Nervous system

1. The interaction function.

3. Ramón y Cajal “the neuron is the anatomical
and functional unit of the nervous system”.
Apart from NEURONS, which are highly
specialized cells that mainly made up the NS,
there are _________ cells too. These give the
neurons support and nutrients.
GLIAL
All together,
make up
Central Nervous System CNS
Perypheral Nervous System PNS

4. They are not mushrooms, things, bugs…
THEY ARE CELLS, with the following parts:
partes:
Cell bodies join and form nervous centres (brain and spinal
cord).
Axons of those neurons make up (joined) the nerves
(sensory, motor, mixed).

5. TRANSMITTING INFORMATION.
The “empty” space between neurons is called
SYNAPSE (a bridge).
In that space, the transmitting neuron releases
a chemical compound, a
NEUROTRANSMITTER.
The receiving neuron, detects that substance,
becoming electrically excited.

6. The transmition of nervous impulse is
electrochemical, it means that:
1. Through the surface of the neuron, it is
electric.
(in a neuron, “in the path”)
2. Trough the synapse, it is chemical.
(between two neurons, “in the bridge”)

8. NERVOUS
SYSTEM
CENTRAL N.S.
Protected by
meninges
BRAIN
CEREBRUM
CEREBELLUM
BRAIN STEM
SPINAL CORD
PERIPHERAL
N.S.
Connects
receptors, CNS
and effectors
NERVES
SENSORY
MOTORS
MIXED

9. CEREBRUM  So cool...
- The most complex organ.
- We can observe 2 HEMISPHERES.
- From the inside to the outside we have:
- White matter (inside)
- Grey matter: Cerebral cortex. (CIRCUNVOLUCIONES)
- Several areas depending on their function: motor,
sensory, hearing, vision and associated area.
- Limbic system: inner part of the cerebral cortex, where
emotions reside. The hypothalamus in its inferior middle part,
is in charge of the autonomic and vegetative functions!!!!
(CHECK sympathetic and parasympathetic NS).

10. CEREBELLUM Dancers like it because…
- Controls:
- Coordination
- Position
Using the information of what receptor… ??
- Two HEMISPHERES are observed too.
- Central band: VERMIS.
- From the inside to the outside:
- White matter (inside)
- Grey matter (outside)

11. BRAIN STEM Sometimes yours are not working.
It is a pack consisting on:
1. Peduncles: axons from each hemisphere.
2. Medulla oblongata (bulbo raquídeo): lower half of
the brainstem continuous with the spinal cord.
Controls:
a. Involuntary actions and responses.
b. Filters the important information (this is a
problem for you…!)
From the inside to de outside:
- Grey matter (inside)
- White matter (outside)

12. - Extension of the brain stem.
- That’s why we have from the inside to the
outside:
- Grey matter (inside)
- White matter (outside)
- Protected by the BACKBONE or VERTEBRAL
COLUMN.
- Funtions:
- Some involuntary actions.
- To connect body-brain-body.

13. It’s good to be nervous.
 They are in charge of connecting:
◦ External and internal receptors.
◦ CNS
◦ Effectors (next unit)
 They go through all body from (the CNS)
◦ Brain: CRANIAL NERVES.
◦ Spinal cord: SPINAL NERVES.

14. Nerves are packages, made up of
- A group of several
NERVOUS FASCICLES
surrounded by a membrane.
- Each fascicle is made of a
Bundle of nervous fibers of
axons.
- * NERVOUS GANGLIA:
a group of nerve cell bodies
(“heads” of neurons) out of the CNS. Nervous fibers come
out from this ganglia, and make up fascicles. They are
MINOR COORDINATION CENTRES.

17. Nerves can be:
a. Sensory: sensory neurons from sensory
organs  CNS.
b. Motor: motor neurons from CNS  organs
that carry out the response. Depending on
the movement response can be:
- Somatic nervous system: voluntary and
reflex actions.
- Autonomic nervous system: involuntary
actions.

18. Be careful
with mixing up
REFLEX actions
and
INVOLUNTARY
movements.

19. Alzheimer, Parkinson, senile dementia, anxiety,
spine injuries, brain tumors…

20.  From simple medular responses to complex
cortical responses (brain cortex).
 They can be
◦ REFLEX: To close eyes when being almost punched.
◦ VOLUNTARY: Shake hands with somebody.
◦ INVOLUNTARY o VEGETATIVE o AUTONOMOUS:
Constant blink. (We will study them later).

21. Came from the central
region of the medula.
It activates the
organism.
It raises the energy
consumption.
When we hear an
extrange sound at night,
it raises the heart rate, it
dilates pupils, raises
breathing frequency and
perspiration...

22. Came from the lower
region of the brain and
the ending region of
the spinal cord.
It calms the organism.
It reduces the energy
consumption.

23. ÓRGANO SISTEMA
PARASIMPATICO
SISTEMA SIMPÁTICO
PUPILA Contracción Dilatación
GLÁNDULAS LACRIMALES Producción de lágrimas “Inactividad”
GLÁNDULAS SALIVALES Saliva poco densa y
abundante
Salvia escasa y espesa
RITMO RESPIRATORIO Relajación Aceleración
TUBO DIGESTIVO Aumenta actividad Reduce actividad
LATIDO CARDIACO Reducción Aceleración
VEJIGA Contracción Relajación
PIEL “Inactividad” Pelo erizado y aumento
de la sudoración