are the CNS and PNS distinguished from each other?
- CNS is located within the spinal cord and the brain. PNS is located
- outside the skull and spine. 2 Divisions: somatic NS and Autonomic NS
- (para/symp ).
- Anterior=towards nose.
- Posterior=towards tail.
- Dorsal=toward the surface of back or top of head.
- Ventral=towards the surface of chest or back of head.
- Medial=towards the midline of the body.
- Lateral=away from the midline toward the body’s lateral surfaces.
Major divisions of the spinal cord
How is the spinal cord central gray organized?
Major divisions of PNS
- Somatic Branch: motor component (skeletal muscle), sensory component (somatosenses).
What are the somatosenses?
Provide information relatingto ovents on the skin and to events occurring within the body
What is proprioception?
Monitors information about theposition of the body that comes from receptors in the muscles, joints andorgans of balance.
In what ways does the brain been favored over evolutionary time (How is the brain favored/protected)?
- Cranium: boney protective covering.
- Meninges: encapsulates brain right under the skull to brain. Prevents the brain and spinal cord from rubbing
- against the bones of the skull and spine.
- Blood flow: there is a lot of overlapping arteries which may help supply blood to alternate places.
- Blood brain barrier: protects it by not letting toxins get through to the brain.
- The ventricular system: The cerebrospinal fluid protects & cushions the brain. The CBF makes it so the brain can be supported and protected against gravity.
- 3 Layers: Dura mater (tough mother), arachnoid membrane (spider web like), & pia mater (pious mother).
- In between the arachnoid membrane and pia mater is the busarachnoid space which contains the cerebrospinal fluid and large blood vessels.
1. Where is CSF produced?
2. How does it flow?
3. Where is it reabsorbed?
- 1. Chroid Plexuses.
- 2. Fills the subarachnoid space, the central canal of the spinal cord & the cerebral ventricles of the brain.
- 3. The excess isabsorbed from the subarachnoid space into dural sinuses which run through thedura mater and drain into the large jugular veins of the neck.
What are the main nuclei or structures we have discussed in association with the
Medulla, pons & midbrain.
lower half of the brain stem. Contains the cardiac, respiratory, vomiting and vasomotor centers. Also deals with autonomic, involuntary functions such as breathing, heart rate and blood pressure.
Superior to the medulla. Contain nuclei that relaty signals from the forebrain to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation and posture.
Tectum & tegmentum.
The nuclei play a role in sleep, arousal, attention, movement, various cardiac, circulatory & respiratory reflexes and the maintenance of muscle tone. The RAS uses two NTs: Cholinergic (SN, basal forebrain, thalamus & cerebellum) and Adrenergic (locus coreuleus).
If it is damaged, it is difficult to control movements & adapt to changing conditions.
Tectum: Superior (visual) & inferior (auditory) colliculi. Tegmentum: Periaqueductal gray (descending modulation of pain & defensive behavior), SN (reward, addiction & voluntary movement), & red nucleus (motor coordination).
What is the corpus collosum?
the largest cerebral commissure (hemisphere connecting tract).
- Analysis of visual input to guide our behavior.
- Deficit: in awareness.
- the postcentral gyrus analyzes sensations from the body & the remaining areas play a role in perceiving the location of both objects and our own bodies and in directing or attention.
- Deficit: Phantom Limb, Asomatognosias & Asnosagnosias.
- Superior--hearing and language
- inferior--identifies complex visual patterns.
- Medial--certain kinds of memory.
- Deficit: Werniche's Aphasia.
- motor function & complex cognitive functions.
- Deficit: Broca's Aphasia.
hemiapraxia with failure to pay attention to bodily grooming and stimuli on one side but not the other, usually due to a lesion in the central nervous system.
What are the major functions associated with the prefrontal lobes?
The ability to differentiate among conflicting thoughts, determine good and bad, better and best, same and different, future consequences of current activities, working toward a defined goal, prediction of outcomes, expectation based on actions, and social "control" (the ability to suppress urges that, if not suppressed, could lead to socially-unacceptable outcomes).
How is the primary motor cortex organized
Can't articulate speech well.
reduced activation in the frontal cortex; schizophrenia.
How does the Wisconsin card sorting task assess hypofrontality?
Separate cards depending on categories. Change criteria within that category. Normal to make occasional error (perseverative error). If you have damage to frontal lobe, you will make a lot of Perseverative errors. This is a lack of mental flexibility. Some may link it to criminality.
What are the major sources of brain damage
Traumatic brain injury, stroke/aneurism, cancer, disease & development.
What kind of damage occurs in TBI’s?
Bruising, swelling,shearing of axons, misalignment, anoxia (lack of 02), Necrosis (dead cells).
What is the difference between ishemic stroke and hemorrhagic stroke?
- Ishemic: blockage
- Hemorrhagic: blood spillage from break in blood vessel.
Locked in Syndrome
(Severe brainstem injuries) individual is alert but cannot control movement or function…except sometimes eyeblinks (the waking nightmare).
severe cortical damage leaves patient without consciousness, but subcortical processess are intact so that eating, drinking, even laughing/crying may occur as reflexive/automatic behaviors (waking death).
Anomias, Functional deafness, Aprosodia, Asomatagnosia, Visual hemi-neglect, Amnesia, Aphasia, Anosagnosias
- Anomias--impairment in
- Functional deafness-- hearing loss or impairment caused by a mental or emotional disorder or trauma and having no evidence of an organic cause.
- Aprosodia-- the inability of a person to properly convey and/or interpret emotional prosody.
- Asomatagnosia-- lack of awareness of the condition of all or part of one's body.
- Visual hemi-neglect-- refers to the
- inability to pay attention to or notice stimuli from one-half of the visual field (i.e., the right or left side of a scene or object) even though more basic visual field abilities are intact.
- Amnesia--disturbed or lost memory.
- Aphasia--impairment in language.
- Anosagnosias--being unaware of one’s disability.