The interaction function.

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.

Be carefulwith mixing up REFLEX actions

and INVOLUNTARY movements.

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

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