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.