ANATOMY AND PHYSIOLOGY
CHAPTER IV: NERVOUS SYSTEM
● Mental Status
○ Level of Alertness, Cooperation
○ Orientation
○ Memory e.g. recent and remote memory
○ Language
■ Comprehension
■ Naming
■ Repetition
● Levels of Consciousness
○ Alert
○ Verbal Stimuli
○ Painful Stimuli
○ Unresponsive
● Nervous System
○ It is a complex network of nerves and cells that carry messages to and from the brain and
spinal cord to various parts of the body
○ It consists of two main functional and structural division: Central Nervous System and
Peripheral Nervous System
○ Two Functional and Structural Divisions:
■ Central Nervous System (CNS)
● Brain and spinal cord
■ Peripheral Nervous System (PNS)
● Cranial nerves (to and from the brain)
● Spinal nerves (to and from the spinal cord)
● Ganglia (clusters of neuron cell bodies located outside the CNS)
● Functions of the Nervous System
○ Major Functions:
1. Sensory input
2. Integration
3. Motor output
● CENTRAL NERVOUS SYSTEM
○ Functions:
■ It is the communication and coordination system of the body.
■ The brain is the seat of intellect and reasoning.
○ Nervous Tissue
■ tissues that transmits impulse and messages to the body
■ consists of two (2) major types of nerve cells:
A. Neuroglia or glial cells
● Insulate, support and protect the neurons.
● “Nerve glue”
● Do not carry nerve impulses.
● Types of Glial cells:
○ Central Nervous System:
■ Astrocytes
, ● Transport nutrients to neurons and restrict
what substances can enter the brain, forming
the blood - brain barrier.
● It provides structural support, regulates ion,
nutrients and dissolved gases concentrations
● It absorbs and recycle neurotransmitters
● Form scar tissue after injury
■ Microglia
● Remove cellular debris, wastes and
pathogens by phagocytosis from the nerve
tissues.
■ Oligodendrocytes
● CNS structures that wrap around the
neuronal axons, forming the myelin sheath.
● It provides the structural framework of the
body.
■ Ependymal Cells
● It is line ventricle (Brain) and central canal
(Spinal Cord)
● It assists in producing, circulating, and
monitoring of cerebrospinal fluid.
○ Peripheral Nervous System
■ Schwann cells/Lemmocytes
● PNS structures that wrap around the
neuronal axons to form the myelin sheath.
● It participates in the process of repairing
after injury.
● They are responsible for myelination of
peripheral axons.
■ Satellite Cells
● It surrounds neuron cell bodies in ganglia
● It regulates Oxygen, Carbon Dioxide,
nutrients, and neurotransmitters levels
around neurons in ganglia.
B. Neurons
● Cells within the nervous system that transmit information to other
nerve cells, muscle, or gland cells.
● Characteristics:
A. Irritability – process of reacting through a certain stimuli
B. Conductivity – wiring that coordinates how your body runs
and the signals travel quickly through the nervous system,
and the ability of nerves to transmit impulses
● Types of Neurons:
A. Efferent Neurons or Motor Neurons - Carry messages from
the CNS to the effectors.
B. Associative Neurons or Interneurons - Carry impulses from
the sensory neurons to motor neurons.
C. Afferent Neuron or Sensory Neuron
, ● Receive stimuli from receptor sites in the sensory
organs (skin, eyes, ears, nose and taste buds) that can
be perceived by the five senses.
● Carry messages or impulses
toward the CNS.
○ Synapse
■ Where the messages go from one cell to the next cell.
■ Messages go from the axon of one cell to the dendrite of another; they never touch
■ The space between them is the synaptic cleft.
■ The conduction is accomplished through neurotransmitters.
■ Neurotransmitters are chemical substances that make it possible for messages to cross
the synapse of a neuron to a target receptor.
○ The Brain
■ An intricate mass of soft nervous tissue.
■ Weighs about 1400 g (3 lbs) and consists of 100 billion neurons.
■ Protected by a bony cranial cavity.
■ Further protection is given by three (3) membranous coverings called meninges, and
the cerebrospinal fluid.
■ Contains white and gray matter.
■ Cerebral cortex, the gray matter, is the outer cortex and considered the highest center
of reasoning and intellect.
■ White matter - located in the deeper part of the cerebral cortex, consists of myelinated
nerve tracts.
■ Adequate oxygenated blood supply is needed by the brain to prevent irreversible
brain damage. Without oxygen, brain damage will occur within 1 to 8 minutes.
■ Memory
● Process of storing “old” information we have learned and packaging
and storing of new information by the brain.
● According to scientists, the hippocampus of the limbic
system, acts like a receptionist, deciding the significance of the event and
determining where in the brain the information should be stored.
● Memory can be short-term or long-term depending how much attention we
given an event, how many times we repeat an activity, and the kinds of
memory associations.
■ Coverings of the Brain (Meninges)
1. Dura mater
● Outer brain covering, which lines the inside of the skull.
● A tough, dense membrane of fibrous connective tissue containing an
abundance of blood vessels.
2. Arachnoid mater
● The middle layer, resembling a fine cobweb with fluid-filled spaces.
3. Pia mater
● Covers the brain surface itself, consisting of blood vessels held
together by fine areolar connective tissue.
■ Spaces in between meninges:
1. Subdural space is between the dura mater and arachnoid mater.
2. Subarachnoid space is between the arachnoid and pia mater, filled with
cerebrospinal fluid, produced within the ventricles of the brain.
● Cerebrospinal fluid
, ○ Acts as a liquid shock absorber and source of nutrients for
the brain.
○ A substance formed inside the brain ventricles from the
blood vessels of the choroid plexus.
○ Protects the delicate brain and the spinal cord.
○ Also removes metabolic waste products from the brain cells.
○ Can be used for detecting selected brain diseases.
● Cerebrospinal Fluid (CSF) Circulation
○ Lumbar puncture/ Spinal tap is the removal of cerebrospinal
fluid for diagnostic purposes. The needle is inserted into the
L3-L4 of the vertebrae.
○ Changes in composition of the fluid withdrawn can be an
indication of an injury, infection or disease. Spinal tap also
serves to alleviate the pressure caused by meningitis, and
especially hydrocephalus.
CHAPTER IV: NERVOUS SYSTEM
● Mental Status
○ Level of Alertness, Cooperation
○ Orientation
○ Memory e.g. recent and remote memory
○ Language
■ Comprehension
■ Naming
■ Repetition
● Levels of Consciousness
○ Alert
○ Verbal Stimuli
○ Painful Stimuli
○ Unresponsive
● Nervous System
○ It is a complex network of nerves and cells that carry messages to and from the brain and
spinal cord to various parts of the body
○ It consists of two main functional and structural division: Central Nervous System and
Peripheral Nervous System
○ Two Functional and Structural Divisions:
■ Central Nervous System (CNS)
● Brain and spinal cord
■ Peripheral Nervous System (PNS)
● Cranial nerves (to and from the brain)
● Spinal nerves (to and from the spinal cord)
● Ganglia (clusters of neuron cell bodies located outside the CNS)
● Functions of the Nervous System
○ Major Functions:
1. Sensory input
2. Integration
3. Motor output
● CENTRAL NERVOUS SYSTEM
○ Functions:
■ It is the communication and coordination system of the body.
■ The brain is the seat of intellect and reasoning.
○ Nervous Tissue
■ tissues that transmits impulse and messages to the body
■ consists of two (2) major types of nerve cells:
A. Neuroglia or glial cells
● Insulate, support and protect the neurons.
● “Nerve glue”
● Do not carry nerve impulses.
● Types of Glial cells:
○ Central Nervous System:
■ Astrocytes
, ● Transport nutrients to neurons and restrict
what substances can enter the brain, forming
the blood - brain barrier.
● It provides structural support, regulates ion,
nutrients and dissolved gases concentrations
● It absorbs and recycle neurotransmitters
● Form scar tissue after injury
■ Microglia
● Remove cellular debris, wastes and
pathogens by phagocytosis from the nerve
tissues.
■ Oligodendrocytes
● CNS structures that wrap around the
neuronal axons, forming the myelin sheath.
● It provides the structural framework of the
body.
■ Ependymal Cells
● It is line ventricle (Brain) and central canal
(Spinal Cord)
● It assists in producing, circulating, and
monitoring of cerebrospinal fluid.
○ Peripheral Nervous System
■ Schwann cells/Lemmocytes
● PNS structures that wrap around the
neuronal axons to form the myelin sheath.
● It participates in the process of repairing
after injury.
● They are responsible for myelination of
peripheral axons.
■ Satellite Cells
● It surrounds neuron cell bodies in ganglia
● It regulates Oxygen, Carbon Dioxide,
nutrients, and neurotransmitters levels
around neurons in ganglia.
B. Neurons
● Cells within the nervous system that transmit information to other
nerve cells, muscle, or gland cells.
● Characteristics:
A. Irritability – process of reacting through a certain stimuli
B. Conductivity – wiring that coordinates how your body runs
and the signals travel quickly through the nervous system,
and the ability of nerves to transmit impulses
● Types of Neurons:
A. Efferent Neurons or Motor Neurons - Carry messages from
the CNS to the effectors.
B. Associative Neurons or Interneurons - Carry impulses from
the sensory neurons to motor neurons.
C. Afferent Neuron or Sensory Neuron
, ● Receive stimuli from receptor sites in the sensory
organs (skin, eyes, ears, nose and taste buds) that can
be perceived by the five senses.
● Carry messages or impulses
toward the CNS.
○ Synapse
■ Where the messages go from one cell to the next cell.
■ Messages go from the axon of one cell to the dendrite of another; they never touch
■ The space between them is the synaptic cleft.
■ The conduction is accomplished through neurotransmitters.
■ Neurotransmitters are chemical substances that make it possible for messages to cross
the synapse of a neuron to a target receptor.
○ The Brain
■ An intricate mass of soft nervous tissue.
■ Weighs about 1400 g (3 lbs) and consists of 100 billion neurons.
■ Protected by a bony cranial cavity.
■ Further protection is given by three (3) membranous coverings called meninges, and
the cerebrospinal fluid.
■ Contains white and gray matter.
■ Cerebral cortex, the gray matter, is the outer cortex and considered the highest center
of reasoning and intellect.
■ White matter - located in the deeper part of the cerebral cortex, consists of myelinated
nerve tracts.
■ Adequate oxygenated blood supply is needed by the brain to prevent irreversible
brain damage. Without oxygen, brain damage will occur within 1 to 8 minutes.
■ Memory
● Process of storing “old” information we have learned and packaging
and storing of new information by the brain.
● According to scientists, the hippocampus of the limbic
system, acts like a receptionist, deciding the significance of the event and
determining where in the brain the information should be stored.
● Memory can be short-term or long-term depending how much attention we
given an event, how many times we repeat an activity, and the kinds of
memory associations.
■ Coverings of the Brain (Meninges)
1. Dura mater
● Outer brain covering, which lines the inside of the skull.
● A tough, dense membrane of fibrous connective tissue containing an
abundance of blood vessels.
2. Arachnoid mater
● The middle layer, resembling a fine cobweb with fluid-filled spaces.
3. Pia mater
● Covers the brain surface itself, consisting of blood vessels held
together by fine areolar connective tissue.
■ Spaces in between meninges:
1. Subdural space is between the dura mater and arachnoid mater.
2. Subarachnoid space is between the arachnoid and pia mater, filled with
cerebrospinal fluid, produced within the ventricles of the brain.
● Cerebrospinal fluid
, ○ Acts as a liquid shock absorber and source of nutrients for
the brain.
○ A substance formed inside the brain ventricles from the
blood vessels of the choroid plexus.
○ Protects the delicate brain and the spinal cord.
○ Also removes metabolic waste products from the brain cells.
○ Can be used for detecting selected brain diseases.
● Cerebrospinal Fluid (CSF) Circulation
○ Lumbar puncture/ Spinal tap is the removal of cerebrospinal
fluid for diagnostic purposes. The needle is inserted into the
L3-L4 of the vertebrae.
○ Changes in composition of the fluid withdrawn can be an
indication of an injury, infection or disease. Spinal tap also
serves to alleviate the pressure caused by meningitis, and
especially hydrocephalus.
