Brain And Soinal Cord Flashcards
What are the functions of the nervous system?
- Activation of muscles for movement
- Control of glandular secretions
- Regulation of heart rate and blood pressure.
- Maintenance of body temperature
- Sensation of various stimuli- pain, touch, physiologic changes (stretch, ischemia)
What is the neuron?
The functional cells of the nervous system, which carries nervous impulses to and from the body and central nervous Lys system
The structure and function of neurons permit rapid transmission of information from one cell to another using electrochemical signals
What is the function of the neuron cell body?
Cell body- contains nucleus, cytoplasm, other organelles- Golgi apparatus, mitichondria, lysosomes, RER
What are the functions of the dendrites?
Dendrites- portions that receive input and carries it toward the cell body, unmyelinated
What is the function of the axon?
Carries information away from the cell body
What are the functions of the axon hillock?
Conical projection of cell body, devoid of Nissl bodies, lacks large organelles
What is the function of the initial segment?
The part of the axon closest to the axon hillock
What is the function of the trigger zone?
Impulses arise from the junction of the axon hillock and the initial segment. It has numerous voltage sensitive channels
Classify neurons based on function
- sensory neurons- from the receptors to the CNS. They are pseudounipolar-(cell body sticking out on the side )they are in the dorsal portion of spinal cord
- motor neurons- from the CNS or ganglia to effector cells( they have a multipolar shape) or bipolar neurons
- interneurons- make up 99.9% of neurons
What are the support cells?
Neuroglial cells are cells that provide structural and biochemical support for neuronal function
PNS- Schwann cells and satellite cells
CNS- oligodendrocytes, astrocytes, microglia, ependymal cells
What are the functions of oligodendrocytes?
Forms and maintains myelin sheaths of multiple axons
What are the functions of astrocytes?
Strengthens and supports the neuronal tissue
- Forms the blood brain barrier
- maintains the homeostatic environment
Protects the brain from the environment (bloo-brain barrier)
What are the functions of the microglia?
Phagocytic, provides defense against in pleading microorganisms
Macrophage of the CNS
What are 5he functions of the ependymal cells?
- Produce and secrete CSF
- monitors CSF
Found in ventricles Of brain and central cabal of spinal cord
What are the functions of the Schwann and satellite cells?
Schwann cells- myelinate 1 portion of an axon
Satellite cells- provides structural support for the PNS. They also regulate exchange of materials between neuronal cell bodies and interstitial fluid
Briefly describe the organization of the nervous system
The nervous system is composed of 2 major structural divisions :
- CNS- brain and spinal cord
Bundles of cell body in CNS= nucleus - PNS- sensory receptors, nerves and ganglia outside the CNS
Explain the functional divisions of the nervous system
Functional classification-
- Somatic Nervous system- voluntary control to and from skin and body wall. (Joints, skin, striated muscle)
- Autonomic nervous system- involuntary to/from smooth muscle, cardiac muscle
Other divisions-
Sensory. -brings information from the periphery to the CNS- brain and spinal cord
Motor- sends information from the CNS to the periphery
The lobes of the brain are named after..
The bones that cover them
What is the function of the frontal lobe?
Motor planning and commands, impulse control, working memory and judgement
What is the function of the parietal lobe?
Reception and perception of sensory information
Name the parts of the brain in order of complexity
- Cerebral cortex
- Duancephalon- thalamus, hypothalamus and pituitary gland
- Cerebellum- midbrain, pons, medulla oblangata
Where does integration of info occur?
Cerebral cortex