1. The Nervous System Lab 8

2. Sensory Function - detect internal stimuli and external stimuli – carried to brain and spinal cord through cranial and spinal nerves
Integrative Function - processes sensory info by analyzing and storing and making decisions…perception is conscious awareness of sensory stimuli
Motor function – NS elicits appropriate motor response by activating effectors (muscles and glands) through cranial and spinal nerves

3. Two main subdivisions:
Central Nervous System – brain and spinal cord
Peripheral Nervous System – all nervous tissue outside the CNS

5. Neurons - nerve cells that provide most of the unique functions of the nervous system, length varies from very short to as long as the body Neuroglia - cells that support, nourish and protect the activities of neurons

6. Neuron Anatomy Cell body – nucleus surrounded by cytoplasm
Dendrites - receiving or input portions of a neuron
Axon - takes nerve impulses toward another neuron, muscle fiber, or a gland cell; joins cell body at axon hillock

7. Neuron Classification
Multipolar neurons – several dendrites and one axon – most neurons in brain and spinal cord
Bipolar neurons – one main dendrite and one axon
Unipolar – dendrites and one axon fused together to form continuous process

8. 6 types of Neuroglia

9. Oligiodenrocyte - main function is the insulation of axons exclusively in the central nervous system of higher vertebrates (the same function is performed by Schwann cells in the peripheral nervous system).
Astrocytes (also known collectively as astroglia) are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical support of endothelial cells which form the blood-brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, and a principal role in the repair and scarring process of the brain and spinal cord following traumatic injuries
Microglia are a type of glial cells that are the resident macrophages of the brain and spinal cord, and thus act as the first and main form of active immune defense in the central nervous system
Satellite cells (syn: mantlecells or amphicytes) are flattened Schwann cells, a type of glial cell, lining the exterior surface of neurons in the peripheral nervous system. Satellite cells also surround neuron cell bodies within ganglia. They are thought to have a similar role to astrocytes in the central nervous system (CNS). They supply nutrients to the surrounding neurons and also have some structural function.

11. Nerve Organization

12. The Central Nervous System
Brain
12 pairs of cranial nerves
Spinal Cord
31 pairs of spinal nerves
Ganglia (singular ganglion) are masses of neurons outide the spinal cord, usually including the first synapse outside of the spinal cord.
A plexus is where several nerves join and branch out. For instance, the brachial plexus includes all the nerves that will be directed into the arm.
Sensory receptors are either parts of neurons or specialized cells that monitor changes in the internal or external environment.

13. Major Parts of the Brain

14. The Hypothalamus

15. Protective Coverings
The dura mater (also rarely called meninx fibrosa, or pachymeninx) is a thick, durable membrane
The pia or pia mater is a very delicate membrane. It is the meningeal envelope which firmly adheres to the surface of the brain and spinal cord. As such it follows all the minor contours of the brain (gyri and sulci). It is a very thin membrane composed of fibrous tissue covered on its outer surface by a sheet of flat cells thought to be impermeable to fluid. The pia mater is pierced by blood vessels which travel to the brain and spinal cord, and its capillaries are responsible for nourishing the brain.

16. Cranial Nerves Oh Once One Takes The Anatomy Final, Very Good
Vacations
Are
Heavenly

17. Name Number Function Olfactory I Special sensory Optic II Oculomotor
III
Motor
Trochlear IV
Trigeminal V
Mixed (Both)
Abduscens VI
Facial
VII
Vestibulocochlear
VIII
Glossopharyngeal IX
Vagus X
Accessory XI
Hypoglossal
XII
Olfactory--sense of smell
Optic--vision
Oculomotor--moves eyeball and upper eyelid
Trochlear--controls eyeball movements. Smallest
Trigeminal--largest. Three portions. Deals with touch pain and temperature as well as mastication
Abduscens--originates in pons. Abduction of the eyeball
Facial--taste buds, facial expression
Vestibulocochlear--equilibrium and hearing
Glossopharyngeal--taste, salivation
Vagus--proprioception and stretching, swallowing, vocalization, enervates heart
Accessory--coordinates head movements
Hypoglossal--speech and swallowing

18. The Spinal Cord Runs from brain stem to coccyx 31 spinal nerves
Cervical (C1-C8)
Thoracic (T1-T12)
Lumbar (L1-L5)
Sacral (S1-S5)
Coccygeal

24. Distribution of Spinal Nerves
Cervical plexus (C1-C5)
Phrenic nerve
Brachial plexus (C5-C8, T1)
Radial, median, ulnar nerves
Lumbar plexus (L1-L4)
Obturator and femoral nerves
Sacral plexus (L4-L5, S1-S4)
Sciatic nerve
Coccygeal plexus (S4-S5, coccygeal)
Cervical plexus supplies the neck
Brachial plexus supplies the arm and upper shoulder
Lumbar plexus supplies the anterolateral abdomen, lower limbs, and external genitals
Sacral plexus supplies the buttocks, perineum, and lower limbs
Coccygeal plexus supplies a small area around the coccyx

25. Reflex Arc
Reflex arc – path followed by nerve impulses that produces a reflex
Sensory receptor--nociceptor, mechanosensor, etc
Sensory neuron--goes to spinal cord
Integrating center--spinal cord
Motor neuron
Effector--muscle effected

26. Ipsilateral occurs on the same side as the stimulus, contralateral occurs on the opposite side
Monosynaptic--one sensory, one motor, polysynaptic--more than one interneuron--most reflexes are polysynaptic
Polysynaptic reflex pathways, one or more interneurons connect afferent (sensory) and efferent (motor) signals

28. Exam Next Week Same set up as all previous exams
50 – 60 % Identification w/ matching, multiple choice, T/F and short answer

29. Today in lab:
A. Exercise 19-pre-lab activities & activities 1, 2, 3, 4, 5 & 6 and “Reviewing your knowledge” parts A&B.
Activities 2-6 use a reflex hammer.
B. Exercise 21, Lab activity 2: Testing Cranial Nerve function & “Reviewing Your Knowledge” parts A& B.
Record results in Table 21.3.
Skip the nerve taste test with sugar &quinine
Throw away used tongue depressors and cotton-tipped applicators.