Biopsychology Chapter 2 (Anatomy of Neurons (nita) (Neurons : Specialized…
Biopsychology Chapter 2
Division of Nervous System
Central Nervous System
Begins at the brainstem and ends at about the second lumbar vertebra
Surrounding the grey mater
The arm at the grey mater
The grey mater except the arm
consist of 5 major division
-The most posterior division of the brain.
-carrying signals between the rest of the brain & the body.
- reticular formation
-Because it contain various nuclei that are involved in variety of functions.
E.g : sleep, attention, movement, the maintenance of muscle tone, various cardiac, circulatory, & respiratory reflexes
ascending & descending tracts & part of the
Pons & Cerebellum
Cerebellum- control movement , deficits in decision making , use of language.
has two divisions: the
tectum & tegmentum
tectum is the dorsal(upper side
)surface of the midbrain, that have
visual motor function.
:check: direct the body’s orientation toward
:check: from particular visual stimuli
tegmentum (the underside )
Contains 3 colorful structures:
the periaqueductal gray the :check: substantia nigra the :check: red nucleus
thalamus & hypothalamus.
Role of nuclei in thalamus are
: receive signals from sensory receptors, process them, & transmit them to appropriate areas of sensory cortex.
:check: regulation of several motivated behaviors
:check: (e.g.: eating, sleeping, & sexual behavior)
largest division of the human brain.
It initiates voluntary movement interprets sensory input, & mediates complex cognitive processes .
learning speaking, & problem solving.
Protector of CNS(saf)
Dura Mater ( tought mother)
the outer meninx
-contain tough collagen fiber and blood
Arachnoid membrane/ mater( spider-like membrane/mother)
-much thinner and more delicate than dura mater
-contains many thin fibers that connect to the underlying pia mater
-Fibers cross a fluid-filled space between the arachnoid mater and pia mater
Pia Mater (tender mother)
-The innermost meninx
Thin and delicate layer of tissue that rests on the outside of the brain and spinal cord
Ventricles & Cerebrospinal Fluid
Cerebrospinal fluid ( CSF)
-form from blood plasma by special structure called
-Absorb shock between brain and skull & spinal cord and vertebrae
-Help maintain chemical homeostasis within the central nervous system
-Support and cushion the brain
-Has FOUR large internal chambers
-Two lateral ventricles
-Barrier between the brain’s blood vessels (capillaries) and the cells and other components
-A defence against disease-causing pathogens and toxins that may be present in blood
-The tight gap allows only small molecules, fat-soluble molecules, and some gases to pass freely through the capillary wall and into brain tissue
-help maintain relatively constant levels of hormones, nutrients and water in the brain
Division of Nervous System
Peripheral Nervous System (alia)
Somatic Nervous System
Greek word 'soma' means body
Receive sensory information from the sensory organs
Controls movements of the skeletal muscles
Strolling around the park and saw someone bitten by a dog, u naturally ran away from that place knowing that theres a dangerous wild dog
Carry sensory signal from internal organ to CNS
Carry motor signal from CNS to external organ
Autonomic Nervous System
Concerns with the regulation of smooth muscle, cardiac muscles, & glands
Also compose Afferent (internal organs to CNS) & Efferent (CNS to internal organs) Nerves
Works automatically, without a person’s conscious effort.
Rate of breathing
Prepares the body for stressful or emergency situations
Heart rate and force of heart contractions
Release of energy stored in the liver
Controls body process during ordinary situations
Slows the heart rate
Reduces blood pressure
Anatomy of Neurons (nita)
: Specialized cell for reception,conduction & transmission of electrochemical signals
External Anatomy of Neurons
(soma) : The metabolic center of the neuron.
: The semipermeable membrane that encloses the neuron.
: The short processes emanating from cell body. Receive most of synaptic contact from other neurons.
: Junction between axon and the cell body.
: The long narrow process tht projects from the cell body.
: The fatty insultation around many axon.
Nodes of Ranvier
: The gaps beween section of myelin.
: The ending of the axon branches. Release chemical into synapess.
: The gaps between adjacent neurons across which chemical signal are transmitted.
Neuron Cell Membrane
Composed of lipid bilayer/ 2 layer of fat molecules.
: certain molecules can pass through.
: transfer signal to the inside neuron when particular molecules bind to then on the outside membrane.
Internal Anatomy of Neurons
: Thespherical DNA-containng structue of the cell body.
: Sites of aerobic(oxygen-consuing)energy release.
: Rapid transport of material throughout neurons.
: 1. Folded membrane in cell body, rough.
Role : Synthesize protein and fat.
: The clear internal fluid of the cell.
: 1. Located on endoplasmic reticulum.
Role : Synthesize protein.
: Connected system of membranes that packages molecules in vesicles.
::pencil2: Spherical membrane.
:pencil2: Store neurotransmitter molecules ready for release near synapses.
: Molecules that are released from active neurons.
Resting Membrane Potential
Focus on :
Sodium ions (Na+)
Potassium ions (K+)
Resting neurons, majority
Na+ ions outside the cell
K+ ions inside the cell
to enter the resting neurons :
: the -70mV charge attracts the Na+ into resting neurons.
Random motion from Na+
: Na+ will randomly move to the lower concentration
Why dont they entered the neuron?
Na+ ion channel is closed
K+ ion channels open in resting neuron, but only few of them go out of the neurons, because attracted by the -70mV charges