head to look in the direction of the sound.
One region in the midbrain is called the substantia nigra, which
produces the neurotransmitter dopamine. Parkinson’s disease is
related to damage to this area and subsequent changes in movement.
*This is examined in more detail in year 12.
The reticular formation runs through the midbrain and hindbrain.
MIDBRAIN: RETICULAR
FORMATION
A network of neurons around as thick as your middle
finger.
Under a microscope looks like white netting or lace.
Functions:
Screens incoming information so you don’t overload
your brain.
Alerts higher order areas of the brain to important
information.
Helps maintain consciousness, regulates awakening
Regulates muscle tone
Includes the reticular activating system.
MIDBRAIN: RETICULAR FORMATION – RETICULAR
ACTIVATING SYSTEM (RAS)
The RAS extends in many directions from the reticular formation.
Influences whether we are awake, drowsy, asleep, etc. When the RAS is less
active we fall asleep.
Many general anaesthetics work by reducing RAS activity to make the patient
unconscious.
Damage to the RAS can disrupt the sleep-wake cycle or could result in coma
or chronic vegetative state.
As it regulates arousal, the RAS influences what we pay attention to.
Can highlight important information and direct attention to significant events.
Eg. the sleepy driver who snaps to attention when a kangaroo appears in the
middle of the road can thank the RAS for arousing the rest of their brain.
THE ROLES OF THE HINDBRAIN, MIDBRAIN AND
FOREBRAIN, INCLUDING THE CEREBRAL CORTEX, IN
BEHAVIOUR AND MENTAL PROCESSES
FOREBRAIN
The largest and most
prominent part of the brain.
Located above the midbrain and
sits on top.
Bit that most people think
about when they think ‘brain’.
Helps coordinate brain activity.
Regulate complex and
sophisticated processes.
Consists of the:
Hypothalamus
Thalamus
Cerebrum
FOREBRAIN
The largest and most prominent part of the brain.
Located above the midbrain and sits on top.
Helps coordinate brain activity.
Regulate complex processes including emotion,
personality and mental processes.
Includes:
Hypothalamus
Thalamus
Cerebrum
FOREBRAIN: HYPOTHALAMUS
Size of a sultana grape.
Helps maintain homeostasis.
Regulates hormone release into the body through the control of the
pituitary gland.
Helps maintain body temperature and blood pressure.
Influences behaviours associated with basic biological needs – hunger,
thirst, tiredness/sleep, sex drive, etc.
Damage to the hypothalamus can have significant effects:
Inability to regulate internal body functioning (such as maintaining
temperature)
Problems with sleep-wake cycle
Overwhelming urge to eat
Uncontrollable anger
Significant reduction in sex drive (males only).
FOREBRAIN: HYPOTHALAMUS
It is part of the limbic system.
Involved in emotions as well as survival behaviours
(eating, reproduction, care for young, fight or flight).
It is involved in emotions such as fear and anger, as well
as emotional/motivated behaviour.
Is involved in the production and regulation of
emotions as well as forming new long-term memories.
If you’ve ever tried not to laugh at an inappropriate
time but couldn’t stop, you can thank your
hypothalamus.
FOREBRAIN: THALAMUS
If you stuck a finger in each ear and pushed until they touched, you’d
find the thalamus.
3cm long and has two oval shapes. Each one lies in a different
hemisphere.
It filters information from all the sense receptor sites (except the
nose) the passes them on to the relevant area for processing.
Relays information from the motor cortex to the cerebellum.
The thalamus doesn’t just relay information, it filters what should
have attention paid to it. It emphasises some things and
de-emphasises others.
Also involved in arousal through the connection with the RAS.
Damage results in:
Lowered arousal ranging from lethargy to coma.
Visual or hearing impairment, or the inability to feel sensation
when touched.
SIDE NOTE: SENSE
OF SMELL
Has its own sensory relay station so it
doesn’t need the thalamus.
It is called the olfactory bulb (sits above
your nasal cavity), which is near emotion.
This is why the sense of smell and memory
are very closely related.
FOREBRAIN: CEREBRUM
Is the wrinkly bit that sits over and in front of the cerebellum and
other brain structures.
The outer surface is called the cerebral cortex (4C).
Massive number of neural tissue that receive, process and deliver
outgoing and incoming messages.
The cerebrum and cerebral cortex are responsible for nearly
everything we consciously think, feel and actions.
Divided into two hemispheres by the longitudinal fissure.
Each hemisphere is divided into four lobes.
Forebrain
REMINDER:
Hemispheric
specialisation and
contralateral function.
LEFT HEMISPHERIC
SPECIALISATION
Controls the right side of the body and receives
sensory information from the right side.
(contralateral function)
Specialises in:
Verbal functions – recognising words and their
use (spoken and written, lyrics, speaking)
Analytical functions – breaking a task into
manageable chunks, sequencing, logic,
problem-solving, decisions, etc.
Left – Language - Logic
RIGHT HEMISPHERIC
SPECIALISATION
Controls the left side of the body and receives
sensory information from the left side.
(contralateral function)
Specialises in non-verbal functions.
Spatial and visual thinking (jigsaws, maps, visualising the
CONSOLIDATION
ACTIVITIES
Using your knowledge, fill in the
diagram on the next slide.
CONSOLIDATION
ACTIVITIES
Answers on the following slide.
CONSOLIDATION
ACTIVITIES
Complete the table following and
label the diagram.
Learning Intentions:
- To examine the structure of the brain (hindbrain, midbrain and forebrain) alongside the
functions of each.
Success Criteria:
- I can explain which brain areas are considered hindbrain, forebrain or midbrain.
- I can describe the function of each area in terms of behaviour or mental processes.
VCAA dot point:
• THE ROLES OF THE HINDBRAIN, MIDBRAIN AND FOREBRAIN, INCLUDING THE CEREBRAL CORTEX, IN BEHAVIOUR AND