Physiology - organisation of nervous system

Nerve

Nerve

Group of axons from many neurons, surrounded by connective tissue

(endoneurium, perineurium, epineurium)

Organisation

• CNS: brain + spinal cord

• Ganglia / Nuclei: integration centres

• Afferent neurons: from periphery to CNS

• Efferent neurons: from CNS to periphery

Brain

Two hemispheres not functionally identical, for opposal sides of the body.

Left - speech; Right - perception of spatial relationships.

Corpus callosum - bundle of axons connecting hemispheres

Grey matter

Cell bodies + dendrites + axon terminals + most synapses

White matter

Axons connecting different parts of grey matter to each other

Cerebrum - Cerebral cortex

• Perception

• Sensory information integration

• Voluntary movement

• Freu Tore his Pants Off - Frontal, Temporal, Parietal, Occipital lobes

Cerebrum - Basal nuclei

Coordination of movement

Cerebrum - Limbic system

Emotional

• Amygdala - emotions: agression / fear

• Hippocampus - learning & memory (from short to long term)

• Olfactory bulb - Smell

Diencephalon - Thalamus

Integration & relay centre for sensory & motoric info.

All senses except smell - filter for unnecessary information.

Diencephalon - Hypothalamus

Control hormonal system to maintain homeostasis: salt/water, appetite, thirst

Diencephalon - Pituitary gland

Hormone secretion

Diencephalon - Pineal gland

Melatonin secretion

Brain stem - Midbrain

Eye movement control

Brain stem - Pons

Connects cerebrum & cerebellum;

coordination of breating;

origin of vestibulocochlear (face, teeth, biting)& trigeminal nerve (ear)

Brain stem - Medulla oblongata

Control of involuntary functions (breathing, cardiovascular).

Vagus nerve origin - sensory info from important organs

Frontal lobe

Personality & decision making.

Temporal lobe

Memories, emotions, language, recognition, language, auditory.

Parietal lobe

filter informations, touch, body position.

Occipital lobe

visual information.

Cerebellum

Gets info from PNS - coordination of movement, organ equilibrium.

Motoric input from cerebrum - movement coordination

Learning & memory

Ventricles

Filled with cerebrospinal fluid CFS produced by choroid plexus.

Protects the brain & spinal cord from chemical/physical injuries (like pH), carries oxygen, glucose.

Glymphatic system

Astrocytes wrap around brain arteries, making a pericapillary tunnel for CSF.

CFS leaves generating convective flow to the veins - cleaning the waste at night.

Spinal nerves

Dorosal tract - info from PNS

Ventral tract - into to PNS

Dermatome - innervation from single dorosal room & its nerve

Patellar reflex

1. Hammer hit, tendon stretch receptors in the muscle - fire action potentials

2. Afferent - Monosynaptic pathway with motor neuron to the ventral horn of spinal cord

3. Efferent - Motor neuron fires action potential back - muscle contraction

4. Inhibition of the motor neuron for the antagonistic muscle - leg extends up

Autonomic nervous system

Rest & digest: pupil constriction, salivation, heathbeat slows, digestion, gonad arousal

Fight or flight: pupil dilatation, airways relaxed, digestion stop, bladder relax, orgasm stimmulation