Chp 3.4: The Brain Flashcards
What are the four major areas of the brain?
- Hindbrain (bottom)
- Midbrain
- Forebrain
- Cerebral Cortex (top)
Why can we think of the brain as a hierarchical structure ?
“older structures” on bottom responsible for basic physiological functions, like breathing and heartbeat regulation
What are the 2 main parts of the hindbrain?
- Brainstem
- Cerebellum
What are the 2 areas in the brainstem?
-Medulla
-Pons
(Hindbrain)
Medulla (2)
- Heart rate & respiration
- Thoroughfare for sensory information
(Hindbrain: Brainstem)
Pons (3)
Regulate sleep, dreaming, respiration
Hindbrain: Brainstem
Cerebellum (2)
-Muscular movement
-Learning and memory
-and more..
(Hindbrain)
The Reticular Formation (3)
- Acts as a kind of a guard, both alerting higher centres of the brain that messages are coming
- Either block those messages or allow them to go forward
- Important for states of consciousness (attending/alert vs. sleep)
(Midbrain)
Appearance of The Reticular Formation
Finger-shaped structure that extends from the hindbrain up into the lower portions of the forebrain
What are the 4 main parts in the forebrain?
- Thalamus
- Basal Ganglia
- Hypothalamus
- The Limbic System
What are the 3 main parts of the The Limbic System?
- Hippocampus
- Amygdala
- Nucleus Accumbens
(Forebrain)
Thalamus (3)
-Sensory switchboard
- Routes sensory information to appropriate place
(e. g., visual goes to visual centres; auditory to auditory centres)
-All senses (except for olfaction) are routed through the thalamus
(Forebrain)
Basal Ganglia (3)
- Distinct structures surrounding the thalamus
- Voluntary motor control
- Initiating voluntary movement
(Forebrain)
What disease is linked to damage of basal ganglia? (2)
Parkinson’s Disease:
- Neurons that supply dopamine to the basal ganglia degenerate
- Eventual paralysis
Hypothalamus (3)
- Major role in controlling biological drives
- eg. Sexual behaviour, eating, drinking, aggression, emotion
- Connection with pituitary gland that controls hormones
- Damage can disrupt all these behaviours
(Forebrain)
Hippocampus (2)
- Forming & retrieving memories
- Damage to hippocampus can result in profound amnesia
(Forebrain: The Limbic System)
Amygdala
-Organizes emotional responses
(Especially those linked to aggression & fear)
(Forebrain: The Limbic System)
Nucleus Accumbens (4)
-Linked to effects of drugs and abuse
(Cocaine, opiates etc. Stimulate release of dopamine in nucleus accumbens)
- Linked to rewards such as food, sexually-relevant cues
- Heightened response to both pleasurable and aversive stimuli
- Critical in forming memories involving both positive and negative environmental stimuli
(Forebrain: The Limbic System)
Cerebral Cortex (3)
- 2/3 cm sheet of grey matter (unmyelinated cells)
- 75% of area lies within fissures (folds)
- Provide landmarks for dividing cortex into major areas
What are the 4 lobes of the Cerebral Cortex?
Frontal, Parietal, Occipital, and Temporal
Motor Cortex (4)
- Controls movement on opposite side of body
- Controls movement of over 600 voluntary muscles
- stimulates muscles that produce speech
- Located at rear of frontal lobe (cerebral cortex)
Somatic Sensory Cortex (3)
- Receives specific sense information from opposite side of body
- At least one specific area for each sense
- Located in parietal lobe (cerebral cortex)
What are the two important areas for speech comprehension and production?
1) Wernicke’s area
2) Broca’s area
Wernicke’s area
important in the comprehension of spoken or written speech
Broca’s area
involved in the production of speech, and stimulates motor cortex
Association Cortex (5)
- the areas of the cerebral cortex that do not have sensory or motor functions
- Found within all lobes
- Thought to be involved in highest level of mental functioning (perception, language, thought, reasoning)
- Referred to as the “silent areas”
- electrically stimulating them does not give rise to either sensory experience or motor response
-Accounts for 75% of human brain
What traits of a person the frontal lobes (prefrontal cortex) are responsible for? (4)
-Self-awareness; planning; initiative; responsibility; emotional experience
Where in the frontal lobe is the prefrontal cortex located?
area of frontal lobe behind the eyes and forehead.
What connects the 2 hemispheres (brain) together?
corpus callosum (white matter)
Lateralization (3)
- Functions localized/more strongly represented in one hemisphere
- Left – verbal and logical abilities
- Right – spatial relations, music processing
What happens if corpus callous is severed? (3)
Split Brain Experiment
- Hemispheres no longer communicate
- But optic nerve remains intact
- With optic nerve, fibers cross over (contralateral processing)
- Fibers cross over
- Left visual field processed in right hemisphere
- Right visual field processed in left hemisphere
Neural Plasticity
Change in structure and function
What is the result of damaged Broca’s/Wernicke’s speech areas?
Aphasia
