Ch 2: Neuroanatomy & Neuroimaging Flashcards
What percent of SCI have a co-occurring TBI?
60%
What three areas of the brain make up the brainstem?
Medulla, Pons, midbrain
What is the brain stem responsible for?
Info going in and out of the brain
What does the brainstem contain?
Centers for senses of hearing, touch, taste, and balance
Reticular Activating System (RAS)
A system (Collection of nerve cell fibers and nuclei) that modulates or changes arousal, alertness, concentration, and basic biological rhythms
Medulla
- First area in the lower part of the brain stem
- vital to life and death
contains reflex centers which control many involuntary functions such as breathing, heart rate, swallowing, blood pressure, vomiting and sneezing.
Pons
- above the medulla
- essential for facial movements, facial sensation, hearing, and coordinating eye movements
Serves as a bridge of nerve fibers connecting the cerebral cortex (thinking part of the brain) to the cerebellum (movement part of the brain)
Disruption can cause a complete loss of ability to coordinate and control body movement
Midbrain
- Smallest part of the brain stem
- involved in elementary forms of seeing and hearing
- plays pivotal role in alertness/arousal.
Diencephalon
- Made up of the thalamus, hypothalamus and other structures
- located cm’s above the midbrain
- master relay center for forwarding info, sensations, and movement
- at times, considered part of the limbic system
Thalamus
- Sits at the top of the brainstem, just below the cortex
- acts as major relay station for incoming/outgoing sensory info. (Each sense relays it’s impulses through the thalamus, with the exception of smell)
Hypothalamus
Control center for hunger, thirst, sexual response, endocrine levels, and temp regulation
Involved in complex responses:
- fight or flight
- anger
- fatigue
- memory
- calmness
Connected to pituitary gland- manages release of hormones
Limbic system
Emotions and basic feelings
Houses basic elemental drives, emotions, and survival instincts
The 2 basic structures associated with the it are the hippocampus and the amygdala
Hippocampus
Most commonly associated with memory functioning; facilitates the encoding and storage of info in a systematic manner that is associative
Susceptible to loss of oxygen
Sits in temporal lobe between ears
Amygdala
Closely tied with emotional memories and reactions
Fight or flight response to stimulus
Directly tied to olfactory fibers
Basal ganglia
Relay info from cerebral cortex to brainstem and cerebellum
Neurons in the BG respond when someone loses balance by sending a signal to the muscles to restore lost equilibrium
Cerebellum
Coordinates, modulates, and stores all body movement
Monitors impulses from motor and sensory centers ( brainstem, BG, sensorimotor cortex) to help control the direction, rate, force, and steadiness of a persons movements
Cerebral cortex
Dedicated to the highest levels of thinking, moving and acting
Projection fibers fan out from the brainstem and relay info to and from the cortex
The association fibers loop and link together different section of the same hemisphere and modulate the cerebral cortex
Frontal lobe
Made up of 2 parts:
- Primary motor cortex
- Prefrontal cortex
Deficits with executive functions
Sense of identity/self-awareness
Responsible for goal oriented behavior/motivation
Prefrontal cortex
Before a final decision is made about a motor action, the PRC reviews the option, predicts likely outcomes, and decides the best courses of action
Inability to learn from mistakes when injured
Parietal lobe
Primary sensory cortex (somatosensory cortex) sits behind the primary motor cortex
1st part of the brain to consciously register physical sensations
Respond to sensory info such as touch, heat, cold, pain and are responsible for body awareness
Occipital lobe
Primary visual center
Temporal lobe
Center for language and hearing; memory
Broca’s area
Located in the lower portion of the motor cortex in the left frontal-temporal lobe
Controls muscles of the face and mouth that enable production of speech
Wernicke’s area
Located in the left temporal-parietal lobe
Governs a persons understanding of speech, as well as the ability to make sense of thoughts that are spoken
Anterior corticospinal tract
(Efferent) motor
Carries impulses from motor cortex to muscles and organs
Lateral corticospinal tract
(Efferent) motor
Sends impulses to control muscles and other organs
Rubrospinal tract
(Efferent) motor
Assists with fine motor control in the upper extremities, facilitates flexor muscle activity
Tectospinal tract
(Efferent) motor
Aides in directing head movements in response to visual and auditory stimuli
Central cord syndrome
Fall resulting in neck hyperextension in a pt with arthritis or spondylosis
Presents as weakness/numbness of UEs and often accompanied by bowel/bladder incontinence
Brown-Sequard syndrome
One side of the spinal cord is injured, resulting in ipsilateral paralysis, loss of light touch on side of lesion, and loss of pain/temp on contralateral side
Anterior cord syndrome
Common b/c the anterior 2/3 of the cord are controlled by 1 artery (aorta) and is more susceptible to injury
Loss of muscle control, pain and temp, but without loss of proprioception and touch.
Posterior cord syndrome
Rare. Occurs primarily with intraoperative complications in spinal surgery.
Pt possesses strength but no proprioception below level of damage
Fascuculus cuneatus and faniculus gracilis
(Afferent) sensory
Transmit joint and muscle sensation to brain
Lissauer’s tract
(Afferent) sensory
Carry sensations of pain and temp
Anterior and posterior spinocerebellar tract
(Afferent) sensory
Sends proprioceptive input to cerebellum
Spinothalamic tract
(Afferent) sensory
Lateral tract= mediates pain and temp
Ventral tract= transmits impulses of touch
Spinoreticular tract
(Afferent) sensory
Sends sensory information from the body to the thalamus
Spinotectal tract
(Afferent) sensory
Carries info from the eyes and other sensory organs
