Human Physiology and Desease Flashcards
Cell and Tissue Disorders
There are four classes of proteins:
Transport, Structural, Enzymes and Receptors.
Cell and Tissue Disorders
Receptor proteins function is to…
receive and respond to signals.
Cell and Tissue Disorders
Cystic fibrosis is a…
genetic decease that affects the respiratory system, the intestine, the pancreas and the male reproductive tract.
Cell and Tissue Disorders
What causes Cystic Fibrosis?
Is due to the mutation of gene CFTR that causes reduced permeability of membrane proteins to chloride ions. Hence, mucus is accumulated as long as bacteria and other viscous substances.
Cell and Tissue Disorders
What are the three ways to diagnose Cystic Fibrosis?
Sweat test, Measurement of pancreatic Trypsin and identification for mutations of the CFTR gene.
Cell and Tissue Disorders
What is the sweat test?
Measurement of chloride ions in sweat. Above 70 mlmoles (3-4 times more than normal)
Cell and Tissue Disorders
What is the most common mutation in the CFTR gene?
Deletion of the codon of phenylalanine in position 508 in the amino acid sequence of the protein.
Cell and Tissue Disorders
What is the present treatment available for Cystic Fibrosis?
Pancreatic enzymes in tablets for pancreatic insufficiency and antibiotics to prevent respiratory infections due to mucus.
Cell and Tissue Disorders
What would be the therapy available for Cystic Fibrosis in the future?
Gene therapy to reinsert the correct CFTR gene into epithilial cell gene sequence.
Cell and Tissue Disorders
What is the cytoskeleton and what is composed of?
The cytoskeleton is the intracellular scaffold that holds the cells shape and helps transport of substances. It is composed of filamentous proteins made form collagen.
Cell and Tissue Disorders
What are the three components of the cytoskeleton network?
Microtubules, Actin filaments and intermediate filaments.
Cell and Tissue Disorders
What are the four functions of the microtubules?
Cell structure, cell motility (e.g. cilia), Cell division (e.g. mitotic spindles) and organelle movements.
Cell and Tissue Disorders
What are the four functions of the Actin filaments (microfilaments)?
Cell structure, cell motility, Muscle contraction and cell division (cleavage furrow at cytokinesis)
Cell and Tissue Disorders
What is Muscular Dystrophy?
Is a genetic X-linked disorder that causes skeletal muscle loss affecting movement and respiration.
Cell and Tissue Disorders
What are the two types of Muscular Dystrophy?
Duchenne Muscular Dystrophy (DMD) and Becker Muscular Dystrophy (BMD)
Neurons
What is the Nervous System?
Is the coordination of body function through electrical signal and release of regulatory molecules
Neurons
What is negative feedback?
Is when the response counteracts the stimulus, shutting off the response loop.
Neurons
What is positive feedback?
Is when the response reinforces the stimulus, sending the variable further from the set point.
Neurons
What is local control in Homeostasis?
Is when a local change happens and cells in the vicinity of the change initiate the response.
Neurons
What is reflex response in Homeostasis?
Is when a change happens and cells at a distant site (e.g. brain) initiate the responce to that change.
Neurons
What are the three ways of local signaling?
Gap Junctions, Contact dependent signals (Receptor proteins) and autocrine/paracrine signals
Neurons
How do signals through gap junctions work?
Gap junctions form direct cytoplasmic channels between two cells.
Neurons
How do contact dependent signal work?
Conatct dependent signal require interaction of two molecules (receptor and substrate) of two adjacent cells.
Neurons
How do autocrine and paracrine signals work?
Autocrine signals act on the same cell that secreted them while paracrine signal act on the adjacent cell.
Neurons
How do the three ways of remote signaling work?
1) Hormones are secreted into the blood and bind only in the target cells with the suitable receptors 2) Neurotransmitters are secreted from neurons after an electrical signal, to the target cell 3) Neurohormones are chemicals released by neurons to act on target cells in the distance.
Neurons
What are the six steps of signal transport?
1) peptides synthesized 2) Transport through the axon 3) Secretion of peptides 4) Synaptic vesicle recycling 5) Transport through the axon back to the nucleus of the cell 6) Old membrane components digested in lysosomes
Neurons
What is the role of Schwann cells in the nervous sytem?
They produce myelin around the axons of the nerve cells.
Neurons
What is multiple sclerosis?
Is a disease that affects myelin in the nerve cells and causes weakened or disruptive nervous signaling.
Neurons
What should happen for a signal to result in an action potential?
The graded signal should be so strong so that it is above threshold when it reaches the target cell despite the fact that it decreases while moving inside the cell.
Neurons
What is depolarization?
Is when a neuron loses its negative charge because of a signal coming through it.
Neurons
What are the 9 steps of depolarization and hyperpolarization of a neural cell?
1) the neuron is a t resting potential 2) Stimulus comes in 3) Membrane depolarizes to threshold and Na+ channels open so that Na+ comes in. N 4) Rapid Na+ depolarizes 5) Maximum membrane potential is reached and Na+ channels close while K+ open. 6) K+ move from cell to extracellular fluid 7) As K+ leaves, membrane hyperpolarizes 8) Less K+ leaks out of cell since potential has reached its minimum. 9) Resting membrane potential is reached and no more ions move in or out of the cell.
Neurons
What are the 5 steps of synaptic signaling?
1) Action potential depolarizes the pre-synaptic axon 2) The depolarization causes Ca+ channels to open allowing Ca+ come in the terminal of the axon 3) The positive charge causes exocytosis of vesicle contents 4)Neurotransmitter diffuses into the post synaptic cleft and binds on the receptors 5) This binding initiates a post synaptic response
Neurons
Outline the three steps of Acetylcholine (neurotransmitter) synthesis and recycling.
1) Acetylcholine is made of Choline and Acetyl CoA. 2) In the synaptic cleft Acetylcholine is broken by an enzyme named acetylcholinesterase 3) Choline is transported back in the axon terminal to be used for the production of more Acetylcholine.
Neurons
What are the 3 ways of removing neurotransmitter from Synapses?
1) Neurotransmitters can be transported to glial cells or re-used 2) Enzymes inactivate neurotransmitters 3) Neurotransmitters can diffuse out of the blood
Neurons
What are the components of forebrain and its subcomponents?
Telencephalon (Cerebrum (Cerebral cortex, White matter and Basal nuclei)) and Diencephalon (Thalamus, Hypothalamus and Epithalamus)
Neurons
What are the components of midbrain and their subcomponents?
Mesencephalon (part of midbrain)
Neurons
What are the components of Hindbrain and its subcomponents?
Metencephalon (Pons and Cerebellum) and Myelencephalon (Medulla Oblongata)
Neurons
What type of disease is Meningitis, what causes it and what does it damage?
Meningitis is a bacterial disease. Infection of the Meninges affects the the protective membranes of the CNS (brain and spinal cord) causing them to inflate, damaging the nerves and brain.
Neurons
What are the four steps of cerebrospinal fluid through ventricles in the brain?
1) The are 4 ventricles, 2 lateral and 2 that continue to the spinal cord. 2) Cerebrospinal fluid is secreted into the ventricles and passes to the subarachnoid space where it cushions the brain 3) The choroid plexus transfers nutrients from the blood into the cerebrospinal fluid 4) Cerebrospinal fluid is reabsorbed into the blood through arachnoid projection call villi
Neurons
What is Congenital Hydrocephalus and what causes to the brain?
It is a disease that causes unbalanced Cerebrospinal fluid which makes ventricles swollen, pushing the brain cortex outside the cranium. It can cause retardation or death at early ages.
Neurons
Sensation is separated in conscious and unconscious. How does conscious sensation work?
We get a sensory input that is received by hypothalamic receptors or sensory neurons. These send an impulse to the Limbic system that would cause behavioral response or the signal would get to hypothalamus, medulla or pons that would cause Endocrine response/ Autonomic Response/ Behavioral response
Neurons
What does the Hypothalamus control?
Temperature, Water Balance, Eating Behavior.
Neurons
What do Pons control?
Respiratory System
Neurons
What does the Medulla control?
Blood Pressure and Urinary Bladder Control.
Neurons
What are the 8 functions of Hypothalamus?
1) Activates Sympathetic Nervous System (adrenal glands, glucose levels) 2) Body temperature (shivering 3) Controls body osmolarity (vasopresin, ADH) 4) Reproductive functions (female hormone secretion) 5) Eating behavior 6) Interacts with Limbic System (emotions behavior) 7)Influences medulla (cardiovascular function) 8) Affects Anterior Pituitary Gland (hormone secretion)
Neurons
Outline how sensory input from the skin is perceived (4 steps).
1) Coarse touch/ Pain cross the middle of the spinal cord 2) Fine touch/ vibration etc. cross the midline in the medulla 3) Sensory pathways synapse in the thalamus 4) Sensations are received in the primary somatic sensory cortex.
Neurons
Where do olfactory pathways end up? (smell related)
Olfactory pathways end up to the olfactory bulb and then to the olfactory cortex.
Neurons
Where do most sensory pathways end up in the brain?
Thalamus where they are modified and led to their cortical centers (cortex).
Neurons
Where do equilibrium pathways end up?
To the cerebellum.
Neurons
Parkinson’s disease. How does it work, what does it affect and how is it treated?
It kills part of the basal ganglia, dopaminergic neurons called substancia nigra. These control movement and mood of a person hence it cause lack of controlling them. Some patients show improvement after administration of L-dopa which is a precursor of Dopamine.
Neurons
What is the way of an external stimuli to the CNS?
Sensory receptors take the information, send it through afferent neurons and led to the CNS.
Neurons
What are the two nervous system that external stimuli information is sent after the CNS?
Autonomic nervous system that controls smooth muscles, cardiac muscles and glands or Motor System that controls skeletal muscles.
Neurons
What are the three divisions of the autonomic nervous system?
Sympathetic division which controls action (fight or flight), parasympathetic division that controlls calming down (digestion, resting) and enteric division that controls digestive tract, gall bladder and pancreas.
Neurons
Stroke. What are the two types, how do they work and what do they cause?
Type 1 (lethal): CVA cerebrovascular disorder is 80% ischemic (thrombosis) and 20% from vascular rapture. Type 2 (not lethal): TIA transient ischemic attack is not lethal but lasts for <1 hour. Strokes are interruptions of cerebral blood causing neurologic deficit.
Immune System
What are leukocytes and what are their subgroups?
Leukocytes are part of the immune response of the body. There are lymphocytes that do not contain granules and circulate in lymph and blood vessels (adaptive immune system) and there are non-lympocytes (macrophages and granules) that are part of the innate immune system.
Immune System
What the precursor of the cells of the immune system and what does it yield?
The precursor of all cells is a pluripotent hematopoietic stem cell from the bone marrow. This could either yield a common lymphoid progenitor that would make cells for the adaptive system (B and T cells) or a common myeloid progenitor that would yield cells for the innate system (macrophages, phagocytes).
Immune System
What are the three main differences of adaptive and innate immune system?
The adaptive immune system has a memory of previous encounters hence it gets improved after the first counteract, while the innate does not. Also, the innate is not specific to antigen.
Immune System
What are the two types of lymphoid tissues based on their function?
There are the primary lymphoid organs that are responsible for the production and development of white cells and all the other lymphoid tissues that circulate them and lead them to the antigen.
Immune System
How are lymphocytes circulated in the body to come in contact with the antigen?
Naive lymphocytes circulate from one lymph node to the other till they encounter one that has drained an antigen from an infected area and become activated entering the bloodstream through the thoracic duct to destroy the infectious agent.
Immune System
What is the anatomy of the spleen and how does it relate to its function?
The spleen has regions called red pulp that veins pass through and the filtration of blood occurs. This is done by the venous sinuses that have macrophages that will filtrate the blood and kill dead red blood cells that would give out aminoacids, billirubin and iron ready for excretion through the liver.
Immune System
What is the function of the second main lymphoid organ, thymus?
Thymus is responsible for the production of T lymphocytes and afterward for their development. The peak of its function is during adolescence where after that is replaced by adipose.
Immune System
What is the yield of embryonic development of T lymphocytes?
They synthesis of the receptors of the T Lymphocytes that would identify the antigen. The ones that are self reactive are eliminated while the others get multiplied by cloning themselves.
Immune System
How does the thymus help in the development of T Lymphocytes?
Its epithilial peptide factors such as interleukins, thymosins etc. that act inside the thymus.
Immune System
What are the lymph nodes, and what is their function?
Lymph nodes are part of the “encapsulated” secondary lymphoid tissues that is full of leukocytes filtering the blood from pathogens.
Immune System
What is the yield of lymph nodes?
Its Lymph which is the filtered blood from lymphoid tissues that returns to the blood stream.
Immune System
What is the most polymorphic molecules in the human body?
MHC
Immune System
What is MHC? How is it used in mice?
MHC are molecules that are expressed by genes involved in identification of another individual in order to multiply. For instance, mice MHC helps them produce odors that help them identify other mice from their family so they don’y multiply with them and keep their MHC genetic code differentiating.
Inflamation
What are the 4 effects of inflammation that define it and why do they occur?
The four effects are heat, pain, redness and swelling and are caused by the cytokines that white blood cells produce in the inflamed area.
Inflamation
Why cytokines cause fever and how does this help the immune system?
Cytokines (e.g. TNF-α) act on the hypothalamus causing the secretion of prostaglandin E2 causing fever. The increased production and maintenance of heat in the body reduces the bacteria growth and increases the activity of the immune system.
Inflamation
What does the inflammatory response include, what are the three steps and what are the main components that help this response be successful?
Bacteria trigger macrophages release cytokines and chemokines that change the permeability of the membrane. Hence, monocytes and neutrophils (which are the main components of inflammatory response) enter the tissues that are infected. The accumulation of all these molecules cause the inflammation effects and cause the destruction of bacteria.
Inflamation
What are the three steps of phagocytosis and how does it conclude?
1) Phagocytes engulf the bacterium forming pseudopodia 2) Lysosomes are released and form a phagolysosome, digesting the bacterium 3) Some of it is released and some of it will be introduced on a membrane cell surface MHC molecule.
Inflamation
What is the membrane attack complex?
The membrane attack complex is the complex formed to make a gap in the bi-layer of the pathogens membrane causing it to destroy.
Inflamation
What is opsonisation?
Opsonisation is the process that involves the binding of an antibody or a complement C3b or both on the membrane of a pathogen in order to enhance the process of phagocytosis.
Inflamation
What are the 4 main antibodies that we can find distributed in the human body?
IgA, IgE, IgM and IgG
Inflamation
What is IgG responsible for and where is it found?
IgG is the main antibody and can be found in the blood
Inflamation
What is IgM responsible for and where is it found?
IgM is the first antibody made when a new immune response is triggered.
Inflamation
What is IgA responsible for and where is it found?
IgA is responsible for protecting body areas that are open to the outside world (digestion tract, stomach etc.)
Inflamation
What is IgE responsible for and where is it found?
IgE is responsible for parasitic infections and allergies. Also, its cross linking triggers histamine secretion from mast cells in the tissue of the body.
Inflamation
What are the three functions of an antibody?
1) Neutralization. Antibodies form toxin-antibody complexes that can’t react with receptors causing their neutralization since they can’t cause pathogeny. 2) Opsonization. Antibodies bind on pathogens helping the identification of them be macrophages and neutrophils hence, their digestion 3) Complement activation. Antibodies bind on pathogens forming a receptor for the proteins that would form a complex and destroy the pathogen by opening a gap on its membrane.
Inflamation
How do antibodies help the extermination of a large parasite?
They bind on it forming receptors that would attract cells of the innate immune system causing the pathogen to die.
Inflamation
How does T cell activation occur through cell to cell communication?
The macrophage that has ingested the virus has class 2 MHC receptors with bound antigens on its membrane. T cells bind on these receptors and interleukin-2 receptors bound promote the proliferation of T cytotoxic cells. These cells differentiate and bind on infected cells on their class 2 MHC receptors and kill them.
Inflamation
How is the generation of antibodies specific to an antigen promoted through cell to cell communication?
The helper T cell (naive) binds on the class-2 MHC receptor on the membrane of the antigen that has ingested the virus. The activated helper T cell binds on the class-2 receptor of a B cell. This promotes its proliferation and differentiation into memory cells and plasma cells.
Inflamation
What is the difference between memory B cells and plasma B cells?
Plasma B cells produce antigen specific antibodies while memory B cells are ready to do the job that a plasma B cell does in a future strike of the virus.
Inflamation
What are the three systems that interact in order to affect the body because of outside factors?
The brain (nervous system), the immune system and the endocrine system.
Inflamation
What does its system use in order to communicate with the other two systems agains outside factors? What is the result of this interaction?
The brain sends neuropeptides, the Immune system cytokines and the endocrine system hormones. The immune system also sends peptide hormones to the target cells. The result is a complex of chemicals towards the target cells in different level in order to fight outside factors.
Immunopathology
What are the three cases that the immune system may go wrong?
1) Hypersensitivity. Its when the immune system becomes overreactive hence it may react even to pollen leading to allergic reactions 2) Immunodeficiency. Its when the immune system gets affected by a virus (such as HIV) and can’t react on viruses 3) Autoimmunity. It happens when the immune system mutinies and starts to attack cells of the body of the host
Immunopathology
Should the immune system react to all antigens of the body?
When the immune system reacts to infectious antigens and tumors its good. However, in the case of a innocuous antigen, a grafted organ or a self organ the immune system is better not to react.
Immunopathology
How does allergy work and with the use of what substances?
Allergy is a response initiated by the cross-link of IgE. This causes mast cells to secrete granules packed with histamine and other inflammatory ingredients.
Immunopathology
Name some allergic diseases…
asthma, eczema, hay fever, rhinitis and anaphylaxis
Immunopathology
How does the IgE cross link occur?
IgE bind on the antigens and a mast cell binds on two IgEs. These antibodies are cross-linked causing the release of the mediators (histamine etc.)
Immunopathology
How do the environmental factors and the genetic factors affect wether a child would be show atopic or non-atopic allergy?
With a hygienic environment and the allergen genes the individual is most likely to be in a Tf2 condition with atopic allergy. However, without the allergen genes and in a non-hygienic environment it drives the immune system to a non-atopic condition without the development of allergy.
Immunopathology
What are the two types of immunodeficiency diseases and what is their difference?
Primary immunodeficiency disease is inherited while secondary is due to an infection.
Immunopathology
Name a primary immunodeficiency disease and how it works.
SCID is a common primary disease that is due to a gene defect. This causes children not to have active B and T cells hence no immune system hence they die at an early age.
Immunopathology
How did scientists used to treat SCID and how is it treated now?
They used to search for a matched bone marrow transplant but it would not always work out. Now they have found that introducing a disabled virus to the body would make the immune system start working again.
Immunopathology
Name a secondary immunodeficiency disease and how it works.
AIDS (acquired immunodeficiency syndrome) is caused by an infectious agent called HIV which is a virus. This immunodeficiency disease causes the destruction of dendrites, T cells and macrophages hence the host is infected by other pathogens and dies.
Immunopathology
Name a immunodeficiency disease based on the autoimmunity and explain how it works.
Myasthenia Gravis is a disease that causes the production of antibodies agains the AcetylCholine receptors of motor endplates. This causes the Na+ reflux to not bind on the receptors hence not allow the signal pass the synaptic cleft. hence, the muscle does not receive the signal and does not contract.
Immunopathology
How is it called when a grafted tissue is transplanted from the same preson for the same person?
Isograft.
Immunopathology
How is it called when the grafted tissue derives from another person of the same species but with non identical genetic material?
Allograft.
Immunopathology
How is it called when the grafted tissue derives from another species?
Xenograft.
Immunopathology
How are the chances of an accepted allograft increased?
By immunosuppressive therapy.
Blood Cells and Blood clotting
What are the three function of the blood?
1) Transport of nutrients, oxygen, hormones and waste products 2) Protection through immune response and homeostasis 3) Homeostasis by keeping a stable internal environment
Blood Cells and Blood clotting
Which are the 5 ingredients of the blood?
Water, Ions, Gases, Organic Molecules and Trace elements and Vitamins
Blood Cells and Blood clotting
What type of organic molecules are contained in the blood?
Amino acids, Lipids, Nitrogenous wastes, Glucose and Proteins
Blood Cells and Blood clotting
What are the three types of plasma proteins contained in blood?
Albumins, α β γ globulins and fibrinogen
Blood Cells and Blood clotting
What is the function of albumins in the blood?
Albumins maintain the osmotic pressure of the blood by draining water from the tissues.
Blood Cells and Blood clotting
What is the function of α and β globulins in the blood?
They transport lipids and fat soluble vitamins.
Blood Cells and Blood clotting
What is the function of γ globulins in the blood?
γ globulins are antibodies made by B lymphocytes.
Blood Cells and Blood clotting
What is the function of Fibrinogen in the blood?
Its an important clotting factor produced by the liver.
Blood Cells and Blood clotting
What are the five types of white blood cells? (Never Let Monkeys Eat Bananas)
Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils
Blood Cells and Blood clotting
What are the two functions of Macrophages?
The ingest pathogens and they present antigens as peptides on MHC molecules to T cells.
Blood Cells and Blood clotting
What is the function of Dendritic cells?
They are the main cells that activate naive T cells that other APCs cant do.
Blood Cells and Blood clotting
What is the function of Neutrophils?
They are the most common cell for phagocytic action agains bacteria.
Blood Cells and Blood clotting
What are the two functions of Eosinophils?
They play a role in asthma and cause damage to parasites.
Blood Cells and Blood clotting
What is the function of Basophils?
They contain granules that have useful ingredients during allergic reactions or attack of parasites.
Blood Cells and Blood clotting
What is the function of Mast cells?
Mast cells can release histamine and other active substances during allergic reactions or parasite infection.
Blood Cells and Blood clotting
What is the function of Natural Killer cells?
They are granular cells that kill other cells that have burden intracellular infections or even tumor cells.
Blood Cells and Blood clotting
What is the function of red blood cells, what’s their life span and what’s their structure?
Red blood cells transfer oxygen and carbon dioxide between lungs and body. They have a 4 month life span and are produced in the liver, spleen and bone marrow. They are packed with hemoglobin.
Blood Cells and Blood clotting
What is the structure of hemoglobin?
Hemoglobin is made of a heme group and Globin protein chains. The heme group is a porphyrin ring with an iron atom at the center.
Blood Cells and Blood clotting
What is the function of platelets, where are they stored and whats their life span?
They play a big role in blood clotting and are stored in the red pulp of the spleen. From there they are released whenever they are needed and their life span is 10 days.
Blood Cells and Blood clotting
Describe thrombopoiesis.
Its the platelet formation which is regulated by TBO (thrombopoietin protein) and is done by the mitosis of megakaryocytes. It can be done up to seven times.
Blood Cells and Blood clotting
How is haemostasis achieved?
Haemostasis is blood clotting hence, in order for the body to do that, three actions are taken. 1) Vasoconstriction 2) Platelet accumulation in the scar 3) Active platelets can transform fibrinogen into fibrin which is an insoluble protein, preventing further blood loss.
Blood Cells and Blood clotting
What are the three step of aggregation (accumulation) of platelets being avoided in intact skin?
Layers of epithelial cells that are intact secrete nitric oxide (NO) and PGl2 prostaglandin which both act as vasodilators hence against platelets. Also, no collagen contacts platelets hence they don’t get activated. Finally CD39 enzyme transforms ADP to AMP repelling platelets
Blood Cells and Blood clotting
How is the platelet plug achieved in skin scars (4 steps) ?
Collagen released comes in contact with the platelets activating them. The active platelets produce VWF (von Willbrand’s factors) which are ADP and thromboxane A. These factors cause the accumulation of other platelets. Platelets stick to the collagen fibers forming a solid platelet plug.
Diseases of the Blood
Which are the three types of blood diseases?
1) Coagulation disorders (blood clotting) 2) Leukocyte disorders (white blood cells) 3) Erythrocyte disorders (red blood cells)
Diseases of the Blood
Name four Coagulation disorders and their overall impact on human body.
1) Haemophilia A 2) Haemophilia B 3) von Willebrand’s factor disorder 4) Thrombocytopenia. They cause easy bruising and extensive bleeding ins severe cases. In the fourth disorder there is not enough number of platelets.
Diseases of the Blood
Name an acquired disease of coagulation disorders.
Vitamin K deficiency bleeding (VKDB) is now called haemoric disease of Newborn (HDN)
Diseases of the Blood
Why do we need vitamin K and how do we get it?
Whe need Vitamin K cause its responsible for the production of clotting factor II, VII, IX and X. We get it through diet including vegetables and is produced by E.Coli in the gut.
Diseases of the Blood
What was the first use of Warfarin and how is it used now?
The first use of Warfarin was a rat/ mouse pesticide and now is used for prevention of thrombosis since it inhibits the factors of clotting produced by vitamin K.
Diseases of the Blood
Name three Leukocyte disorders and their action.
1) Leukopenia which is lack of leukocytes which leads to infections due to lack of phagocytosis 2) Leukocutosis causing inflammatory diseases after an infection since there are more than needed leukocytes 3) Leukemia which causes infectious tumors because of Leukocyte precursors in the Bone marrow and after in the blood.
Diseases of the Blood
What is Leukemia, where does it arise and what is its outcome in cell terms?
Leukemia is a Leukocyte disorder caused by leukocyte precursors forming tumors from the myeloid and lymphoid lineages. It can lead to acute lymphocytic leukemia (ALL) or acute myelogenous leukemia (AML) and in severe instances to their chronic forms (CLL or CML)
Diseases of the Blood
What is anaemia?
Its a disorder that causes low red blood cell count.
Diseases of the Blood
What are the 5 forms of Anaemia and how are they caused?
1) Plastic anaemia is when radiation or arsenic exposure causes bone marrow defects 2)Pernicious anaemia is caused by low absorption of Vitamin B12 by the gut due to lack of essential factor 3) Iron deficiency anaemia is caused by blood loss due to mensturation or low iron intake 4) Sickle-cell anaemia is caused by an amino acid abnormality in the haemoglobin molecule 5) Haemolytic anaemia is a hereditary disease causing red blood cells to burst due to cytoskeleton defect
Diseases of the Blood
How and why does sickle-cell anaemia occur and what does it cause to the human body?
Sickle-cell anaemia is a hereditary disease that is caused by the substitution of A from T at position 6 causing an abnormal amino acid in the β-globin protein. At low PO2 conditions Haemoglobin S cross-links forming the sickle type of form being less flexible, blocking small vessels and causing ischemia.
Cardiovascular System
What is the structure of the Cardiovascular System?
IT is composed of the heart the works as a pump, blood vessels (veins and arteries) and the blood hat is the liquid (mean of transport)
Cardiovascular System
What is the function of the Cardiovascular system?
Its function is to transport nutrients, oxygen, waste materials the cell-cell communication and the help the immune defense.
Cardiovascular System
Define membrane potential.
Membrane potential is the differentiation of electrical charge between the inside and the outside of the cell
Cardiovascular System
Define Depolarization.
Depolarization is the loss of negative charge hence, becoming positive.
Cardiovascular System
Define Hyperpolarization.
Hyperpolarization is the gain of negative charge hence, become more negative.
Cardiovascular System
Define action potential.
Its a charge change in a membrane conducted along a nerve fibre or the membrane of a muscle cell.
Cardiovascular System
What does the CNS contain?
The brain and the spinal cord.
Cardiovascular System
What are the three types of neurons that the peripheral nervous system contains?
Motor neurons, Autonomic neurons (sympathetic / parasympathetic) and sensory neurons.
Cardiovascular System
What type of neurons do they control heart and blood vessels?
Autonomic neurons.
Cardiovascular System
How are myocardial muscle cells organized?
They have one nucleus, they are branched and are connected by intercalated discs.
Cardiovascular System
Explain how the Myocyte of cardiac muscle contracts.
At the beginning its at resting potential. Then, Na+ channels open depolarizing the membrane. At highest value K+ channels close. When hyperpolarization begins Ca++ channels open remaining the charge high for some seconds. However, these channels close and K+ channels open letting the positive charge leave reaching resting potential again.
Cardiovascular System
Define Refractory period.
Refractory period is the time needed for another action potential to be triggered to the heart. Till then the muscle fiber must have been completely relaxed and hyperpolarized.
Cardiovascular System
How the pacemaker reaches threshold and what does it happen then?
Na+ channels open causing depolarization. When the charge reaches threshold, Ca++ channels open causing rapid increase in charge. At its peak, Ca++ channels close and K+ channels open. This causes hyperpolarization till it reaches its resting potential.
Cardiovascular System
How does the autonomic system of neurons affect the heart rate?
The autonomic system has two types of neurons, sympathetic and parasympathetic. Sympathetic neurons increase the frequency of action potentials hence the rate of depolarization. Parasympathetic neurons do the opposite.
Cardiovascular System
How does the current pass through the heart?
The autonomic system triggers its action potentials through the SA node. The SA node passes the current through Internodal pathways and to the AV node. Then, the current passes through the Bundle of His in the septum of the heart and is spread through the ventricles through Purkinje fibers.
Cardiovascular System
What is the relation of Electrical activity and Cardiac contraction?
The depolarization of atria is the P wave. The conduction of this signal from SA to AV node is the PQ wave where atria contract. The Q wave is the passage of the current through the bundle of His while the S wave is the spread of the current through the purkinje fibers. After the S wave the ventricles contract. Finally. The T wave is the hyperpolarization of the ventricles.
Cardiovascular System
Define Diastole.
Diastole is when the heart muscles relax the volume increases and let the heart fill its chambers with blood.
Cardiovascular System
Define Systole.
Is when the heart muscles contract, the volume decreases and blood is pushed out of the chambers of the heart.
Cardiovascular System
Define Cardiac Cycle.
Is the period from the contraction till the relaxation of the heart muscles.
Cardiovascular System
Outline the 5 steps of the Cardiac Cycle.
1) Late diastole. Both set of chambers are relaxed and passive ventricular filling occurs. 2)Atrial Systole. The contraction of atria causes a small amount of blood to enter ventricles 3) AV valves close but semilunar valves don’t open. 4) Ventricular Systole. Ventricles contract opening semilunar valves pushing blood out of the heart. 5) Pressure drops, semilunar valves close.
Cardiovascular System
Which is the smallest blood vessel with the smallest wall thickness?
Capillaries
Cardiovascular System
Which is the thickest blood vessel?
Veins
Cardiovascular System
Which has the thickest walls?
Arteries
Cardiovascular System
What does the microcirculation include?
Venules, Capillaries and Arterioles.
Cardiovascular System
How is the blood flow through microcirculation controlled?
It is controlled in metarterioles with the use of sphincters.
Cardiovascular System
How is the blood flow determined?
Through pressure in the blood vessels which is affected by vessel distance, radius of vessel and viscosity of the fluid.
Cardiovascular System
How is the mean arterial pressure determined?
=Diastolic + 1/3 (Systolic-diastolic)
Cardiovascular System
What are the three steps for measuring blood pressure?
The cuff is inflated so the systolic pressure is passed and blood flow is stopped. 2) The cuff is deflated just below systolic pressure when the Korotkoff sound is heard. (Systolic) 3) Cuff is deflated until sound disappears. (Diastolic)
Cardiovascular System
What determines the mean arterial pressure?
Is determined by the cardiac output (left ventricle to aorta) (heart rate x stroke volume) times the arterial blood flow resistance.
