66 Questions
Which of the following best describes innate defenses in the immune system?
Innate defenses are non-specific and act as the first line of defense against pathogens.
What is the primary function of surface membrane barriers in the immune system?
To physically block the entry of pathogens into the body.
Which of the following is a component of internal defenses in the immune system?
Inflammation
What is the role of NK cells in the immune system?
Recognizing and killing virus-infected cells and cancer cells.
Which type of immunity is characterized by the production of antibodies by B cells?
Humoral immunity
What distinguishes adaptive defenses from innate defenses in the immune system?
Adaptive defenses are specific to particular pathogens and provide long-term immunity.
Which type of cells mediate cellular immunity?
T8 cells
What is the main function of class I MHC proteins?
Always recognized by CD8 T cells
What is the role of complement fixation in antibody action?
Enhances the inflammatory response
What is the function of antibodies in antigen-antibody complexes?
Inactivate and tag the antigen for destruction
Where are class II MHC proteins found?
On antigen-presenting cells
What is the main role of monoclonal antibodies in commercial use?
To provide passive immunity
Which type of immunity involves B cells encountering antigens and producing antibodies against them?
Active Humoral Immunity
Which antibody class is the most abundant and diverse, crosses the placenta, and confers passive immunity?
IgG
What is the fate of most clone cells in the process of clonal selection?
They become plasma cells
Which cells can mount an immediate response to subsequent exposures of the same antigen?
Memory cells
What is the primary function of antibodies in the humoral immune response?
To prevent attachment of pathogens to cell surfaces
Which immune response occurs on the first exposure to a specific antigen, with a lag period of 3 to 6 days?
Primary immune response
What is the key growth factor that encourages activated T cells to divide?
Interleukin 2
Which cells directly attack and kill virus-infected cells, cancer cells, and foreign cells from transplants?
Cytotoxic T cells
What happens to T cells without co-stimulation?
They become tolerant to antigens, are unable to divide, and do not secrete cytokines
Which cells interact directly with B cells to stimulate antibody formation?
Helper T cells
What is used to achieve prevention of tissue rejection in organ transplants?
Immunosuppressive drugs
What can lead to immunodeficiency, resulting in severe weight loss, opportunistic infections, and other symptoms?
Hodgkin’s disease and AIDS
Which of the following is a key mechanism of the innate immune response?
Release of inflammatory chemicals
What is the primary role of natural killer cells in the immune system?
Attacking and killing virus-infected cells, cancer cells, and foreign cells from transplants
What is the main function of fever as a response to invading microorganisms?
Aiding in tissue repair and speeding up the metabolic rate at moderate levels
Which cells are involved in the release of antimicrobial proteins like interferon and complement?
Phagocytes
What is the primary role of adaptive defenses in the immune system?
Mounting attacks against specific foreign substances
What is the first line of defense provided by the immune system?
Surface barriers like skin, mucous membranes, and their secretions
Which type of cells are involved in the internal defenses of the innate immune system?
Macrophages and neutrophils
What is the main function of surface barriers in the innate immune system?
Providing mechanical and chemical barriers against microorganisms
What is the key mechanism of the innate immune response triggered by tissue injury?
Inflammation
Which of the following is a sign of the inflammatory response?
Redness, heat, and swelling
What is the role of antimicrobial proteins in the immune system's defense?
Attacking microorganisms directly and hindering their ability to reproduce
What is the main function of the immune system's adaptive defenses?
Mounting attacks against specific foreign substances
Which gland is the neural control center for all endocrine systems in vertebrates?
Pituitary gland
Which organ is not mentioned as one of the major endocrine glands in humans?
Liver
What is the function of the hypothalamus in the endocrine system?
Linking the endocrine system to the nervous system
Which organ has a secondary endocrine function in addition to its primary function?
Heart
What is the study of the endocrine system and its disorders known as?
Endocrinology
Which gland is responsible for the regulation of calcium levels in the body?
Parathyroid gland
Which organ secretes the endocrine hormone erythropoietin?
Kidneys
Which term is used to refer to glands that signal each other in sequence?
Endocrine cascade
Which system does the hypothalamus and pituitary glands belong to?
Endocrine system
Which organ has a secondary endocrine function and is part of the endocrine system?
Bone
Which embryonic structure is responsible for the primary synthesis of steroids during the early postnatal weeks?
Adult adrenal cortex zone
At what stage of gestation are the parathyroid glands capable of physiological function?
14 weeks
Which gene plays an important role in the development of the parathyroid gland?
HOX15
Which embryonic structure serves as the precursor of the thyroxine (T4) producing follicular cells?
Thickening of the pharyngeal floor
Around which day of gestation do the two structures of the thyroid gland become apparent?
16 to 17 days
At what stage of gestation is the fetal thyroid capable of storing iodine for the production of TRH, TSH, and free thyroid hormone?
12 weeks
Which embryonic cells are responsible for the development of the parafollicular calcitonin-secreting cells in the thyroid gland?
Caudal extensions of the fourth pharyngobranchial pouches
At what stage of gestation do the medial and lateral anlage of the thyroid gland fuse together?
50 days
Which embryonic structure develops into a bilobed structure at approximately 24 to 32 days of gestation?
Median anlage
At what stage of gestation does the embryo form five sets of endoderm-lined pharyngeal pouches?
Four weeks
Which of the following hormones is not secreted by the anterior pituitary gland?
Leptin
Which gland is responsible for the production and secretion of aldosterone?
Adrenal glands
Which hormone is primarily involved in the regulation of calcium and phosphate levels in the body?
Parathyroid hormone (PTH)
Which of the following is a neuroendocrine organ?
Pituitary gland
Which type of cells in the pancreas secrete hormones to maintain homeostatic blood sugar levels?
Beta cells
Which gland is responsible for the production and secretion of melatonin?
Pineal gland
Which hormone is stored and secreted by the posterior pituitary gland?
Antidiuretic hormone (ADH)
Which hormone stimulates the production and secretion of T3 and T4 by the thyroid gland?
Thyroid-releasing hormone (TRH)
Which endocrine organ is derived from ectodermal cells?
Adrenal medulla
Which endocrine system is one of the first to develop during prenatal development?
Fetal endocrine system
Study Notes
Immune System Defenses Overview
- The immune system has two main defense systems: innate (nonspecific) and adaptive (specific) defenses
- Innate defenses include surface barriers (skin, mucous membranes) and internal defenses (phagocytes, natural killer cells, inflammatory response)
- Surface barriers like skin, mucous membranes, and their secretions are the first line of defense, providing mechanical and chemical barriers against microorganisms
- Internal defenses involve cells like phagocytes (macrophages, neutrophils, eosinophils) and natural killer cells that protect the body using nonspecific cellular and chemical mechanisms
- Inflammation is a key mechanism of the innate immune response, triggered by tissue injury to prevent the spread of damaging agents and dispose of pathogens and cell debris
- Inflammatory response involves the release of inflammatory chemicals, leading to signs like redness, heat, swelling, and pain
- Inflammation also involves leukocytosis, margination, diapedesis, and chemotaxis, followed by the release of antimicrobial proteins like interferon and complement
- Antimicrobial proteins attack microorganisms directly and hinder their ability to reproduce, with interferon activating antiviral proteins and complement amplifying the inflammatory response
- Fever is a response to invading microorganisms, with high fevers being dangerous and moderate fever aiding in tissue repair and speeding up the metabolic rate
- The immune system's adaptive defenses involve humoral and cellular immunity, mounting attacks against specific foreign substances and working in conjunction with the innate system
- The immune system's defenses play a crucial role in protecting the body from infections and maintaining overall health
- The text also includes an assignment to find an autoimmune disease as part of a learning activity.
Human Endocrine System Overview
- Hormones can be amino acid complexes, steroids, eicosanoids, leukotrienes, or prostaglandins.
- Endocrine glands secrete hormones directly into interstitial spaces, absorbed into the blood, with no ducts and are vascular.
- Major endocrine systems include feedback loops mediated via the hypothalamus and pituitary, involving hormones like TRH, TSH, GnRH, LH/FSH, CRH, ACTH, renin, angiotensin, aldosterone, leptin, and ghrelin.
- Major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus, and adrenal glands.
- The hypothalamus and pituitary gland are neuroendocrine organs, part of the HPA axis which plays a role in cell signaling in the nervous system.
- The endocrine system comprises cells like those in the hypothalamus, anterior pituitary gland, pineal gland, posterior pituitary gland, thyroid gland, parathyroid gland, thymus gland, adrenal glands, and pancreas.
- The posterior pituitary gland stores and secretes hormones such as antidiuretic hormone (ADH) and oxytocin.
- The thyroid gland's follicular cells produce and secrete T3 and T4 in response to elevated levels of TRH and TSH.
- The parathyroid gland's epithelial cells secrete parathyroid hormone (PTH) to regulate calcium and phosphate levels in the body.
- The pancreas contains nearly 1 to 2 million islets of Langerhans, including alpha, beta, delta, and F cells that secrete hormones to maintain homeostatic blood sugar.
- The fetal endocrine system is one of the first systems to develop during prenatal development.
- The fetal adrenal cortex can be identified within four weeks of gestation and originates from the thickening of the intermediate mesoderm, with the adrenal medulla derived from ectodermal cells.
Test your knowledge of T cell activation, immune deficiencies, and the immune system's defenses with this quiz. Learn key points about T cell function, immune deficiencies, and the innate and adaptive immune system defenses. Master essential concepts for understanding the body's immune response and defense mechanisms.
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