Exam 1 Study Guide: Origins, Evolution, Nervous System Function, Cells & Genetics

Flashcards created from the Exam 1 Study Guide transcript covering key concepts in mentalism/materialism, nervous system divisions, brain anatomy, evolution, neural cells, and genetics.

What is Mentalism, and how does it explain the primary way behavior is created?

Mentalism proposes that behavior is created by a nonmaterial mind existing outside of the body.

What did Aristotle believe was the function of the brain?

To cool the blood.

How is the psyche defined in the context of Mentalism?

A nonmaterial mind that was proposed to be the source of behavior.

What is Materialism, and who were the two theorists behind it?

Materialism states that behavior is a function of the nervous system. The two theorists behind it were Alfred Wallace and Charles Darwin.

What is natural selection?

The process where traits which increase the likelihood of survival and reproduction are passed down to further generations.

What are gyri and sulci, and why is the brain folded?

Gyri are bumps observed on the surface of the brain, and sulci are grooves between gyri. The brain is folded to allow more neurons to be present.

What are the components and main functions of the Central Nervous System (CNS)?

Components: Brain and spinal cord. Functions: Thinking, planning, and integrating information from all over the body.

What are the components and main functions of the Peripheral Nervous System (PNS)?

Components: Nerves and processes outside the CNS which connect to sensory receptors, muscles, and internal organs. Functions: Send information to the CNS about the world, move muscles, and control internal organs.

What are the roles of the Somatic Nervous System (SNS) and Autonomic Nervous System (ANS)?

SNS controls voluntary movement and muscle movements. ANS controls involuntary responses, the fight or flight response, and the rest and digest response.

What is the timeline for the origins of life, first brain cells, first brain, first human-like brain, and the modern human brain?

First forms of life: $3.5 \times 10^9$ years ago (3.5 billion years ago); First brain cells: $700 \times 10^6$ years ago (700 million years ago); First brain: $250 \times 10^6$ years ago (250 million years ago); First human-like brain: $6 \times 10^6$ years ago (6 million years ago); Modern human brain: 200,00 years ago.

What are the characteristics associated with each level of taxonomy from Kingdom to Species?

Kingdom (Animals): Neurons and muscles used for locomotion; Phylum (Chordates): Brain and spinal cord; Class (Mammals): Large brains and social behavior; Order (Primates): Visual control of hands; Family (Great apes): Tool use; Genus (Human): Language; Species (Modern human): Complex culture.

What are the four key characteristics of a Chordate Nervous System?

1. Bilaterally symmetrical and segmented. 2. Brain and spinal cord encased in cartilage or bone. 3. Crossed organization: each hemisphere receives information from and controls the opposite side of the body. 4. Emergence of 'complex behavior.'

What are the defining characteristics of Australopithecus, Homo habilis, Homo erectus, and Homo neanderthalensis?

Australopithecus: Walked upright, human characteristics, brain $\frac{1}{2}$ the size of modern brain. Homo habilis: 'Handy human,' $2 \times 10^6$ years ago in Africa, made simple stone tools. Homo erectus: 'Upright human,' $1.6 \times 10^6$ years ago in Europe and Asia, more sophisticated tools. Homo neanderthalensis: Larger brain than Homo sapiens, overlapped with Homo sapiens and other hominid species.

Why do fruit eaters like spider monkeys have larger brains than foragers like howler monkeys?

Finding fruit is more difficult than eating grass and leaves, requiring more spatial memory and good sensory systems.

What are the primary functions of the four lobes of the brain?

Frontal Lobe: 'Executive' functions and decision making. Parietal Lobe: Integrates sensations into body coordinates. Temporal Lobe: Hearing, language, memory, smell, taste. Occipital Lobe: Visual processing.

Define neuroplasticity, genotype, phenotype, and epigenetics.

Neuroplasticity: Nervous system's capacity to adapt to the world by changing how its functions are organized. Genotype: Genetic material. Phenotype: Outward appearance and behavior. Epigenetics: How a person's genetic make-up interacts with the environment to create a specific phenotype.

What are the functions of the Enteric, Sympathetic, and Parasympathetic Nervous Systems?

Enteric Nervous System: Neurons lining the esophagus, stomach, intestines, and colon for digestion. Sympathetic Nervous System: Arouses the body for action, including increasing heart rate and blood pressure (fight or flight). Parasympathetic Nervous System: Prepares the body to rest and digest and reverses the fight or flight response.

What do the anatomical directions Dorsal, Ventral, Anterior, Posterior, Medial, and Lateral refer to?

Dorsal: Top/above; Ventral: Bottom/below; Anterior: Front; Posterior: Back; Medial: Middle; Lateral: Side.

What are the three meninges listed from superficial to deepest layer?

1. Dura mater ('hard mother'): Tough outer layer of fibrous tissue. 2. Arachnoid layer ('like a spider's web'): Thin sheet of delicate connective tissue. 3. Pia mater ('soft mother'): Moderately tough inner layer that clings to the brain's surface.

How many ventricles are in the brain, what do they produce, and what does this fluid consist of?

There are $4$ ventricles. They produce Cerebrospinal fluid (CSF), which flows around the brain and spinal cord and consists of sodium chloride and other salts in water.

What is the difference between Gray Matter, White Matter, and the Corpus Callosum?

Gray Matter: Composed mostly of cell bodies and blood vessels. White Matter: Mostly made up of fat-sheathed neural axons. Corpus Callosum: Large white matter tract connecting the two hemispheres.

What is the difference between neurons and glial cells?

Neurons (around $80 \times 10^9$) carry out the brain's major functions, whereas glial cells support and modulate neurons' activities.

What is the difference between a nerve and a tract?

A nerve is a large collection of neurons coursing together outside the CNS, whereas a tract is a large collection of neurons coursing together within the CNS.

What are the functions of the Hindbrain structures: Cerebellum, Reticular Formation, Pons, and Medulla?

Cerebellum: Complex movements, cognitive functions, fine movements, and dexterity. Reticular Formation: Reticular activating system, stimulates forebrain, sleep-wake behavior, behavioral arousal. Pons: 'Bridge' connecting cerebellum to the rest of the brain, controls important movements. Medulla: Control of breathing and heart rate.

What are the functions of the Tectum and Tegmentum in the Midbrain?

Tectum (roof of midbrain): Sensory processing and producing orienting movements. Tegmentum (floor of midbrain): Eye and limb movements, species-specific behaviors, and perception of pain.

What are the functions of the Thalamus and Hypothalamus in the Diencephalon?

Thalamus: Major relay for sensory information coming into the brain, sensory and motor processing, and integrative functions. Hypothalamus: Control of hormone release through the pituitary gland, feeding, sexual behavior, sleeping, temperature regulation, and emotional behavior.

What structures make up the Basal Ganglia, what do they control, and what disorders are associated with them?

Structures: Caudate nucleus, Putamen, and Global pallidus. They control voluntary and involuntary behavior. Associated disorders: Parkinson's disease and Touratte's syndrome.

How many layers are in the cortex, and which layer receives the most afferent projections?

There are $6$ layers in the cortex. Layer $4$ receives the most afferent projections.

What structures make up the Limbic System and what is it associated with?

Structures: Amygdala, Hippocampus, and Cingulate cortex. Associated with: Regulation of emotional behaviors, memory, and spatial navigation.

How many cranial nerves are there, which nervous system are they part of, and which one is the most important?

There are $12$ cranial nerves. They are part of the CNS. The most important is the vagal nerve, which causes the heart to beat.

What is the functional difference between Dorsal and Ventral spinal nerves?

Dorsal spinal nerves are afferent (sensory neurons going into the brain). Ventral spinal nerves are efferent (carry information from the spinal cord to the muscles).

How did Golgi's and Ramon Y Cajal's theories on neural function differ?

Golgi believed the nervous system is composed of a network of interconnected fibers ('nerve net'). Ramon Y Cajal proposed the neuron hypothesis, stating that the nervous system is made of discrete cells.

What are the three basic subdivisions of a cell and their functions?

1. Dendrite: Gathers information from other neurons. 2. Cell body (soma): Core region containing the nucleus; integrates information. 3. Axon: Carries information to be passed on to other cells.

Define dendritic spine, axon hillock, terminal button, and synapse.

Dendritic Spine: Protrusion from a dendrite that increases surface area and is the usual point of contact. Axon Hillock: Junction of soma and axon where action potential begins. Terminal Button: Knob at tip of axon conveying information to other neurons (end foot/axon terminal). Synapse: Gap between neurons where neurotransmitter is released.

What are the roles of Sensory neurons, Interneurons, and Motor neurons?

Sensory neurons: Afferent; bring information to the CNS. Interneurons: Associate sensory and motor activity within the CNS. Motor neurons: Send signals from the brain and the spinal cord.

What are the functions of Ependymal cells, Astrocytes, Microglia, Oligodendrocytes, and Schwann Cells?

Ependymal: Make CSF in ventricles. Astrocyte: Structural support, brings nutrients from capillaries, forms scar tissue. Microglia: Immune system function, scavenges debris (phagocytosis). Oligodendrocytes: Myelinate axons in CNS. Schwann Cells: Myelinate axons in PNS.

What is myelin and what is its purpose?

Myelin is a glial coating that surrounds axons to improve action potentials.

What are the functions of the Nucleus, Nuclear Membrane, Mitochondria, Endoplasmic Reticulum, Microtubules, Microfilaments, Golgi Bodies, and Intracellular Fluid?

Nucleus: Contains chromosomes and genes. Nuclear Membrane: Surrounds nucleus. Mitochondria: Gathers, stores, releases energy. Endoplasmic Reticulum: Folded layers where proteins are assembled. Microtubules: Transport molecules and give shape. Microfilaments: Threadlike fibers of cell skeleton. Golgi Bodies: Packages protein molecules for transport. Intracellular Fluid: Fluid where internal structures are suspended.

What are the roles of the Phospholipid Bilayer, Channels, Gates, and Pumps in the cell membrane?

Phospholipid Bilayer: Has hydrophilic heads and hydrophobic tails; regulates movement of substances in and out. Channel: Protein opening allowing passage of ions. Gate: Protein allowing passage only when open. Pump: Protein actively transporting substances across the membrane.

What are the four nucleotide bases of DNA and how do they bond together?

Adenine, Thymine, Guanine, Cytosine. Adenine binds to thymine, and Guanine binds to cytosine.

What occurs during gene transcription and gene translation, and which cell structures are involved?

Transcription: DNA unwinds and complementary mRNA is created. Translation: mRNA leaves nucleus and is translated into amino acids to form a protein. Endoplasmic reticulum builds proteins, Ribosomes activate protein synthesis, and Golgi bodies package proteins.

How many pairs of chromosomes do humans have, and how are autosomes distinguished from sex chromosomes?

Humans have $23$ pairs of chromosomes. There are $22$ pairs of autosomes creating most characteristics and $1$ pair of sex chromosomes creating sexual characteristics.

What is an allele, and how do homozygous and heterozygous genotypes differ?

An allele consists of $2$ matched copies of a gene (one from mother, one from father). Homozygous means the alleles are the same (e.g., both brown eyes), while heterozygous means the alleles are different (e.g., brown eyes from dad, blue eyes from mom).

What is the likelihood of Sickle Cell Anemia expression in children if both parents carry the recessive trait versus if only the father carries it?

If both father and mother have the recessive trait, there is a $250 \times 10^{-1}\%$ ($25\%$, or $1$ in $4$) chance of expression. If only the father has the recessive trait, there is a $0\%$ chance of expression.

What are three mechanisms by which epigenetics changes gene expression?

1. Histone Modification: Blocks or causes DNA to unwrap. 2. DNA Modification: Transcription of DNA into mRNA may be blocked or enabled. 3. mRNA Modification: mRNA translation may be enabled or blocked.