A&P Final Exam

14. What is the function of i. Inner ear: perilymph, endolymph, cochlea, vestibule, semicircular canals, ampulla 1. Organ of Corti: hair cells, basilar membrane, tectorial membrane, helicotrema 2. Vestibular apparatus: a. Otolith organs (utricle and saccule): Maculae, otoliths, hair cells b. Semicircular canals: crista ampullaris, Cupula (gelatinous cap), hair cells

1. Cochlea: The cochlea is a coiled, fluid-filled structure that is responsible for hearing. It contains the organ of Corti, which is located on the basilar membrane. The organ of Corti contains hair cells that are responsible for transducing mechanical vibrations into neural signals. The tectorial membrane sits above the hair cells and bends the stereocilia on the hair cells when sound waves move the basilar membrane. This causes ion channels to open, leading to the depolarization of the hair cells and the generation of action potentials that travel along the cochlear nerve to the brain. The helicotrema is the opening at the apex of the cochlea that allows fluid to move freely. 2. Vestibular apparatus: The vestibular apparatus is responsible for sensing head movements and maintaining balance. It consists of the otolith organs (utricle and saccule) and the semicircular canals. The otolith organs detect linear acceleration and gravity and are composed of hair cells that are embedded in a gelatinous layer covered by otoliths (small stones). The semicircular canals detect rotational acceleration and are composed of hair cells that are embedded in a gelatinous cap called the cupula. When the head moves, the movement of the gelatinous layer causes the hair cells to bend, leading to the generation of action potentials that travel along the vestibular nerve to the brain.

25. Histology of Adrenal Glands

1. The capsule is the outermost layer of the adrenal gland, consisting of a thin, fibrous covering. It serves to protect the gland from damage and infection. The cortex : 2. The zona glomerulosa is the outermost layer of the cortex, and it produces mineralocorticoids, such as aldosterone. Aldosterone plays a key role in regulating blood pressure and electrolyte balance in the body. 3. The zona fasciculata is the middle layer of the cortex, and it produces glucocorticoids, such as cortisol. Cortisol is involved in regulating metabolism, immune function, and stress response. 4. The zona reticularis is the innermost layer of the cortex, and it produces androgens, such as dehydroepiandrosterone (DHEA). Androgens are primarily male hormones, but they are also present in females, where they play a role in the development of secondary sexual characteristics. 5. The medulla is the innermost part of the adrenal gland, and it produces catecholamines, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones play a key role in the body's stress response, by increasing heart rate, blood pressure, and glucose levels.

32.Interal diagram of male reproductive system

1. semniferous tubules (testis) 2. duct system(epididyms, ductus (vas) deferns, urethra) 3. Accessory organs (Seminal vesicles, prostate, bulbourethral glands) 4. External genitalia (penis, scrotum)

24. Describe the endocrine glands and their locations in the human body (mammalian body) discussed in lab and lecture. For example: This diagram is a good place to start: can you label the glands, explain the hormones that come from each of the glands, what are the target organs of the hormones and their effect on the body?

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10. 1. Describe the sensory pathway. Be able to define/explain the following: adequate stimulus, transduction, receptor potential, graded potential, action potential, perception.

Adequate stimulus: The type of stimulus that a sensory receptor is best suited to respond to. For example, photoreceptors in the eye respond to light, while mechanoreceptors in the skin respond to pressure. Transduction: The process by which sensory receptors convert the energy of a stimulus into a neural signal that can be transmitted to the brain. This typically involves the opening or closing of ion channels in the receptor membrane, which generates a receptor potential. Receptor potential: A graded potential that is generated in the sensory receptor in response to a stimulus. The size of the receptor potential is proportional to the intensity of the stimulus. Graded potential: A change in the membrane potential that is proportional to the strength of the stimulus. Graded potentials are often generated in sensory receptors and are used to generate action potentials. Action potential: A brief electrical impulse that is generated in the axon of a neuron in response to a stimulus. Action potentials are the means by which information is transmitted along neural pathways. Perception: The conscious awareness of a sensory stimulus. Perception is the end result of the processing of sensory information in the brain. The sensory pathway typically consists of three main stages: sensory reception, transduction, and transmission. In sensory reception, a sensory receptor detects a stimulus and generates a receptor potential. In transduction, the receptor potential is converted into an action potential, which is transmitted along a sensory neuron to the central nervous system. In the central nervous system, the action potential is processed and integrated with other sensory information, leading to the perception of the stimulus Example exam questions: 1. The conversion of a stimulus into an electrical signal is called ________. Answer: Transduction 2.The minimum amount of stimulus needed for a sensory receptor to respond is called the ________. Answer: Adequate stimulus 3. A temporary change in the voltage across the cell membrane of a sensory receptor caused by a stimulus is called the ________. Answer: Receptor potential

9. How do neuronal and non-neuronal sensory receptors differ in terms of signal transmission?

Answer: Neuronal receptors generate action potentials in response to a stimulus, which are then transmitted along the axon to other neurons or to effector cells, such as muscles or glands. Non-neuronal receptors, on the other hand, do not generate action potentials but instead produce graded potentials or chemical signals that are transmitted to other cells. For example, when a non-neuronal receptor in the skin detects a temperature change, it produces a graded potential that is transmitted to nearby neurons or to effector cells, such as sweat glands or blood vessels, which then respond accordingly.

9. What is the function of non-neuronal sensory receptors?

Answer: Non-neuronal sensory receptors are responsible for detecting stimuli in various parts of the body and converting them into signals that can be interpreted by the nervous system. For example, the hair cells in the ear are non-neuronal sensory receptors that detect sound waves and convert them into electrical signals that are transmitted to the brain. Similarly, taste buds in the mouth are non-neuronal sensory receptors that detect different tastes and transmit this information to the brain.

29. Describe factors that determine biological sex in a variety of organisms (provide examples).

Clownfish: Clownfish are born as sexually undifferentiated individuals, meaning they have both male and female reproductive tissue. However, when a dominant female dies or leaves the group, the largest male will change sex and become the dominant female. This process is called protandrous hermaphroditism. Hyenas: Female hyenas have a pseudo-penis that is used for urination, mating, and giving birth. This means that male and female genitalia can be difficult to distinguish from one another. However, females still have ovaries and give birth to live young. Wrasses: Many wrasse species are protogynous hermaphrodites, meaning they are born female and later change sex to male. This often occurs when the dominant male in a social group dies or is removed, allowing the largest female to change sex and become the new dominant male. Turtles: The sex of many turtle species is determined by the temperature at which the eggs are incubated. For example, in some species, eggs incubated at warmer temperatures will develop into females, while eggs incubated at cooler temperatures will develop into males. Wolbachia: Wolbachia are bacteria that infect a variety of arthropod species, including insects and crustaceans. In some cases, Wolbachia can cause a form of cytoplasmic incompatibility that can affect the reproductive success of infected individuals. This can lead to a range of effects, including male killing, feminization of males, and parthenogenesis (asexual reproduction). Overall, the factors that determine sex in different species can be quite varied and complex, reflecting the diverse range of evolutionary and ecological pressures that shape sexual development and reproduction.

14. What controls equilibrium? What are the differences between static & dynamic equilibrium?

Dynamic equilibrium: the crista ampullaris are responsible for dynamic equilibrium, which provides information about changes in head position and angular acceleration.. It has the Cupula (gelatinous cap) Receptive hair cells lie on a ridge in the ampulla. The semicircular canals contain fluid-filled channels that are arranged in three different planes, with each plane being sensitive to a different type of rotational movement. At the base of each canal, there is an enlarged region called the ampulla, which contains receptor hair cells that are responsible for detecting movement of the fluid within the canal. The receptive hair cells lie on a ridge within the ampulla and are connected to nerve fibers that transmit signals through the vestibulocochlear nerve to the cerebellum and vestibular nuclei. Static equilibrium: The maculae are responsible for static equilibrium, which provides information about the position of the head with respect to gravity. otolith organs (Utricle & Saccule) provide information about the position of the head. These signals from the above (apparatus) are carried through the vestibulocochlear nerve to the cerebellum and vestibular nuclei.

21. Distinguish between endocrine glands and exocrine glands? What trends do we see across animal taxa with the endocrine system? What is a hormone? Discuss the mechanisms that allow only the target cells to respond. What other chemicals exist for communication but are not classified as hormones. Provide examples of exocrine glands. Know the difference between pheromones and allelochemicals. What are the different types of allelochemicals (provide examples)?

Endocrine glands secrete hormones directly into the bloodstream while exocrine glands secrete products into ducts. The endocrine system is conserved across animal taxa and hormones are signaling molecules that bind to specific receptors on target cells. Other chemicals for communication include neurotransmitters and pheromones. Examples of exocrine glands include sweat, salivary, mammary, and sebaceous glands. Pheromones are chemicals used for communication between individuals of the same species, while allelochemicals are chemicals used for communication between individuals of different species. Allelochemicals can be classified into several types, including: Allomones: chemicals released by one species that benefit that species by harming another species, such as the toxins produced by some plants to deter herbivores. Kairomones: chemicals released by one species that benefit another species, such as the pheromones released by prey to attract predators. Synomones: chemicals released by one species that benefit both that species and another species, such as the chemicals released by some plants to attract pollinators.

28. Define fertilization and copulation. Define biological sex.

Fertilization is the fusion of male and female gametes (reproductive cells) to form a zygote, which develops into an embryo. In most animals, fertilization occurs internally, within the female reproductive tract, or externally, outside the body of the female. During fertilization, the sperm penetrates the egg and delivers its genetic material, which combines with the genetic material of the egg to form a diploid zygote. Copulation, also known as sexual intercourse, is the act of mating between individuals of the opposite sex, which typically leads to fertilization. In most animals, copulation involves the insertion of the male's reproductive organ into the female's reproductive tract, allowing for the transfer of sperm to fertilize the egg. Biological sex refers to the classification of an organism as male or female based on its reproductive system and the presence of sex chromosomes. In most animals, including humans, biological sex is determined by the presence of either an X and a Y chromosome (male) or two X chromosomes (female). This genetic sex determines the development of the reproductive system and secondary sex characteristics, such as body hair, breast development, and voice pitch. However, biological sex can also be influenced by environmental and hormonal factors, and not all individuals fit neatly into the binary male/female classification.

2. What adult structures are found in the forebrain, midbrain, and hindbrain (mammal brain) (review lab 4 & illustrations from class & textbook)? Be able to identify the following in a diagram or picture of the brain and explain functions of these structures: cerebellum, frontal/occipital/parietal/temporal lobes of cerebral cortex, Broca's area, Wernicke's area, central sulcus, pre-central gyrus, post-central gyrus, corpus callosum, hypothalamus, inferior and superior colliculi, medulla oblongata, olfactory bulbs, optic chiasm, pineal gland, pituitary gland, pons, thalamus, choroid plexus, basal nuclei, hippocampus, amygdala.

Forebrain: Cerebral cortex: The outer layer of the brain responsible for complex thought processes, sensory perception, and voluntary motor functions. Broca's area: A region in the left hemisphere responsible for speech production. Wernicke's area: A region in the left hemisphere responsible for language comprehension. Corpus callosum: A band of nerve fibers that connects the two hemispheres of the brain and allows for communication between them. Hypothalamus: A region of the brain responsible for regulating basic physiological functions, such as body temperature, hunger, and thirst. Thalamus: A structure that relays sensory and motor signals to and from the cerebral cortex. Basal nuclei: A group of structures involved in voluntary motor control, cognition, and emotion. Hippocampus: A structure involved in memory formation and spatial navigation. Amygdala: A structure involved in emotional processing. Midbrain: Inferior and superior colliculi: Structures that process auditory and visual information, respectively. Hindbrain: Cerebellum: A structure involved in motor coordination and balance. Medulla oblongata: A structure that regulates vital functions such as breathing and heart rate. Pons: A structure that relays signals between the cerebellum and cerebral cortex. Choroid plexus: A structure that produces cerebrospinal fluid. Pineal gland: A structure that produces the hormone melatonin, which helps regulate sleep-wake cycles. Olfactory bulbs: Structures involved in processing odor information. Optic chiasm: A structure where the optic nerves cross, allowing for visual information from both eyes to be processed.

26. 1.A patient presents with hyperthyroidism. What type of feedback loop is involved in this condition? Explain the normal regulation of thyroid hormone production and how it is disrupted in hyperthyroidism. 2. A patient presents with symptoms of diabetes mellitus. What type of feedback loop is involved in this condition? Explain the normal regulation of blood glucose levels and how it is disrupted in diabetes mellitus. 3. A patient presents with symptoms of Cushing's syndrome. What type of feedback loop is involved in this condition? Explain the normal regulation of cortisol production and how it is disrupted in Cushing's syndrome.

Hyperthyroidism is a condition characterized by an overactive thyroid gland, resulting in an excess of thyroid hormone production. The regulation of thyroid hormone production involves a negative feedback loop. The hypothalamus produces thyrotropin-releasing hormone (TRH), which stimulates the anterior pituitary gland to produce thyroid-stimulating hormone (TSH). TSH then stimulates the thyroid gland to produce thyroid hormones (T3 and T4). When the levels of T3 and T4 are sufficient, they exert negative feedback on both the hypothalamus and pituitary gland, which reduces TRH and TSH production, respectively. In hyperthyroidism, there is an excess of thyroid hormones, which disrupts the negative feedback loop. This can be caused by a variety of conditions, including Graves' disease, toxic adenoma, and thyroiditis. In Graves' disease, the immune system produces antibodies that stimulate the thyroid gland to produce excessive amounts of thyroid hormones. In toxic adenoma, a benign tumor on the thyroid gland produces excess thyroid hormones. In thyroiditis, inflammation of the thyroid gland can cause it to leak excessive amounts of thyroid hormones into the bloodstream. Diabetes mellitus is a condition characterized by high levels of glucose in the blood. The regulation of blood glucose levels involves a negative feedback loop. After a meal, the level of glucose in the blood rises, which stimulates the pancreas to produce insulin. Insulin promotes the uptake of glucose by cells throughout the body, reducing the level of glucose in the blood. When the level of glucose in the blood falls, the pancreas reduces insulin production, allowing the liver to release stored glucose into the bloodstream. In diabetes mellitus, there is a disruption of the negative feedback loop due to a lack of insulin or insulin resistance. In type 1 diabetes, the pancreas is unable to produce insulin due to autoimmune destruction of the insulin-producing cells. In type 2 diabetes, the cells become resistant to the effects of insulin, and the pancreas may not produce enough insulin to compensate. This results in high levels of glucose in the blood, which can lead to complications such as cardiovascular disease, kidney failure, and neuropathy. Cushing's syndrome is a condition characterized by excess cortisol production. The regulation of cortisol production involves a negative feedback loop. Cortisol is produced by the adrenal glands in response to adrenocorticotropic hormone (ACTH) produced by the anterior pituitary gland. ACTH is regulated by corticotropin-releasing hormone (CRH) produced by the hypothalamus. When the levels of cortisol in the blood are sufficient, they exert negative feedback on both the hypothalamus and pituitary gland, reducing CRH and ACTH production, respectively. In Cushing's syndrome, there is a disruption of the negative feedback loop, leading to excess cortisol production. This can be caused by a variety of conditions, including pituitary tumors that produce excess ACTH, adrenal tumors that produce excess cortisol, or prolonged use of corticosteroid medications. Excess cortisol can lead to a variety of symptoms, including weight gain, muscle weakness, and high blood pressure.

4. What is the Limbic System and why is it important (consider what would happen if you didn't have some of those structures)? Where is it located in the vertebrate brain? What does the limbic system do? a. Often times five major brain structures are included in the limbic system: hypothalamus, hippocampus, amygdala, olfactory bulbs/ mammillary bodies, & cingulate gyrus. How does each structure contribute to the limbic system?

Hypothalamus - involved in regulating basic survival functions such as hunger, thirst, body temperature, and sexual behavior. Hippocampus - plays a crucial role in the formation and consolidation of new memories. Amygdala - involved in the processing and regulation of emotions, particularly fear and anxiety. Olfactory bulbs/mammillary bodies - involved in processing and integrating sensory information, particularly related to smell. Cingulate gyrus - plays a role in emotional processing and decision making, as well as regulating autonomic functions such as blood pressure and heart rate.

31. Effects of aromatase inactivation or overactiveness

If aromatase activity is disrupted, it can have various effects on the body depending on the timing and duration of exposure, as well as the specific tissues and hormones involved. For example, if aromatase activity is inhibited, there will be a decrease in the production of estrogen, which can lead to reduced fertility, altered reproductive development, and other physiological changes. In females, this can result in delayed puberty, menstrual irregularities, and decreased bone density, while in males, it can lead to impaired sperm production and increased risk of osteoporosis. On the other hand, if aromatase activity is overactivated, there will be an increase in the production of estrogen, which can also have adverse effects on the body. For example, excess estrogen can lead to the growth of estrogen-sensitive tumors such as breast cancer, and it can also cause feminization of male reproductive tissues, leading to decreased sperm production and other reproductive abnormalities. Overall, disruptions in aromatase activity can have far-reaching effects on the endocrine system and overall health, highlighting the importance of understanding the mechanisms of endocrine disruption and developing strategies to mitigate the risks associated with exposure to endocrine-disrupting chemicals.

31. Why did welks females grow pensises on their heads

In female snails, the normal development of sexual organs is suppressed by the presence of a hormone called estradiol. However, when female snails are exposed to tributyltin (TBT), a type of endocrine-disrupting chemical, it can activate genes that promote the development of male sexual organs. Specifically, TBT can activate a gene called the imposex-response gene, which is responsible for inducing the growth of male sex organs in female snails. The growth of male sex organs in female snails is referred to as imposex, and it is characterized by the development of a penis-like structure on the head of the snail, as well as the appearance of testicular tissue and the masculinization of other reproductive structures. The development of these male sex organs is thought to be due to TBT's ability to interfere with the normal regulation of hormone receptors, causing abnormal activation and expression of genes involved in sexual development. In addition to the development of male sexual organs, exposure to TBT can also cause other physiological changes in snails. For example, TBT exposure has been shown to affect the growth and development of the digestive gland, a key organ involved in metabolism and waste elimination. TBT exposure can also lead to changes in behavior, such as increased activity levels and changes in feeding patterns. Overall, the TBT-induced development of male sex organs in female snails is a consequence of endocrine disruption caused by exposure to a chemical that interferes with normal hormonal regulation. This effect is specific to whelks and has not been observed in other snail species, highlighting the diversity of responses to endocrine-disrupting chemicals in different animal species.

17. There are multiple ways in which two cells in an organism can communicate with each other: gap junctions, paracrine and autocrine signals, endocrine signals, and neural signals. Discuss the advantages and drawbacks for endocrine and neural types of signals

In summary, endocrine signals involve the release of hormones into the bloodstream, allowing for long-distance signaling with precise control of signal intensity and duration. However, endocrine signals can be slow to take effect and have systemic effects. Neural signals involve the transmission of electrical impulses through neurons, allowing for rapid and precise communication between specific tissues and organs. However, neural signals are limited to specific tissues and can be disrupted by physical damage or disease. Organisms use different modes of communication depending on the specific physiological processes involved.

5. What cellular mechanisms might promote learning/memory? Explain the roles that the AMPA and NMDA receptors play in long-term potentiation.

Learning and memory involve different cellular mechanisms, such as synaptic plasticity, which is the ability of synapses to change their strength. Long-term potentiation (LTP) is the process of strengthening synapses and is thought to be a cellular mechanism of learning and memory. AMPA and NMDA receptors are two types of ionotropic glutamate receptors that play crucial roles in LTP. AMPA receptors cause a depolarization and influx of calcium ions, while NMDA receptors sustain the increase in synaptic strength. The activation of AMPA and NMDA receptors, and the influx of calcium ions, lead to the changes in synaptic strength that underlie LTP and learning/memory. Besides AMPA and NMDA receptors, other mechanisms that promote learning and memory include changes in gene expression, protein synthesis, and growth of new synaptic connections. Neuromodulators, such as dopamine and acetylcholine, also enhance synaptic plasticity and promote learning and memory.

30. Explain the details behind mammalian sex determination (with either XY or XX), include key genes, proteins, cells, hormones, anatomy (external & internal), etc. a. List/identify the male and female analogs that develop from the following bipotential structures: Bud (genital tubercle), Urogenital groove (urethral folds and groove), labioscrotal swellings, gonad, Wolffian duct, Müllerian duct.

Mammalian sex determination is determined by the presence of sex chromosomes, with XX typically developing as female and XY typically developing as male. Key genes and proteins involved include SRY, SOX9, WNT4, Anti-Müllerian hormone, and estrogen. The developing gonads produce hormones that further shape the development of the reproductive system. In males, the testes produce androgens that stimulate the development of the Wolffian ducts and suppress the Müllerian ducts, while in females, the ovaries produce estrogen that stimulates the development of the Müllerian ducts and suppresses the Wolffian ducts. External genitalia and internal structures also develop from bipotential structures. In males, the genital tubercle becomes the penis, the urogenital folds and groove fuse to form the urethra, and the labioscrotal swellings become the scrotum. In females, the genital tubercle becomes the clitoris, the urogenital folds and groove develop into the labia minora and majora, and the labioscrotal swellings remain separate and become the labia majora.

7. 1. Explain each sensory receptor based on modalities.

Mechanoreceptors: These are sensory receptors that respond to mechanical stimuli, such as pressure, touch, vibration, and stretch. They are found in the skin, muscles, tendons, and internal organs. Thermoreceptors: These are sensory receptors that respond to changes in temperature. They are located in the skin, hypothalamus, and other internal organs. Chemoreceptors: These are sensory receptors that respond to chemical stimuli, such as taste and smell. They are located in the mouth, nose, and other internal organs. Photoreceptors: These are sensory receptors that respond to light. They are located in the eyes and are responsible for vision. Nociceptors: These are sensory receptors that respond to painful stimuli, such as heat, cold, and pressure. They are located in the skin, muscles, and internal organs. Electromagnetic receptors: These are sensory receptors that respond to electromagnetic fields, such as electric and magnetic fields. They are found in some animals, such as sharks and birds, and are used for navigation and communication.

11 Explain the different stimulus properties (type of stimulus-modality, location of stimulus, & intensity of stimulus).

Modality: This refers to the type of stimulus or sensory modality, such as touch, vision, hearing, taste, or smell. Each sensory modality has its own set of sensory receptors that are specialized to detect specific types of stimuli. Location: This refers to the place where the stimulus is detected in space, such as on the skin, in the eye, or in the ear. Sensory receptors have receptive fields that define the area of the body or sensory organ that can elicit a response when stimulated. Intensity: This refers to the strength or magnitude of the stimulus, which can range from very weak to very strong. The intensity of a stimulus can be encoded by the firing rate of sensory neurons, with stronger stimuli causing a higher frequency of action potentials

26. Most of the hormones we have studied are controlled via negative feedback loops. Describe or diagram the reflex pathways of specific hormones in order to demonstrate simple endocrine reflexes and neuroendocrine reflexes. a. Diagnose endocrine pathologies by applying knowledge of feedback loops and hormone hypersecretion, hyposecretion, and abnormal tissue responsiveness.

Negative feedback loops are important in regulating hormone levels in the body. In a negative feedback loop, a stimulus results in a response that counteracts the stimulus, thus maintaining homeostasis. One example of a simple endocrine reflex is the release of insulin in response to an increase in blood glucose levels. When blood glucose levels rise, the pancreas releases insulin, which stimulates the uptake of glucose by cells in the body, thus lowering blood glucose levels. As blood glucose levels decrease, insulin secretion decreases as well, resulting in a negative feedback loop. A neuroendocrine reflex involves the release of a hormone in response to a neural stimulus. An example of this is the release of oxytocin during childbirth. When the baby's head pushes against the cervix, it triggers nerve impulses that stimulate the hypothalamus to release oxytocin, which causes uterine contractions and further stimulates the release of oxytocin, resulting in a positive feedback loop. Endocrine pathologies can result from a disruption in the feedback loop that regulates hormone levels. Hypersecretion occurs when too much of a hormone is produced, which can result in a range of symptoms depending on the hormone involved. For example, hypersecretion of growth hormone can result in acromegaly, a condition characterized by enlarged hands, feet, and facial features. Hyposecretion occurs when too little of a hormone is produced, which can also result in a range of symptoms. For example, hyposecretion of insulin can lead to diabetes mellitus, a condition characterized by high blood glucose levels. Abnormal tissue responsiveness occurs when cells do not respond appropriately to a hormone, despite normal hormone levels. This can result from mutations in hormone receptors or downstream signaling pathways. An example of this is insulin resistance, a condition in which cells do not respond properly to insulin, leading to high blood glucose levels and eventually diabetes mellitus.

3. Cranial Nerves ooh ooh ooh to touch and feel very good velvet such joy

Olfactory Optic Oculomotor Trochlear TRigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Spinal accessory Hypoglossal

14. Explain the anatomy of a receptor hair cell (tip links, kinocilium, sterocilia, mechanically gated cation channel, neurotransmitter vesicles, voltage gated Ca++ channel). Explain the physiology of a receptor hair cell (how do they work when it comes to sound). What happens during a depolarization? What happens during a hyperpolarization?

Receptor hair cells are specialized sensory cells located in the inner ear that detect sound waves and convert them into electrical signals that can be transmitted to the brain. Anatomy: Each hair cell contains a bundle of stereocilia, which are small hair-like structures arranged in a staircase-like pattern. These stereocilia are connected by tip links, which are protein filaments that connect the tips of adjacent stereocilia. At the top of the bundle, there is a single, longer hair-like structure called the kinocilium. Mechanically gated cation channels are located at the tips of the stereocilia, and neurotransmitter vesicles are located at the base of the cell. Voltage-gated Ca++ channels are also located at the base of the cell. Physiology: When sound waves enter the ear, they cause the stereocilia to bend back and forth. This bending causes the tip links to stretch and pull open the mechanically gated cation channels at the tips of the stereocilia. This allows positively charged ions, such as potassium, to flow into the cell and cause depolarization. The influx of positive charge causes neurotransmitter vesicles at the base of the cell to release neurotransmitters, which then stimulate nearby sensory neurons and transmit the signal to the brain. During depolarization, the inside of the cell becomes more positive, which increases the likelihood of the cell firing an action potential and transmitting a signal to the brain. During hyperpolarization, the opposite occurs - the inside of the cell becomes more negative, making it less likely to fire an action potential. This can occur when the stereocilia are pushed in the opposite direction, causing the mechanically gated channels to close and stopping the influx of positive ions. The membrane potential then returns to its resting state.

9. Compare and contrast neuronal and non-neuronal sensory receptors (i.e., give both similarities and differences).

Sensory receptors are specialized cells that convert various stimuli from the external or internal environment into electrical signals that can be processed by the nervous system. These receptors can be broadly classified into two categories: neuronal and non-neuronal receptors. Neuronal receptors are specialized nerve cells that respond to specific stimuli by producing electrical signals called action potentials. These receptors are located in the peripheral nervous system and have axons that transmit the signals to the central nervous system. Examples of neuronal receptors include mechanoreceptors in the skin that detect pressure, thermoreceptors that detect temperature changes, and photoreceptors in the eye that respond to light. Non-neuronal receptors, on the other hand, are specialized cells that respond to specific stimuli by releasing chemical messengers, which in turn activate neurons to produce electrical signals. These receptors are located in various organs and tissues throughout the body, such as the taste buds in the mouth, olfactory receptors in the nose, and endocrine cells in glands. Non-neuronal receptors are essential for regulating many physiological processes, including hormone secretion, digestion, and immune responses. Despite their differences in signaling mechanisms, neuronal and non-neuronal receptors share some similarities. Both types of receptors have a high degree of specificity for the type of stimulus they detect, and both can adapt to changes in the intensity or duration of the stimulus. Additionally, both types of receptors play important roles in maintaining homeostasis in the body by providing feedback about the internal and external environment. However, there are also significant differences between neuronal and non-neuronal receptors. Neuronal receptors are capable of generating action potentials, which allow them to transmit information rapidly over long distances. Non-neuronal receptors, on the other hand, are slower and do not have the ability to generate action potentials. Non-neuronal receptors also tend to have a lower degree of sensitivity and specificity compared to neuronal receptors. In summary, while both neuronal and non-neuronal receptors play important roles in the detection and processing of sensory information, they differ in their signaling mechanisms, speed of response, and degree of specificity.

10. Explain the process of sensory transduction and the role it plays in generating an action potential. In your answer, be sure to describe the steps involved in sensory transduction, including the role of the receptor potential and graded potential. Additionally, explain how the action potential is generated and how it leads to the perception of a sensory stimulus. Finally, provide an example of sensory transduction in the human body and describe how the specific receptor type responds to a stimulus.

Sensory transduction is the process by which sensory stimuli in the environment are converted into electrical signals that can be interpreted by the nervous system. The process of sensory transduction involves a series of steps that ultimately lead to the generation of an action potential. The first step in sensory transduction is the detection of a stimulus by a specialized sensory receptor. When a stimulus is detected, it causes ion channels in the receptor to open, resulting in the generation of a receptor potential. The receptor potential is a graded potential that is proportional to the strength of the stimulus. If the receptor potential is strong enough, it can trigger the opening of voltage-gated ion channels and generate a graded potential in the sensory neuron. The graded potential in the sensory neuron can then lead to the generation of an action potential. When the graded potential reaches a certain threshold, voltage-gated ion channels in the axon hillock of the sensory neuron open, allowing positively charged ions to flow into the cell and depolarize the membrane. This depolarization triggers a chain reaction that causes the opening of more voltage-gated ion channels, leading to the rapid influx of positively charged ions and the generation of an action potential. The action potential then travels along the axon of the sensory neuron and is transmitted to the central nervous system, where it is interpreted as a sensory stimulus. The perception of the sensory stimulus is the result of the interpretation of the action potentials by the brain. An example of sensory transduction in the human body is the detection of light by the photoreceptor cells in the retina of the eye. The photoreceptor cells contain specialized pigments called rhodopsins, which are sensitive to light. When a photon of light strikes a rhodopsin molecule, it causes the molecule to change shape, which leads to the opening of ion channels and the generation of a receptor potential. The receptor potential then triggers the generation of an action potential in the sensory neuron, which is transmitted to the brain and interpreted as a visual stimulus. In summary, sensory transduction is the process by which sensory stimuli are converted into electrical signals that can be interpreted by the nervous system. The process involves the detection of a stimulus by a specialized receptor, the generation of a receptor potential and graded potential, and the eventual generation of an action potential that is transmitted to the central nervous system. The perception of the sensory stimulus is the result of the interpretation of the action potentials by the brain.

19. Explain the role of the parasympathetic and sympathetic nervous systems in the body and how they relate to the endocrine system.

The autonomic nervous system regulates involuntary body functions. The parasympathetic system slows down heart rate, stimulates digestion and urination, and promotes relaxation, while the sympathetic system increases heart rate and blood pressure, dilates pupils, and diverts blood flow away from digestion towards muscles, preparing the body for action. Both systems are regulated by the hypothalamus. The endocrine system regulates stress response through the HPA axis, with the hypothalamus releasing CRH, stimulating the pituitary gland to release ACTH, which produces cortisol to help the body cope with stress. Together, these systems maintain balance in the body's internal environment and respond to external stressors.

1. Distinguish the differences between the central nervous system and the peripheral nervous system. List and describe the two principal divisions of the peripheral nervous system and their subdivisions.

The central nervous system (CNS) is composed of the brain and spinal cord, while the peripheral nervous system (PNS) is composed of all the nerves that extend outside of the brain and spinal cord. The PNS is divided into two principal divisions: the somatic nervous system and the autonomic nervous system. The somatic nervous system is responsible for voluntary movements and relaying sensory information from the body to the CNS. It consists of sensory neurons, motor neurons, and interneurons. The sensory neurons carry information from the body to the CNS, while the motor neurons carry information from the CNS to the muscles and glands. Interneurons connect the sensory and motor neurons within the CNS. The autonomic nervous system is responsible for regulating the involuntary functions of the body, such as heart rate, digestion, and respiration. It is further divided into the sympathetic and parasympathetic divisions. The sympathetic division is responsible for the "fight or flight" response, which prepares the body for action in response to stress or danger. The parasympathetic division, on the other hand, is responsible for the "rest and digest" response, which promotes relaxation and digestion. Overall, the PNS works in conjunction with the CNS to coordinate the functions of the body and respond to internal and external stimuli.

14. c. Describe pitch and loudness and how these properties of sound are processed by the cochlea.

The cochlea is responsible for processing both pitch and loudness of incoming sound waves. Sound waves enter the cochlea through the oval window, which causes the fluid in the cochlear canal to move. This movement causes the basilar membrane, a thin membrane running the length of the cochlear canal, to vibrate at different frequencies. Stereocilia, small hair-like structures, are located on the hair cells of the organ of Corti, which is located on the basilar membrane. When the basilar membrane vibrates, it causes the stereocilia to move, which opens mechanically gated ion channels in the hair cell membrane. This allows potassium ions to enter the hair cell, which depolarizes it and triggers the release of neurotransmitters onto the cochlear nerve fibers. The round window at the end of the cochlear canal acts as a pressure relief valve, allowing the fluid to move freely without causing a buildup of pressure in the cochlea. The cochlear nerve fibers transmit theinformation about the frequency and amplitude of the sound wave to the brain for interpretation. The signal transduction in the cochlea relies on the movement of fluid, vibration of the basilar membrane, movement of stereocilia, influx of potassium ions, neurotransmitter release, and activation of the cochlear nerve fibers. In summary, the cochlea processes pitch by tonotopy, where different regions of the cochlear canal are more sensitive to specific frequency ranges. Loudness is processed by adjusting the sensitivity of the hair cells based on the amplitude of the sound wave. This process relies on the movement of fluid in the cochlear canal, vibration of the basilar membrane, movement of stereocilia, influx of potassium ions, neurotransmitter release, activation of the cochlear nerve fibers, and transmission of the signal to the brain for interpretation.

35. What are the "gate keepers" to puberty? What is the "hormone of darkness" and what does it have to do with reproduction (consider non-humans as well)?

The gatekeepers to puberty are the hypothalamus and pituitary gland. The hypothalamus, which is a part of the brain, produces gonadotropin-releasing hormone (GnRH), which signals the pituitary gland to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These hormones stimulate the gonads (ovaries in females and testes in males) to produce sex hormones, such as estrogen and testosterone, which trigger the physical changes of puberty. The "hormone of darkness" is melatonin, which is produced by the pineal gland in the brain during periods of darkness. Melatonin is known to play a role in regulating the sleep-wake cycle, but it also affects the reproductive system. In many non-human animals, melatonin acts as a signal for seasonal breeding, regulating the timing of puberty and the breeding season. In humans, the role of melatonin in puberty is less clear, but studies have suggested that melatonin may be involved in regulating the onset of puberty and the timing of the menstrual cycle.

14. What is the function of i. Middle ear: oval window, round window, eustachian tube, malleus, incus, stapes

The middle ear consists of the oval window, round window, eustachian tube, and three small bones called the ossicles: the malleus (hammer), incus (anvil), and stapes (stirrup). The oval window is a small, oval-shaped opening that connects the middle ear to the inner ear. It is located on the medial wall of the middle ear, adjacent to the footplate of the stapes. The vibrations of the stapes against the oval window create pressure waves in the fluid of the inner ear, which are detected by the hair cells of the cochlea. The round window is a small, circular membrane located on the lateral wall of the cochlea, adjacent to the middle ear. It acts as a pressure release valve, allowing the fluid of the inner ear to move in response to the pressure waves created by the vibrations of the stapes against the oval window. The eustachian tube is a narrow tube that connects the middle ear to the back of the throat. Its main function is to equalize the pressure between the middle ear and the outside environment, allowing the eardrum to vibrate properly. The eustachian tube also helps to drain fluid from the middle ear and prevent the buildup of pressure that can lead to pain or infection. The three ossicles (malleus, incus, and stapes) are small bones that transmit sound vibrations from the eardrum to the inner ear. The malleus is attached to the eardrum and the incus, which in turn is attached to the stapes. When the eardrum vibrates, it causes the ossicles to vibrate as well, amplifying the sound and transmitting it to the oval window. The movement of the stapes against the oval window creates pressure waves in the fluid of the inner ear, which are detected by the hair cells of the cochlea.

•18. Where do the nervous system and endocrine system work together (consider the brain and the adrenal glands).

The nervous system and endocrine system work together in various parts of the body, including the brain and the adrenal glands. The hypothalamus, located in the brain, is a key structure that integrates signals from both systems. The hypothalamus produces and releases various hormones, including GnRH, which stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. The pituitary gland also produces several hormones that act on the adrenal glands, including adrenocorticotropic hormone (ACTH), which stimulates the production of cortisol from the adrenal cortex. The adrenal glands, located above the kidneys, produce hormones such as cortisol, adrenaline, and noradrenaline. These hormones are involved in the body's stress response and are regulated by the hypothalamus and pituitary gland through a complex feedback system known as the hypothalamic-pituitary-adrenal (HPA) axis. When the body experiences stress, the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release ACTH. ACTH then acts on the adrenal glands to produce cortisol, which helps the body cope with stress. In summary, the nervous system and endocrine system work together in various ways, including through the hypothalamus-pituitary-adrenal (HPA) axis, to regulate bodily functions and respond to internal and external stimuli.

25. histology of pancreas

The pancreas is a glandular organ that is both an endocrine and exocrine gland. The exocrine part of the pancreas can be identified by the presence of pancreatic acini, which are clusters of cells that secrete digestive enzymes into the pancreatic duct. These cells appear as small, densely packed, circular or hexagonal structures and often stain red due to the presence of zymogen granules containing the digestive enzymes. The endocrine part of the pancreas is made up of the islets of Langerhans, which are small, round clusters of cells scattered throughout the pancreas. These cells are responsible for producing and secreting hormones such as insulin and glucagon into the bloodstream. They appear as larger, more irregularly shaped structures, and often stain blue/purple due to the presence of the hormone-containing granules.The alpha cells are typically found at the periphery of the islets and appear darker due to the presence of granules containing glucagon. The beta cells are located in the center of the islets and appear lighter due to the absence of granules. The delta cells are interspersed between the alpha and beta cells and appear smaller and less distinct. The exocrine pancreas can also be observed as acinar cells that form grape-like clusters around ducts. Alpha cells produce the hormone glucagon, which raises blood sugar levels by stimulating the liver to release stored glucose. Beta cells produce insulin, which lowers blood sugar levels by promoting the uptake and storage of glucose by muscle and fat cells. Delta cells produce somatostatin, which inhibits the secretion of insulin and glucagon. F cells produce pancreatic polypeptide, which regulates pancreatic exocrine and endocrine functions.

34. List and briefly explain the pathway an egg would take in the biological female starting at the ovary and out the body assuming no fertilization. If fertilization were to happen where does it occur? And where does the egg implant?

The pathway an egg would take in the biological female starting at the ovary and out the body assuming no fertilization is as follows: Ovary: The egg is released from the ovary during ovulation, which typically occurs once a month. Fallopian tube: The egg travels through the fallopian tube, which is a narrow, muscular tube that connects the ovary to the uterus. The fallopian tube is lined with tiny hair-like structures called cilia, which help to move the egg along. Uterus: If the egg is not fertilized, it will continue to travel through the fallopian tube and into the uterus. The uterus is a muscular organ where a fertilized egg can implant and develop into a fetus. Cervix: The cervix is the lower part of the uterus that connects to the vagina. It contains a small opening called the cervical os, which allows menstrual blood to flow out of the body and allows sperm to enter the uterus during intercourse. If fertilization were to happen, it would most likely occur in the fallopian tube, where the sperm and egg can meet and fuse together to form a zygote. After fertilization, the zygote will continue to travel through the fallopian tube and into the uterus, where it will implant in the lining of the uterus and begin to develop into an embryo.

14. What is the physiology of hearing? How do we detect sound waves & then transmit that information to the brain? Be able to map out a sound wave traveling from the pinna to the brain (like we did in class). What might happen in cases of deafness?

The process begins with the outer ear, where the pinna collects sound waves and funnels them into the external auditory meatus (ear canal). The sound waves then reach the eardrum, or tympanic membrane, causing it to vibrate. These vibrations are transmitted through the middle ear by a series of small bones called the malleus, incus, and stapes, also known as the ossicles. The stapes bone then pushes and pulls the oval window, creating pressure waves in the fluid-filled cochlea of the inner ear. As the pressure waves move through the cochlea, they cause the basilar membrane to vibrate up and down. Hair cells located on the organ of Corti, a structure located on the basilar membrane, are stimulated by the movement of stereocilia, small hair-like structures on the tips of the hair cells. This movement triggers the opening of mechanically-gated ion channels on the hair cell membrane, leading to the influx of potassium ions and depolarization of the cell. The depolarization of hair cells results in the release of neurotransmitters from the base of the hair cell, which then activate the cochlear nerve fibers synapsing on them. These nerve fibers send electrical signals to the brainstem and ultimately to the auditory cortex of the brain, where they are processed and interpreted as sound. In cases of deafness, damage to any part of the ear or the nerve pathway connecting the ear to the brain can result in the loss of hearing. Some common causes of deafness include damage to the hair cells in the inner ear due to aging or exposure to loud noises, infections or diseases affecting the middle ear, or congenital defects.

20. Explain the key anatomical differences between the sympathetic and parasympathetic divisions.

The sympathetic division originates from the thoracic and lumbar regions of the spinal cord, while the parasympathetic division originates from the brainstem and sacral region of the spinal cord. The sympathetic division has short preganglionic fibers and long postganglionic fibers, while the parasympathetic division has long preganglionic fibers and short postganglionic fibers. The sympathetic division releases norepinephrine as its main neurotransmitter, and has a stimulating effect on organs to prepare the body for action in response to stress or perceived threats. In contrast, the parasympathetic division releases acetylcholine as its main neurotransmitter, and has a relaxing effect on organs to promote rest and digestion. These differences reflect the distinct functions of the two divisions in the body.

25. Histology of thyroid

The thyroid gland consists of follicles and parafollicular cells, also called C cells, which secrete different hormones. Follicles produce two main hormones: Triiodothyronine (T3): contains three iodine atoms, and is considered the more active form of thyroid hormone. Thyroxine (T4): contains four iodine atoms, and is considered the precursor of T3. Parafollicular cells or C cells secrete a hormone called calcitonin.C cells, also known as parafollicular cells, are part of the thyroid gland. They are located between the follicular cells in the thyroid gland and are responsible for producing and secreting the hormone calcitonin. Calcitonin is involved in regulating calcium and phosphate levels in the body.

13. Compare tonic and phasic receptors and their uses. Briefly describe the difference between tonic and phasic receptors

ToNiC" - tonic receptors have a "ToNed down" response to stimuli, while phasic receptors have a "Phasic" response that is more "Hyperactive." Tonic receptors are sensory receptors that are always active and respond continuously to a stimulus, as long as the stimulus is present. Tonic receptors are important for detecting and maintaining the body's position in space, such as the receptors responsible for static equilibrium in the vestibular apparatus. Tonic receptors also play a role in detecting pain, as the pain receptors (nociceptors) are always active. Phasic receptors, on the other hand, are sensory receptors that are only active in response to a change or movement in a stimulus. Phasic receptors are important for detecting changes in the environment, such as pressure or vibration, and for detecting movement of the body. For example, the receptors responsible for dynamic equilibrium in the vestibular apparatus are phasic receptors, as they respond to changes in rotational or angular acceleration or deceleration of the head. The main difference between tonic and phasic receptors is the way they respond to a stimulus. Tonic receptors respond continuously to a stimulus, while phasic receptors only respond to changes in the stimulus. Both types of receptors are important for different sensory functions in the body. Examples of tonic receptors include nociceptors (pain receptors), which continue to fire as long as a painful stimulus is present, and proprioceptors, which provide information about body position and muscle tension. Phasic receptors, on the other hand, adapt to a sustained stimulus and show a rapid decrease in firing rate over time. They respond best to changes in stimulus intensity or frequency. Examples of phasic receptors include Meissner's corpuscles, which are sensitive to light touch, and Pacinian corpuscles, which are sensitive to vibration. In summary, tonic receptors show sustained responses to stimuli, while phasic receptors respond best to changes in stimuli.

31. Be able to explain different examples of variations in sex development observed in mammals and other animals: Consider genetic variations discussed (like XXY, XO, androgen insensitivity, alpha-5 reductase, etc.) Consider endocrine disruption from various chemicals (like pesticides, etc.). c. Consider endocrine disruptive chemicals or how drugs might work within the endocrine system and what the various effects would be. For example, what if we were to disrupt various receptors or enzymes for sex hormones would be the possible effects (like inactivating or over-activating aromatase).

Variations in sex development can occur due to genetic variations, endocrine disruption, or the effects of certain drugs. Genetic variations include XXY, XO, androgen insensitivity, alpha-5 reductase deficiency, and others. Endocrine disruption can be caused by exposure to chemicals such as pesticides, which can interfere with the body's normal hormone regulation. These disruptions can result in changes to sexual development, including differences in genitalia and reproductive function. Drugs that disrupt the endocrine system can also have similar effects, such as inactivating or over-activating enzymes involved in hormone production or receptors for sex hormones. The possible effects of these disruptions can include alterations in sexual development, infertility, and increased risk of certain diseases such as cancer.

35. Explain the hormones that are key to maintaining a pregnancy (where do they come from).

Viability of the corpus luteum maintained by HCG, secrete by trophoblasts. hCG prompts CL to secrete PROGESTERONE & ESTROGEN. Chorion- develoed from trophoblasts, continues this hormonal stimulus. 2/3 months, the placenta take the role of creating PROGESTERONE & ESTROGEN. Povides nutrients and removed waste.

23.Apply knowledge of different hormone interactions (syngergism, permissiveness, and antagonism) to predict the expected response from a target cell in the presence of multiple hormones.

When multiple hormones are present, different types of hormone interactions can occur. Synergism occurs when the effects of two hormones acting together are greater than the sum of their individual effects. An example of this is the interaction between estrogen and progesterone in the female reproductive system. Permissiveness occurs when one hormone is necessary for another hormone to exert its full effect. For example, thyroid hormone is required for epinephrine and norepinephrine to stimulate metabolic rate. Antagonism occurs when one hormone opposes the action of another hormone. An example of this is the interaction between insulin and glucagon in regulating blood glucose levels. Insulin and glucagon have opposite effects on blood glucose levels. Insulin stimulates glucose uptake by cells, lowering blood glucose levels, while glucagon stimulates glycogen breakdown and glucose release by the liver, raising blood glucose levels. When both hormones are present, their opposing effects should balance each other out to some extent, resulting in a relatively stable blood glucose level. However, in conditions such as diabetes mellitus, where insulin secretion or action is impaired, glucagon can dominate and cause high blood glucose levels. Thyroid hormone enhances the responsiveness of target cells to epinephrine and norepinephrine by increasing the number of adrenergic receptors on the surface of cells. This allows for a greater cellular response to the catecholamines, resulting in an increased metabolic rate and mobilization of energy stores. This permissive effect is beneficial in a stress response, where the body needs to rapidly respond to a perceived threat or danger. By increasing the sensitivity of target cells to epinephrine and norepinephrine, thyroid hormone allows for a more rapid and effective stress response.

12. Explain how acuity is influenced by receptive field size and by lateral inhibition. a. Describe how lateral inhibition allows for localization of a stimulus. b. How was the two-point discrimination test performed in lab related? Somatosensory projections in the cortex of mammals are distorted. What factors determine the extent of innervation of each body part?

a. Lateral inhibition is a neural process that allows for localization of a stimulus by enhancing the contrast between adjacent receptive fields. This process involves inhibitory neurons that are activated by the primary sensory neurons in the area surrounding the receptive field of the stimulated neuron. The inhibitory neurons then send signals to neighboring neurons, suppressing their responses to the stimulus. This results in an enhanced response of the stimulated neuron, allowing for better localization of the stimulus. b. The two-point discrimination test is a measure of acuity that is related to receptive field size and lateral inhibition. The test involves touching two points simultaneously on the skin with progressively closer distances. The minimum distance at which the two points can be discriminated is used as a measure of acuity. The test is related to receptive field size because smaller receptive fields allow for better discrimination of two points that are closer together. Lateral inhibition also plays a role in the test because it enhances the contrast between adjacent receptive fields, making it easier to discriminate the two points. c. Somatosensory projections in the cortex of mammals are distorted, with some areas of the body having a larger representation than others. The extent of innervation of each body part is determined by the size of the receptive fields of the sensory neurons in that area. Areas of the body with smaller receptive fields have a larger representation in the cortex, allowing for better acuity and discrimination of stimuli. This is why the hands and face, which have smaller receptive fields, have a larger representation in the somatosensory cortex compared to the back, which has larger receptive fields. Additionally, experience and use of a body part can also influence the extent of innervation in the cortex, with greater use resulting in a larger representation.

15. Eye Anatomy & Physiology: How do we detect light waves & then transmit that information to the brain? Be able to map out a light wave traveling from the cornea to the brain. What might happen in cases of blindness? Be able to identify the following in a diagram or picture and explain functions of these structures: i. sclera, cornea, choroids, ciliary body, lens, iris, pupil, retina, rods, cones, optic nerve, fovea centralis, aqueous humors, vitreous humors, tapetum lucidum. ii. fovea centralis---why greater visual acuity here—provide two reasons. iii. Make sure to review the retina histology and know the order by which cells communicate information from photoreceptor to the optic nerve for a vertebrate. How does this differ compared to a cephalopod eye (squid, octopus, etc.)? iv. Compare & contrast cones & rods. v. Explain the phototransduction pathway for a vertebrate. How does it differ in an insect eye? (REVIEW LAP 8 Homework)

a. Light waves are detected by photoreceptor cells called rods and cones in the retina. The information is then transmitted via the optic nerve to the brain, where it is processed to create the visual experience. A light wave enters the eye through the cornea and passes through the pupil, which is regulated by the iris. The lens then focuses the light on the retina, where it is detected by photoreceptor cells. The information is then transmitted to the optic nerve and carried to the brain for processing. In cases of blindness, there may be damage to the retina, optic nerve, or other parts of the visual pathway that prevent the transmission of visual information to the brain. b. i. Sclera: The white outer layer of the eye that provides protection and support. Cornea: The clear, dome-shaped outer covering of the eye that helps to focus incoming light. Choroid: A layer of blood vessels that provides oxygen and nutrients to the retina. Ciliary body: A structure that produces and controls the flow of aqueous humor, a fluid that nourishes the eye. Lens: A clear structure that helps to focus incoming light onto the retina. Iris: The colored part of the eye that regulates the size of the pupil. Pupil: The opening in the center of the iris that allows light to enter the eye. Retina: A layer of cells at the back of the eye that contains photoreceptor cells (rods and cones) that detect light. Rods: Photoreceptor cells in the retina that are responsible for detecting light in low-light conditions. Cones: Photoreceptor cells in the retina that are responsible for detecting color and visual detail in bright light conditions. Optic nerve: A bundle of nerve fibers that carries visual information from the retina to the brain. Fovea centralis: A small, central area of the retina that contains a high density of cones and provides the sharpest vision. Aqueous humor: A clear fluid that nourishes the eye and helps to maintain its shape. Vitreous humor: A gel-like substance that fills the back of the eye and helps to maintain its shape. Tapetum lucidum: A reflective layer in the eyes of some animals that helps to enhance their night vision. ii. The fovea centralis has greater visual acuity because: It contains a high density of cones, which are responsible for detecting color and visual detail. Light that enters the eye is focused directly onto the fovea, providing a clearer and sharper image. iii. In vertebrates, photoreceptor cells (rods and cones) communicate with bipolar cells, which in turn communicate with ganglion cells. The axons of the ganglion cells converge to form the optic nerve, which carries visual information to the brain. In cephalopods, the photoreceptor cells communicate directly with the ganglion cells, bypassing the need for bipolar cells. iv. Cones are responsible for detecting color and visual detail in bright light conditions, while rods are responsible for detecting light in low-light conditions. v. In vertebrates, the phototransduction pathway begins when light is absorbed by a photopigment molecule in a rod or cone cell. This triggers a series of chemical reactions that ultimately leads to the release of neurotransmitters and the generation of an electrical signal that is transmitted to the brain via the optic nerve. In insects, the phototransduction pathway is similar but involves a different type of photopigment molecule and a different set of chemical reactions.

24 d. Discuss the role of hormones in maintaining osmoregulation. Should be able to discuss two key hormones and their targets/effects. Discuss the role of hormones in social/mate-pair bonding. Should be able to discuss two key hormones and their targets/effects. Explain how thyroid hormones (T3/T4) and growth hormone are involved with the growth of an individual. What other functions do these hormones do besides growth? Discuss the hormones involved with stress responses in the body. i. Distinguish between "short-term" and "long-term" stress. What hormones are involved in each and what are the targets/effects. ii. Under stressful or dangerous situations, organisms enter into the "flight-or-fight" response. This response has both neural and endocrine components. Discuss the functions of each component and how they interact with each other.

e. Osmoregulation is the maintenance of water balance in the body. Two key hormones involved in this process are antidiuretic hormone (ADH) and aldosterone. ADH is released by the posterior pituitary gland and acts on the kidneys to increase water reabsorption, thus reducing urine output and conserving water. Aldosterone is released by the adrenal cortex and acts on the kidneys to increase sodium reabsorption, which in turn increases water reabsorption and also helps to maintain blood pressure. f. Social/mate-pair bonding is influenced by hormones such as oxytocin and vasopressin. Oxytocin is released during physical touch and social bonding experiences, and is involved in maternal bonding, trust, and social attachment. Vasopressin is also involved in social bonding and pair-bonding in males. Both hormones act on various brain regions involved in social behavior, including the amygdala and prefrontal cortex. g. Thyroid hormones (T3/T4) and growth hormone (GH) are involved in the growth and development of an individual. T3/T4 are involved in cell growth and differentiation, and are important for skeletal and nervous system development. GH is involved in stimulating growth and cell division, and is particularly important during childhood and adolescence. Additionally, thyroid hormones and GH play a role in metabolism and energy regulation. h. Stress responses in the body involve the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the release of cortisol. Cortisol is released by the adrenal glands and acts on various organs in the body to increase blood sugar levels, suppress the immune system, and promote the breakdown of fats and proteins for energy. i. Short-term stress is also known as acute stress, and is characterized by a brief, intense response to a perceived threat. Hormones involved in short-term stress include adrenaline and noradrenaline, which are released by the adrenal glands and act on various organs to increase heart rate, blood pressure, and respiration, preparing the body for a fight or flight response. Long-term stress is characterized by a prolonged, chronic response to stressors, and is associated with increased levels of cortisol. Long-term stress can have negative effects on health, including increased risk of cardiovascular disease, depression, and impaired immune function. ii. The "flight-or-fight" response to stress involves both neural and endocrine components. The neural component involves the sympathetic nervous system, which releases adrenaline and noradrenaline, while the endocrine component involves the HPA axis and the release of cortisol. The sympathetic nervous system prepares the body for action, while cortisol helps to maintain the body's response to stress over a longer period of time. The two components interact with each other to produce a coordinated response to stress, including increased heart rate, blood pressure, and respiration, as well as increased blood sugar levels and breakdown of fats and proteins for energy.

What does the HPA axis do?

regulates stress response and releases cortisol

33. List the three accessory glands of the male reproductive system and describe their function.

seminal vesicles, prostate gland, and bulbourethral glands. Each of these glands produces a fluid that is added to the sperm to create semen. Here is a brief description of the function of each gland: Seminal vesicles: The seminal vesicles are two small glands located behind the bladder. They secrete a thick, yellowish fluid that makes up about 60% of the volume of semen. This fluid contains fructose and other nutrients that provide energy to the sperm, as well as prostaglandins that stimulate the female reproductive tract. Prostate gland: The prostate gland is a walnut-sized gland located beneath the bladder. It secretes a thin, milky fluid that makes up about 30% of the volume of semen. This fluid contains enzymes that help to activate and protect the sperm, as well as citric acid that provides additional energy. Bulbourethral glands: The bulbourethral glands, also known as Cowper's glands, are two small glands located beneath the prostate gland. They secrete a clear, slippery fluid that is added to the semen just before ejaculation. This fluid helps to lubricate the urethra and neutralize any acidity that may be present. Overall, the secretions from these accessory glands help to provide the sperm with the nutrients and protection they need to successfully fertilize an egg.

8. What are the special senses? What other senses exist beyond the classic 5 senses of the body?

there are other senses beyond the classic 5 senses of the body, which are known as somatic senses. These include the senses of touch, temperature, pain, pressure, and proprioception. Some additional senses beyond the classic 5 senses of the body include: Thermoception: the ability to detect changes in temperature Nociception: the ability to sense pain Equilibrioception: the ability to sense balance and spatial orientation Chronoception: the ability to sense the passage of time Interoception: the ability to sense internal bodily sensations, such as hunger or thirst