Human Nervous System Level3By Graciela Garcia

Functions of the Nervous System: Brain detects changes in the environment externally

and internally Brain stores information Brain responds by starting changes in the nerves

and glands Maintains homeostasis Brain processes signals

The cross section layers of the brain:• Longitudinal

Tissue-Separates brain medially • Lateral Tissue-Separates temporal and frontal lobes.

• Central Sulcus-Separates frontal and parietal lobes

Divisions of the Nervous System:

Central Nervous System-Brain-Spinal Cord

Peripheral Nervous System

• Autonomic-Controls are involuntary-Blood flow, digestion, and heart Beat

• Somatic (not automatic)

-Chewing, walking, and running

The four lobes

Description of the four lobes of the brain: Frontal Lobe • Reasoning• Planning• Problem Solving• Thinking

Parietal Lobe • Recognizing • Stimuli orientation• Speech

Temporal Lobe• Memory• Speech • Auditory stimuli

Occipital Lobe• Visual Processing • Hallucinations

Spinal Nerves: Sacral

TailboneSpinal nerves: 5-Innervate posterior legs and buttocks ThoracicChestSpinal Nerves: 12-Innervate trunk and parts of arms

CervicalNeckSpinal nerves: 8-Innervate back of head, upper back, and neck

Lumbar Lower backSpinal nerves: 5-Innervate lower abdomen and anterior legs

Diagram

Cranial Nerves:-Olfactory: the sense of smell

-Optic: does the vision -Abducent: abduction of the eye

-Facial: Facial expressions, saliva, tears, and taste

The Neuron & it’s Parts: A neuron is a nerve cell that forms chains that go through-out

your whole body including the brainPARTS OF A NEURON:

Dendrite (receives transmitters from environment) Cell Body (contains nucleus, and is largest part of cell) Nucleus (in cell body and contains DNA) Axon (tube that sends signals from cell body to axon terminal) Myelin Sheath (lipid [fat] that keeps chemicals inside axon to

speed up transmission of the signal) Axon Terminal (end of axon where neurotransmitters are released) Neurotransmitters: chemical released into synaptic elect and to

attach themselves to receptors on next neuron) Synaptic Cleft: gap between neurons)

Neuron

Flow of the CSF:• Cerebrospinal Fluid – Clear fluid that is made in the

spaces of the brain and circulates around the brain and spinal cord to cushion the brain and gives it nutrients.

-Some made in choroid plexus of lateral ventricle in brain-Travels through interventricular forearm to 3rd ventricle-Travels through 4th ventricle through cerebral aqueduct

Some travels to surround whole brain Some travel to spinal cord

• Absorbed by the arachnoid villi and filtered with the blood

The flow of CSF

Meninges:• Skin of scalp

Greater density of hair follicles

• Periosteum Connective tissue

layer

Bone Duramater Arachnoid Piamater