Chapter 1: Biology and Behavior Flashcards
Sensory Neurons
(Also known as afferent neurons) transmit sensory information from receptors to the spinal cord and brain.
Motor Neurons
(Also known as efferent neurons) transmit motor information from the brain and spinal cord to muscles and glands.
Interneurons
Interneurons are located predominantly in the brain and spinal cord and are often linked to reflexive behavior.
Reflex Arcs
Consider what occurs when someone steps on a nail. Receptors in the foot detect pain and the pain signal is transmitted by sensory neurons up to the spinal cord. At that point, the sensory neurons connect with interneurons, which can then relay pain impulses up to the brain. Rather than waiting for the brain to send out a signal, interneurons in the spinal cord send signals to the muscles of both legs directly, causing the individual to withdraw the foot with pain while supporting with the other foot. The original sensory information still makes its way up to the brain; however, by the time it arrives there, the muscles have already responded to the pain, thanks to the reflex arc.
The nervous system is divided up into what two parts?
The nervous system is made up of the central nervous system (CNS; brain and spinal cord) and peripheral nervous system (PNS; nerve tissue and fibers outside the brain and spinal cord).
The peripheral nervous system is divided into what parts?
The PNS is divided into the somatic (voluntary) and autonomic (automatic) divisions.
The autonomic nervous system is divided into what parts?
“he autonomic system is further divided into the parasympathetic (rest-and-digest) and sympathetic (fight-or-flight) branches.
What is the main neurotransmitter used in the parasympathetic nervous system?
Acetylcholine.
Meninges
The meninges help protect the brain, keep it anchored within the skull, and resorb cerebrospinal fluid.
The brain develops from what embryonic portion?
The neural tube.
What are the subdivisions of the brain?
Hindbrain, Midbrain, Forebrain.
Overall Function of the Hindbrain
Located where the brain meets the spinal cord.
Controls balance, motor coordination, breathing, digestion, and general arousal processes such as sleeping and waking. In short, the hindbrain manages vital functioning necessary for survival.
What parts makeup the Hindbrain?
Medulla oblongata = Responsible for regulating vital functions such as breathing, heart rate, and blood pressure.
Pons = Contains sensory and motor pathways between the cortex and the medulla.
Cerebellum = Helps maintain posture and balance and coordinates body movements. Damage to the cerebellum causes clumsiness, slurred speech, and loss of balance. (ex: alcohol)
Overall Function of the Midbrain
The midbrain is associated with involuntary reflex responses triggered by visual or auditory stimuli.
What are the two types of nuclei in the midbrain?
Superior Colliculi = Receives VISUAL sensory input
Inferior Colliculus = Receives sensory information from the AUDITORY system.
Overall Function of the Forebrain
Associated with complex perceptual, cognitive, and behavioral processes. Among its other functions, the forebrain is associated with emotion and memory.
It is the forebrain that has the greatest influence on human behavior.
What are some methods of studying the brain?
Methods of studying the brain include studying humans and animals with lesions, electrical stimulation and activity recording (including electroencephalography [EEG]), and regional cerebral blood flow.
What parts make up the Forebrain?
Thalamus Hypothalamus Basal ganglia Limbic system Cerebral cortex
Thalamus
Relay station for all sensory information EXCEPT smell.
Sorts and transmits info to the cerebral cortex.
Hypothalamus
Maintains homeostasis (regulates metabolism, temperature, and water balance) and integrates with the endocrine system through the hypophyseal portal system that connects it to the anterior pituitary.
A key player in emotional experiences during high arousal states, aggressive behavior, and sexual behavior.
4 Fs of the Hypothamus
Feeding
Fighting
Flighting
(Sexual) Functioning
Lateral Hypothalamus
The hunger center. It has special receptors thought to detect when the body needs more food or fluids.
When destroyed, one Lacks Hunger.
Ventromedial Hypothalamus
Identified as the “satiety center,” and provides signals to stop eating. Brain lesions to this area usually lead to obesity.
When destroyed, one is Very Much Hungry.
Anterior Hypothalamus
Controls sexual behavior. In many species, damage to the anterior hypothalamus leads to permanent inhibition of sexual activity. The anterior hypothalamus also regulates sleep and body temperature.
When destroyed, one is Asexual.
Basal Ganglia
Smoothen movements and help maintain postural stability.
Limbic System
Emotion and Memory
Septal Nuclei
Involved with feelings of pleasure, pleasure-seeking behavior, and addiction.
Amygdala
Controls fear and aggression.
Hippocampus
Consolidates memories and communicates with other parts of the limbic system through an extension called the fornix.
Anterograde vs. Retrograde Amnesia
Anterograde amnesia is characterized by not being able to establish new long-term memories, whereas memory for events that occurred before brain injury is usually intact.
The opposite kind of memory loss, retrograde amnesia, refers to memory loss of events that transpired before brain injury.
What are the 4 lobes of the cerebral cortex?
F-POT
Frontal
Parietal
Occipital
Temporal
Frontal Lobe
Controls executive function, impulse control, long-term planning, motor function, and speech production.
Prefrontal Cortex tells other parts of the brain what to do.
Parietal Lobe
Controls sensations of touch, pressure, temperature, and pain; spatial processing; orientation; and manipulation.
Occipital Lobe
Controls visual processing.
Where is Broca’s area located?
The frontal lobe. Broca’s area is vitally important for speech production.
Broca’s area is usually found in the dominant hemisphere (which is usually the left hemisphere).
Temporal Lobe
Controls sound processing, speech perception, memory, and emotion.
Where is Wernicke’s area located?
Associated with language reception and comprehension.
Wernicke’s area is located in the temporal lobe in the dominant hemisphere.
How do the cerebral hemisphere’s (left & right communicate)?
Contralaterally. For example, the motor neurons on the left side of the brain activate movements on the right side of the body.
EXCEPTION : Hearing! In regards to hearing, cerebral hemispheres communicate with the same side of the body. In such cases, the hemispheres communicate ipsilaterally.
Dominant Hemisphere (usually the left)
Primarily analytic in function, making it well-suited for managing details. For instance, language, logic, and math skills are all located in the dominant hemisphere.
Again, language production (Broca’s area) and language comprehension (Wernicke’s area) are primarily driven by the dominant hemisphere.
NonDominant Hemisphere (usually the right)
Associated with intuition, creativity, music cognition, and spatial processing. The nondominant hemisphere simultaneously processes the pieces of a stimulus and assembles them into a holistic image.
The dominant hemisphere thus screens incoming language to analyze its content, and the nondominant hemisphere interprets it according to its emotional tone.
Corpus Callosum
Connects and shares info between the two cerebral hemispheres.
When the corpus callosum is severed, an object felt only by the left hand (which projects to the right hemisphere) could not be named (because language function is usually in the left hemisphere).
Neurotransmitters
Released by neurons to carry a signal to another neuron or effector (a muscle fiber or a gland).
Acetylcholine
Used by the somatic nervous system (to move muscles), the parasympathetic nervous system, and the central nervous system (for alertness).
Dopamine
Maintains smooth movements and steady posture.
Endorphins and Enkephalins
Act as natural painkillers.
Epinephrine and Norepinephrine
Maintain wakefulness and alertness, and mediate fight-or-flight responses.
γ-aminobutyric acid (GABA)
Acts as a brain “stabilizer”.
Serotonin
Modulates mood, sleep patterns, eating patterns, and dreaming.
Family studies
Look at the relative frequency of a trait within a family compared to the general population.
Twin studies
Compare concordance rates between monozygotic (identical) and dizygotic (fraternal) twins.
Adoption studies
Compare similarities between adopted children and their adoptive parents, relative to similarities with their biological parents.
Rooting Reflex
The infant turns his or her head toward anything that brushes its cheek.
Moro Reflex
The infant extends the arms, then slowly retracts them and cries in response to a sensation of falling.
Babinski Reflex
The big toe is extended and the other toes fan in response to the brushing of the sole of the foot.
Grasping reflex
The infant grabs anything put into his or her hand.
