Textbook Notes (368,611)
Canada (162,009)
Psychology (2,981)
PSY290H1 (52)
all (1)
Chapter 3

Psy290-Chapter 3 summary

8 Pages
119 Views
Unlock Document

Department
Psychology
Course
PSY290H1
Professor
All Professors
Semester
Fall

Description
Chapter 3: Neuroanatomy 3.1) General layout of the nervous system % Divisions of the Nervous system - CNS: is the division of the nervous sytem that is located within the skull and spine -PNS: is the divison that is located outside the skull and spine -under PNS:1) Somatic nervous system: interacts with the external environment. it is composed of Affferent nerves that carry sensory signals from the skin, skeletal muscles, joints, eyes, ears, and so on to the central nervous syste. Efferent nerves that carry motor signals from the cns to the skeletal muscles. 2) Autonomic nervous system: regulates the body's internal environment. it carries afferent nerves that carry sensory signals from internal organs to the cns and efferent nerves that carries motor signals from the cns to internal organs. a) sympathetic nerves: autonomic motor nerves that project from the cns in the lumbar and thoracic regions of the spinal cord b) Parasympathetic neves: autonomic motor nerves that project from the brain and sacral region of the spinal cord. - the sympathetic and parasympathetic systems differ in that the sympathetic neurons that project from the CNS synapse on second-stage neurons at a substantial distance from their target organs, whereas the parasympathetic neurons that project from the CNS synapse near their target organs on very short secondstage neurons - The conventional view of the respective functions of the sympathetic and parasympathetic systems stresses three important principles: (1) that sympathetic nerves stimulate, organize, and mobilize energy resources in threatening situations, whereas parasympathetic nerves act to conserve energy; (2) that each autonomic target organ receives opposing sympathetic and parasympathetic input, and its activity is thus controlled by relative levels of sympathetic and parasympathetic activity; and (3) that sympathetic changes are indicative of psychological arousal, whereas parasympathetic changes are indicative of psychological relaxation. % Meninges, ventricles and cerebrospinal fluid - outter to inner: Dura mater (tough mother) -Arachnoid membrane (inside the dura mater) - Subarachnoid space (space containing many large blood vessels and crebrospianl fluid) - Pia mater (innermost menix, delicate, adheres to the surface of the cns) -Also protecting the CNS is the cerebrospinal fluid (CSF), which fills the subarachnoid space, the central canal of the spinal cord, and the cerebral ventricles of the brain - The central canal is a small central channel that runs the length of the spinal cord; the cerebral ventricles are the four large internal chambers of the brain: the two lateral ventricles, the third ventricle, and the fourth ventricle - The subarachnoid space, central canal, and cerebral ventricles are interconnected by a series of openings and thus form a single reservoir - The cerebrospinal fluid supports and cushions the brain.: problem with csf, they experience stabbing pain each time they jerk their head. -Cerebrospinal fluid is continuously produced by the choroid plexuses networks of capillaries (small blood vessels) that protrude into the ventricles from the pia mater. The excess cerebrospinal fluid is continuously absorbed from the subarachnoid space into large bloodfilled spaces, or dural sinuses, which run through the dura mater and drain into the large jugular veins of the neck. - cerebral aqueduct, which connects the third and fourth ventricles. - The resulting buildup of fluid in the ventricles causes the walls of the ventricles, and thus the entire brain, to expand, producing a condition called hydrocephalus (water head). Hydrocephalus is treated by draining the excess fluid from the ventricles and trying to remove the obstruction. % Blood- brian barrier - The blood brain barrier does not impede the passage of all large molecules. Some large molecules that are critical for normal brain function (e.g., glucose) are actively transported through cerebral blood vessel walls.Also, the blood vessel walls in some areas of the brain allow certain large molecules to pass through them unimpeded. 3.2) Cells of the Nervous system - neurons are cells that are specialized for the reception, conduction, and transmission of electrochemical signals. % Glial cells: the forgotten cells: - Oligodendrocytes, for example, are glial cells with extensions that wrap around the axons of some neurons of the central nervous system. These extensions are rich in myelin, a fatty insulating substance, and the myelin sheaths that they form increase the speed and efficiency of axonal conduction. - peripheral nervous system by Schwann cells, a second class of glial cells - Notice that each Schwann cell constitutes one myelin segment,whereas each oligodendrocyte provides several myelin segments, often on more than one axon.Another important difference between Schwann cells and oligodendrocytes is that only Schwann cells can guide axonal regeneration (regrowth) after damage. That is why effective axonal regeneration in the mammalian nervous system is restricted to the PNS. - Microglia make up a third class of glial cells.Microglia are smaller than other glia thus their name. They respond to injury or disease by multiplying, engulfing cellular debris, and triggering inflammatory responses - Astrocytes constitute a fourth class of glial cells. They are the largest glial cells and they are so named because they are star-shaped (astron means star ). The extensions of some astrocytes cover the outer surfaces of blood vessels that course through the brain; they also make contact with neuron cell bodies. These particular astrocytes play a role in allowing the passage of some chemicals from the blood into CNS neurons and in blocking other chemicals. the function of astrocytes was merely to provide support for neurons providing them with nutrition, clearing waste, and forming a physical matrix to hold neural circuits together - For example, astrocytes have been shown to send and receive signals from neurons and other glial cells, to control the establishment and maintenance of synapses between neurons to modulate neural activity to maintain the function of axons and to participate in glial circuits 3.6) Major structures of brains % Myelencephalon - the myelencephalon (or medulla), the most posterior division of the brain, is composed largely of tracts carrying signals between the rest of the brain and the body. - reticular formation: It is a complex network of about 100 tiny nuclei that occupies the central core of the brain stem from the posterior boundary of the myelencephalon to the anterior boundary of the midbrain. - Sometimes, the reticular formation is referred to as the reticular activating system because parts of it seem to play a role in arousal. However, the various nuclei of the reticular formation are involved in a variety of functions including sleep, attention, movement, the maintenance of muscle tone, and various cardiac, circulatory, and respiratory reflexes. % Metencephalon - These structures create a bulge, called the pons, on the brain stems ventral surface. The pons is one major division of the metencephalon -The cerebellum is the large, convoluted structure on the brain stems dorsal surface. It is an important sensorimotor structure; cerebellar damage eliminates the ability to precisely control one s movements and to adapt them to changing conditions. However, the fact that cerebellar damage also produces a variety of cognitive deficits (e.g., deficits in decision making and in the use of language suggests that the functions of the cerebellum are not restricted to sensorimotor control. % Mesencephalon - The two divisions of the mesencephalon are the tectum and the tegmentum - The tectum (roof) is the dorsal surface of the midbrain. In mammals, the tectum is composed of two pairs of bumps, the colliculi (little hills). The posterior pair, called the inferior colliculi, have an auditory function; the anterior pair, called the superior colliculi, have a v
More Less

Related notes for PSY290H1

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit