CH 11- Functional Organization of Nervous Tissue

Part 1

Cells of nervous tissue

• Neurons

• Glial Cells

Neurons

Electrically excitable cells of the nervous system

Glial cells

Supportive cells

Central nervous system cells

• Neurons

• Microglia

• Astrocytes

• Ependymal

• Oligodendrocytes

Peripheral Nervous System Cells

• Neurons

• Satellite

• Schawnn

Functions of the nervous system

• Maintaining homeostasis

• Receiving sensory input

• Controlling muscles and glands

• Establishing and maintain mental activity

Divisions of the nervous system

• Central nervous sytem (CNS)

• Peripheral nervous system (PNS)

Central nervous system (CNS)

• Receives information from and sends information to the body

• Decision maker

• Consists of the brain and spinal cord

Peripheral nervous system (PNS)

• Detects stimuli in an around the body

• Carries information to the CNS and from the CNS to the body

• Consists of nerves, ganglia, and sensory receptors

Structures of the CNS

• Brain

  -Housed in the skull

• Spinal cord

  -Housed in the vertebral column

Structures of the PNS

• Nerves

  -Collection of axons outside the brain and spinal cord

  -Can carry electrical signals away from or towards the CNS

  -Cranial nerves-12 pairs of nerves originating from the brain

  -Spinal nerves- 31 pairs of nerves of nerves originating from the spinal cord

  -Plexus-bundle of nerves outside the brain and spinal cord

• Ganglia

  -Group of neuron cell bodies outside the brain and spinal cord

• Sensory receptors

  -Cells that respond to specific stimuli

  -Can be neurons or specialized cells

  -Distributed throughout the body

Types of nerves

• Cranial

• Spinal

• Plexus

Nerves

• Collection of axons outside the brain and spinal cord

• Can carry electrical signals away from or towards the CNS

Cranial nerves

12 pairs of nerves originating from the brain

Spinal nerves

31 pairs of nerves originating from the spinal cord

Plexus

Bundle of nerves outside the brain and spinal cord

Ganglia

Group of neuron cell bodies outside the brain and spinal cord

Sensory receptors

• Cells that respond to specific stimuli

• Can be neurons or specialized cells

• Distributed throughout the body

Division of PNS

• Sensory (afferent) division

• Motor (efferent) division

Sensory (afferent) division

transmits electrical signal from receptors to the CNS

Motor (efferent) division

• Transmits electrical signals from the CNS to effector organs

• Effector organs include muscle (skeletal, cardiac, smooth) and glands