Ch 8 - A & P.docx

Anatomy & Physiology Ch 8 Nervous System SmartBook The main purpose of the nervous system is to detect, analyze, and respond to changes. The central nervous system is made up of the brain and spinal cord. Which division of the nervous system is responsible for involuntary control of cardiac striated muscle, smooth muscle tissue, adipose tissue, and glands? Autonomic division. Select all of the common features of the various types of neurons.  Dendrites  Cell body  Axon Ganglia are specialized masses of nerve tissue formed by nerve cell bodies of neurons in the peripheral nervous system. Which of the following are the general functions of the nervous system?  Analysis of detected changes  Detection of changes  Maintaining homeostasis through response to changes  Initiation of appropriate action in response to detected changes True: In the central nervous system, there are more neuroglial cells than neurons. What division of the nervous system is comprised of the brain and the spinal cord? Central nervous system. Select the two unique functional characteristics of neurons.  Irritability  Conductivity The division of the nervous system that is divided into the somatic and autonomic nervous systems is the motor division.

A resting neuron has a higher concentration of sodium ions outside of the cell and a higher concentration of potassium ions inside the cell. Neurons generate action potentials to communicate with each other and other cells. Specialized masses (swellings) of nerve tissue formed by cell bodies of neurons and are located outside of the brain and spinal cord are ganglia. When the trigger zone of a neuron reaches threshold stimulus it will send an action potential. The cells responsible for providing support and protection for neurons are neuroglia cells. A shift in membrane voltage back toward the resting membrane potential is called repolarization. Irritability can be defined as a sensitivity to changes in the environment (stimuli) which results in the formation of an impulse. At resting membrane potential, potassium ion (K + ) concentration inside the cell is higher than outside the cell. Arrange these events leading to the conduction of an action potential. 1. With a threshold stimulus voltage gated sodium channels open. 2. Sodium enters 3. Voltage gated potassium channels open 4. Potassium diffuses out A neuron will produce an action potential of full strength every time it receives a threshold stimulus or greater because of a property known as the all or none response. Soon after depolarization, voltage-sensitive potassium channels open and potassium diffuses out causing the membrane to repolarize.

What two terms best describe the image?  Synaptic cleft  Synapse A neurotransmitter that brings the postsynaptic membrane closer to threshold and thus more likely to fire an action potential is an excitatory neurotransmitter. In an axon, a local depolarization or action potential can trigger an action potential in the adjacent, more distal membrane. In a neuron, a stimulus that is weaker than the threshold stimulus will not produce an action potential. Identify the three membranes that form the meninges.  Arachnoid mater  Dura mater  Pia mater Repolarization is due to the movement of potassium ions out of the neuron. The brainstem connects distally (caudal) to the spinal cord. A synapse is the point where an axon meets  a muscle cell  a dendrite  a gland  another axon Match the neurotransmitter type with the action it causes.  Depolarization  Excitatory neurotransmitter  Hyperpolarization  Inhibitory neurotransmitter The portion of the brain that performs brain functions involved with sensations, voluntary actions, reasoning, planning, and problem solving is the cerebrum.

What immediately follows depolarization? Repolarization. Which part of the brain is located centrally between all other areas of the brain? Diencephalon. The three layers of membranes surrounding most of the CNS are collectively called the meninges. Which of these is a set of brain structures associated with emotion and memory? Limbic system. The whole brain can be divided into four major portions: the cerebrum , the diencephalon , the cerebellum , and the brainstem. Which structure connects the brain and the spinal cord? Brainstem. What is the space between the presynaptic cell and the postsynaptic cell called? Synaptic cleft. The cerebrum is  in control of voluntary actions  the largest portion of the brain Identify the part of the brain circled on the image. Diencephalon The "part" of the brain that is not a distinct structure but it includes parts of the cerebral cortex, diencephalon, and the basal nuclei is the limbic system.

A web of grey matter scattered throughout the brainstem, cerebrum and cerebellum that functions to arouse the cerebrum to wakefulness is called the reticular formation. The pons, medulla oblongata, and midbrain are subparts of what part of the brain? Brainstem. A structure called the vermis connects the two hemispheres of the cerebellum. The largest ventricles are the lateral ventricles, which are located within the cerebral hemispheres. What space does the spinal cord fill? Vertebral canal Which part of the brain is located centrally between all other areas of the brain? Diencephalon. Injury to the reticular formation can result in  unconsciousness  coma The funiculi of the white matter in the spinal cord contain nerve tracts. A structure called the vermis connects the two hemispheres of the cerebellum. There are four ventricles within the brain What structure conducts action potentials towards and away from the brain, and also acts as a motor reflex center. Spinal cord. The spinal cord extends from the foramen magnum to the second lumbar vertebra. The region of the brain that is located above the midbrain, below the corpus callosum, and between the two cerebral hemispheres is the diencephalon. The peripheral nervous system includes cranial and spinal nerves. The outer portion of the spinal cord is white matter. Select the functions of the spinal cord.  Information transmittal to and from the brain

 Spinal reflexes A total of 12 pairs of cranial nerves emerge from the brain and brainstem. Nerves from the spinal cord are called spinal nerves and they are all mixed nerves. The cranial nerves and spinal nerves make up the peripheral nervous system. The first part of a reflex arc is the receptor , which generates action potentials which move along the sensory, or afferent, neuron. Select the regions of white matter in the spinal cord.  Anterior funiculus  Posterior funiculus  Lateral funiculus Homeostasis is maintained by the actions of the autonomic division of the nervous system. Spinal nerves are mixed nerves that provide two-way communications. The nerve fibers of the autonomic nervous system are motor fibers. Which of the following is not a component of a reflex arc? Spinal plexus. Sympathetic and parasympathetic preganglionic fibers release the neurotransmitter called acetylcholine or Ach. What is the role of the parasympathetic part of the nervous system? Regulates body functions while in restful situations; "resting and digesting" response1 What functions are regulated by the autonomic nervous system?  Body temperature  Heart rate  Blood pressure  Breathing rate An autonomic motor pathway consists of  postganglionic neuron  preganglionic neuron

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