History
Who coined the term “Natural-selection”?
Charles Darwin
The central and peripheral nervous system.
What are the major divisions of the brain their subdivision(s)?
Forebrain -> Telencephalon and Diencephalon
Midbrain -> Mesencephalon
Hindbrain -> Metencephalon and myelencephalon
What are the principle functions of the spine?
1. Distribute motor fibers to the organs of the body (gland and muscles)
2. Collect somatosensory information to Be passed on to the brain
What is the cauda equina?
A bundle of spinal roots located caudal to the end of the spinal cord
Define natural selection and functionalism
Natural Selection - inherited traits that produce a selective advantage become more prevalent
Functionalism - Charcteristics of living organisms perform useful functions
What are the two systems of the PNS and what do they do?
Autonomic nervous system- Controls muscles and glands of internal organs
Somatic nervous system - Voluntary control of skeletal muscles
What are the features/functions of the telencephalon and diencephalon?
Telencephalon: Cerebral Cortex (primary sensory/motor and association cortex), Central and lateral fissure, pre/post central gyrus, superior temporal gyri, the limbic system (functions: emotion, memory, motivation, olfaction)
Diencephalon: surrounds the 3rd ventricle, thalamus and hypothalamus, pituitary glands (regulates hormones, ventral stalk of the hypothalamus)
What are the four sections the spine is divided into?
8 cervical (neck, hands, and arms)
12 thoracic (chest muscles and abdomen)
5 lumbar (legs)
5 Sacreal (sacral and coccygeal fused; bowels bladder, sexual funcation)
**Numbers = number of vertebrae
What is the dermatome?
Localized area of skin that has sensation via a single nerve of the spinal cord.
Scientific explanation takes two forms, what are they?
Generalization - Behaviour as general laws
Reduction - Complex phenomena explained in terms of simpler ones
What are the parts to the autonomic nervous system and what do they do?
Sympathetic nervous system - increases heart rate and blood pressure/sugar, preps for fight or flight, decreases digestion, shuts down non-essential functions
Parasympathetic nervous system - Decreases heart rate and blood pressure/sugar, increases digestion
What are the functions/features of the mesencephalon?
Neural tube in mesencephalon becomes the cerebral aqueduct.
Tectum: Superior (eye movement/visual reflexes) and inferior (part of auditory pathway) colliculi
Tegmentum: General area in the brain stem and contains homeostatic & reflexive pathways. Periaqueductal gray, substantia nigra, red nucleus
What are three general features of the spinal cord?
1. Central Canal - CSF filled tube that runs longitudinally through the center of the cord
2. Gray matter - Darker tissue containing sensory and motor cell bodies, unmyelinated acts, and glia
3. White matter - Contains myelinated axons
What is the path that the CSF flows in?
What sets the human brain apart form the brains of other species?
The neocortex
Describe the meninges
3 layers of tissue that encase the CNS:
Dura mater - outermost of the meninges; tough and flexible
Arachnoid membrane - soft translucent middle layer of the meninges.
Pia mater - layer of meninges that clings to the surface of the brain; thin and delicate
What are the features and functions of the metencephalon and myelencephalon?
Metencephalon: pons (relay btwn forebrain and cerebellum. Functions: respiration, bladder control, equilibrium, posture). Cerebellum (receives sensory input then regulates motor movement. Functions: Posture, coordination, balance). 4th Ventricle
Myelencephalon: Reticular Formation (sleep and arousal). Medulla (Blood pressure, breathing, digestion, sneezing, swallowing)
What are the major structures of the spinal cord?
1. Dorsal root (posterior horn) - Sends sensory info to the brain (afferent)
2. Ventral root (anterior horn) - Sends motor info back to the muscles (Efferent)
What is ALS?
Lou Gehrigs Disease: Neuromuscular condition involving destruction of anterior horn motor neurons and fibers of the pyramidal tract (neurons going to/from cortex). A de-myelinating disease
Loss of ability to speak, swallow, and breathe. Death often occurs within 5 years
Name the 4 scientist that had a significant impact in the field of neuroscience and what did they do?
René Descartes - Father of modern Philosophy, Mind/body connection, believed mind-body connection took place in the pineal body
Luigi Galvani - Electrical stim. Of a frogs nerves caused contraction of attached muscle
Pierre Flourens - Experimental ablation; removed parts of animals brains to observe behaviour
Paul Broca - Experimental ablation in humans
How does the CNS develop? (Talk about the neural tube, ventricular zone, progenitor cells)
Ectoderm forms neural groove -> edges form up and from neural tube -> Neural tube becomes brain and spinal cord.
The neural tube serves as the origin of the CNS, and is a hollow tube that closes at the rostral end and forms from the ectodermal tissue.
The ventricular zone is a layer of cells that line the inside of the neural tube and contains progenitor cells.
Progenitor cells form the brain form from the inside-out and divide and give rise to the cells of the CNS. Symmetrical division is when there are two identical progenitor cells and increases the size of the ventricular zone/brain. Asymmetrical division is one there is another progenitor cell and a neuron that migrates away form the ventricular zone and towards its final resting place in the brain.
What are the 12 cranial nerves and their function?
Olfactory - Sensory nerves that convey smell
Optic - Carries messages from the retina to the brain
Oculomotor - Movement of eye muscles
Trochlear - Movement of the eye (looking down)
Trigeminal - Sending pain, touch, temp, sensations from face to brain
Abducens - Move of the eye (side to side)
Facial - Facial movements/expressions
Auditory/vestibulocochlear - sends sound and balance info from inner ear to brain and throat
Glossopharyngeal - Provides motor, parasympathetic, and sensory info to mouth
Vagus - regulates functions of organs in the thoracic abdominal cavities
Accessory - neck and shoulder movement
Hypoglossal - enables tongue movement
What is the difference between afferent and efferent signals?
Afferent - Going towards the CNS (Incoming info, sensory)
Efferent - Going away from the CNS (Outgoing info, motor)
Describe the two kinds of spinal cord trauma?
1. Paralysis: Loss of motor function
If you injure ventral (motor) spinal cord: Flaccid Paralysis. No voluntary or involuntary control of muscles or reflexes. Impulses do not reach muscles.
If you injure higher up: Spastic paralysis. Only motor neurons of the primary motor cortex are damaged. No voluntary control of muscles, but reflexes remain intact.
2. Transection
Cross sectioning of the spinal cord at any level results in total motor and sensory loss in regions below the cut.
Paraplegia: transaction between T1 and L1 (Damage to the cervical or below the cervical.
Quadriplegia: Transection in the cervical region; how high determines the extent of the damage