1) The document discusses various concepts in animal behavior including warm-up effects, inhibition, feedback control, and reflex rebound.
2) Warm-up effects refer to behaviors that increase in intensity over time without a change in stimulus, due to summation of nerve signals. Inhibition operates at all levels of the nervous system to prevent conflicting behaviors.
3) Feedback control is important for maintaining homeostasis, exemplified by standing posture which is monitored and corrected. Both open and closed loop models of behavior are described.
Kin selection theory explains the evolution of altruism. While altruism seems to go against individual survival and fitness, kin selection demonstrates that altruistic behavior can persist if the altruistic individual helps genetically similar relatives to survive and pass on shared genes. Key examples discussed are sterile worker ants helping their queen sister reproduce since they share three-quarters of their genes, and ground squirrels whose alarm calls risk individual safety but benefit genetically related neighbors. The theory was developed by W.D. Hamilton and others to explain how natural selection can favor altruism between kin.
1. A fixed action pattern is a series of instinctive behaviors that are automatically elicited by a sign stimulus in animals.
2. Examples include herring gull chicks pecking at the red spot on their parents' beaks and male sticklebacks displaying aggressive behaviors towards other males showing red belly coloration.
3. The innate releasing mechanism is the neural network in the brain that is activated by a sign stimulus to trigger a fixed action pattern response.
Animal behavior types can be categorized into several types including learning, habituation, imprinting, classical conditioning, trial and error learning, latent learning, insight, reasoning, and cognition. Learning is the modification of behavior based on experiences and can range from simple to complex. Habituation is the decrease in response to repeated stimuli over time. Imprinting occurs during a sensitive period where young animals learn recognition and attraction patterns. Classical conditioning pairs an innate response with a new stimulus. Trial and error and insight involve solving problems through testing or understanding relationships. Latent learning occurs without reinforcement. Animal cognition allows perception, processing, and use of information.
There are two main animal mating systems: monogamy and polygamy. Monogamy involves an animal having only one mate, while polygamy involves having multiple mates. Polygamy includes polygyny, where one male mates with multiple females, polyandry, where one female mates with multiple males, and polygynandry, where multiple males mate with multiple females. Polygyny is the most common type of polygamy in the animal kingdom. It provides advantages for males in increasing reproductive success but can negatively impact genetic diversity, while females may experience infanticide from new dominant males.
Animal behaviour includes all the ways animals interact with other organisms and the physical environment. It is defined as a change in the activity of an organism in response to a stimulus.
This document discusses evolutionary theories around sexual selection and relationships. It explains that sexual selection occurs through intrasexual competition between males to attract females, and intersexual selection where females choose their mates. Research by Buss (1989) found cross-cultural differences in mate preferences, with females prioritizing resources and males prioritizing youth and attractiveness. Studies also show females' preferences change across their menstrual cycle and they favor more masculine traits when fertile. However, critics argue these theories are reductionist and deterministic by not accounting for free will or environmental influences on relationships.
Habituation is the gradual reduction in response to a repeated stimulus that is irrelevant or harmless to an animal. When a stimulus such as a sound or sight is encountered repeatedly without negative consequence, the animal will stop responding to it as the stimulus loses its novelty and significance. This allows the animal to ignore unimportant stimuli and conserve its energy and time for responses that are actually important for survival. Examples show how various animals like snails, chicks, prairie dogs, and sea anemones eventually stop responding to repeated stimuli through habituation once they learn the stimuli do not pose a threat.
Kin selection theory explains the evolution of altruism. While altruism seems to go against individual survival and fitness, kin selection demonstrates that altruistic behavior can persist if the altruistic individual helps genetically similar relatives to survive and pass on shared genes. Key examples discussed are sterile worker ants helping their queen sister reproduce since they share three-quarters of their genes, and ground squirrels whose alarm calls risk individual safety but benefit genetically related neighbors. The theory was developed by W.D. Hamilton and others to explain how natural selection can favor altruism between kin.
1. A fixed action pattern is a series of instinctive behaviors that are automatically elicited by a sign stimulus in animals.
2. Examples include herring gull chicks pecking at the red spot on their parents' beaks and male sticklebacks displaying aggressive behaviors towards other males showing red belly coloration.
3. The innate releasing mechanism is the neural network in the brain that is activated by a sign stimulus to trigger a fixed action pattern response.
Animal behavior types can be categorized into several types including learning, habituation, imprinting, classical conditioning, trial and error learning, latent learning, insight, reasoning, and cognition. Learning is the modification of behavior based on experiences and can range from simple to complex. Habituation is the decrease in response to repeated stimuli over time. Imprinting occurs during a sensitive period where young animals learn recognition and attraction patterns. Classical conditioning pairs an innate response with a new stimulus. Trial and error and insight involve solving problems through testing or understanding relationships. Latent learning occurs without reinforcement. Animal cognition allows perception, processing, and use of information.
There are two main animal mating systems: monogamy and polygamy. Monogamy involves an animal having only one mate, while polygamy involves having multiple mates. Polygamy includes polygyny, where one male mates with multiple females, polyandry, where one female mates with multiple males, and polygynandry, where multiple males mate with multiple females. Polygyny is the most common type of polygamy in the animal kingdom. It provides advantages for males in increasing reproductive success but can negatively impact genetic diversity, while females may experience infanticide from new dominant males.
Animal behaviour includes all the ways animals interact with other organisms and the physical environment. It is defined as a change in the activity of an organism in response to a stimulus.
This document discusses evolutionary theories around sexual selection and relationships. It explains that sexual selection occurs through intrasexual competition between males to attract females, and intersexual selection where females choose their mates. Research by Buss (1989) found cross-cultural differences in mate preferences, with females prioritizing resources and males prioritizing youth and attractiveness. Studies also show females' preferences change across their menstrual cycle and they favor more masculine traits when fertile. However, critics argue these theories are reductionist and deterministic by not accounting for free will or environmental influences on relationships.
Habituation is the gradual reduction in response to a repeated stimulus that is irrelevant or harmless to an animal. When a stimulus such as a sound or sight is encountered repeatedly without negative consequence, the animal will stop responding to it as the stimulus loses its novelty and significance. This allows the animal to ignore unimportant stimuli and conserve its energy and time for responses that are actually important for survival. Examples show how various animals like snails, chicks, prairie dogs, and sea anemones eventually stop responding to repeated stimuli through habituation once they learn the stimuli do not pose a threat.
This document discusses different types of imprinting, including filial imprinting where young animals imprint on their parents, sexual imprinting where young imprint on characteristics of adults that influence mate choice, and reverse sexual imprinting known as the Westermarck effect where individuals living in close proximity early in life are desensitized to sexual attraction to one another to avoid inbreeding. It also discusses limbic imprinting where prenatal, perinatal, and postnatal experiences leave lifelong imprints on the limbic system of the brain that shape deep-seated beliefs and values. Examples are provided for each type of imprinting.
This document discusses different theories for how altruistic behavior evolved in animals despite natural selection favoring selfish behavior. It describes theories of group selection, kin selection, and reciprocal altruism. Group selection proposes that groups with more altruistic members are more likely to survive. Kin selection explains that animals help relatives to increase indirect fitness. Reciprocal altruism occurs when organisms help each other with the expectation of future help in return. The document analyzes these theories in terms of evolutionary biology to explain the prevalence of altruism in animal societies.
Animal behaviour is any activity performed by an animal in response to an internal or external stimuli or combination of both. Every behaviour of animal is more or less controlled by a genetical component. Some behaviours are controlled by a single or a few genes. Other behaviours are controlled by a set of genes through complex interplay.
This document discusses the history of theories of animal behavior from ancient philosophers like Aristotle to modern ethologists. It covers early ideas like Lamarck's theory of the inheritance of acquired characteristics and Darwin's theory of natural selection. Later, William James rejected the idea that animal behavior is purely instinctual while Skinner's experiments with operant conditioning in a Skinner Box influenced ideas of learning. Ethologists like Lorenz, Tinbergen, and von Frisch studied animal communication and behavior in natural environments.
1. The document discusses various methods for studying animal behavior, including ad libitum observation, focal animal observation, scanning/instantaneous sampling, all occurrences sampling, and one-zero sampling.
2. It provides examples of how to create an ethogram to catalog an animal's behaviors and create a time budget to track how much time an animal spends on different behaviors like hunting, eating, sleeping, and grooming.
3. The procedure outlines observing a single animal for an hour, recording its behaviors and the time spent on each one in order to analyze which behaviors are most and least frequent.
The document discusses different types of innate animal behavior, including innate, reflexive, instinctive, and learned behaviors. It provides examples and definitions for each type. Innate behaviors are inborn and do not require learning, such as fish swimming and geese migrating. Reflex behaviors are automatic responses to stimuli that do not involve consciousness. Instinctive behaviors are complex, innate behaviors that are performed without prior learning or experience, such as fixed action patterns in animals.
This document provides an overview of animal behaviour, including definitions, history, types of behaviours, and specific topics. It begins with definitions of animal behaviour and ethology. It then discusses the history of the field and pioneers. Behaviours are classified as innate or learned, and the various types of each are defined. Neural bases of learning and forms of behaviour are also summarized. Specific sections cover thermoregulation mechanisms, bioluminescence including types and functions, and conclusions with references.
Ethology is the scientific study of animal behavior. It is a branch of biology that focuses on observational studies of animal behavior in natural contexts, in relation to their anatomy and physiology. Key founders included Lorenz, Frisch, and Tinbergen who studied innate behaviors like fixed action patterns and instinctual responses triggered by sign stimuli. They also studied learned behaviors and communication within and between animal species including bees' dances and wasps' ability to locate their nest based on visual cues. Ethology provided insights into aggression, imprinting, displacement activities and supernormal stimuli exploitation.
The document discusses physiological mechanisms and behavior from the perspective of the nervous system and hormones. It provides details on the evolution of the nervous system across organisms from unicellular to multicellular to vertebrates. Key points made include the increasing differentiation and centralization of the nervous system correlating with increased behavioral complexity. Examples are given comparing nervous system anatomy and organization between invertebrate and vertebrate species in relation to different lifestyles and behaviors.
This document summarizes key concepts around the evolution of behavior through natural selection and genetic inheritance. It discusses how behaviors are co-adapted through evolution to maximize survival and reproduction. Behaviors can be culturally transmitted between individuals without genetic changes. Kin selection theory explains how behaviors that help reproduce relatives' genes can also be selected for, if the degree of relatedness and benefits are high enough. Examples of genetic studies of behaviors in insects and vertebrates are provided to show the interaction between genes, development and environment in determining behaviors.
This document discusses different types of learned behaviors in animals, including non-associative learning like habituation and sensitization, as well as associative learning through classical and operant conditioning. Classical conditioning is demonstrated through Ivan Pavlov's experiment with dogs, where he conditioned them to salivate when hearing a bell through repeated pairing with food. Operant conditioning is shown through B.F. Skinner's experiments with rats in a Skinner box, where pressing a lever was reinforced with food rewards. Other learned behaviors discussed include latent learning, imprinting, and insight learning.
Learned behavior in animals can occur through various forms of conditioning, as well as observation and reasoning. Animals are able to learn behaviors that help them adapt to their environments and ensure survival. Learning allows animals to be more flexible than if they relied solely on innate behaviors determined by their genetics. The types of learning include habituation, classical and operant conditioning, observation, food hoarding, imprinting, and insight learning. An animal can only learn behaviors that its physical form allows, as a dolphin cannot ride a bicycle due to its lack of legs and fingers.
- Hormones secreted by endocrine glands and neurons affect behaviour over minutes, days or months by influencing the nervous system, sensory perception, effector systems, and development.
- Hormones can have direct and indirect effects on behaviour depending on factors like genotype, season, experience, and ecology.
- Biological rhythms that regulate behaviours are controlled by neural and hormonal mechanisms and allow for immediate and long-term patterns aligned with environmental cycles.
The document discusses animal behavior and its use as a screening tool in biomedical research. It defines animal behavior and describes ethology, the scientific study of animal behavior. It discusses pioneers in the field like Niko Tinbergen and covers different types of behaviors like feeding, social, and communicative behaviors. The document also discusses the nature vs nurture debate and different learning processes in animals. It describes using animal models to study behaviors related to pain, anxiety, depression, and other conditions to gain insights into human behaviors and disorders.
This document discusses parental care and parent-offspring conflict from an evolutionary perspective. It explains that parental care involves behaviors that increase offspring survival at a cost to the parent's ability to invest in other offspring. While parental care benefits offspring fitness, it limits parental reproduction. This can lead to conflict between parents and offspring over how much care is provided as their interests are not fully aligned. The document outlines Robert Trivers' theory of parent-offspring conflict and how it results from differing relatedness levels between parents, offspring, and siblings.
Hormones play an important role in regulating animal behavior. Gonadal hormones like testosterone and estrogen influence sexual, aggressive, and parental behaviors. The pituitary gland releases hormones like LH, FSH, and prolactin that affect reproductive behaviors. Thyroid hormones control metamorphosis and migration. Hormones have bidirectional relationships with behavior - hormones can influence behavior and behavioral stimuli can trigger hormone release. For example, mating stimulates LH and oxytocin release in some species. Together, the endocrine and nervous systems coordinate the complex behaviors necessary for survival and reproduction.
When a perfectly harmless animal resembles in its colour and shape, with a well protected species, the phenomenon is called mimicry.
The concept of mimicry was first given by H. W. Bates in 1862.
Mimicry is an important feature of organism which protect the animals against enemies. Mimicry often used as self defense which increases the survival value of organisms.
Reproductive behaviour: 1-Sexual behaviour in animalsrhfayed
Reproductive Behaviour involve behaviour patterns associated with courtship, copulation, birth, maternal care and with suckling attempts of newborn. It is species specific behaviour
This document discusses different types of imprinting, including filial imprinting where young animals imprint on their parents, sexual imprinting where young imprint on characteristics of adults that influence mate choice, and reverse sexual imprinting known as the Westermarck effect where individuals living in close proximity early in life are desensitized to sexual attraction to one another to avoid inbreeding. It also discusses limbic imprinting where prenatal, perinatal, and postnatal experiences leave lifelong imprints on the limbic system of the brain that shape deep-seated beliefs and values. Examples are provided for each type of imprinting.
This document discusses different theories for how altruistic behavior evolved in animals despite natural selection favoring selfish behavior. It describes theories of group selection, kin selection, and reciprocal altruism. Group selection proposes that groups with more altruistic members are more likely to survive. Kin selection explains that animals help relatives to increase indirect fitness. Reciprocal altruism occurs when organisms help each other with the expectation of future help in return. The document analyzes these theories in terms of evolutionary biology to explain the prevalence of altruism in animal societies.
Animal behaviour is any activity performed by an animal in response to an internal or external stimuli or combination of both. Every behaviour of animal is more or less controlled by a genetical component. Some behaviours are controlled by a single or a few genes. Other behaviours are controlled by a set of genes through complex interplay.
This document discusses the history of theories of animal behavior from ancient philosophers like Aristotle to modern ethologists. It covers early ideas like Lamarck's theory of the inheritance of acquired characteristics and Darwin's theory of natural selection. Later, William James rejected the idea that animal behavior is purely instinctual while Skinner's experiments with operant conditioning in a Skinner Box influenced ideas of learning. Ethologists like Lorenz, Tinbergen, and von Frisch studied animal communication and behavior in natural environments.
1. The document discusses various methods for studying animal behavior, including ad libitum observation, focal animal observation, scanning/instantaneous sampling, all occurrences sampling, and one-zero sampling.
2. It provides examples of how to create an ethogram to catalog an animal's behaviors and create a time budget to track how much time an animal spends on different behaviors like hunting, eating, sleeping, and grooming.
3. The procedure outlines observing a single animal for an hour, recording its behaviors and the time spent on each one in order to analyze which behaviors are most and least frequent.
The document discusses different types of innate animal behavior, including innate, reflexive, instinctive, and learned behaviors. It provides examples and definitions for each type. Innate behaviors are inborn and do not require learning, such as fish swimming and geese migrating. Reflex behaviors are automatic responses to stimuli that do not involve consciousness. Instinctive behaviors are complex, innate behaviors that are performed without prior learning or experience, such as fixed action patterns in animals.
This document provides an overview of animal behaviour, including definitions, history, types of behaviours, and specific topics. It begins with definitions of animal behaviour and ethology. It then discusses the history of the field and pioneers. Behaviours are classified as innate or learned, and the various types of each are defined. Neural bases of learning and forms of behaviour are also summarized. Specific sections cover thermoregulation mechanisms, bioluminescence including types and functions, and conclusions with references.
Ethology is the scientific study of animal behavior. It is a branch of biology that focuses on observational studies of animal behavior in natural contexts, in relation to their anatomy and physiology. Key founders included Lorenz, Frisch, and Tinbergen who studied innate behaviors like fixed action patterns and instinctual responses triggered by sign stimuli. They also studied learned behaviors and communication within and between animal species including bees' dances and wasps' ability to locate their nest based on visual cues. Ethology provided insights into aggression, imprinting, displacement activities and supernormal stimuli exploitation.
The document discusses physiological mechanisms and behavior from the perspective of the nervous system and hormones. It provides details on the evolution of the nervous system across organisms from unicellular to multicellular to vertebrates. Key points made include the increasing differentiation and centralization of the nervous system correlating with increased behavioral complexity. Examples are given comparing nervous system anatomy and organization between invertebrate and vertebrate species in relation to different lifestyles and behaviors.
This document summarizes key concepts around the evolution of behavior through natural selection and genetic inheritance. It discusses how behaviors are co-adapted through evolution to maximize survival and reproduction. Behaviors can be culturally transmitted between individuals without genetic changes. Kin selection theory explains how behaviors that help reproduce relatives' genes can also be selected for, if the degree of relatedness and benefits are high enough. Examples of genetic studies of behaviors in insects and vertebrates are provided to show the interaction between genes, development and environment in determining behaviors.
This document discusses different types of learned behaviors in animals, including non-associative learning like habituation and sensitization, as well as associative learning through classical and operant conditioning. Classical conditioning is demonstrated through Ivan Pavlov's experiment with dogs, where he conditioned them to salivate when hearing a bell through repeated pairing with food. Operant conditioning is shown through B.F. Skinner's experiments with rats in a Skinner box, where pressing a lever was reinforced with food rewards. Other learned behaviors discussed include latent learning, imprinting, and insight learning.
Learned behavior in animals can occur through various forms of conditioning, as well as observation and reasoning. Animals are able to learn behaviors that help them adapt to their environments and ensure survival. Learning allows animals to be more flexible than if they relied solely on innate behaviors determined by their genetics. The types of learning include habituation, classical and operant conditioning, observation, food hoarding, imprinting, and insight learning. An animal can only learn behaviors that its physical form allows, as a dolphin cannot ride a bicycle due to its lack of legs and fingers.
- Hormones secreted by endocrine glands and neurons affect behaviour over minutes, days or months by influencing the nervous system, sensory perception, effector systems, and development.
- Hormones can have direct and indirect effects on behaviour depending on factors like genotype, season, experience, and ecology.
- Biological rhythms that regulate behaviours are controlled by neural and hormonal mechanisms and allow for immediate and long-term patterns aligned with environmental cycles.
The document discusses animal behavior and its use as a screening tool in biomedical research. It defines animal behavior and describes ethology, the scientific study of animal behavior. It discusses pioneers in the field like Niko Tinbergen and covers different types of behaviors like feeding, social, and communicative behaviors. The document also discusses the nature vs nurture debate and different learning processes in animals. It describes using animal models to study behaviors related to pain, anxiety, depression, and other conditions to gain insights into human behaviors and disorders.
This document discusses parental care and parent-offspring conflict from an evolutionary perspective. It explains that parental care involves behaviors that increase offspring survival at a cost to the parent's ability to invest in other offspring. While parental care benefits offspring fitness, it limits parental reproduction. This can lead to conflict between parents and offspring over how much care is provided as their interests are not fully aligned. The document outlines Robert Trivers' theory of parent-offspring conflict and how it results from differing relatedness levels between parents, offspring, and siblings.
Hormones play an important role in regulating animal behavior. Gonadal hormones like testosterone and estrogen influence sexual, aggressive, and parental behaviors. The pituitary gland releases hormones like LH, FSH, and prolactin that affect reproductive behaviors. Thyroid hormones control metamorphosis and migration. Hormones have bidirectional relationships with behavior - hormones can influence behavior and behavioral stimuli can trigger hormone release. For example, mating stimulates LH and oxytocin release in some species. Together, the endocrine and nervous systems coordinate the complex behaviors necessary for survival and reproduction.
When a perfectly harmless animal resembles in its colour and shape, with a well protected species, the phenomenon is called mimicry.
The concept of mimicry was first given by H. W. Bates in 1862.
Mimicry is an important feature of organism which protect the animals against enemies. Mimicry often used as self defense which increases the survival value of organisms.
Reproductive behaviour: 1-Sexual behaviour in animalsrhfayed
Reproductive Behaviour involve behaviour patterns associated with courtship, copulation, birth, maternal care and with suckling attempts of newborn. It is species specific behaviour
Posture is maintained through a balance of muscle contractions regulated by reflexes. The key reflex is the stretch reflex, where muscle spindles detect changes in muscle length and signal the spinal cord to contract or relax muscles. There are two types of postural reflexes - static and statokinetic. Static reflexes maintain posture against gravity, while statokinetic reflexes allow for voluntary movement. Multiple areas of the central nervous system integrate these reflexes, including the spinal cord, brainstem, cerebellum and cerebral cortex. Vision and vestibular signals also provide important inputs. Together this network allows humans to maintain an upright stance through low levels of continuous muscle contraction adjusted by reflexes.
Posture is maintained through a combination of muscle tone and reflexes. The muscles that maintain posture contain a high proportion of slow-twitch fibers to allow for sustained contraction. Postural reflexes integrate inputs from proprioceptors, the vestibular system and visual system to make continuous corrections to muscle activity and maintain balance. The spinal cord, brainstem and cerebellum are involved in regulating these reflexes. Upright human posture relies on minimal muscle activity but reflex adjustments of antigravity muscles in response to sway to oppose the effects of gravity.
This document discusses different types of spinal reflexes and their components. It describes autonomic reflexes which control organs and glands, and somatic reflexes which control muscles. Specific examples of reflex tests are provided, including the patellar reflex test for somatic reflexes and pupillary light reflex test for autonomic reflexes. Sensory receptors like muscle spindles, Golgi tendon organs, and their roles in reflexes are also explained.
1. Coordination of movement involves the interaction of multiple body systems working together, including the skeletal, muscular, and nervous systems.
2. The nervous system plays a key role in coordination through pathways that transmit signals from sensory neurons detecting stimuli to the central nervous system and then to motor neurons initiating responses.
3. These pathways involve afferent neurons carrying signals to the central nervous system, efferent neurons carrying signals from the central nervous system to effectors like muscles, and association neurons linking the afferent and efferent neurons.
Reflex activity is the response to a peripheral stimulation that occurs without our consciousness.
Is an involuntary response to a stimulus.
It is a type of protective mechanism.
BRUNNSTROM'S approach for stroke patient.pptxParulBawa4
The document outlines Brunnstrom's stages of motor recovery following a neurological injury. It describes 7 stages, beginning with flaccidity and no movement, and progressing to restoration of normal motor function. As recovery advances, spasticity develops and peaks before declining. Early stages involve basic limb synergies dominated by flexion or extension patterns. Later stages achieve more complex movements and coordination approaches normal. The evaluation methods described assess tonic reflexes, associated reactions, sensory function, and motor abilities like range of motion and speed of movement through the recovery stages.
This document discusses different types of innate animal behaviors, including:
1. Innate behaviors are inborn and do not need to be learned, such as fish swimming and geese migrating.
2. Other innate behaviors include irritability, tropisms (turning responses to stimuli), nasties (non-directional responses), taxes (directional responses to stimuli), kineses (non-directional responses to stimuli), reflex actions, instincts (complex behaviors performed without prior experience), and fixed action patterns (unchangeable sequences of innate behaviors).
3. Motivation arises behaviors toward goals and can be intrinsic (driven by interest/enjoyment) or extrinsic (driven by external rewards/
Postural reflexes help maintain upright posture and balance during movement. They involve afferent pathways from proprioceptors and vestibular/visual systems, integrating centers in the brainstem and spinal cord, and efferent motor pathways. There are static and statokinetic reflexes. Static reflexes respond to gravity and include local, segmental, and general reflexes like the stretch reflex. Statokinetic reflexes maintain balance during movement via visual and vestibular placing reactions and hopping responses. Decerebrate animals have increased muscle tone from loss of supraspinal inhibition, intact spinal reflexes, and absent righting reflexes. Decorticate animals have moderate rigidity and characteristic flexed posture with
1. The regulation of posture and movement involves integration at multiple levels of the central nervous system, from the spinal cord to the cortex.
2. At the spinal cord level, afferent inputs produce simple reflex responses, while higher centers produce more complex responses and motor behavior.
3. Isolating centers through experimental lesions allows studying their specific influence on posture and movement.
Reflexes are involuntary or automatic responses of the body to stimuli. A reflex arc consists of a receptor, afferent nerve, center, efferent nerve, and effector organ. There are various ways to classify reflexes, including by anatomical location of the reflex center, number of synapses, whether they are somatic or visceral, and whether they are normal or pathological. Common reflexes include withdrawal reflexes, deep tendon reflexes, and visceral reflexes like the pupillary reflex. Pathological reflexes include Babinski's sign and clonus. Reflexes are lost or exaggerated in different ways depending on whether the lesion is of the upper or lower motor neuron.
This document discusses motor control and reflexes. It defines motor control as the study of the causes of movement and how movement is regulated in organisms with nervous systems. Reflexes are described as automatic responses to stimuli that do not involve conscious thought. Several types of reflexes are discussed, including monosynaptic/monosegmental reflexes involving one spinal cord segment, and multisynaptic/intersegmental reflexes involving more than one segment. Examples of reflexes like the knee jerk, sneezing, and withdrawing from a hot object are provided. The basic components of a reflex arc, including receptors, sensory and motor neurons, and effectors, are outlined. Limitations of explaining all movements as reflexes are noted
The document provides an overview of classical and operant conditioning concepts. It defines classical conditioning and discusses Ivan Pavlov's experiments. It then explains various classical conditioning processes like acquisition, extinction, generalization, and discrimination. It also defines operant conditioning and discusses B.F. Skinner's experiments. It explains operant conditioning concepts like reinforcement, schedules of reinforcement, and punishment. It concludes by discussing observational learning research by Albert Bandura and applications of behaviorism.
There are three main levels of control involved in maintaining posture: spinal, brainstem, and cortical. At the spinal level, stretch reflexes and supporting reactions maintain static stability. At the brainstem level, labyrinthine reflexes and tonic neck reflexes react to gravitational pull and head position. At the cortical level, visual and proprioceptive cues integrate to allow for complex postural adjustments.
This document discusses key concepts in operant conditioning and learning, including:
1) Extinction refers to the weakening and disappearance of conditioned responses when reinforcement is no longer provided. An initial response surge may occur followed by a gradual decline.
2) Discriminative stimuli influence behavior by indicating when responses will or will not be reinforced. Stimulus generalization and discrimination govern reactions.
3) Reinforcement schedules, such as fixed ratio and variable interval, differentially impact the acquisition and extinction of behaviors.
4) Negative reinforcement strengthens responses that reduce unpleasant stimuli, while positive reinforcement strengthens responses followed by rewards. Escape and avoidance learning are examples.
Animal behavior can be defined as the response of an organism to stimuli in its usual or specific way. It arises from coordination between the nervous system and endocrine system. The nervous system detects stimuli through sensory neurons and responds through motor neurons, with interneurons relaying signals between them. Within neurons, stimuli trigger nerve impulses which are electrical signals propagated along axons. These cause synaptic potentials that may excite or inhibit neighboring neurons. Behavior is controlled by neuronal circuits in the brain and spinal cord that integrate synaptic inputs and trigger action. For example, prey capture in toads involves feature detectors in the brain that recognize worm-like stimuli and trigger a capture reflex, while escape behavior in crayfish involves motor neurons that trigger rapid tail
Roods approach a For Neuro PhysiotherapyDr. Muzahid
This document discusses Rood's sensory motor approach for gaining motor control in patients. It describes the levels of motor control from reflex mobility to skilled movement. Sensory inputs like light touch, vibration and vestibular stimulation can facilitate movement while rocking inhibits it. Proprioceptive techniques like stretching and resistance activate muscles. The document also outlines Rood's principles of using activity to demand purposeful response and practicing sensory motor responses for motor learning.
This document provides an overview of learning in psychology from several perspectives. It discusses classical and operant conditioning, including their basic principles and examples of how they are applied in everyday life. Classical conditioning involves associating an unconditioned stimulus that elicits a reflexive response with a conditioned stimulus through repeated pairing. Operant conditioning examines how voluntary behaviors are strengthened by reinforcement or weakened by punishment. The document also covers types of learning like shaping behavior through successive approximations and uses of reinforcement schedules.
Learning is a process of acquiring knowledge through experience or being taught. There are several types of learning, including classical conditioning, operant conditioning, and observational learning. Classical conditioning involves associating a neutral stimulus with an unconditioned stimulus to elicit a conditioned response, as demonstrated in Pavlov's experiments. Operant conditioning involves voluntary responses that are reinforced or punished to increase or decrease a behavior. Observational learning occurs through observing and imitating others. Factors that influence learning include intelligence, prior knowledge, motivation, and the learning material and methods used. Various therapies also apply learning principles, such as systematic desensitization for phobias.
This document summarizes key concepts about protein structure and collagen. It discusses the forces involved in protein folding like hydrophobic interactions and hydrogen bonding. It describes accessory proteins that assist folding like chaperones. Collagen is introduced as the most abundant protein, composed of tropocollagen triple helices with characteristic Gly-X-Y motifs. Post-translational modifications of collagen including hydroxyproline, hydroxylysine and cross-linking are outlined.
This document discusses biomolecules, specifically peptides and proteins. It outlines the levels of protein structure from primary to quaternary. Primary structure refers to the amino acid sequence, secondary structure includes alpha helices and beta sheets stabilized by hydrogen bonding. Tertiary structure is the overall 3D shape of a protein, and quaternary involves interaction of multiple polypeptide subunits. Techniques for protein analysis include electrophoresis, chromatography, mass spectrometry and X-ray crystallography. Myoglobin and hemoglobin are compared as examples of monomeric and multimeric protein structures and functions.
This document discusses biomolecules and amino acids. It outlines key topics like the properties of amino acids, their pKa values and titration curves. At physiological pH, both the carboxyl and amino groups of amino acids are charged. Only L-amino acids are found in proteins. Some examples of clinical aminoacidurias caused by metabolic or absorption defects are also provided. The document further discusses post-translational modifications, peptide bonds, and the different conformations and restrictions placed on protein structure by the planar nature of peptide bonds.
This document discusses water, pH, and dissociation. It provides information on homeostasis and how the body maintains water distribution and pH levels. Water comprises 70% of human mass and has polar properties allowing it to hydrate molecules and act as a solvent. Very low dissociation of water leads to a constant ion product and pH of 7 for pure water. The Henderson-Hasselbalch equation relates pH to concentrations of acids and bases. Physiological buffers like bicarbonate and phosphate systems regulate blood and cellular pH. Deviations from normal pH ranges can indicate acidosis requiring monitoring of acid-base parameters.
This document provides an outline for a lecture on biomolecules and medical biochemistry. It introduces topics like chemical nomenclature, biomolecules like carbohydrates and lipids, and cellular structures. Major causes of disease are discussed. The document also summarizes the human genome project and its findings. Predictions are made for advances in molecular medicine and genomics over the next 40 years, including personalized gene-based treatments and lifespan extension.
The pentose phosphate pathway generates NADPH and ribose-5-phosphate. It occurs in the cytosol in two phases: an oxidative phase that produces NADPH and ribose-5-phosphate from glucose-6-phosphate, and a non-oxidative reversible phase. NADPH is used to produce fatty acids, amino acids, and reduced glutathione which protects cells from reactive oxygen species. A deficiency in glucose-6-phosphate dehydrogenase, which produces the first NADPH, can cause hemolytic anemia due to increased oxidative damage from a lack of protection against reactive oxygen species. The pathway is regulated by NADPH levels, with more NADPH production when NADPH is used in other pathways
The document discusses hormonal regulation of blood glucose levels. It explains that insulin, glucagon, and epinephrine work to keep blood glucose within a narrow range. Insulin is released when glucose is high and signals cells to take up and store glucose. Glucagon is released when glucose is low and signals the liver to produce glucose through gluconeogenesis and glycogen breakdown. Epinephrine prepares the body for activity by stimulating glycogen and fat breakdown. Diabetes results from defects in insulin production or action, leading to high blood glucose and ketone production. Prolonged fasting relies on gluconeogenesis and ketone bodies for fuel. Alcohol excess can cause hypoglycemia by inhibiting gluconeogenesis in the liver.
1. Glycogen is the major storage form of carbohydrate in liver and muscle.
2. Glycogen is synthesized and broken down through separate pathways to service tissues via blood glucose or as fuel for muscle.
3. Cyclic AMP regulates glycogen metabolism by activating phosphorylase for breakdown and inhibiting synthase for storage. Insulin has opposite effects.
Ubiquinone (Coenzyme Q, or Q) Electron CarrierHamid Ur-Rahman
Ubiquinone, also known as coenzyme Q, is a small, hydrophobic and lipid-soluble benzoquinone electron carrier. It exists in a reduced form, ubiquinol, and an oxidized form, ubiquinone. The reduction of ubiquinone to ubiquinol requires two electrons and two protons and occurs in two steps through a semiquinone radical intermediate.
Electron Transport and Oxidative PhosphorylationHamid Ur-Rahman
The document summarizes electron transport and oxidative phosphorylation in mitochondria. It describes how:
1) The electron transport chain in the inner mitochondrial membrane is made up of four complexes that transfer electrons from nutrients to oxygen, pumping protons from the matrix to the intermembrane space.
2) As electrons are passed through the complexes, energy is used to transport protons against their concentration gradient, building up a electrochemical proton gradient across the inner membrane.
3) ATP synthase uses the potential energy in this proton gradient to phosphorylate ADP, producing ATP through oxidative phosphorylation.
The citric acid cycle provides precursors for biosynthetic pathways and serves catabolic and anabolic processes. It is regulated by substrate availability and product inhibition. Anaplerotic reactions replenish cycle intermediates used for biosynthesis. Acetyl-CoA derived from the cycle is used in fatty acid synthesis in the cytoplasm. The glyoxylate cycle allows conversion of acetate to carbohydrates in some organisms.
The citric acid cycle is a series of chemical reactions in the mitochondria that break down acetyl groups from carbohydrates, fats, and proteins into carbon dioxide, generating reduced coenzymes used in oxidative phosphorylation to produce ATP. Pyruvate is converted to acetyl-CoA by the pyruvate dehydrogenase complex, then the citric acid cycle oxidizes acetyl-CoA in 8 steps, producing NADH, FADH2, and GTP or ATP while releasing CO2. This cycling of intermediates allows for the efficient breakdown of fuels to generate energy.
Glycolysis is a metabolic pathway that converts glucose into pyruvate, generating ATP and NADH. It is catalyzed by 10 cytosolic enzymes in 10 steps. There is a net gain of 2 ATP per glucose molecule. The NADH must be recycled to NAD+ either through aerobic respiration or by converting pyruvate to lactate anaerobically. Glycolysis is regulated at three irreversible steps catalyzed by hexokinase, phosphofructokinase-1, and pyruvate kinase. Other hexoses can also enter this ubiquitous pathway.
1) Bioenergetics examines the energy flow in living organisms using concepts like entropy, enthalpy, and free energy.
2) ATP acts as the energy currency of cells, being produced through exergonic reactions and consumed to power endergonic reactions.
3) Standard free energy changes can be added for coupled reactions and actual free energy depends on reactant and product concentrations, driving reactions towards or away from equilibrium.
- The study determined the distribution, population, and food habits of the Indian pangolin (Manis crassicaudata) in Chakwal district, Pakistan.
- Surveys found the species distributed across the district, with a population density estimate of 0.3 individuals/km2 based on burrow counts.
- Analysis of fecal samples revealed the diet consisted primarily of ants (100% frequency) and ant body parts (30% volume), with soil particles also present (62% volume).
- Threats to the near threatened species were noted as hunting for trade and slow reproduction rate. Conservation strategies were recommended.
Trophy hunting provides socioeconomic benefits to communities in Gilgit Baltistan. Through community conservation programs, local communities conserve wildlife habitats and populations in return for sharing revenues from permit fees for hunting large trophy animals like markhor, ibex, and blue sheep. Hunting programs have led to increased populations of endangered species. Communities receive 80% of permit fees, providing a significant source of income. This study found that trophy hunting improved local incomes and incentivized conservation, with wildlife populations and trophy sizes increasing in community-managed areas. The programs have educated communities about conservation while supporting sustainable use of natural resources.
This study examined the prevalence of tick infestation on livestock in Pothwar, Pakistan. A total of 1804 animals were examined from October 2008 to August 2009, of which 814 (45.1%) were infested with ticks. Cattle had the highest rate of infestation at 58.8% while goats were the lowest at 38.8%. Six tick genera were identified with Haemaphysalis being the most prevalent. Tick infestation rates and burdens were highest in summer months like July and August when humidity and temperatures are higher, and lowest in winter months.
This document summarizes a study that developed a simplified method for purifying the Thermus aquaticus (Taq) DNA polymerase expressed in Escherichia coli. Key steps included:
1) Overproducing the Taq DNA polymerase in E. coli by cloning the Taq gene into an expression vector and inducing high-level expression.
2) Lysing the E. coli cells and heat-treating the lysate to inactivate endogenous nucleases.
3) Precipitating the Taq polymerase from the lysate using polyethyleneimine and eluting it from an ion exchange resin.
4) Obtaining a purified Taq polymerase preparation in a single-day procedure yielding 40-60 mg of
Study of avian diversity in and around chinariHamid Ur-Rahman
This study surveyed the avian diversity in and around Chinari, Azad Jammu and Kashmir, Pakistan over different seasons in 2009. A total of 72 bird species from 13 orders and 39 families were observed. Species richness and abundance were highest in summer with 54 species and 316 individuals, respectively. The most common orders observed were Passeriformes and Coraciformes. The study found variation in avian diversity and population between seasons likely due to food availability and breeding periods. It recommends further surveys and conservation programs to protect endangered species in the area.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
3. Warm-up' or facilitation
• Sherrington found that some reflexes
do not appear at full strength at first
but, with no change in the stimulus,
their intensity increases over a few
seconds.
• Neurons, as we saw, show synaptic
facilitation, each successive PSP being
larger than the one before.
4. • At a behavioural level,Hinde (1954) found that
chaffinches show a similar type of 'warm-up'
effect
• The bird's response to the owl is to give a
mobbing call. (Fig. 1.7).
5. • Sherrington was able to show that 'warm-up1
in some reflexes is due summation of stimuli
that come to evoke a response from more and
more nerve fibers, producing a stronger
contraction. He called this phenomenon
'motor recruitment'.
7. • In complex behaviour, not only a
change in the intensity of response
but in the nature of the behaviour as
well.
• Sherrington (1917) provides an
excellent example from what he calls
the cat's 'pinna reflex'.
9. • Inhibition
• Inhibition operates at every level within
the nervous system. As we have seen,
nerve cells can actively inhibit each
others' transmission of information.
• Prevention of one activity's occurrence
while another is in progress constitutes
inhibition at behavioural level.
• Inhibition is just as important for
coordination of behaviour as excitation
10. • Muscles are commonly arranged in
antagonistic pairs,
• Mutual inhibition: to alternate flexion
and extension of the limbs-
• it is not only antagonists on same limb
that inhibit each other, but that muscles
located on opposite limbs also have
antagonistic effects during locomotion.
• When flexors of one limb r contracting,
flexors of opposite limb inhibited.
Reciprocal inhibition
11. • Inhibition of the
scratch reflex by the
flexion reflex. The
stimulus denoted on line A
invokes the scratch reflex,
but this response is
inhibited when the
stimulus on line B evokes
the flexion reflex.
• The moment B is removed
the scratch reflex returns,
and much more vigorously
than before—an instance
of‘ reflex-rebound'
12. The role of inhibition in complex
behaviour is superficially less obvious
13. • The role of inhibition in complex
behaviour is superficially less obvious
than that of excitation.
• We stimulate an animal and the
conspicuous result is it makes a response.
• But in so doing it has made a swift
transition that requires inhibition of its
behaviour prior to the stimulus and of
other behaviour that it may be stimulated
to perform at the same time.
14. • reflexes 'competing' for the final common
pathway, i.e. the muscles whose action is
common to several different reflexes.
• analogous, fighting, feeding and sleeping
competing for the control of the animal's
musculature..
• Such systems are incompatible, only
one behaviour can occur at a time.
15. Reflex Rebound in dust-bath
• Vestergaard (1980) found that if laying
hens are kept on wire so that they
have no substrate to dust-bath, when
eventually given access to litter they
start dustbathing quickly
• It is possible that the system
controlling dustbathing shows
something akin to reflex rebound.
16. The Winged Aphids
Mutual inhibition between the
systems controlling flights and those
controlling settling
17. Kennedy,
• Winged Aphids, alternates between
periods of flight and settling /feeding on
leaves.
• If aphid settles on an ‘old leaf—,it does
not stay long and soon takes off but flies
relatively weakly and soon settles again.
• settled on a young shoot, it stays for a
long period but, when it takes off, flies
vigorously and for a long time.
18. • activation of the settling system may
temporarily inhibit the expression of the
flight system but, at the same time,
gradually lower the threshold for flight.
20. Feedback control_ to Maintain
Homeostasis
Commonly, reflex or complex behaviour
consists of a steady output of some
activity that has to be held at a given
level.
Exmp 1 'stand at ease',
21. Examp 2
• animals maintain a very
constant body weight and eat
and drink sufficient for their
needs at regular intervals. do
not overeat.
• In times of scarcity, they
consume more when the
chance arises.
Feedback&
HomeoStasis
22. • the end result of
behavior(posture and balance
whilst standing; state of
nutrition) is monitored
• When it deviates, control
mechanisms correct the
imbalance and bring the end
result back to the set value
again.
Feedback&
HomeoStasis
23.
24. • Open Loop Model of Reflex
• It has no monitor and input coming to
behavioral system(BS) is interacted
and we get the output(response).
• Even if the output is subjected to
some disturbances it is not going to
effect the the BS
25. Strike of Mantis, open loop
• No time to modify a swift movement.
• The mantis orientates its body( involve
feedback control)
but, once aimed, the strike is an all-or-
none movement.
• If the fly moves , it will hit the wrong
place
• (without feedback),
26.
27. • Close Loop Model
• Any alteration in out put feeds back to the input
to affect the behavior system and thus changes
the out put.
• Thus out put is adjusted proportional to the feed
back.
• This model works in slow and precise movements
28. • Applying the Close Loop Mechanism
shown in Figure to STAND at EASE.
• The output (state of tension in the
muscle) is affected by a disturbance
(being stretched by other muscles)
• muscle spindle, records the change
and feeds back to change the input
(motor nerve) and restore the original
output.
29. • Figure 1.10, represents a typical muscle on the
limb of a mammal, involved in maintaining
posture.
30. • —excitation, inhibition, summation,
facilitation and feedback control
• common to many levels. neurons,
reflexes and more complex behavior
share many basic properties
• in many cases, very different
concepts.
• It is often possible to break down
complex into smaller units.
31. • There are differences in complexity
and these often require different
types of approach.
• what sort of questions about
behaviour we are trying to answer.
Editor's Notes
Counting the number of calls given "by a chaffinch in successive 10s periods after the owl is shown to it indicates that it begins by calling at a relatively low rate and that the maximum calling rate is not reached for about 2.5 min, after which it gradually declines
Repeated tactile .stimulation to the cat's car first causes it to be laid back. If stimulation persists, the ear is fluttered; thirdly the cat shakes its head and when all else fails to remove irritation, it brings its hind leg up and scratches
Inhibition operates at every level within the nervous system. As we have seen, nerve cells can actively inhibit each others' transmission of information.
Similarly, prevention of one activity's occurrence while another is in progress constitutes inhibition at behavioural level. In many ways, inhibition is just as important for coordination of behaviour as excitation
Muscles are commonly arranged in antagonistic pairs,
Mutual inhibition allows them to take the lead in turn during limb movements, and to alternate flexion and extension of the limbs- Sherrington found that it is not only antagonists on die same limb that inhibit each other, but that muscles located on opposite limbs also have antagonistic effects during locomotion. When die flexors of one limb arc contracting, die flexors of die opposite limb arc inhibited. Reciprocal inhibition of this type is one of the basic integrating mechanisms
In an analogous, systems controlling patterns of complex behaviour like fighting, feeding and sleeping competing for the control of the animal's musculature..
Such systems are obviously incompatible in sense that only one behaviour can occur at a time. When animal starts feeding, other behaviour must be inhibited for the time being.
We observe that when a particular type of complex behaviour, e.g. courtship, has not been elicited for some time, it has a lowered threshold and is performed with high intensity when it is, at last, evoked.
and dustbath in very much longer session than hens kept all the time on litter.
In an elegant series of experiments, Kennedy was able to exclude any simple explanation for this relationship based on physical exhaustion during flight and recovery after resting and feeding on a young leaf. He suggested that there is mutual inhibition
feedback control loop (plural feed·back con·trol loops) noun
connection from output to input: the connection or path that forms an electrical loop from the output to the input of a feedback circuit
Very commonly, reflex or complex behaviour consists of a steady output of some activity that has to be held at a given level. When we 'stand at ease', our body is evenly balanced over the pelvic girdle and easily corrects for any slight jostling we may receive. To do so, the muscles of the legs and back must be held at a constant level of tension and, if shifted away from this level, they must correct to bring the body upright again. Analogously, under normal circumstances animals maintain a very constant body weight and eat and drink sufficient for their needs at regular intervals. If a surplus is available they do not overeat. In times of scarcity, they spend a higher proportion of their time in feeding and consume more when the chance arises to replace any deficit.
Analogously, under normal circumstances animals maintain a very constant body weight and eat and drink sufficient for their needs at regular intervals. If a surplus is available they do not overeat.
In times of scarcity, they consume more when the chance arises to replace any deficit.
these examples SHOW
behaviour acting as homeostatic.
In the first case, this was achieved through reflex systems controlling the leg and trunk muscles;
in the second case it was achieved by a series of more complex systems regulating the search for food, feeding and satiation.
In both cases the operation requires that the end result of behavior(posture and balance whilst standing; state of nutrition) is monitored in some way.
When it deviates from a set value a signal is sent to the control mechanisms to correct the imbalance and bring the end result back to the set value again.
This idea is shown diagrammatically in Figure on next slide. It is disscused in more detail in chapter 4.
e.g simple reflexes like, flexion reflexes, touching hot or cold.
No time to modify a swift movement.
The mantis orientates its body slowly and precisely ( involve feedback control) but, once aimed, the strike is an all-or-none movement.
If the fly moves after the strike is initiated, it will hit the wrong place
without feedback,
So, despite the many levels at which the be-
The mantis moves towards a fly and orientates its body slowly and precisely (operations that certainly involve feedback control) but, once aimed, the strike is an all-or-nothing movement.
If the fly moves after the strike is initiated, this makes no difference to the form of the movement and the mantis strikes in the wrong place.
Such behaviour, which occurs without feedback, is said to be under 'open-loop' control (as opposed to the 'closed-loop' control of a homeosta-tic system).
This is a simplified picture of the real situation, which in fact includes other regulatory mechanisms allowing for very fine graded control over the muscle contractions involved both in the maintenance of posture and in movements, but it serves to illustrate the reality of feedback control at a reflex level.
The homeostatic control of posture is understood at a neurophysiological level. In some cases we know the paths of the neurons.
Motor neurons that have their cell bodies in the ventral horn of the spinal cord run to the muscle and it is their activity that determines the tension developed by the muscle.
In parallel with every skeletal muscle, and embedded within its fibers so that they contract and relax it, are muscle spindles. These are specialized sense organs for recording the degree of tension in the muscle.
Their sensory nerves run back to the spinal cord and, entering through the dorsal root, synapse with the motor neurons to the muscle. Thus a loop that forms the basis of the stretch reflex is closed. When a muscle is stretched by the contraction of its antagonists, the muscle spindles are also stretched and their sensory fibres increase their rate of firing, stimulating the motor neurons so that the muscle contracts.
—excitation, inhibition, summation, facilitation and feedback control—that appear to be common to many different levels. Studying single neurons and studying the behaviour of whole animals may require very different techniques and, in many cases, very different concepts. Nevertheless, as we have seen, neurons, reflexes and more complex behavior share many basic properties. It is often possible to break down complex behaviour patterns into smaller units, some of which are immediately equitable with reflexes. However, we cannot always explain behavioral observations using reflex terminology nor is there any point in trying to do so in many cases. There are differences in complexity and these often require different types of approach. Which we choose may well depend on what sort of questions about behaviour we are trying to answer. We must now turn to consider what these might be.