ANAT LEC Ch. 13 - The Nervous System

Endocrine system has a ____ onset and _____ effects

Nervous system has a ____ onset and _____ effects

• Brain & Spinal cord

• Processing & coordinates SENSORY input

• all higher thinking & func

• Peripheral nerves

• Provides SENSORY info to the CNS

• Carries out MOTOR commands sent down by the cns

Carries info FROM:

• SOMATIC sensory receptors monitor and send info abt muscles, joints and skin

• VISCERAL sensory receptors monitor other internal organs from systems (Ex. Cardiovascular & Respiratory)

Divided into 2 systems:

• SOMATIC Nervous System (NS): Controls muscle CONTRACTIONS (voluntary/involuntary)

• AUTONOMIC NS: Regulates smoot & cardiac muscle & glandular activity (INvoluntary)

Touching the stove gives info, to the brain, on the texture/ temp/ feel

Touching the stove gives info, to the brain, to reflex the hand AWAY from the hot stove

Support and Protect nervous system and neurons

• Astrocytes

• Oligodendrocytes

• Microglia

• Ependymal Cells

Largest & most numerous

Functions:

• Control INTERSITIAL environment

• Maintain Blood-Brain Barrier

• Form 3D framework for the CNS

• Repair damaged nervous tissue

• Guide neural development EMBRYONICALLY

• Improve conduction of the axon

  • thru MYELIN SHEATH

• Wrapped areas = INTERNODES

• Myelin sheath Gaps = Nodes of Ranvier

• Act as PHAGOCYTIC cells of CNS

• Attack viruses, microorganisms, tumor cells

• 5% of CNS cells (#s increase when needed)

(Keep the CNS clean)

• Lines ventricles of the brain & central canal of spinal cord

• Assist in producing, circulating, monitoring CEREBROSPINAL Fluid

Axons of the PNS group together to form ____

Peripheral Nervous System is composed of

Schwann Cell’s membrane is _____

• Extends & Wraps around PART of axon of single nerve cell

Multiple Schwann line a _____ nerve axon

Oligodendrocytes encircle ______ axon at once

• Responsible for transfer/processing of info in the Nervous system

  • thru ELECTRICAL Impulses

• Anaxonic

• Bipolar

• Pseudounipolar

• Multipolar

Small & found ONLY in CNS

Cell body lies b/w the Dendrite & Axons

Cell body lies OUTSIDE the plane of the Dendrite & Axons

The most common neuron in the CNS (Unidirectional)

• Sensory

• Motor

• Interneurons

• Form AFFERENT Division of PNS

• Deliver info abt Internal & External environment to the CNS

• Form EFFERENT Division of CNS

• Stimulate activity of peripheral motor or organ systems

  • Divided into SOMATIC (body) & VISCERAL (organ) motor

• B/w Sensory and Motor neurons

• Found within brain & Spinal cord

• Analyze sensory input and organize motor outputs

• Either EXCITATORY or INHIBITORY based on post synaptic membranes

Ability of the plasma membrane to conduct electrical Impulses

Change in membrane potential AFTER the membrane stimulation reaches THRESHOLD

Site of cellular/neuronal communication

• May be chemical (VESICULAR) or Electrical

At an electrical synapse, the PRESYNAPTIC and POSTSYNAPTIC membranes are

Allow for passage of the electrical signals b/w cells

• Elec. Synapses convey info BOTH directions

  • Chem. Synapses CANNOT