Week 1 Flashcards
Where is extracellular fluid?
Outside the cell
What is it called when pH is too low?
Acidosis
When is MRI used?
For soft tissue. MRI is the gold standard for soft tissue imaging
What are the levels of organization in an organism?
- Atom
- Molecule
- Macromolecule
- Organelle
- Cell
- Tissue
- Organ
- Organ system
- Organelle
What are the four levels of protein organisation?
- Primary
- Secondary
- Tertiary
- Quaternary
Proximal
Closer to the axial body along an appendage
Pathogenesis of Rickets
- Insufficient/no vitamin D3, meaning osteoclasts have the sole responsibility of maintaining calcium levels.
- Bone breakdown increases
- Decreased bone density -> rickets
What are the consequences of too much glucose in the bloodstream?
Glucotoxicity: osmotic gradient draws water out of cells, causing dehydration and death of cells.
Why are carbohydrates the primary source of energy for the body?
They can be rapidly and easily converted into energy for use.
Why is ultrasound not used when air and calcification are involved?
Air and calcified structures reflect sound strongly, creating a hyperechogenic line that obscures structures deep to it
Mid-sagittal plane
Divides the body into equal left and right halves
Describe blood pressure homeostatic regulation
Blood pressure changes -> baroreceptors detect -> sent via afferent neurons to brainstem -> information sent along efferent nerves cause heart rate to adjust
What type of feedback is involved in homeostatic regulation?
Negative
Why are pregnant women and children at higher risk from ionising radiation?
The effects of ionising radiation unfold over time. Since unborn (and born) children have more of their lives ahead of them, they are at higher risk of experiencing adverse effects from this exposure.
Advantages of MRI
- No ionising radiation exposure
- Very high image quality
Rostral
Superior-anterior tip
What is a polypeptide with less than 50 amino acids called?
Peptide
Define Regional anatomy
Study of features in a specific anatomical region
State the basic feedback loop of homeostatic regulation
Stimulus -> receptor -> control center -> effector -> response -> homeostasis
Describe the quaternary level of protein organisation
Multiple 3D polypeptide joined together
Why does it make sense that IV contrast could cause acute renal failure?
The kidneys are reponsible for filtering IV contrast out of the blood. Therefore, kidneys are closely related to the processing of IV contrast, and any negative effects of the substance could act upon the kidneys.
What does physiology pertain to?
The function of body parts
What elements are in carbohydrates?
Carbon, Hydrogen and Oxygen (think: glucose) About 1:2:1 ratio
Describe how the body increases calcium levels
- Calcium decreases
- Parathyroid cells detect this change
- This increases the cell’s secretion of Parathyroid Hormone (PTH)
- PTH acts on bone, kidney and gut cells.
> Osteoclasts break down bone to get calcium
With the help of the steroid hormone vitamin D3:
> More calcium is digested from food
> More calcium is reabsorbed into blood
Define cytology
The study of cells (cyto-plasm)
Para-sagittal plane
Divides the body into unequal left and right halves
Why is endocrine signalling slower than nervous signalling?
Endocrine communication requires molecules to flow through the bloodstream to target sites, which is much slower than the electrical impulses used in nervous signalling
What are two kinds of extracellular fluid?
Interstitial: Between cells and vessels
Intravascular: Within vessels
What does physiology pertain to?
The function of body parts
How does CT differ from x-rays?
CT scans involve taking multiple images from varying angles, which are then reconstructed into multi-slice sections that can be reformatted into multiple planes
What are the disadvantages of x-ray?
- Radiation exposure
- Limited detail of images
- Static image
List some factors that are homeostatically regulated
- Blood pressure
- Blood pH
- Blood glucose
- Blood volume
- Core body temp (not peripheral)
List some physiological responses that occur when core body temperature is too low
- Shivering
- Lack of sweating
- Vasoconstriction (smooth muscles contract; less flow to superficial arterioles)
- Increased brown fat metabolism (therefore increased heat generation)
- Piloerection (leads to goosebumps)
Where is the appendicular body?
Appendages and girdles (e.g. connections to the axial body)
True or false: homeostasis always tends toward the same internal conditions
False. Homeostasis is a dynamic steady state, meaning it can adapt to determine the ideal environment for the body depending on external stimuli
What is the natural pH of the human body?
7.4
Where is intracellular fluid?
Inside the cell
When is CT used?
- Diagnostic tool
- Ongoing monitoring in oncology
- Preoperative planning
- When detail of lung, bone, and soft tissue is needed
What are the advantages of computed tomography scans?
- Relatively accessible
- Relatively cheap
What are the risks of x-rays?
Ionising radiation associated with increased cancer risk (lower exposure than CT)
Posterior (dorsal)
The “back” surface of the body
What is the basic definition of lipids?
Organic molecules that cannot readily dissolve in water
Distal
Further from the axial body along an appendage
What fluid-balancing hormone is made in the hypothalamus? What are its names?
- ADH
- Vasopressin
What elements are in lipids (+ ratio)
Carbon, hydrogen and oxygen, at about ~1:2:<1
Define embyrology
The science of the development of the embryo from fertilization to the foetal stage
Structure and function of the lymphatic system
Structure: lymph, lymph vessels and lymph organs
Function: Fluid balance, defense and immunity
Caudal
Inferior-posterior tip
What are the three types of RNA and their functions?
- mRNA: formed during transcription during protein synthesis
- tRNA: has corresponding anticodons to mRNA that deliver amino acids to ribosome
- rRNA: structural unit of ribosomes
Disadvantages of MRI
- Claustrophobia
- Limited accessibility (expensive, immobile, large machines)
- Loud
Is access to nuclear medicine limited or abundant?
Limited
What are the three levels of organisation of matter?
- Atoms
- Elements
- Compounds
What are the risks of CT scans?
Ionising radiation exposure
Transverse plane
Divides the body into superior and inferior components
How does MRI work?
- Body is placed in magnetic field that aligns all the protons in the body
- Radio waves are projected through the body, disturbing proton alignment
- Protons return to alignment differently according to various tissues
- Therefore, proton alignment can be processed into an image
What is positive feedback?
Any feedback loop that amplifies an initial stimulus (e.g. blood clotting -> platelet coagulation)
Is body fat proportional or inversely proportional to water content? Why does this make sense?
Inversely proportional. Lipids are insoluble in water.
Blood pressure/volume regulation (too high)
Detected -> stimulate Atrial Natriuretic Peptide -> inhibits aldosterone production -> less water and salt are reabsorbed, decreasing BP and volume back to regular levels
Anterior (ventral)
Closer to the “front” surface of the body
Why is thermoregulation important?
Critical enzymes in the body will become inactive or denatured if allowed outside of a narrow temperature range, thus impairing bodily functions.
What are the four kinds of cellular signalling used in homeostasis?
- Juxtacrine: Between two touching cells
- Paracrine: Between two cells that are separated by a short distance
- Endocrine: Where a message is relayed through vessels from one cell to another
- Autocrine: A cell sends a message to itself
True of false: the same IV contrast is used in CT and MRI?
False
Which imaging techniques involve the use of ionising radiation?
CT and X-ray
Where are osmoreceptors located?
The hypothalamus
Why can hypoglycemia cause neural dysfunction?
- CNS and PNS almost exclusively use glucose for cellular respiration
- Therefore, when less glucose is present, neurons have insufficient energy, and so neural dysfunction occurs
What is the main function of carbohydrates?
Primary source of energy for the body
Pathogenesis of Type 2 Diabetes
- Body develops a resistance to insulin
- Blood sugar levels cannot be monitored as easily
What are the risks of MRI?
- Metal cannot be in the body
- Risk in pregnancy
- IV contrast can be used
Inferior
Closer to the plantar surface of the foot
Define systematic anatomy
The study of structures that make up an organ system
Structure and function of the cardiovascular system
Structure: Blood, blood vessels, heart
Function: Transport and exchange of nutrients, waste, and gases around the body
Describe the tertiary level of protein organisation
3D polypeptide structure