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.