Body Logistics Flashcards
What are some methods of measuring temperature?
What are the temperature ranges for:
- Heat exhaustion.
- Heat stroke.
- Fever.
- Normal.
- Mild hypothermia.
- Severe hypothermia.
and what are the clinical symptoms?
What are the two buffering systems used in the body, and what are they used for?
Carbonic acid - bicarbonate system, used for blood pH maintenance.
Sodium phosphate buffering system, used for intracellular pH.
What happens if there is insufficient water in the body?
What happens if there is too much water in the body, and what can be done clinically?
What are the 4 classifications of tissue?
Muscle.
Nerve.
Connective.
Epithelial.
What can enlarged red blood cells, under a microscope, indicate?
Vasculitis.
What does periodic acid-Schiff stain?
Sugars.
How does a confocal microscope work?
Multiple snapshots are taken in the 3 dimensions and put together.
What are confocal microscopy used for in clinical practice?
Evaluation of eye diseases.
How are living cells prepared?
What are morphogenesis and differentiation?
Mophogenesis = development of form and structure.
Differentiation = specialisation for function.
What is the timeline of the pre-embryonic, to embryonic to fetal development?
Pre-embryonic = first 2 weeks.
Embryonic = weeks 3-8.
Fetal = weeks 9-38.
NOTE: remember to add the first 2 weeks from the last menstrual period.
Where is the oocyte usually fertilised?
Ampulla, where it becomes the zygote.
What is the zona pellucida?
Glycoprotein shell, encasing the (totipotent) morula.
Prevents the further fertilisation of more sperm.
What is PGD (Pre-implantation Genetic Diagnosis) and what is it used in?
Where one cell from the morula is removed and tested for serious inheritable diseases.
It is used in IVF treatment.
What are the resultant structures after compaction?
The zona pellucida encases the trophoblasts.
The embryoblasts are a mass, attached to the trophoblasts.
The space within the trophoblasts is called the blastocoele.
What are totipotent and pluripotent stem cells? Give an example.
Totipotent can divide into any type of cells, such as blastomeres (cells of the morula).
Pluripotent can divide into many types of cells, such as embryoblasts.
What needs to occur before the blastocyst can interact with the uterine surface? When does this occur?
Hatching from the zona pellucida.
Between day 5 and 6.
What occurs in implantation?
The fibrin plug closes, which can cause bleeding.
A maternal blood flow through the placenta is established.
What type of blood vessels invade the syncytiotrophoblasts?
Sinusoids.
How does the neural tube form, during neurulation? What does it give rise to?
The notochord signals the overlying ectoderm to thicken and form the neural plate.
The neural plate then curls towards each other, until they reach, forming the neural tube.
These give rise to the brain and spinal cord.
What are somites made of? What does each component become?
Sclerotome and dermatomyotome.
The sclerotome becomes the bone.
Dermatome becomes the innervated area of the dermis of skin.
Myotome becomes the innervated muscles.
Where are the cilia that control the flow of signalling molecules during embryology located?
Primitive node - the signals are sent by the primitive streak.
Where are tight junctions located, and what is their function?
Apical, between the two epithelial cells.
They can transiently open to allow molecules to reach the deeper layers of the organ, through paracellular transport.
What are adhesion junctions formed from, and what are they linked to?
Formed from actin filaments and linked to E-cadherins.
What is the only cell-to-cell adhesion found in the upper epidermal layer?
Desmosomes, to provide mechanical strength and prevent tissue destruction.
What do hemi-desmosomes attach?
Extracellular matrix laminin of the basal lamina to the intermediate filaments of cytokeratin within the cell, through integrins.
What do focal adhesions attach?
Extracellular matrix fibronectin of the basal lamina to the actin filaments within the cell, through integrins.
When are integrins at their strongest?
When two dimers come together via phosphorylation.
What are the layers of the basement membrane?
Basal lamina - contains two layers, the lamina lucida which is clear, and the lamina denser which is dense.
Reticular layer - very dense layer containing lots of collagen.
What do adhesion proteins require to function?
Calcium ions.
What does mucous contain?
Mucin proteins, electrolytes, water, lysozyme (antiseptic enzymes) and immunoglobulins.
What are the 5 layers of the GI tract, from inside to out?
Mucosa - mucous membrane that projects epithelial cells into the lumen.
Muscularis mucosae - thin smooth muscle layer.
Submucosa - connective tissue layer containing some blood vessels.
Muscularis external - contains an inner circular and an out longitudinal muscle layer.
Serosa - connective tissue layer with some blood vessels and nerve fibres.
What specialisations does the GI tract have to aid its functions?
Epithelial cells have microvilli to aid absorption.
Lamina propria contains lymphatic tissue to prevent ingress of pathogens.
Muscularis mucosae has folds to increase the surface area for absorption.
Muscularis external can contract for peristalsis to move contents.
What is the structure of the trachea and primary bronchi?
Mucosa - ciliated cells with a thin lamina propria but not longitudinal muscularis mucosa.
Submucosa - connective tissue layer, also contains goblet cells.
C-shaped hyaline cartilage - 2 layers, 1 containing fibroblasts that synthesise collagen and 1 containing chondrocytes that synthesise cartilage.
What is the basement membrane formed of?
Basal lamina (lamina lucida and denser) + reticular layer.
What is the structure of pseudostratified epithelia?
All cells touch the basement membrane with the nuclei at different heights. Not all cells reach the epithelial surface.
The basement membrane undulates as the cells try and pull it up to reach the surface.
What is the mucociliary escalator?
The production of mucous in combination with ciliated cells.
The mucous traps dirt and pathogens and the cilia waft it towards the mouth where it can be swallowed and digested or spat out.
How are goblet cells specialised and how do they release their products?
They have microvilli on the apical surface.
They release mucin in vesicles through exocytosis.
What gene is mutated in cystic fibrosis, and what can be the complications of it, e.g., airway, liver, pancreas, small intestine, reproductive system, skin?
The CFTR gene - can’t release sufficient Cl- ions so sticky mucous.
What is stratified squamous epithelia, and how are the cells held together?
It is multiple layers of cells, with the outermost being squamous epithelia.
They’re held together by desmosomes.
How does early stage smoking damage the lungs?
Normal mucous layer thickens.
Cilia die off and take 2-4 days to regenerate.
How does chronic stage smoking damage the lungs?
Goblet and basal cells proliferate, leading to excess mucous.
Club cells metaplaise or die.
Carcinogens can act as initiators and cause mutations for cancer.
Pneumocytes die and fibroblasts lay down scar tissue, decreasing the ability for gas exchange.
How does branching and elongation of exocrine glands occur?
FGF10 is secreted by immature fibroblasts and epithelial cells grow towards the signal by:
- Elongation, stimulated by growth factor 1.
- Branching, stimulated by growth factor 2.
They occur one after another, never at the same time.
State the 7 types of gland shape and an example for each.
Simple tubular - intestinal glands.
Simple branched tubular - stomach glands.
Compound tubular - duodenal glands.
Simple alveolar - foetal glands.
Simple branched alveolar - sebaceous glands.
Compound alveolar - mammary glands.
Compound tubuloalveolar gland - salivary.
Define the terms:
- Striated.
- Demilune.
- Intercalating.
- Acinar.
All relating to glands.
Straited = striped.
Demilune = half-moon.
Intercalating = between two glands.
Acinar = sac-like.
How do the glands of the breasts develop?
Oestrogen and progesterone during puberty, and prolactin during pregnancy, that all stimulate the growth of the glands.
What is a cytocrine, merocrine, apocrine, and holocrine gland?
Cytocrine - whole cells are released.
Merocrine - a form of exocytosis.
Apocrine - partial loss of cytoplasm.
Holocrine - whole loss of cytoplasm.
How does merocrine secretion occur?
Vesicles are stimulated to move via Ca2+ ions.
They move along microtubules.
The vesicle fuses to the cell membrane and the contents are released.
What are the different methods of transepithelial transport?
Paracellular transport - between cells.
Transcellular transport - lipid-soluble molecules that can diffuse through the membranes.
Carrier proteins.
Endocytosis, followed by exocytosis - transcytosis.
What are the different types of hormones, their methods of:
- synthesis and storage.
- transport in the blood.
- location of receptor.
- response to the binding of receptor.
- examples.
What do the pituitary, thyroid, parathyroid, pancreas and adrenal glands develop from in embryology?
Pituitary - hypophyseal pouch and neurohypohpyseal bud.
Thyroid - the floor of the pharynx.
Parathyroid - pharyngeal pouches.
Pancreas - foregut.
Adrenal - intermediate mesoderm and neural crest.
What are all the pituitary hormones secretion methods?
Constitutive or regulated merocrine secretions.
What type of cells are parafollicular cells, what do they release, and what are the effects of it?
They are neuroendocrine cells of the thyroid.
They release calcitonin.
Calcitonin inhibits osteoclast function and decrease the (re-)absorption of calcium to decrease the plasma levels.
What is the definition of a stress response?
The response to a perceived or real threat to homeostasis.
What is the structure of the serous pancreatic glands, and how are the ducts connected?
They are acinar glands that are grouped into lobules, containing zymogens.
They are connected through intercalated ducts to the pancreatic duct, which joins the bile duct to make the common bile duct.
Why do goblet cells appear white with H&E staining?
They contain sugars which does not stain with H&E.
What types of glands are blocked with inflammation of the parotid gland?
Striated ducts.
What is the pattern of gland accumulation to secretion?
Intralobular duct - inside the lobule.
Intercalated duct - between 2 lobules.
Striated duct - accumulation of intercalated ducts, they’re stripy.
Excretory duct - striated ducts come together.
Main collecting duct - multiple excretory ducts come together and products are secreted onto the surface.
What is the function of striated ducts?
To prevent water loss.
What are the 3 types of capillary vessels, describe them and where are they found?
Continuous, intact basement membrane with small intercellular clefts - brain and most of the body.
Fenestrated, intact basement membrane with small fenestrations in the endothelium - kidney, pituitary, small intestine, and around some endocrine glands.
Sinusoid, incomplete basement membrane and large intercellular gaps - spleen, liver, bone marrow and lymph nodes.
How many nuclei do liver cells have?
2 or 3.
Explain the route of bile from the liver to gall bladder.
Bile canaliculi between the hepatocytes.
Interlobular tributaries in the duct/ periportal bile ductules in the triads (same but different name).
Bile duct.
Left and right hepatic ducts.
Where do Ito/ stellate cells hold the vitamin A, and what can they differentiate into in liver cirrhosis?
The vitamin A is held in vacuoles.
They can lose their vitamin A storage and differentiate into fibroblasts.
Describe the organelles of hepatocytes.
Numerous mitochondria.
Extensive Golgi and endoplasmic reticulum (R and S).
Lots of free ribosomes.
Glycogen deposits.
Describe the regeneration ability of the liver, depending on the extent of damage, and its recovery time.
Less than 50% damage, due to viral infection or occasional alcohol use will regenerate in around 7-8 days.
50-70% damage, due to heavy alcohol use, drug toxicity or liver transplant, will regenerate in around 30-40 days.
Over 70% damage, wide to chronic alcohol misuse, suicide attempts and cirrhosis, leads to liver failure and will never regenerate.
Explain the storage function of the liver.
Explain the anabolic function of the liver.
Explain the catabolic function of the liver.
What are some other functions of the liver?
Bile production - its exocrine function.
Filtering debris from the blood.
Hormone and growth factor production - endocrine function.
Modifying hormones, such as thyroxine to T3.
What is extracellular matrix?
Ground substance and fibres.
What are the 3 substances that are held in mast cell granules?
Histamine - increase blood vessel wall permeability.
Heparin - anticoagulant.
Cytokines - attract neutrophils and eosinophils.
What is ground substance, and what is its function?
It is a clear, viscous and slippery substance with a high water content.
It contains proteoglycans - core protein with glycosaminoglycans covalently bound.
GAGs are hydrophilic and attract more water.
This allows for rapid diffusion and high compression resistance.
What are the symptoms of scurvy?
Bleeding - poor wound healing.
Tooth loss.
Bruising of the skin and hair loss.
Weakness and fatigue.
Impaired bone development in the young.
What are some symptoms of Marfan’s syndrome?
Excessively tall.
Arachondactyly - spider-like fingers and toes.
Frequent joint dislocation.
Aortic rapture.
What is the structure of elastin fibres and where is it found?
It is elastin surrounded by fibrillin.
It is found in the dermis of the skin, in artery walls, in the lungs and in elastic cartilage.
In the aorta, what is it that produces the elastin, collagen and matrix?
The smooth muscle cells.
What are the terms for myoglobin in the blood and urine?
Blood = myoglobinaemia.
Urine = myoglobinuria.
What are the names for the plasma membrane, cytoplasm, mitochondria, functional unit and SER of a muscle cell?
What are the dark and light striations of a muscle cell - what is the line in the middle of the light band?
Dark = A band.
Light = I band.
Line in the middle of the light band = Z band.
What is a motor unit?
A motor neurone and the muscle fibres it innervates.
What is the function of smooth muscle that surrounds passageways or cavities?
To modify the volume.
Which cell type undergoes hyperplasia following skeletal muscle injury?
Satellite cells - they can also fuse with existing muscle cells to increase mass: hypertrophy.
What are the thick filaments made of?
Multiple myosin molecules.
What are the two components of actin?
F-actin fibres.
G-actin globules.
What forms the thin filament of skeletal muscles?
Actin, tropomyosin and toponins.