What were the four main observations made by Charles Darwin, and what inference was derived from these observations?
- Reproduction increases a population rapidly unless factors limit it
- Individuals of a given species are not identical
- Some of the variations among individuals is inherited
- Not all the offspring of a given generation survive to reproduce
The inference is that of natural selection; Darwin concluded that variations among individuals affect the probability of their surviving long enough to reproduce, thus increasing or decreasing the chances of adaptation and subsequent changes to a species long-term
Describe how the encephalization factor is measured and explain it significance in the evolution of the central nervous system
The encephali is Ehsan factor is a measure of brain size relative to body size. It corresponds to the distance between the ‘line of best fit’ (prediction line for brain size among mammals as a group) and the brain weight value for that species.
List 4 structures of the limbic system and identify a specific function for one of them
- Amygdala
- Mammillary bodies
- Hippocampus
- Fornix
All structures contribute to learning and memory. One of the amygdala is functions is emotional regulation
Name and describe the six stages of the nervous system development in order
- Neurogenesis: the division of nonneuronal cells to produce neurons
- Cell migration: the movement of cells to their appropriate regions - establishing distinct nerve cell populations
- Differentiation: the transformation of cells into distinctive types of neurons and glial cells
- Synaptogenesis: the establishment of synaptic connections as axons and dendrites grow
- Neuronal cell death: the selective death of many nerve cells
- Synapse Rearrangement: the loss of some synapses and development of others to refine synaptic connections
Describe the sequence of events that precede and follow the generation of an action potential
Can be described in five stages
- Resting membrane potential, required to set a baseline of activity (open K+ channels)
- Incremental depolarization towards the threshold and the axon hillock
- At threshold, sharp rise in polarity due to the opening of Na+ channels
- Afterpotential - Na+ channels close automatically, K+ channels open, repolarizing and even hyperpolarizing the cell
- All voltage-gated ion channels close. The cell returns to resting potential.
- refractory period?
Delineate the two major dopaminergic pathways and describe their major functions
Mesostratial Pathway: plays a crucial role in motor control. Significant loss of these neurons has been associated with Parkinson’s
Mesolimbocortical Pathway: important in reward and reinforcement. Abnormalities in this Pathway are associated with schizophrenic symptoms.
Explain all the ways that exogenous chemicals can influence information transmission on the postsynaptic neuron and give an example drug for each mechanism
- Effects on transmitter receptors
- blockade of receptors (antipsychotic drugs block dopamine D2 receptors)
- activation of receptors (nicotine activates ACH receptors) - Effects on cellular processes
- regulation of the number of postsynaptic receptors (alcohol increases the number of receptors for GABA)
- modulation of intracellular signals (mood-stabilizer lithium is believed to directly affect second messenger systems, leading to changes in gene expression and receptor density)
Explain the functional role and mechanics of metabotropic receptors
receptors are protein molecules embedded in the postsynaptic membrane that recognize a specific transmitter
Metabotropic receptors, when activated by a Nero transmitter, activate G proteins that open other ion channels and/or alter the functioning of the postsynaptic cell
Identify the names and sources of the two primary hormones released in the posterior pituitary. Describe a behavioural function for one of them
The posterior pituitary hosts 2 hormones, produced by the hypothalamus
- Vasopressin
- Oxytocin- stimulates the release of milk by mammary glands
Name and describe the four stages of reproductive behaviour in animals
- Sexual attraction: first step in the meeting behaviour of animals, in which animals emit stimuli that attract members of the opposite sex (peacock feathers, primate “sex skin”, odours in most female mammals)
- Appetitive behavior: helps stop wish or maintain sexual interaction (birds engage in elaborate songs or nest building behavior; mammals stay in close proximity)
- Copulation: also known as coitus. The sexual act, which includes one or more intromissions and the ejaculation of semen, followed by a refractory period where an individual cannot recommence copulation.
- Post copulation behavior: species specific post copulatory behaviors. For mammals and birds, post copulatory behaviours include extensive parental behaviours to nurture the offspring.
Identify the four major neural systems that mediate sleep and describe each of their roles
- A forebrain system that by itself can display SWS
- A brainstem system that activates the forebrain into wakefulness
- A pontine system that triggers REM sleep
- A hypothalamic system that affects the other three brain regions to determine whether the brain will be awake or asleep
Identify five levels of analysis that are considered to be under the purview of biological psychology and give a brief description of each
1. 2. 3. 4. 5.
List five cranial nerves that have exclusively motor functions
The Oculomotor, Trochlear, and Abducens - innervate muscles to move the eyes
Spinal Accessory - Controls neck muscles
Hypoglossal - Controls the tongue
Explain in full detail how the resting membrane potential is established and maintained
cells contain many large, negatively charged molecules, such as proteins, that do not cross the membrane. The sodium-potassium pump continually pushes Na+ ions out and K+ ions in. Na+ ions cannot pass back inside. The departure of potassium ions leaves the inside of the cell more negative than the outside. When enough potassium ions have departed to bring the membrane potential to -65 mV or so, electrical attraction pulling K+ in is exactly nbalance by the concentration gradient pushing K+ out. This is the K+ equilibrium potential, approximately the cells resting potential.
Identify the five monoamines that act as classical neurotransmitters
Two classes - Catecholamines 1. dopamine 2. epinephrine 3. norepinephrine Indoleamines 4. melatonin 5. serotonin
Forebrain
Telencephalon - Cortex, basal ganglia, and limbic system
Diencephalon - thalamus and hypothalamus
Midbrain
Mesencephalon
Hindbrain
Metencephalon - Cerebellum and Pons
Myelencephalon - The Medulla
Meninges
Dura matter - The outermost of the three meninges that surround the brain and spinal cord
Pia matter - The innermost of the three meninges that surround the brain and spinal cord
Arachnoid - The thin covering of the brain that lies between the Dura matter and Pia matter
About how many neurons are in the adult human brain
80-90 billion
About how many synapses are thought to be in the human brain?
A Quadrillion
Brain arteries from the basal view
Basilar arteries
Vertebral arteries
Circle of Willis (including internal carotid arteries)
Two types of strokes
Hemorrhagic Stroke: occurs when a rupture allows blood to leak into the brain
Ischemic Stroke: clots of other debris prevent blood from reaching a region of the brain, causing it to die
Main role of cerebral ventricles
Production and secretion/distribution of cerebrospinal fluid
