Development Aspects of the Development Aspects of the Nervous SystemNervous System

Slide 7.75a

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The nervous system is formed during the first month of embryonic development

Any maternal infection can have extremely harmful effects

The hypothalamus is one of the last areas of the brain to develop

Development Aspects of the Development Aspects of the Nervous SystemNervous System

Slide 7.75b

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

No more neurons are formed after birth, but growth and maturation continues for several years

The brain reaches maximum weight as a young adult

Traumatic Brain Injuries (all one)Traumatic Brain Injuries (all one)

Slide 7.49Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Concussion Slight brain injury No permanent brain damage

Contusion Nervous tissue destruction occurs Nervous tissue does not regenerate

Cerebral edema Swelling from the inflammatory response May compress and kill brain tissue

Paralyzation• Damage suffered to the spinal cord

– Causes: trauma (car/motorcycle accident, gunshot, falls, sports injuries, etc), or disease (Transverse Myelitis, Polio, Spina Bifida)

– Quadriplegia= if the injury is in the Cervical (neck) region (C4-C7)

• Paralysis of whole trunk plus arms and legs

– Paraplegia= if the injury is in the Thoracic or Lumbar regions (T1-L1)

• Usually paralysis of legs and possibly areas of trunk (Bladder and bowel may be affected)

– Hemiplegia = damage to motor areas on one side of brain (leads to paralysis of opposite side of body)

Cerebrovascular Accident (CVA)Cerebrovascular Accident (CVA)

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Commonly called a stroke

third leading cause of death in America and a leading cause of adult disability

Occurs when blood clot, blocks an artery or a blood vessel, breaks interrupting blood flow to an area of the brain

Brain tissue supplied with oxygen from that blood source dies

abilities controlled by that area of the brain are lost

abilities include speech, movement and memory (depends on part of brain affected and how severely damaged)

Remember from Cardio. Unit

• Atherosclerosis-build of fatty deposits

• Thrombus- blood clot that develops – If in brain a stroke will follow

Bleeding within the brain• Intracerebral hemorrhage - bleeding in

the tissue of the cerebrum• Subarachnoid hemorrhage – rare:

spontaneous rupture of an artery near the brain and leaks blood into subarachnoid space between coverings of brain. Life threatening and needs emergency medical treatment. Cut off blood to that vessel

• Subdural hemorrhage – bleeding inside skull between two outer membranes – Caused by blow to head (can build up)– Surgery to drain blood necessary

Alzheimer’s DiseaseAlzheimer’s Disease

Slide 7.51Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Progressive degenerative brain disease

Mostly seen in the elderly, but may begin in middle age

Structural changes in the brain include abnormal protein deposits and twisted fibers within neurons

Victims experience memory loss, irritability, confusion and ultimately, hallucinations and death

Parkinson’s• disorder of the central nervous system

• causes shaking, rigid muscles, slow movements, and poor balance

• chemical imbalances in a small area deep within the middle of the brain (Lack Dopamine)– Neurotransmitter (neurons do not

communicate)

• Cause is Unknown (Family/injury????)

• Progressive – worsens with time

Cerebral Palsy• Abnormalities of movement and posture

• Caused by damage to immature brain

• Not a specific disease– Group of disorders from damage to a

developing brain

Epilepsy

• Recurrent seizures or brief episodes of altered consciousness

• Caused by abnormal electrical activity in the brain– Causes of this activity unknown