Neuropsychology. Essential Question 1 How do nerve cells generate impulses, communicate with other nerve cells, and become influenced by neurotransmitters?

Neuropsychology

Essential Question 1

How do nerve cells generate impulses, communicate with other nerve cells, and become influenced

by neurotransmitters?

Neural Anatomy

‣ The body’s information system is built from billions of interconnected cells called neurons

‣ Interconnected neurons make up a nerve

Action Potential‣ A brief electrical charge that travels down a neuron

‣ Sodium-potassium pumps pump positive ions out from the inside of the neuron, making them ready for another action potential

• Depolarization occurs when positive ions enter the neuron, making it more prone to firing an action potential

• Hyperpolarization occurs when negative ions enter the neuron, making it less prone to firing an action potential

Action Potential‣ Threshold: Minimum electrical current required to fire an action

potential

‣ All-or-None Response: When the positive ions minus the negative ions exceed the threshold, the neuron fires an action potential

• If the current fails to exceed the threshold, a neuron will not fire

‣ Intensity of an action potential remains the same throughout the length of the axon

‣ Refractory Period: After a neuron fires it pauses for a short period to recharge itself to fire again

Neurotransmitters‣ Synapse: Junction between an axon terminal of a sending neuron

and a dendrite or cell body of the receiving neuron

‣ Neurotransmitters (chemicals) released from the sending neuron travel across the synapse and bind to receptor sites on the receiving neuron generating an action potential

‣ Reuptake: Neurotransmitters in the synapse are reabsorbed into sending neurons

Neurotransmitters‣ Neurotransmitters bind to the

receptors of a receiving neuron in a lock and key mechanism

‣ Agonists mimic neurotransmitters

• Example - Morphine mimics endorphins as a pain reliever

‣ Antagonists block neurotransmitters

• Example - Curare (poison) blocks ACh receptors involved in muscle movement

Neurotransmitters

Essential Question 2

What are the functions of thenervous and endocrine systems?

Nervous System‣ The nervous system consists of all nerve cells and is the body’s speedy, electrochemical communication system

‣ Central Nervous System

• Brain and spinal cord

‣ Peripheral Nervous System

• Sensory and motor neurons that connect the central nervous system to the rest of the body

Central Nervous System

‣ Interconnected neurons form networks in the brain and spinal cord

• Networks are complex and modify with growth and experience

Central Nervous System• Sensory (afferent) neurons send information from the body’s tissues and sensory organs inward to the CNS

• Interneurons communicate within the CNS and intervene between the sensory inputs and the motor outputs• Motor (efferent) neurons carry outgoing information from the CNS to the body’s tissues and organs

Peripheral Nervous System

‣ Somatic Nervous System

• Controls the body’s voluntary movement

‣ Autonomic Nervous System

• Controls the glands and involuntary muscles

- Sympathetic Nervous System: Arouses the body, mobilizing its energy in stressful situations

- Parasympathetic Nervous System: calms the body, conserving its energy

Endocrine System

‣ The body’s “slow” chemical communication system

‣ Hormones (chemicals produced by endocrine glands) are secreted into the bloodstream

• Example - epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar and feelings of excitement during emergency situations

Endocrine System‣ Hypothalamus - maintains body’s homeostasis

‣ Pituitary Gland - master gland

• Monitors hormones in the blood and corrects imbalances

• Secretes growth hormone

‣ Pineal Gland - regulates activity levels with melatonin

‣ Thyroid (Para) Gland - regulates metabolic and calcium rate

‣ Adrenal Glands - secretes epinephrine and norepinephrine and regulates salt and carbohydrate metabolism

‣ Pancreas - secretes insulin and glucagon to balance sugar

‣ Gonads - involved in sex determination, sex development, secondary sexual characteristics, and sexual motivation

• Ovaries: female reproductive glands; secrete estrogen

• Testes: male reproductive glands; secrete androgen (testosterone)

• Both genders produce both hormones

Immune System

‣ Monitors the body internally for the presence of foreign and harmful material and attempts to eliminate it

• Autoimmune disorders: immune system attacks normal cells

Essential Question 3

What are the functions or each of the components of the brain stem

and limbic system?

History of the Mind

‣ Plato correctly placed the mind in the brain

‣ Phrenology - Franz Gall suggested that bumps of the skull represented mental abilities

‣ Today we believe mind and brain coincide

Research Strategies

‣ Story of Phineas Gage

‣ A brain lesion can experimentally destroy brain tissue to study resulting behaviors

• Frontal labotomies use to be used to calm patients

‣ Clinical observations record behaviors of disorders

Research Technologies

‣ EEG - recording of electrical waves sweeping across the brain

‣CAT scan - similar to an X-ray but uses cross-sections of the brain

‣ MRI - computer generated images that distinguish among different types of brain tissue

• CAT scans and MRIs show brain structure, not function or activity

‣ PET Scan - visual display of brain activity while the brain performs a given task

Brain Regions‣ Brainstem - responsible for autonomic survival functions

• Reticular Formation (RAS) - controls arousal

• Medulla - controls heartbeat and breathing

• Pons - regulates breathing and sleep (dreams)

• Thalamus - directs messages to areas of the cortex

• Cerebellum - coordinates voluntary movement and balance

Brain Regions‣ Limbic System - associated with emotions and drives

• Amygdala - controls emotion

• Hippocampus - consolidates memory

• Hypothalamus - directs maintenance activities

- Eating, drinking, body temperature, and control of emotions

- Helps govern the endocrine system via the pituitary gland

Essential Question 4

What are the regions and functionsof the cerebral cortex?

Brain Lobes‣ Cerebral Cortex (cerebrum) - intricate fabric of interconnected neural cells that functions as the brain’s information processing center divided into lobes

• Frontal - logic, reasoning, personality, creativity, LTM, speech

• Parietal - integrates senses, language

- More intelligent animals have increased “uncommitted” or association areas

• Occipital - visual info• Temporal - auditory info

Cortical Areas‣ Motor Cortex - controls voluntary movements

‣ Sensory Cortex - receives information from sense organs

‣ Homunculus

Cortical Areas‣ Aphasia - Language disorder caused by left hemisphere damage

• Broca’s area - impaired speaking

• Wernicke’s area - impaired understanding

Neuroplasticity

‣ The brain’s ability to modify itself after injury or illness

• Due to changes in behavior or the environment

‣ The brain changes throughout life; Not static

Essential Question 5

How does split-brain research help us understand the functions of the two

brain hemispheres?

Hemispheric Specialization‣ Corpus callosum - bundle of neural fibers connecting the left and right cerebral hemispheres facilitating communication

‣ With the corpus callosum severed, objects in the right visual field can be named while objects in the left visual field cannot

‣ Split brain patients might suffer from severe epilepsy

Hemispheric Specialization‣ Our brain is divided into two hemispheres

• Left - processes reading, writing, speaking, mathematics, and comprehension skills

- Dominant brain

• Right - processes perceptual and spatial tasks

Essential Question 6

What is the interaction between heredity and environment?

Read pages 95-106 in the text

Essential Question 7

How do evolutionary psychologists use natural selection to explain

individual differences?

Read pages 107-113 in the text