nervous system
TRANSCRIPT
Ramón y Cajal “the neuron is the anatomicaland functional unit of the nervous system”.
Apart from NEURONS, which are highlyspecialized cells that mainly made up the NS, there are _________ cells too. These give theneurons support and nutrients.
GLIAL
All together, make up
Central Nervous System CNSPerypheral Nervous System PNS
They are not mushrooms, things, bugs… THEY ARE CELLS, with the following parts:
partes:
Cell bodies join and form nervous centres (brain and spinalcord).Axons of those neurons make up (joined) the nerves(sensory, motor, mixed).
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.
The transmition of nervous impulse iselectrochemical, it means that:
1. Through the surface of the neuron, it iselectric.
(in a neuron, “in the path”)
2. Trough the synapse, it is chemical.
(between two neurons, “in the bridge”)
NERVOUS SYSTEM
CENTRAL N.S.
Protected bymeninges
BRAINCEREBRUM
CEREBELLUM
BRAIN STEM
SPINAL CORD
PERIPHERAL N.S.
Connectsreceptors, CNS and effectors
NERVES
SENSORY
MOTORS
MIXED
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, whereemotions reside. The hypothalamus in its inferior middle part, is in charge of the autonomic and vegetative functions!!!! (CHECK sympathetic and parasympathetic NS).
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)
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)
- Extension of the brain stem.
- That’s why we have from the inside to theoutside:- Grey matter (inside)
- White matter (outside)
- Protected by the BACKBONE or VERTEBRAL COLUMN.
- Funtions:- Some involuntary actions.
- To connect body-brain-body.
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.
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.
Nerves can be:
a. Sensory: sensory neurons from sensoryorgans CNS.
b. Motor: motor neurons from CNS organsthat carry out the response. Depending onthe movement response can be:
- Somatic nervous system: voluntary and reflex actions.
- Autonomic nervous system: involuntaryactions.
From simple medular responses to complexcortical 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).
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...
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.
ÓRGANO SISTEMAPARASIMPATICO
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
ÓRGANOS SEXUALES Activación Inhibición