Chapter 2: Biology and Psychology

Chapter 2: Biology and Psychology. PSYCH, 7e. [image] PSYCH7.

Icebreaker: What Do You Think?. Break into small groups and discuss: What makes you nervous? What physical signals does your body send when you are nervous? Have you ever responded to a situation and then after the event was over, realized how nervous you were, even though you didn’t feel nervous at the time?.

[Virtual Presenter] Review objectives. Chapter Objectives (1 of 2).

[Virtual Presenter] Review objectives. Chapter Objectives (2 of 2).

The Nervous System: On Being Wired. Section 2-1.

Neurons: Into The Fabulous Forest (1 of 2). Neurons: Specialized cells of the nervous system that receive and pass messages Vary according to function and location Glial cells Remove dead neurons and waste products Nourish and insulate neurons Form myelin and play a role in neural transmission of messages Increase with the development of the nervous system Include a cell body, an axon, and dendrites Maturation of an individual lengthens axons and proliferates the dendrites and terminals.

Neurons: Into The Fabulous Forest (2 of 2). Myelin Fat that insulates the axon from electrically charged atoms, or ions Minimizes leakage of the electrical current Afferent neurons Neurons that transmit messages from sensory receptors to the spinal cord and brain. Also called sensory neurons When you touch a hot stove these neurons tell your brain “this hurts” Efferent neurons Neurons that transmit messages from the brain or spinal cord to muscles or glands, also called motor neurons When this hurts, you move your hand from the hot stove.

Figure 2.1 The Anatomy of a Neuron. A diagram illustrates the anatomy of a neuron. Two neurons are depicted with centers labeled, nucleus. The nucleus is surrounded by the cell body, soma, and branches off in several parts labeled, dendrites. The neurons are connected by the axon and covered by the myelin sheath. Axon terminals connect the axon to the dendrites. The neural impulse travels through the axon. A close up of an axon terminal button and synapse indicates the end of the axon terminal, which is made up of neurotransmitters that are released over the synaptic cleft into the receptor sites. The caption reads, "Messages" enter neurons through dendrites, are transmitted along the trunklike axon, and then are sent from axon terminal buttons to muscles, glands, and other neurons. Axon terminal buttons contain sacs of chemicals called neurotransmitters. Neurotransmitters are released into the synaptic cleft, where many of them bind to receptor sites on the dendrites of the receiving neuron..

The Neural Impulse: “The Body Electric” (1 of 2).

The Neural Impulse: “The Body Electric” (2 of 2).

Firing: How Messages Voyage From Neuron To Neuron (1 of 2).

Firing: How Messages Voyage From Neuron To Neuron (2 of 2).

Knowledge Check Activity 1. Messages travel in the brain by means of an electrochemical process. True False.

Knowledge Check Activity 1 Answer. Messages travel in the brain by means of an electrochemical process. Answer: TRUE! It is true that messages within neurons travel by means of electricity. However, chemicals (including sodium and chloride ions) are also involved in the neural impulse. Moreover, communication between neurons is carried out by transmitting chemicals from one neuron to the other..

Neurotransmitters: The Chemical Keys To Communication (1 of 3).

Neurotransmitters: The Chemical Keys To Communication (2 of 3).

Neurotransmitters: The Chemical Keys To Communication (3 of 3).

The Divisions of the Nervous System. Section 2-2.

Figure 2.3 The Divisions of the Nervous System. A flowchart illustrates the divisions of the nervous system. The nervous system is divided into 2: central nervous system and peripheral nervous system. The central nervous system consists of the brain and the spinal cord. The peripheral nervous system is divided in 2: somatic nervous system and autonomic nervous system. The somatic nervous system comprises afferent nerves and efferent nerves. The autonomic nervous system has 2 divisions: the sympathetic division and the parasympathetic division..

The Peripheral Nervous System: The Body’s Peripheral Devices.

Figure 2.3 The Branches of the Autonomic Nervous System.

The Central Nervous System: The Body’s Central Processing Unit (1 of 2).

The Central Nervous System: The Body’s Central Processing Unit (2 of 2).

Discussion Activity 1. One thing that distinguishes a human from other species in the ability to use symbols and language, and adopt or create new environments. Which process allows us to do things other species cannot?.

Discussion Activity Debrief 1. Our central nervous system consists of the spinal cord and the brain, creating an “information superhighway” as it transmits messages from sensory receptors to the brain, and from the brain to muscles and glands. It is your CNS that makes you so special. Other species see more sharply, smell more keenly, and hear more acutely. Other species run faster, or fly through the air, or swim underwater, without the benefit of artificial devices such as airplanes and submarines. But it is your CNS that enables you to use symbols and language, the abilities that allow people not only to adapt to their environment but also to create new environments and give them names..

The Brain: Wider Than The Sky. Section 2-3.

Understanding The Brain. Experimenting with the brain Assessing damage from disease and accidents Intentionally damaging parts of the brain in animals Using electrical probes to stimulate parts of the brain Electroencephalograph (EEG) Helps record the natural electrical activity of the brain Detects brain waves that pass between electrodes placed on the scalp.

Figure 2.7 Brain-Imaging Techniques. The figure displays diagrams and samples of brain-imaging techniques. Computerized axial tomography, the CAT scan allows a 3-dimensional image of the head. Positron emission tomography, the PET scan assesses brain activity. Magnetic resonance imaging, the M R I, studies brain activity through radio waves from a magnetic field that reveal changes in the blood flow..

Polling Activity 1. Which type of imaging technique will show the brain working in real time by taking repeated scans while subjects engage in activities? Computerized axial tomography Positron emission tomography Magnetic resonance imaging Functional MRI.

Polling Activity 1 Debrief. Which type of imaging technique will show the brain working in real time by taking repeated scans while subjects engage in activities? d. Functional MRI Functional MRI (fMRI) provides a more rapid picture and therefore enables researchers to observe the brain in real time by taking repeated scans while subjects engage in activities such as mental processes and voluntary movements. fMRI can be used to show which parts of the brain are active when we are, say, listening to music, using language, or playing chess..

A Voyage Through the Brain. Section 2-4.

Figure 2.8 Parts of the Brain. A diagram of the brain, split top to bottom, illustrates parts of the brain. The pea-sized pituitary gland sits in the base of the skull and secretes hormones that regulate many body functions, including secretion of hormones from other glands. It is sometimes referred to as the master gland. The Hypothalamus is near the pituitary gland and secretes hormones that stimulate secretion of hormones by the pituitary gland. It is also involved in basic drives such as hunger, sex, and aggression. The Corpus callosum is a thick bundle of axons that serves as a bridge between the two cerebral hemispheres. The Cerebrum is the center of thinking and language; its prefrontal area contains the executive center of brain. The thalamus lies near the center of the brain and functions as the relay station for sensory information. The Cerebellum lies at the back of the brain and is essential to balance and coordination. The Reticular formation, in the brainstem, is involved in regulation of sleep and waking; stimulation of reticular formation increases arousal. The Pons is in the brainstem and involved in regulation of movement, sleep and arousal, and respiration. The Medulla, the lower half of the brainstem, is involved in regulation of heart rate, blood pressure, respiration, and circulation..

Structures and Functions of the Brain (1 of 3). Hindbrain: Where the spinal cord meets the brain. Includes three major structures Medulla: Generates functions such as heart rate, blood pressures and respiration Pons: Transmits information about body movement and functions related to attention, sleep and arousal, and respiration Cerebellum: Maintains balance and control motor (muscle) behavior Reticular formation Lower part is within the hindbrain Sends messages to the cerebral cortex when stimulated Makes one alert to sensory information.

Structures and Functions of the Brain (2 of 3). Forebrain Thalamus: Relay station for sensory stimulation Hypothalamus: Regulates body temperature, concentration of fluid, storage of nutrients, motivation, and emotion Involved in hunger, thirst, sexual behavior, caring for offspring, and aggression Limbic system Amygdala: Connected with aggression, fear, vigilance, emotions, learning, and memory.

Structures and Functions of the Brain (3 of 3). Cerebrum: Responsible for thinking and language Cerebral cortex: Surface of the cerebrum Wrinkled or convoluted with ridges and valleys (fissures) Connected with cognitive abilities Corpus callosum Connects the two hemispheres of the cerebrum created by fissures.

Polling Activity 2. Which part of the brain is involved in emotions, learning, and memory, and helps us focus attention on matters that are novel and important to know more about? Amygdala Limbic system Hypothalamus Medulla.

Polling Activity 2 Debrief. Which part of the brain is involved in emotions, learning, and memory, and helps us focus attention on matters that are novel and important to know more about? a. Amygdala The amygdala is near the bottom of the limbic system and looks like two little almonds. Studies using lesioning and electrical stimulation show that the amygdala is connected with aggressive behavior in monkeys, cats, and other animals. The amygdala is also connected with vigilance. It is involved in emotions, learning, and memory, and it behaves something like a spotlight, focusing attention on matters that are novel and important to know more about..

The Cerebral Cortex. Section 2-5.

The Structure of the Cerebral Cortex. Outer layer of the cerebrum Involved in bodily activities, sensations, and perceptions Hemispheres – Separate the left and right lobes Occipital lobe deals with vision Temporal lobe deals with hearing and auditory functions Parietal lobe contains the somatosensory cortex Frontal lobe contains the motor cortex.

Thinking, Language, and the Cerebral Cortex (1 of 2).

Thinking, Language, and the Cerebral Cortex (2 of 2).

Left Brain, Right Brain?. Left-handed Have greater-than-average probability of language problems and certain health problems More likely than right-handed people to be gifted artists, musicians, and mathematicians Origins of handedness may be genetic Being left-handed was once seen as a deficiency Heritability makes about a 24% contribution to the likelihood of being right- or left-handed.

Split-Brain Experiments. People with severe cases of epilepsy may require a split-brain operation, where corpus callosum is severed Similar to having two brains Caused by the inability of one hemisphere to communicate with the other.

The Endocrine System. Section 2-6.

The Endocrine System. A diagram illustrates the components of the endocrine system in a human male and female. The parts are located as follows. The pineal gland, hypothalamus, and pituitary gland are located in the brain. The parathyroid glands and thyroid gland are located in the lower neck area. The thymus is in the upper chest. Within the abdomen is the pancreas. The kidneys are below the ribs in the back, and the adrenal glands are above the kidneys. The placenta develops in the uterus during pregnancy. The ovaries are part of the female reproductive system, and the testes are part of the male reproductive system..

The Pituitary and The Hypothalamus. The pituitary gland lies below the hypothalamus Labeled as the master gland Secretes hormones that regulate the functioning of other glands Growth hormone, prolactin, vasopressin, and oxytocin Hypothalamus regulates pituitary activity.

The Pineal and Thyroid Glands. Pineal gland secretes melatonin that: Regulates sleep-wake cycle May affect the onset of puberty Connected with aging Acts as a mild sedative Thyroid gland produces thyroxin that affects the body’s metabolism Variation in levels can lead to: Hypothyroidism Hyperthyroidism Cretinism.

The Adrenal Gland. Located above the kidneys Comprise an outer layer (cortex) and an inner core (medulla) Cortical steroids (corticosteroids) Secreted by the adrenal cortex Adrenal medulla secretes epinephrine and norepinephrine Epinephrine has emotional and physical effects.

The Testes and the Ovaries (1 of 2). Testosterone Produced by the testes (produced in small amounts by the adrenal gland) Enables development of male sex characteristics Primary sex characteristics are involved in reproduction Secondary sex characteristics, such as the presence of a beard and a deeper voice, differentiate males form females but are not involved in reproduction.

The Testes and the Ovaries (2 of 2). Estrogen and progesterone Produced by the ovaries along with small amounts of testosterone Estrogen fosters female reproductive capacity and secondary sex characteristics such as fatty tissue in the breasts and hips Progesterone stimulates growth of the female reproductive organs and prepares the uterus to maintain pregnancy.