5 Steps to a 5 AP Psychology, 2010-2011 Edition (21 page)

The genetic makeup for a trait of an individual is called its
genotype
. The expression of the genes is called its
phenotype
. For traits determined by one pair of genes, if they are the same (homozygous), the individual expresses that phenotypic characteristic. If the genes are different, the expressed gene is called the
dominant gene
; the hidden gene is the recessive gene. Numerous recessive genes are responsible for syndromes in the homozygous condition.
Tay-Sachs syndrome
produces progressive loss of nervous function and death in a baby.
Albinism
arises from a failure to synthesize or store pigment and also involves abnormal nerve pathways to the brain, resulting in quivering eyes and the inability to perceive depth or three-dimensionality with both eyes.
Phenylketonuria (PKU)
results in severe, irreversible brain damage unless the baby is fed a special diet low in phenylalanine within 30 days of birth; the infant lacks an enzyme to process this amino acid which can build up and poison cells of the nervous system. Thus, heredity and environment interact to determine a trait.
Huntington’s disease
is an example of a dominant gene defect that involves degeneration of the nervous system. Progressive symptoms involve forgetfulness, tremors, jerky motions, loss of the ability to talk, personality changes such as temper tantrums or inappropriate accusations, blindness, and death. Recessive genes for color blindness are located on the X chromosome with no corresponding gene on the Y chromosome. As a result, males show
sex-linked traits
like
color blindness
much more frequently than females. Behaviors and diseases may have variations only some of which are genetically based. A form of familial
Alzheimer’s disease
has been attributed to a gene on chromosome 21, but not all cases of Alzheimer’s disease are associated with that gene.

1.
A neuron without terminal buttons would be unable to

(A) receive information from neighboring neurons

(B) generate an action potential

(C) direct the synthesis of neurotransmitters

(D) secrete neurotransmitters to postsynaptic neurons

(E) transport ions across the cell membrane

2.
Paul Broca found that the loss of the ability to speak intelligibly is associated with damage to a region of the brain in the

(A) thalamus

(B) right parietal lobe

(C) right occipital lobe

(D) left temporal lobe

(E) left frontal lobe

3.
Scientists are able to see changes in the brain as it processes information by means of

(A) lesioning

(B) autopsy

(C) CT

(D) MRI

(E) PET

4.
The simplest behaviors we carry on

(A) are learned when we are infants

(B) do not involve the central nervous system

(C) are called instincts

(D) include sneezing and blinking

(E) must be processed by the medulla

5.
Of the following, the effect of adrenalin on the body is most similar to the effect of the

(A) cerebellum

(B) parathyroids

(C) somatic nervous system

(D) parasympathetic nervous system

(E) sympathetic nervous system

6.
Mr. Jenkins’ suffered a “stroke” as a result of a brain injury. Although he can still move the fingers on his right hand, he has lost sensation in these parts. Of the following, the site of damage to his brain is most likely in the

(A) right frontal lobe

(B) right temporal lobe

(C) left frontal lobe

(D) left parietal lobe

(E) hypothalamus

7.
Of the following, which are located exclusively in the central nervous system?

(A) afferent neurons

(B) interneurons

(C) efferent neurons

(D) glial cells

(E) effectors

8.
Which of the following glands interact(s) most directly with all of the others to help regulate body processes?

(A) pituitary

(B) adrenals

(C) parathyroids

(D) thyroid

(E) ovaries

9.
Gunshot wounds, tumors, and strokes all result in

(A) infections

(B) significant loss of function

(C) lesions

(D) pain

(E) necessity for surgery

10.
Which of the following must be males?

(A) dizygotic twins

(B) monozygotic twins

(C) Down syndrome children

(D) Klinefelter’s syndrome children

(E) Turner’s syndrome children

11.
Which includes all of the others?

(A) autonomic nervous system

(B) peripheral nervous system

(C) somatic nervous system

(D) parasympathetic nervous system

(E) sympathetic nervous system

12.
Which stimulate a muscle to contract?

(A) adrenal hormones

(B) receptors

(C) sensory neurons

(D) motor neurons

(E) interneurons

13.
The part of the brain most closely associated with maintaining balance and the coordination of complex sequences of movements is the

(A) hypothalamus

(B) thalamus

(C) pons

(D) medulla

(E) cerebellum

14.
Loss of the ability of the brain to produce adequate levels of dopamine often leads to

(A) aphasia

(B) Alzheimer’s disease

(C) Parkinson’s disease

(D) bipolar disorder

(E) amnesia

15.
Which task is primarily a right cerebral hemisphere function in most people?

(A) understanding written language

(B) understanding spoken language

(C) processing visual information from the left eye

(D) recognizing faces

(E) processing sensory information from the right leg

1. D
—Terminal buttons secrete neurotransmitters into the synapse.

2. E
—Broca’s area is a region in the left frontal lobe anterior to the motor cortex.

3. E
—PET scans visualize changes in the brain as it functions. While fMRI also shows changes in the brain as it functions, MRI and CT scans show structure only.

4. D
—Our simplest behaviors are reflexes. Sneezing and blinking are reflexes.

5. E
—Adrenalin is a hormone that speeds up breathing and heart rate, sends a message to change stored food back to glucose, etc. The sympathetic nervous system stimulates the same changes in the body.

6. D
—The center for sensation in the brain is the somatosensory region of the cerebral cortex located in the front of the parietal lobes. Nerves carrying sensations from the right side of the body cross over to the left side of the brain, so the most probable site of damage is the left parietal lobe.

7. B
—Interneurons are found in the brain and spinal cord only. The others can be found in the peripheral nervous system.

8. A
—The pituitary gland, which is sometimes called “the master gland,” produces many tropic hormones that stimulate other glands, including the adrenals, parathyroids, thyroid, and ovaries.

9. C
—Lesions are interruptions in tissue. While the other choices may accompany wounds, tumors, and strokes, they also may not.

10. D
—Presence of the Y chromosome determines the sex of a human baby. Of the choices, only a Klinefelter’s child (XXY) must have a Y chromosome.

11. B
—The peripheral nervous system comprises the autonomic nervous and somatic nervous system. The autonomic nervous system is subdivided into the parasympathetic and sympathetic nervous systems.

12. D
—Motor neurons or efferent neurons cause muscles to contract or glands to secrete.

13. E
—The cerebellum functions in balance and coordination.

14. C
—Parkinson’s disease is associated with depletion of cells that produce dopamine.

15. D
—Pattern matching and picture and facial recognition are all right hemispheric functions.

Neuropsychologists
—those who explore the relationships between brain/nervous systems and behavior. Neuropsychologists are also called biological psychologists or bio-psychologists, behavioral geneticists, physiological psychologists, and behavioral neuroscientists.

Studying patients with brain damage linked loss of structure with loss of function.

Lesions
—precise destruction of brain tissue, enables more systematic study of the loss of function resulting from surgical removal (also called ablation), cutting of neural connections, or destruction by chemical applications.

CT scans and MRIs show structure.

Computerized axial tomography (CAT or CT)—
creates a computerized image using x-rays passed through the brain to show structure and/or the extent of a lesion.

Magnetic resonance imaging (MRI)
—creates more detailed computerized images using a magnetic field and pulses of radio waves that cause emission of signals that depend upon the density of tissue.

EEGs, PET scans, and fMRIs show function.

EEG (electroencephalogram)
—an amplified tracing of brain activity produced when electrodes positioned over the scalp transmit signals about the brain’s electrical activity (“brain waves”) to an electroencephalograph machine.

Evoked potentials
—EEGs resulting from a response to a specific stimulus presented to the subject.

Positron emission tomography (PET)
—shows brain activity when radioactively tagged glucose rushes to active neurons and emits positrons.

Functional MRI (fMRI)
—shows brain activity at higher resolution than the PET scan when changes in oxygen concentration near active neurons alter magnetic qualities.

Central nervous system (CNS)
—brain and spinal cord.

Peripheral nervous system (PNS)
—portion of the nervous system outside the brain and spinal cord; includes all of the sensory and motor neurons, and subdivisions called the autonomic and somatic nervous systems.

Autonomic nervous system (ANS)
—subdivision of PNS that includes motor nerves that innervate smooth (involuntary) and heart muscle. Its sympathetic nervous system prepares the body for “fight or flight”; the parasympathetic nervous system causes bodily changes for maintenance or rest.

Sympathetic nervous system
—subdivision of PNS and ANS whose stimulation results in responses that help your body deal with stressful events.

Parasympathetic nervous system
—subdivision of PNS and ANS whose stimulation calms your body following sympathetic stimulation by restoring normal body processes.

Somatic nervous system
—subdivision of PNS that includes motor nerves that innervate skeletal (voluntary) muscle.

Spinal cord
—portion of the central nervous system below the level of the medulla.

Brain
—portion of the central nervous system above the spinal cord.

According to the evolutionary model, the brain consists of three sections:reptilian brain (medulla, pons, cerebellum); old mammalian brain (limbic system, hypothalamus, thalamus); and the new mammalian brain (cerebral cortex).

According to the developmental model, it consists of three slightly different sections:the hindbrain (medulla, pons, cerebellum), the midbrain (small region with parts involved in eye reflexes and movements), and the forebrain (including the limbic system, hypothalamus, thalamus, cerebral cortex).

•
Convolutions
—folding-in and out of the cerebral cortex that increases surface area of the brain.

•
Gyri
—folding-out portions of convolutions of the cerebral cortex.

•
Sulci
—folding-in portions of convolutions of the cerebral cortex.

•
Contralaterality
—control of one side of your body by the other side of your brain.

The functions of parts of your brain include:

Medulla oblongata
—regulates heart rhythm, blood flow, breathing rate, digestion, vomiting.

Pons
—includes portion of reticular activating system or reticular formation critical for arousal and wakefulness; sends information to and from medulla, cerebellum, and cerebral cortex.

Cerebellum
—controls posture, equilibrium, and movement.

Basal ganglia
—regulates initiation of movements, balance, eye movements, and posture.

Thalamus
—relays visual, auditory, taste, and somatosensory information to/from appropriate areas of cerebral cortex.

Hypothalamus
—controls feeding behavior, drinking behavior, body temperature, sexual behavior, threshold for rage behavior, activation of the sympathetic and parasym-pathetic systems, and secretion of hormones of the pituitary.

Amygdala
—influences emotions such as aggression, fear, and self-protective behaviors.

Hippocampus
—enables formation of new long-term memories.

Cerebral cortex
—center for higher order processes such as thinking, planning, judgment; receives and processes sensory information and directs movement.

Association areas
—areas of the cerebral cortex that do not have specific sensory or motor functions, but are involved in higher mental functions such as thinking, planning, and communicating.