Kinesiology 03
Terms
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- blood-brain barrier
- unique anatomical feature of capilliaries in the brain where endothilial cells of brain capilliaries are very close together making them less permiable than other body capilliaries. The foot-like processes of the astrocytes also contribute to this. The blood-brain barrier is permiable to oxygen, CO2, and glucose, but very few other blood-borne solutes. This is to help maintain the chemical homeostasis of the brain, by mitigating sudden chemical changes. It protects the brain from harmful blood-borne chemicals. Makes it difficult to treat some neural infections, because only drugs that can cross the BBbarrier will work.
- CSF
- cerebro-spinal fluid. Probably functions to play protective role, avenue for nutrients to travel to brain and spine. Is secreted by the choroid plexus.
- brainstem
- consists of the medulla oblongata, the pons, and the midbrain. Sleep patterns, emotional responses and pleasurable sensations are associated with this area of the brain.
- cerebrum
- telencephalon. groupings of densly packed nerve cells within the cerebral hemisphers. Majority of higher levels of function of brain occur: thought, intelligence, problem solving.
- choroid plexus
- higly vascular specialized tissue of the ventricular system of the brain. Secretes cerebrospinal fluid.
- thalamus
- large mass of neural tissue alongside third ventrical, contains cell bodies that receive input from sensory fibres, referred to as the brains relay station, it integrates activity from the cerebrum and periphery and sends the information to the cerebellum, cortex, and other areas. Also connects with cerebral cortex and hypothalamus and is involved with motor function and emotional processing.
- slow wave sleep
- a period of sleep characterized by delta waves.
- Wernicke's area
- Language comprehension
- Telencephalon
- (Cerebrum). groupings of densely packed nerve cells within the cerebral hemisphers. This is where the majority of higher levels of mental function such as intelligence, problem solving, and thought are believed to take place.
- interneuron
- a neuron between a sensor neuron and a motor neuron.
- Metencephalon
- cerebellum + pons. Cerebellum processes and coordinates conscious and unconscious movement and reflexes related to body posture. Pons connects both halves of the cerebellum, and links cerebellum to medullary nuclei.
- CSF circulates where?
- bathes ventricular system and outer cortical regions, flows along spinal cord, returns to brain and is reabsorbed itno blood from the arachnoid villi.
- thoracic spinal nerves
- the set of twelve spinal nerves that exit the spine at the thoracic (chest) level.
- parietal lobe
- receive sensory input from the body. See homonculus. (areas of parietal lobe don't correspond in size to areas that they receive input from.)
- limbic system
- not a separate defined structure. A ring of interconnecting pathway structures which also includes part of the thalamus and hypothalamus. is important in emotion, behaviour and motivation, including the facial expressions associated with emotion.
- sympathetic nervous system
- the portion of the autonomic nervous system associated with 'fight or flight' reactions.
- alcohol
- a simple molecule which is absorbed directly into the blood from the stomach. with higher doses can cause behaviour changes decreased muscular coordination, reduced inhibitions, and memory loss.
- cerebellum
- little brain. multi folded portion of the brain below and behind the occipital and frontal lobes of the cerebrum. receives information from the spinal cord about the position of groups of muscles, and is responsible for helping maintain posture and muscle tone. Also controls fine control over repetitive movements such as pianoplaying and typing.
- dorsal root
- the back half portion of a spinal nerve. it has a swelling called a dorsal root ganglion, and joint to the ventral root portion of the spinal nerve a short distance from the spine, to form a complete spinal nerve.
- cranial nerves
- the 12 pairs of nerves that exit the central nervous system directly from the brain, through small holes in the skull. most are sensory nerves carrying information from periphery to brain.
- reticular formation
- network of widely spread neuron fibres from the spinal cord up through the brainstem. Signal the cortex for arousal, alertness, attention. Destruction of different areas of the ret.form. can result in either hyper-alertness or a coma.
- parasympathetic nervous system
- system works in concert with the sympathetic nervous system as part of the autonomic (unconscious, basic physiological functioning) nervous system to assist in the regulation of homeostatic control. The parasympathetic system does this by releasing the neurotransmitter acetylcholine, while it's regulatory partner - the sympathetic nervous system - releases norepinephrine, both in response to similar signals from the body. The release of these neurotransmitters give the autonomic nervous system very fine control over homeostatic elements such as heart and respiratory rates and blood pressure.
- Premotor cortex
- Coordinates complex movements
- pons
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means bridge. contains neurons that control the rhythm of breathing as well as origins of the three spinal nerves, to connect with the spinal cord and other areas of the brain. connects two halves of cerebellum and links cerebellum to medullary
nuclei. - peripheral nervous system
- cranial + spinal nerves. carry info to and from CNS.
- autonomic nervous system
- non-voluntary portion of the nervous system responsible for basic requirements of life and homeostasis of the body. includes the sympathetic and parasympathetic nervous systems, takes info from glands, smooth muscles, and heart. regulates blood pressure, gastrointestinal activity, heart distension.
- afferent nerve fibre
- nerves that carry information back to the central nervous system from the skin, muscles, bones, joints.
- crossed extensor reflex
- the reflex involving multiple synapses and muscle groups which causes the opposite leg to extend in reaction to a stimulus on the first leg. i.e. if you were to step on a tack, the crossed extensor reflex automatically allows you to take the weight off of the effected foot.
- gyri
- elevated portions of the cerebral cortex
- Medulla
- Controls cardiovascular and respiratory function
- sulci
- depressions between the gyri on the cerebral cortex
- ventral root
- the forward half of a spinal nerve, that joins to the dorsal portion a short distance away from the spine. Efferent nerves generally join with the dorsal portion and then synapse with a ventral portion, which may be in direct contact with motor nerves.
- temporal lobe
- involved in speech comprehension, the temporal lobes integrate written and oral symbols to make them meaningful.
- ventricles
- series of chambers within the brain that contain cerebral spinal fluid. act as a protective internal shock absorber + helps support weight of brain. may also be a vehicle for transporting nutrients and chemicals to different parts of the brain, by transporting CSF throughout the brain.
- meninges
- a composite of tough membranes that contain a gel-like substance and help protect the brain and spinal cord from injury. Three meninges surround the spinal cord and four surround the brain.
- efferent nerves
- usually at the conscious level - carries information away from the central nervous system to the periphery, i.e. voluntary skeletal muscles.
- EEG
- Electro encephalogram - records changes in voltage at the skull to monitor electrical brain wave activity.
- short term memory
- receptors are stimulated, information is carried to the brain, and recall of the event which stimulated the receptors is easy for a short time.
- cocaine
- at low doeses causes ental alertness and reduces fatigue. at higher doses, coordination is lost, followed by seizures, and possibly death due to heart or respiratory failure. A highly addictive and dangerous drug.
- Parietal-posterior cortex
- Integrates visual, auditory, and somatic information
- primary motor cortex
- controls voluntary muscle movement
- monoamines
- modified amino acid neurotransmitters that include epinephrine, serotonin, histamine, and dopamine. some are used to treat parkinsons disease.
- long term memory
- the continued accumulation of new synaptic circuits that enable the information of the longer memories to be more readily accessible.
- Somatosensory cortex
- Initial processing site of sensory information
- occipital lobe
- primary visual area of the brain, located in the rearmost portion of the cortex.
- monosynaptic stretch reflex
- a muscle reflex in which only a single synapse is involved, i.e. patellar reflex.
- homonculus
- sensory or motor cortical distribution - i.e. that the proportionate sizes of brain area does not correspond to the size of the body part from which input is received. For example, the arm is much less sensitive to touch than the tongue, with far less nerves, so takes up a much smaller cortical area.
- corpus collossum
- large bundle of nerve fibres located under longitudinal fissure, connects left and right brain hemispheres. allow brain halves to share information and co-ordinate integrated function.
- Somatic
- Carries motor information from CNS to the voluntary skeletal muscles, via EFFERENT nerves - conscious level: vision, hearing, smell,muscles, joints, skin.
- Autonomic (ANS)
- takes information to and from glands, smooth muscles, heart via sympathetic and parasympathetic systems. regulates homeostatic control, blood pressure, gastro-intestinal activity, heart distension.
- CNS
- Central Nervous system - includes all of the nervous system parts located in the bony structures of the body - the skull and the spinal column. (brain, spinal cord.)
- Two branches of PNS?
- Somatic and Autonomic
- PNS
- Peripheral nervous system - all of the neural elements that are not part of the CNS.
- longitudinal fissure
- runs down middle of brain, makes two halves obvious.
- grey matter
- also called the cerebral cortex - the outer part of the brain - a greyish area that is series of convoluted folds.
- cerebral cortex
- also called grey matter, contains mainly cell bodies and neuron dendrites
- white matter
- just below the cerebral cortex, a mass of myelinated fibres that have a white cast.
- glial cells
- fill about half of the brain cavity and consist of astrocytes (which regulate the ionic environment of the brain),oligodendrocytes (which secrete myelin), and schwann cells, (which take myelin to the axons.)
- astrocytes
- star shaped cells of the glia, with foot shaped projections, these help to regulate the ionic environment for the brain, maintaining homeostasis.
- oligodendrocytes
- produce and secrete the myelin that encases myelinated nervous fibres.
- non-neural elements of brain?
-
glial cells, astrocytes, oligodendrocytes.
i.e. those that function mostly in structure - not involved, as neurons are, in transmission of brain function messages. - split brain patients
- have their corpus collossum surgically severed to alleviate severe epileptic symptoms. Can perform most tasks fine, but if an object is placed so that visual projection is only to the right, they will be able to see, but not name the object. These patients demonstrate that the brain hemispheres are functionally different and communication/coordination between both is required to function properly.
- REM sleep
- sleep characterized by rapid eye movment, increased respiration, and brain metabolism, also called paradox sleep because it is strange for a person to be asleep during this level of brain activity
- Hypothalamus
- Controls food intake
- decussation
- the crossing over of the axons in the medulla. this results in cerebral lateralization.
- neuropeptides
- neurotransmitters composed of short chains of polypeptides.include enkephlins and endorphins. are both neuropeptides and hormones - can cause a broad range of effects.
- withdrawal reflex
- an unconscious reaction hard wired into our nervous system and designed to remove us from danger quickly.
- proprioceptors
- receptors which signal position of limbs and body.
- frontal lobe
- the front part of the cortext of the brain, largely responsible for programming and coordinating complex voluntary movements. includes the primary motor cortex and the pre-motor cortex.
- nicotine
- a drug which stimulates receptors which are sensitive to the neurotransmitter acetylcholine. at higher doses can produce tremors and convulsions. at lower doses, produces relaxation, increased alertness, but also increased heart rate and blood pressure.
- Similarities and differences between cranial and spinal nerves?
- both are part of peripheral nervous system, carrying info to and from the CNS. most of the cranial nerves are sensory. Spinal nerves are both sensory and motor nerves, and actually are made up of two nerves that join, so a sensory nerve may synapse directly with a motor nerve.
- Broca's area
- Controls speaking ability
- basic components of a reflex arc
- source stimulus creates action potential-->enervates sensory neuron-->synapse to motor neuron enervates motor neuron-->enervates muscle, causes reflex.
- glial cells versus neurons.
- While glial cells, such as astrocytes (regulate ionic environment) and oligodendrocytes (secrete myelin), serve a regulatory and structural function within the brain to help maintain the blood-brain barrier, neurons are actual "working" parts of the brain and spinal cord, which carry out the function of the brain by transmitting the electrical and chemical signals within the brain. The three types of neurons include sensory neurons (carry messages from senses to CNS), motor neurons(Carry messages from CNS to muscles), and interneurons (CNS neurons that communicate between sensory and motor neurons) The glial cells then, could be seen to serve a "supporting" role in brain function. Without them, the neurons could not properly carry out their work as they might have chemical interruptions by unwanted chemicals entering the brain from the bloodstream, or they may not have the structural support that they require to effectively transmit their signals. Both are required for proper brain function, however glial cells are supportive and in this way, "passive", while neurons are active and carrying out the fundamental brain function.
- General functions of the limbic system
- not a separate defined structure, but a ring of interconecting pathway structures which also includes part of the thalamus and hypothalamus. is important in emotion, behaviour and motivation, including the facial expression associated with emotion.
- hypothalamus controlled behaviours?
- regulates many of the homeostatic mechanisms and biorhythms of the body, such as sleeping and waking, body temperature and blood pressure, heart rate, salt and water balance within the body, and fundamental behavioural drives such as thirst, hunger, sex, etc. If the hypothalamus does not function, the most basic functions of life can not be carried out.
- compare and contrast the sympathetic and parasympathetic nervous systems.
- The systems act together to maintain homeostasis. Sympathetic- generally accelerates activity- the fight or flight response. Pupils dilate, HR increases, respiratory rate increases. Parasympathetic- causes general deceleration or inhibition of bodily activities, effects opposite of sympathetic. Conservation of energy.
- relationship between flexor and extensor muscle groups?
- each muscle that attaches to two bones so that contraction of that muscle causes the bones to move together or further apart. For each muscle, there is a muscle that acts in opposition to it. for example, if the biceps femoris of the leg contracts, this causes flexion of the leg, and the rectus femoris that opposes the biceps femoris then relaxes, opposing the action of the biceps femoris. The opposite is also true - contraction of the rectus femoris causes extension of the leg, and the relaxation of the biceps femoris.
- instability in neurotransmitters and physiological changes
- instabilities can produce unpredictable effects, personality changes, and disease (parkinsons, alzheimers). Drug effects can produce a "high", calming, rage, antisocietal behaviour, or can have drastic physiological effects, even causing death.
- origin, preganglionic and postganglionic fibre length and neurotransmitters of the sympathetic and parasympathetic nervous systems.
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SYMPATHETIC - origin: exit spinal cord and enter ganglia near cord, far from target organs. pregang. are SHORT. post-gagnlionic are LONG. may travel some distance before ending in adrenergic endings. Neurotransmitter: norepinephrine.
PARASYMPATHETIC: exit CNS from some cranial nerves & from lowest level of spinal cord - sacral. pre-ganglionic - long. postganglionic - far removed from CNS, close to organ they enervate, SHORT. neurotransmitter: acetylcholine. - Four lobes of brain and their functions.
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Frontal: coordinating complex voluntary movement. Incl. primary
motor and pre-motor cortex.
Occipital: rearmost portion of cortex - primary visual area.
Parietal: receives sensory input.
Temporal: speech and language comprehension. - Difference between CNS, PNS, ANS.
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CNS - brain, spinal cord, composed of neurons, neuroglia, CSF,
intricately involved in behaviours, learning, + reflexes. PNS -
completes commands from CNS and collects data via sensory
receptors. ANS - part of the PNS, provides means for involuntary
control of vital organs.