NERVOUS SYSTEM
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
Reaction command sent down efferent
OVERVIEW OF THE NERVOUS SYSTEM pathway along motor neuron (motor
output)
● Nervous System - one of the smallest
and yet the most complex of all body
systems CELLS OF THE NERVOUS SYSTEM
● Forms the major control system for
body functions (along with endocrine) NEURONS NEUROGLIA OR GLIA
● This intricate network of billions of ● The CNS contain over 100 billion
neurons and even more neuroglia is neurons (50-100x this number in glial
organized into two main divisions: cells)
1.) Central Nervous System (CNS) - ● 40% human genes participating in
❖ brain formation
❖ spinal cord
2.) Peripheral Nervous System (PNS) NEURONS (VARY IN SIZE AND SHAPE)
❖ nerves in other parts of ● designed to transmit 💬 (nerve impulse)
the body ● nerve cells, carry electrical signals
❖ spinal and cranial nerves rapidly and over long distances
● structural and functional unit
● similar to other cell having nucleus and
most organelles in cytoplasm except:
■ dendrites and axons
■ no centrosome (loss power
of division)
■ contain and secrete
neurotransmitter
Classification of Neuron: Depending on (1)
number of poles, (2) function, (3) length of
axon
FUNCTIONS OF THE NERVOUS SYSTEM
Sensory (Input) - gather information
I. DEPENDING UPON NUMBER OF POLES
Integration
Motor (Output) - information carried UNIPOLAR: only one pole
from CNS to PNS, directions acted upon ■ from a single pole, axon and
dendrites arise
Homeostasis: ■ present in embryonic stage
💬 is received from sensory receptor + BIPOLAR: two poles
■ one main dendrite, and one axon
sensory neurons (afferent pathway)
💬reaches brain and is integrated MULTIPOLAR: multiple
■ usually have several dendrites
(control center) and one axon
TRANS BY: ELMIRA S. SALAZAR 1
, NERVOUS SYSTEM
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
Cell Body or Soma - maintains the
functional and anatomical integrity of
axon
- typical cell structures; nucleus,
cytoplasm, etc
- present in: (1) grey matter of
CNS, (2) nuclei of brain, (3) all
neurons
■ Cytoplasm contains nucleus, nissl
granules, neurofibrillae,
mitochondria, golgi apparatus
II. DEPENDING UPON FUNCTION
Nucleus
- one centrally in soma
Motor(Efferent) Sensory (Afferent) - prominent nucleoli which contains
Neurons Neurons ribose nucleic acid
carry impulses from CNS carry impulses from PNS
to peripheral effector to CNS Nissl granules or bodies
organ eg. muscles Proprioceptors - detect - named after FRANZ NISSL (19th
stretch or tension century)
- also called tigroid substance
has long axon and short has short axon and long
dendrites dendrites
- small membrane bound cavities found
in clumps in soma
- present in cell body & dendrites
Interneurons (association neurons) - absent in axon
- composed of RNA + protein
■ found in neural pathways in the
CNS Neurofibrillae (Microtubules & Microfilaments)
■ connect sensory and motor - thread like structure present all over
neurons
Mitochondria
- present in soma and axon
III. DEPENDING UPON THE LENGTH OF AXON
- form the power house of nerve cell
GOLGI TYPE I GOLGI TYPE II Golgi Apparatus
NEURONS NEURONS - concerned with processing and
packing of proteins into granules
have long axons have short axons
cell body situated in CNS present in cerebral cortex
& their axons reaches and spinal cord Dendrites - conduct impulses toward
remote peripheral organs the cells body
- receive incoming signals
NEURON STRUCTURE: THREE BASIC PARTS - rootlike structures at the ends
- may be absent or many
TRANS BY: ELMIRA S. SALAZAR 2
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
Reaction command sent down efferent
OVERVIEW OF THE NERVOUS SYSTEM pathway along motor neuron (motor
output)
● Nervous System - one of the smallest
and yet the most complex of all body
systems CELLS OF THE NERVOUS SYSTEM
● Forms the major control system for
body functions (along with endocrine) NEURONS NEUROGLIA OR GLIA
● This intricate network of billions of ● The CNS contain over 100 billion
neurons and even more neuroglia is neurons (50-100x this number in glial
organized into two main divisions: cells)
1.) Central Nervous System (CNS) - ● 40% human genes participating in
❖ brain formation
❖ spinal cord
2.) Peripheral Nervous System (PNS) NEURONS (VARY IN SIZE AND SHAPE)
❖ nerves in other parts of ● designed to transmit 💬 (nerve impulse)
the body ● nerve cells, carry electrical signals
❖ spinal and cranial nerves rapidly and over long distances
● structural and functional unit
● similar to other cell having nucleus and
most organelles in cytoplasm except:
■ dendrites and axons
■ no centrosome (loss power
of division)
■ contain and secrete
neurotransmitter
Classification of Neuron: Depending on (1)
number of poles, (2) function, (3) length of
axon
FUNCTIONS OF THE NERVOUS SYSTEM
Sensory (Input) - gather information
I. DEPENDING UPON NUMBER OF POLES
Integration
Motor (Output) - information carried UNIPOLAR: only one pole
from CNS to PNS, directions acted upon ■ from a single pole, axon and
dendrites arise
Homeostasis: ■ present in embryonic stage
💬 is received from sensory receptor + BIPOLAR: two poles
■ one main dendrite, and one axon
sensory neurons (afferent pathway)
💬reaches brain and is integrated MULTIPOLAR: multiple
■ usually have several dendrites
(control center) and one axon
TRANS BY: ELMIRA S. SALAZAR 1
, NERVOUS SYSTEM
ANATOMY & PHYSIOLOGY
Mr. Eric Mahinay| 1St Semester | BSN – 1B
S.Y. 2023 – 2024
Cell Body or Soma - maintains the
functional and anatomical integrity of
axon
- typical cell structures; nucleus,
cytoplasm, etc
- present in: (1) grey matter of
CNS, (2) nuclei of brain, (3) all
neurons
■ Cytoplasm contains nucleus, nissl
granules, neurofibrillae,
mitochondria, golgi apparatus
II. DEPENDING UPON FUNCTION
Nucleus
- one centrally in soma
Motor(Efferent) Sensory (Afferent) - prominent nucleoli which contains
Neurons Neurons ribose nucleic acid
carry impulses from CNS carry impulses from PNS
to peripheral effector to CNS Nissl granules or bodies
organ eg. muscles Proprioceptors - detect - named after FRANZ NISSL (19th
stretch or tension century)
- also called tigroid substance
has long axon and short has short axon and long
dendrites dendrites
- small membrane bound cavities found
in clumps in soma
- present in cell body & dendrites
Interneurons (association neurons) - absent in axon
- composed of RNA + protein
■ found in neural pathways in the
CNS Neurofibrillae (Microtubules & Microfilaments)
■ connect sensory and motor - thread like structure present all over
neurons
Mitochondria
- present in soma and axon
III. DEPENDING UPON THE LENGTH OF AXON
- form the power house of nerve cell
GOLGI TYPE I GOLGI TYPE II Golgi Apparatus
NEURONS NEURONS - concerned with processing and
packing of proteins into granules
have long axons have short axons
cell body situated in CNS present in cerebral cortex
& their axons reaches and spinal cord Dendrites - conduct impulses toward
remote peripheral organs the cells body
- receive incoming signals
NEURON STRUCTURE: THREE BASIC PARTS - rootlike structures at the ends
- may be absent or many
TRANS BY: ELMIRA S. SALAZAR 2
