Where in the lymph node do the t cells first encounter antigens presented by dendritic cells?
Answer:
Which of the following are functions of lymphoid tissue?
A. furnish an ideal surveillance vantage point for lymphocytes and macrophages
B. house and provide a proliferation site for neutrophils
C. house and provide a proliferation site for lymphocytes
D. A and C
Explanation:
its A
Answer:
deep in the cortex
Explanation:
the T cells encounter antigens presented by dendritic cells in the deeper part of the cortex. The cortex is the outer area of the lymph node
Which of the following separates the stomach from the duodenum?
(a) Pyloric sphincter
(b) Esophageal sphincter
(c) Ileocecal sphincter
(d) Hepatopancreatic sphincter
Answer:
a) Pyloric sphincter.
Explanation:
The function of Pyloric sphincter is defined as a band of smooth muscle that plays an important function in moving the contents of your stomach in t the small intestine. In other words this muscle is at the junction between the pylorus of the stomach and the duodenum of the small intestine.
What role does the skin play in the regulation of body temperature?
The skin helps regulate body temperature through sweating and blood vessel constriction.
The skin plays a crucial role in regulating body temperature through a process called thermoregulation. When the body gets too hot, sweat glands in the skin produce sweat, which evaporates and helps to cool the body down. When the body gets too cold, the blood vessels in the skin constrict, reducing blood flow to the surface of the skin and conserving heat.
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How is anaerobic respiration affected by changes in temperature?
(5 points)
Based on the conditions of early Earth, what conclusion can you draw about the amount of anaerobic respiration that was occurring at Earth’s beginning? Explain your answer.
(5 points)
If there was a sudden drop in temperature after the evolution of the first living cells, predict how that might have affected the changes in the atmosphere and the evolution of cyanobacteria and other autotrophs. Explain your answer.
(5 points)
Answer:
1. When the beginning of Earth occurred, there was little to no oxygen. So, some cells had to adapt to this and the process of anaerobic respiration allowed them to do so. In the grand scheme of things, there must have been a great number of anaerobic respiration occurring given the clement.
2. That probably would have caused the
atmosphere to cool down dramatically. The
cyanbacteria could have assisted, because it puts
oxygen into the atmosphere. The other autotrophs
would be affected, because if the temperature
dropped, the air would have cooled down.
Then, the autotrophs would not have
food from the carbon dioxide, or
other inorganic materials.
Explanation:
Anaerobic respiration is a type of respiration that occurs in the absence of oxygen, the change in temperature will either lead to the cooling or heating of the atmosphere, and the cooling of the atmosphere means more oxygen which will affect the rate of anaerobic respiration in prokaryotes.
In the early stages of the earth the earth was void and there was very little oxygen present. due to the absence of oxygen it can be concluded that organisms adapted more through anaerobic respiration.
The drop in temperature will lead to the cooling of the atmosphere and decrease in carbon dioxide which will have an effect on the evolution of autotrophs relying on carbon dioxide and other inorganic materials for food. the activities of cyanobacteria contributes oxygen to the atmosphere hence the drop in temperature
Hence the changes in temperature affects the rate of anaerobic respiration and there was a larger percentage of anaerobic respiration during early earth.
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What is Heimlich maneuver and why is it performed?
Answer:
The Heimlich maneuver is a procedure used to help a choking person who is conscious and unable to talk. The Heimlich maneuver pushes air out of the person's lungs and makes him cough. The force of the cough may then move the object out of his airway.
What tissue type has polarity and is avascular?
Answer:
Epithelia has polarity and is avascular.
Which of the following statements is INCORRECT about how the components of hemoglobin are recycled?
a. Hemoglobin can be recycled only if phagocytized by macrophages.
b. Each heme is stripped of its iron and converted to bilirubin, then excreted in bile.
c. The alpha and beta chains are released into the bloodstream for use by other cells.
d. Iron ions are either stored in a phagocytic cell or circulate in the blood, bound to transferrin (a plasma protein).
Answer:
C
Explanation:
The globin of the RBC is broken down into constituent amino acids that can be reutilized by the phagocytic cells (this can occur in the spleen, liver and lymph node). The chains cannot be reused in their large form. The heme(iron) is transported by the blood to the bone marrow and is used to make new red blood cells.
What is the structural unit of compact bone?
Answer:
Osteon is the structural unit of compact bone.
Explanation:
Compact bone is present around the medullary cavity and forms the external layer of the bones. Compact bone is made up of structural units called osteon.
Osteon is also known as haversian sysytem. Osteons contain mineral matrix and connencted by canaliculi. Osteons helps in the transportation of blood. Osteonic canal is known as haversian canal and aligned parallel with the long bones. Osteon contains lamellae that forms the layer of the compact matrix. Osteon prevents the bone from fracture and resist the bending of bones.
Final answer:
The osteon is the structural unit of compact bone, containing concentric lamellae around a central Haversian canal with blood vessels and nerves. Osteocytes in lacunae receive nutrients through canaliculi, illustrating the bone's intricate support system.
Explanation:
The structural unit of compact bone is the osteon, also known as the Haversian system. Each osteon is composed of concentric lamellae, which are rings of calcified matrix. The laminated rings encircle the central canal, or Haversian canal, that houses blood vessels, nerves, and lymphatic vessels. These osteons are the fundamental functional units that provide strength and support to compact bone, allowing it to resist various stresses.
The lamellae are arranged around the central Haversian canal, forming a cylindrical structure. Osteocytes, which are mature bone cells, reside in small cavities called lacunae within the lamellae. Nutrition for the osteocytes is transported through tiny channels called canaliculi that connect the lacunae to the Haversian canal. This sophisticated network allows for nutrients and waste to be efficiently exchanged, maintaining the health of bone tissue.
Furthermore, Volkmann's canals run perpendicular to the Haversian canals, providing an avenue for the vascular and nerve supply from the periosteum and endosteum to reach each osteon. This integration of structure and function makes the osteon an exceptional example of the complex architecture found in compact bone tissue.
List the functions of the cell membrane proteins.
Answer:
Membrane receptor proteins
Transport proteins
Membrane enzymes
Explanation:
hope that helps
Compare and contrast mitosis and meiosis in terms of where and when they occur and their products.
Answer:
Mitosis: Occurs in somatic cells during growth, development and healing. Produces two genetically identical daughter cells from one parent cell.
Meiosis: Occurs in germ cells during gamete formation for sexual reproduction.
Produces genetically different four daughter cells from one parent cell.
Explanation:
Mitosis is the cell division that occurs during growth and healing process in somatic cells. It gives rise to two diploid daughter cells from one diploid parent cell. The daughter cells are genetically identical to the parent cell.
Meiosis is the reductional cell division and occurs in germs cells for gamete formation. It forms four haploid daughter cells from one diploid parent cell. The daughter cells also carry some new gene combinations.
A neuron is stimulated with an electric pulse. The action potential is detected at a point 3.70 cm down the axon 0.0052 s later.When the action potential is detected 7.20 cm from the point of stimulation, the time required is 0.0063 s. What is the speed of the electric pulse along the axon? (Why are two measurements needed instead of only one?)
Answer:
[tex]32 \frac{meter}{sec}[/tex]
Explanation:
Speed is defined as the distance traveled per unit time.
Distance traveled is equal to the difference between the initial and final position of the neuron.
Speed can be derived from under given equation -
[tex]\frac{delta (x)}{delta (t)}\\[/tex]
Where delta x is the change in distance
delta t is the change in time.
Substituting the given values in above equation we get -
[tex]\frac{\frac{7.20}{100} -\frac{3.70}{100} }{0.0063-0.0052} \frac{meter}{sec} \\= 31.81 \frac{meter}{sec} \\[/tex]
[tex]= 32 \frac{meter}{sec}[/tex]
There can be a time delay between the point of neuron stimulation to detection of action potential. Hence, two measurements are needed.
The sternal angle indicates the location of the __________ pair of ribs.
Answer: second pair
Explanation:
The sternal angle is a synarthrotic joint brings together by sternum body and manubrium. It marks approximately second pair of costal cartilages. Coastal cartilage is attached with second rib.
The complete statement is "The sternal angle indicates the location of the second pair of ribs."
How to complete the statement?The sternal angle, also known as the Angle of Louis or the manubriosternal joint, is an important anatomical landmark located at the junction between the manubrium (the upper part of the sternum) and the body of the sternum. It can be palpated as a prominent ridge or angle on the front of the chest.
The sternal angle serves as a reference point for various anatomical and clinical measurements. One notable significance of the sternal angle is that it corresponds to the level of the second pair of ribs. Specifically, it aligns with the cartilaginous connection between the second rib and the sternum.
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Describe how Schwann cells form the myelin sheath and the neurilemma.
Answer:
Schwann cells or neurilemma cells are the cells which form the myelin sheath around neuronal axons in the peripheral nervous system (PNS) only.
Neurilemma is the collective term used for cytoplasm and nuclei present around the myelin sheath which helps in the regeneration process of nerves.
A Schwann cell surrounds the axon, invaginate it and the plasmalemma of the Schwann cells joins and from a double membrane structure called mesaxon. This mesaxon starts wrapping the axon in spiral fashion and cytoplasm start condensing into the compact myelin sheath.
Schwann cells, a type of glial cell, form the myelin sheath and neurilemma by wrapping layers of their cell membrane around an axon segment. This insulates the axon facilitating the transmission of electrical signals. A single Schwann cell insulates one axon segment, unlike oligodendrocytes which can insulate multiple axon segments.
Explanation:Schwann cells are a type of glial cell that forms the myelin sheath and the neurilemma around the axons in the peripheral nervous system. Schwann cells wrap several layers of their cell membrane around the axon segment, creating the myelin sheath. The wrapping process is similar to a pastry being wrapped around a hot dog, with the glial cell wrapping around the axon multiple times with minimal cytoplasm between the layers.
The outermost layer of the Schwann cell membrane contains cytoplasm and the nucleus of the cell, creating a bulge on one side of the myelin sheath which forms the neurilemma. This process creates an insulation layer around the axon, facilitating the transmission of electrical signals along the axon. Differences exist between Schwann cells and other myelinating cells like oligodendrocytes, with a single Schwann cell insulating only one segment of axon, whereas an oligodendrocyte in the central nervous system may insulate multiple axon segments.
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Forensic anthropologists: a. apply anthropological techniques to legal matters. b. are primarily concerned with the recovery of material culture remains. c. examine the relationships between medical treatment and culturally determined views of disease. d. study disease and trauma in ancient populations. e. study nonhuman primates.
Final answer:
Forensic anthropologists a) apply anthropological techniques to legal matters, examining human remains to aid in criminal investigations and providing court evidence. They estimate vital statistics and use cultural cues for identification, often collaborating with law enforcement.
Explanation:
Forensic anthropologists a) apply anthropological techniques to legal matters. Their work focuses on the examination of human remains to identify deceased individuals and provide evidence in court. These professionals estimate an individual’s stature, health, injuries, sex, age, and lifestyle through analyzing bones and sometimes DNA. Forensic anthropologists may also use cultural cues such as clothing and jewelry to assist in identification. They collaborate with law enforcement and medical experts to piece together the story of a crime, often testifying as witnesses in trials. Forensic anthropology is a subfield of biological anthropology applied in real-world problems, such as the identification of individuals in mass graves, natural disaster victims, or crime victims. They play a crucial role in supporting law enforcement in identifying human remains and providing insights into the causes and circumstances of death.
Cpr stands for cardiopulmonary resuscitation. true or false'
CPR is an acronym for cardiopulmonary resuscitation.
This means that this statement is...
True!
Hope this helped!
~Just a girl in love with Shawn Mendes
Yes, CPR stands for Cardiopulmonary Resuscitation. It is an emergency procedure involving chest compressions and artificial respiration to maintain the flow of oxygen-rich blood to the brain. Proper training is crucial for its correct application.
Explanation:The statement you have made is true. CPR does indeed stand for Cardiopulmonary Resuscitation. This emergency life-saving technique consists of simultaneous chest compressions and artificial respiration. CPR is applied when someone's breathing or heartbeat has stopped, with the purpose of maintaining a flow of oxygen-rich blood to the brain until the patient's heartbeat and breathing can be restored.
Proper execution of CPR can increase the chance of survival substantially. The process consists of applying pressure with the flat portion of one hand on the sternum, in order to manually compress the blood within the heart enough to push a portion of it into the pulmonary and systemic circuits. This is especially important for the brain, as loss of blood flow can result in irreversible damage and death of neurons within minutes.
However, proper training is essential for correct application of CPR as incorrect technique can, in some cases, cause severe damage to the patient.
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What is LDL cholesterol? Explain in details.
Answer:
LDL Cholesterol
Explanation:
First of all, LDL stands for low-density lipoprotein and this specific protein is one of the five major groups of lipoprotein that help transport all the fat molecules.
Name the calf muscle.
Answer:
The calf muscle
Explanation:
U said name the calf muscle
Which of these is characteristic of the photic zone of a freshwater biome?the presence of algaerelatively cool waterelatively stable water temperaturedead organic matterlow oxygen level
Answer:
The correct option is this: THE PRESENCE OF ALGAE.
Explanation:
Freshwater biome refers to bodies of water that contain relatively small amount of salt (typically about 1%) in comparison with the ocean. Examples of freshwater include: lake, ponds, streams, rivers, etc.
The freshwater biome is usually divided into different zones depending on the water depth and the amount of sunlight that is available at each depth.
The photic zone is the first layer of the water body, which receives direct sunlight. The large quantity of sunlight receive by this zone make it possible for photosynthesis to take place in the region.
This zone is very important because it made up of plants such as algae and phytoplankton, which are primary producers of the biome; the rest of the living creature in the water bodies depend on these plants to survive.
What is the purpose of the pericardial sac?
Answer:
The main purpose of pericardial sac is the fixation of heart at mediastinum, protection and lubrication of heart.
Explanation:
Pericardial sac is also known as pericardium and contains heart and large vessels. Two main layers of pericardium are fibrous pericardium and serous pericardium.
Pericardial sac secretes the fluid that provide lubrication and reduces the friction of heart. The sac fixes the position of the heart and limits the heart movement. The pericardial sac also reduces the excessive dilation of heart during acute volume overload.
Organ where defecation reflex is initiated
The answer is rectum
Describe the functions of T cells and B cells.
Answer:
T cells ( The thymus cells) and B cells ( The bone marrow) are the major cellular components of the adaptive immune response . T cells are involved in cell- mediated immunity , whereas B cells are primarily responsible for humoral immunity
Explanation:
Your body can produce the most effective weapons that are against the invaders, which may be bacteria, viruses or parasites. Other types of T-cells recognise and kill virus-infected cells directly. Some help B-cells to make antibodies, which circulate and bind to antigens. A T-cell (orange) killing a cancer cell (mauve).
Which of the following are primary lymphoid organs?bone marrow and thymus appendix and spleen lymph nodes and tonsils spleen and thymus
Answer:
The correct answer is bone marrow and thymus
Explanation:
Primary lymphoid organs are bone marrow and thymus. Both organs consist of primary lymphoid tissue where B and T cells are produced.
Lymphocytes are also complete the early phases of maturation in the primary lymphatic organs in the body. In humans, B cells are generated and mature in the bone marrow. However, T cells are produced in the bone marrow and maturation takes place in the thymus.
Thus, the correct answer is the bone marrow and thymus gland.
Answer:
bone marrowthymusExplanation: Primary lymphoid tissues are responsible for the creation and maturation of white blood cells.
The primary lymphoid organs are:
bone marrowthymusWhich of the following is not a prerequisite for continuous aerobic production of ATP?
a. acetyl COA must be present
b NAD and FAD must be available
c. oxygen must be present in the tissues
d. cellular enzymes must be present in sufficient concentration
e. all the above are necessary
Answer:
E
Explanation:
Aerobic respiration mainly occurs in the mitochondria of the cell and is known as the Krebs/Citric acid cycle. It begins when pyruvate from anaerobic respiration in the cytoplasm which is converted to acetyl-CoA before entering the Krebs cycle. Acetyl-CoA is transformed and the energy in its bond used to enable oxidation of NADH and FADH2. The H+ ions are pumped to the mitochondrial intermembrane space. The generated proton motive force is then used to generate ATPs by ATP synthase enzyme. Oxygen becomes the ultimate proton acceptor which is reduced to water. This whole process is facilitated by enzymes in the cell such as dehydrogenases.
The cell continually produces carbon dioxide as a by-product of cellular respiration. How does the cell keep the carbon dioxide from building up in the cytoplasm and poisoning the cell?
Answer:
Breathing out the carbon dioxide
Explanation:
Blood is the medium through which carbon dioxide is transported to the lungs from where it is exhaled out.
The Carbon dioxide produced in cells after respiration diffuses into the blood in exchange of oxygen delivered to the cells for further respiration. Blood while flowing through the lungs passes carbon dioxide to its alveoli which is then exhaled out and oxygen is inhaled from outside.
Hence, cell keep the carbon dioxide from building up in the cytoplasm and poisoning the cell by exhaling CO2.
Which of the following statements is TRUE regarding a basic amino acid? The positively charged R group of a basic amino acid could bind DNA. All of these choices are correct. The hydrophilic R group of a basic amino acid will be located in the interior of a protein. A basic amino acid would be considered both polar and hydrophobic. The R group of a basic amino acid would only be able to form covalent bonds with other molecules.
Final answer:
The correct statement about a basic amino acid is that its positively charged R group could bind DNA. Basic amino acids have hydrophilic R groups on the surface of proteins and are polar, not hydrophobic. The correct answer is a. The positively charged R group of a basic amino acid could bind DNA.
Explanation:
The true statement regarding a basic amino acid is that the positively charged R group could bind DNA. Basic amino acids like lysine and arginine have hydrophilic and positively charged side chains that can interact with negatively charged molecules, such as DNA.
On the contrary, the hydrophilic R groups of basic amino acids would typically be located on the exterior of a protein to interact with the aqueous environment. Basic amino acids are considered polar due to their charge but are not hydrophobic. While they can form various types of bonds, including hydrogen and ionic bonds, they do not only form covalent bonds with other molecules.
Which muscle extends the fingers?
a. extensor carpi radialis
b. extensor digitorum longus
c. extensor digitorum
d. supinator
Answer:
c. extensor digitorum
Explanation:
the extensor digitorum communis extends the phalanges, then the wrist, and finally the elbow. It tends to separate the fingers as it extends them. In the fingers, the extensor digitorum acts principally on the proximal phalanges, acting to extend the metacarpophalangeal joint.
_______ is a brain-imaging technique that shows us precisely which areas of the brain are active at a particular moment in time; _______ is a technique that shows us the exact structure of each of the brain’s parts.
Answer:
see below
Explanation:
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fMRI is a neuroimaging technique that maps brain activity in real-time by detecting changes in blood flow, while MRI provides detailed structural images of the brain.
The technique that shows us precisely which areas of the brain are active at a particular moment in time is functional magnetic resonance imaging (fMRI), which measures changes in blood oxygen levels and can map out active regions with a three-dimensional representation. In contrast, the technique that shows us the exact structure of each of the brain’s parts is magnetic resonance imaging (MRI), which takes images of the brain structure itself in cross-sectional "slices" without requiring any blood flow measurement.
fMRI is particularly useful for observing brain activity during specific tasks as it can indicate which parts of the brain are engaged based on increased blood flow and oxygen usage, though it provides only an indirect measure of neuron activity and has limited temporal resolution. Conversely, while MRI offers detailed pictures of brain structures, it does not indicate which areas are active during tasks.
Which cranial nerve moves the eye left to right?
Answer: The four cranial nerves involved in vision and movement of the eyes are the optic (I) nerve, oculomotor (III) nerve, trochlear (IV) nerve and the abducen (VI) nerve.
For a person to be diagnosed with major depressive disorder, he or she must have experienced a significant depressive episode and depressed characteristics, suchas lethargy and hopelessness, for at least
Answer:
For at least 2 weeks
Explanation:
Final answer:
To be diagnosed with major depressive disorder, one must experience a total of five symptoms for at least two weeks, including feeling down or depressed and experiencing anhedonia.
Explanation:
To receive a diagnosis of major depressive disorder, one must experience a total of five symptoms for at least two weeks; these symptoms must cause significant distress or impair normal functioning, and they must not be caused by substances or a medical condition. At least one of the two symptoms mentioned above must be present, plus any combination of the following symptoms (APA, 2013):
Feeling down or depressedExperiencing anhedonia-loss of interest or pleasure in things that one typically enjoysSignificant weight loss or gainInsomnia or hypersomniaPsychomotor agitation or retar-dationFatigue or loss of energyFeelings of worth-lessness or excessive guiltDiminished ability to think or concentrateRecurrent thoughts of de-ath or sui-cidal ideationWhich of the following is NOT a muscle of respiration?
a. internal intercostals
b. erector spinae
c. diaphragm
d. external intercostals
Answer:
The erector spinae is NOT a muscle of respiration
Erector spinae the following is not a muscle of respiration. The correct option is B.
Thus, One of the core and paraspinal muscles, the erector spinae (ES) comes from the erector spinae aponeurosis (ESA) and is a big, superficial muscle that is located right under the thoracolumbar fascia.
With a proximal attachment on the sacrum and the spinous processes of the lumbar vertebra.
The ESA is a common aponeurosis that fuses with the thoracolumbar fascia.
Thus, Erector spinae the following is not a muscle of respiration. The correct option is B.
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