Lecture Exam 2 - Chapter 16 and 19 Study Guide Flashcards
Define: Sensation
conscious or subconscious awareness of a change in the environment (internal or external).
Define: Perception
conscious awareness and interpretation of sensation.
Know the order of events in the process of sensation.
1) Stimulation of a sensory receptor. 2) Transduction of the stimulus - the sensory receptor transduces (converts) the stimulus with a graded impulse. 3) Generation of a nerve impulse. 4) Integration of the sensory input (interpretation of information in the cerebral cortex).
Know the classification of sensory receptors according to: microscopic features.
1)Free nerve endingins - bare dendrites associated with pain, thermal, tickle, itch, and some touch 2)Encapsulated nerve endings - dendrites enclosed in a connective tissue capsule for pressure, vibration, and some touch sensation. 3) Separate cells - receptor cells synpase with first-order sensory neurons. Located in the retina of the eye, inner ear, and taste buds of the tongue.
Know the classification of sensory receptors according to: receptor location.
1) Exteroceptors - on or near external service of body and responsive to external signals. 2) Interoceptors - in blood vessels, visceral organs, muscles, nervous system - monitor internal environment. 3) Proprioceptors - in muscles, tendons and joints, inner ear - give information about the position of the body.
Know the classification of sensory receptors according to: type of stimulus detected.
1) Mechanoreceptors - detect stretch,touch, pressure, vibration. 2) Thermoreceptors - detect temperature. 3) Nociceptors - detect pain. 4) Photoreceptors - detect light. 5) Chemoreceptors - detect chemicals (taste, smell, blood acidity). 6) Osmoreceptors - detect osmotic pressure of body fluids.
Know how sensory receptors we have discussed fit into classifications.
Gustatory receptors, photoreceptors, and hair cells in the inner ear are all separe cells. hair cells in inner ear are proprioceptors and mechanoreceptors. gustatory receptors are exteroceptors and chemoreceptors photoreceptors are exteroceptors and photoreceptors.
Know the types of sensory receptors in the skin.
Nociceptors, Messiner corpuscles (corpuscle of touch), Type 1 mechanoreceptor (Merkel disc), Type 2 mechanoreceptor (Ruffini corpuscle), hair root plexus, and lamellated corpuscle.
Name 4 different types of somatic sensation.
Tactile Sensations (including pressure, itch and tickle Thermal sensations (hot and cold) Pain sensations (via nociceptors) Proprioceptive sensations
Are sensory receptors capable of adaptation? What does this mean?
Sensory receptors adapt - the receptor potential decreases with a constant stimulus. Adaptation may be: rapid e.g. receptors associated with touch, pressure slow e.g. receptors associated with pain, body position.
What is meant by the term “final common pathway”?
Lower motor neurons extend from the brain stem or spinal cord to skeletal muscles. These lower motor neurons are called the final common pathway because many regulatory mechanisms converge on these peripheral neurons.
What parts of the brain control body movement?
– motor portions of cerebral cortex • initiate & control precise movements – basal ganglia help establish muscle tone & integrate semivoluntary automatic movements – cerebellum helps make movements smooth & helps maintain posture & balance
What are the 4 neural circuits that participate in the control of movement?
Four distinct neural circuits (somatic motor pathways) participate in control of movement by providing input to lower motor neurons: – Local circuit neurons are located close to lower motor neuron cell bodies in the brain stem and spinal cord. – Local circuit neurons and lower motor neurons receive input from upper motor neurons. – Neurons of the basal ganglia provide input to upper motor neurons. – Cerebellar neurons also control activity of upper motor neurons.
Where are the basal nuclei and what are their roles in movement?
The basal nuclei are paired masses of gray matter in each cerebral hemisphere The circuit from the cerebral cortex to basal nuclei to thalamus to cortex seems to function in initiating and terminating movement. – basal nuclei also suppress unwanted movements – basal nuclei may influence aspects of cortical function including sensory, limbic, cognitive, and linguistic functions. • Damage to the basal nuclei results in uncontrollable, abnormal body movements, often accompanied by muscle rigidity and tremors. Control large automatic movements of skeletal muscles
What diseases are known to be the result of damage to the basal nuclei?
Parkinson disease and Huntington disease result from damage to the basal nuclei.
How does the cerebellum modulate movement?
The cerebellum is active in both learning and performing rapid, coordinated, highly skilled movements and in maintaining proper posture and equilibrium. • The four aspects of cerebellar function – monitoring intent for movement, – monitoring actual movement, – comparing intent with actual performance, and – sending out corrective signals • Damage to the cerebellum is evidenced by ataxia and intention tremors.
What area of the brain regulates sleep and wakefulness?
Sleep and wakefulness are integrative functions that are controlled by the reticular activating system. Arousal, or awakening from a sleep, involves increased activity of the RAS. When the RAS is activated, the cerebral cortex is also activated and arousal occurs. The result is a state of wakefulness called consciousness.
What is the difference between NREM and REM sleep? What happens in each of these sleep phases?
Normal sleep consists of two types: – non-rapid eye movement sleep (NREM) and – rapid eye movement sleep (REM)
How do you define learning?
Learning is the ability to acquire new knowledge or skills through instruction or experience.
How do you define memory? What are the differences between immediate, short-term and long-term memory?
Memory is the process by which that knowledge is retained over time. Memory occurs in stages over a period and is described as immediate memory, short term memory, or long term memory. – Immediate memory is the ability to recall for a few seconds. – Short-term memory lasts only seconds or hours and is the ability to recall bits of information; it is related to electrical and chemical events. – Long-term memory lasts from days to years and is related to anatomical and biochemical changes at synapses.
Know major features and potential causes of the following: amnesia
• Amnesia refers to the loss of memory • Anterograde amnesia is the loss of memory for events that occur after the trauma; the inability to form new memories. • Retrograde amnesia is the loss of memory for events that occurred before the trauma; the inability to recall past events.
Know major features and potential causes of the following: phantom pain
• Phantom pain is the sensations of pain in a limb that has been amputated. • Brain interprets nerve impulses arising in the remaining proximal portions of the sensory nerves as coming from the nonexistent (phantom) limb. • Another explanation is that the neurons in the brain that received input from the missing limbs are still active.
Know major features and potential causes of the following: spinal cord injury
Spinal cord injury can be due to damage in a number of ways e.g compression or transection. Location and extent of damage determines the type and degree of loss in neural abilities. Multiple causes e.g. tumor, herniated disc, clot, trauma.
Know major features and potential causes of the following: paralysis
Paralysis – monoplegia is paralysis of one limb only – diplegia is paralysis of both upper or both lower – hemiplegia is paralysis of one side – quadriplegia is paralysis of all four limbs
Know major features and potential causes of the following: cerebral palsy
• Loss of motor control and coordination • Damage to motor areas of the brain – infection of pregnant woman with rubella virus – radiation during fetal life – temporary lack of O2 during birth • Not a progressive disease, but irreversible
Know major features and potential causes of the following: Parkinson’s disease
• Parkinson’s disease is a progressive degeneration of CNS neurons of the basal nuclei region due to unknown causes that decreases dopamine neurotransmitter production. – Environmental toxins may be the cause in some cases • Neurons from the substantia nigra do not release enough dopamine onto basal nuclei – tremor, rigidity, bradykinesia (slow movement) or hypokinesia (decreasing range of movement) – may affect walking, speech, and facial expression
How is blood classified as a tissue?
liquid connective tissue
What are the transport functions of blood?
Transports oxygen to the cells of body and carbon dioxide from body cells to lungs. Carries nutrients to GI. Carries hormones from endocrine glands to target tissues. Transports heat to surface of skin to dissipate. Transports toxic substances to liver and waste products to kidneys, sweat glands. Transports immune cells to sites of injury or pathological invasion.
What are the regulatory functions of blood?
Helps maintain homeostasis of all body fluids. Helps regulate pH through buffers. Helps adjust body temperature. Helps maintain water content of cells by maintaining balance of dissolves ions and proteins.
Know all the details of the information present in Fig.19.3 - Origin, development, and structure of blood cells
Reference - Table 19.3
