TRAUMATIC BRAIN INJURY: Part 3

ANATOMY OF THE BRAIN:

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cerebrum:

  • Commonly known as “the brain”

  • Lies on top of the brain stem

  • Largest area of the brain

  • Divided into 2 halves: Right hemisphere that controls left side of the body

    Left hemisphere that controls the right side of the body

  • Main FUNCTIONS include: consciousness, thought, reason, memory, vision, hearing, touch, motor control, coordination and emotions.

  • FUNCTIONAL AREAS are divided into 4 lobes. Frontal, Parietal, Temporal, Occipital

FRONTAL LOBE:

  • Regulates the higher intellectual behaviors (executive functions)

  • Important role in social functions

  • Regulates emotions, cognition, error detection, sense of self, ability to recognize right and wrong, ability to recognize future outcomes from present actions, suppress unacceptable behavior, retain long term memory, moderates emotions to fit socially acceptable standards.

  • BROCA’s AREA is in the frontal lobe cortex and is important for the production of written and spoken language. Required for the ability to find appropriate words and grammar.

PARIeTAL LOBE:

  • Located above the Temporal, between the Frontal and Occipital lobes

  • Movement, touch, vision, hearing, memory, spatial sense of direction

  • Motor cortex within the parietal lobe is responsible for movement

  • Somatosensory cortex is responsible for touch

  • Large portion of the Parietal lobe acts as a coordination center for all the senses allowing us to be aware of people, places and things around us.

TEMPORAL LOBE:

  • Located below the Parietal and in front of the Occipital lobes. On both sides of the brain

  • Responsible for speech, memory and hearing

  • Auditory cortex is responsible for hearing and understanding what is heard

  • FUNCTIONS include Long term memory, vision, sexual behavior and personality

  • WERNICKE’S AREA is located in the left temporal lobe and is involved in the formation and comprehension of language. Required to form sentences and understand others speech.

OCCIPITAL LOBE:

  • Located at the back of the brain, smallest of the 4 lobes

  • Visual center is responsible for receiving and coordinating input from the eyes

  • Motion, color and other visual inputs are organized and interpreted in this area

CEREBELLUM:

  • Means “little brain”, located at the base of the brain

  • There are 3 parts to the cerebellum: Cerebrocerebellum, Spinocerebellum and Vestibulorcerebellum

  • Responsible for coordination of movement

  • Contains 10% of the brains volume but contains at least 50% of the brains neurons

  • It is divided into 2 hemispheres that are covered by a thin layer of gray mater called the cortex

  • Receives input from other areas of the brain and brain stem

  • Receives information on position and movement of the body’s limbs

  • Uses this information for equilibrium and coordination

BRAIN STEM:

  • Distal part of the brain made up of three parts, Mid Brain, Pons and Medulla Oblongata

  • Each part has their own function but together they regulate, breathing, heart rate and blood pressure

  • Plays an important role in being awake and alert, attention, arousal and consciousness

  • The brain stem houses the reticular activating system which acts as the “on/off” switch, controlling, sleeping, being awake and motivation

  • The brain stem as acts as a conduit for messages coming from the body to the brain

  • Many of the cranial nerves originate in the brain stem which are responsible for vision, hearing, taste, smell, control of eye movement and coordination and movement of the face

HYPOTHALAMUS:

  • Located just above the brain stem

  • Links the nervous system to the endocrine system

  • Responsible for metabolism

  • Controls blood pressure, body temperature, fluid and electrolyte balance and body weight

  • It influences, hunger, moods, sex drive, circadian cycles, thirst and release of hormones from the pituitary gland

LEFT HEMISPHERE:

  • The left hemisphere of the brain is dominant for language, mathematical skills, and the ability to solve problems in a sequential order. For this reason, the left hemisphere is often considered the logical or analytical brain

RIGHT HEMISPHERE:

  • The right hemisphere of the brain seems to be dominant in terms of artistic ability, musical skills, face recognition, and spatial perception. Problems tend to be solved in a more comprehensive, artistic way

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MENINGES:

The brain and spinal cord are covered by 3 layers of tissue (meninges) that protect them:

  • Pia Mater: Thin, innermost layer which adheres to the brain and spinal cord

  • Arachnoid Mater: Delicate, spider web-like, middle layer

  • Dura Mater: Outermost, toughest layer

CEREBROSPINAL FLUID:

Helps cushion the brain from sudden jarring and minor injury, also removes waste products from the brain.