Psych quiz hindbrain, midbrain, forebrain

Brain stem:

the portion of the brain formed by the swelling of the spinal cord as it enters the skull; its structures regulate basic survival functions of the body, such as heart rate and respiration.

Medulla:

A brain stem structure that controls vital functions, including heartbeat and respiration.

What happens during damage to the medulla

Damage: damage to the medulla results in death or life support.

Suppression of medulla activity can occur at high levels of alcohol intoxication, resulting in death by heart or respiratory failure.

Finish the sentence: the medulla is also a 2 way passage for...

The medulla is also a two-way passage for all the sensory and motor nerve tracts coming up from the spinal cord and descending from the brain. Most of these tracts cross over within the medulla, so the left side of the brain receives sensory input from and exerts motor control over the right side of the body, and the right side of the brain serves the left side of the body.

Pons:

A brain stem structure having sensory and motor tracts whose functions are involved in sleep and dreaming. The motor neurons it contains control the muscles and glands of the face and the neck.

It serves as a bridge carrying nerve impulses between higher and lower levels of the nervous system.

Damage to the pons

Like the medulla pons help control vital functions especially respiration and damage can result to death.

Cerebellum:

involved in motor coordination(muscle movement) and some aspects of learning and memory. Critical for controlling reflexive, automatic, and rapid movements.

Specific motor movements are initiated in higher brain centres, but their timing and coordination depend on the cerebellum. The cerebellum regulates complex, rapidly changing movements that require exquisite timing. Such as those of a ballet dancer or a competitive diver.

Damage to the cerebellum

The motor control functions of the cerebellum are easily disrupted by alcohol, producing the coordination difficulties. Intoxicated people may be unable to walk a straight line or touch their nose with their index finger.

Physical damage to the cerebellum results in severe motor disturbances characterized by jerky, uncoordinated movements, as well as an inability to perform habitual movements, such as walking. The behavioural effects of a rapidly developing cerebellar tumour.

Case of damage to cerebellum:

Ed could no longer walk a straight line. His gait involved wide separation of his legs. The timing of his steps was jerky and irregular, causing him to lurch from side to side. . . . By the fifth day he could no longer stand without assistance, and he began to display rapid and jerky eye movements. Ed was admitted to a hospital, where imaging techniques revealed a cerebellar tumor. Surgical removal of the tumor resulted in a marked improvement in his motor coordination.

Midbrain

Brain structures above the hindbrain that are involved in sensory and motor functions and in attention and states of consciousness.

Reticular formation:

acts as a kind of guard, both alerting higher centres of the brain that messages are coming and then either blocking those messages or allowing them to go forward.

Forebrain

Consists of 2 large cerebral hemispheres that wrap around the brain stem

Thalamus:

A sensory processing and relay station (like a switchboard that organizes inputs from sense of organs and routes them to the appropriate areas of the brain). The visual, auditory, and body senses (balance and equilibrium) all have major relay stations in the thalamus.

Basal Ganglia:

critical for voluntary motor control. Plays an important role in deliberate and voluntary control of movements.

Basal Ganglia: in parkinsons disease

In Parkinson's disease, the neurons that supply dopamine to the basal ganglia degenerate and die. Since dopamine is lost from the basal ganglia, the basal ganglia does not function properly, and the ability to initiate voluntary movement is lost.

When the basal ganglia has been largely depleted of dopamine and hence does not function, there is complete paralysis.

Hypothalamus:

plays a major role in controlling many different basic biological drives; including sexual behaviour, temperature regulation, eating, drinking, aggression, and the expression of emotion.

Hypothalamus: Damage:

Destruction of one area of a male's hypothalamus results in a complete loss of sexual behaviour; damage to another portion produces an overwhelming urge to eat that results in extreme obesity

Limbic System:

helps to coordinate behaviours needed to satisfy motivational and emotional urges that arise in the hypothalamus, its also involved in memory. The limbic system appears to organize many instinctive activities in lower animals, such as mating, attacking, feeding, and fleeing from danger

Hippocampus:

involved in forming and retrieving memories.

Hippocampus: Damage

Damage to the hippocampus can result in severe memory impairment for recent events and an inability to transfer information from short-term memory to long-term memory.

Amygdala:

organises emotional response patterns, particularly those linked to aggression and fear. Electrically stimulating certain areas of the amygdala causes animals to snarl and assume aggressive postures, whereas stimulation of other areas results in a fearful inability to respond aggressively, even in self-defence.

Nucleus Accumbens:

Electrical stimulation of the hypothalamus activates neurons within that brain region and also activates axons that are going from neuron cell bodies in the midbrain to a limbic structure called the nucleus accumbens.

It is the activation of axons going to the nucleus accumbens that is important for reward and motivation.