Anatomy & Physiology Flashcards
Luteinizing Hormone
Main function: cause ovulation.
Increasing levels of estrogen leads to the LH surge which causes ovulation
Follicle-stimulating Hormone (FSH)
Main function: stimulates the development of the ovarian follicles. These will become a Graatian follicle which is an egg released to be fertilized.
Estrogen (Menstrual Cycle)
Increasing levels of estrogen thicken the wall of the uterus to prepare for implantation of the blastocyst. The increased levels also lead to a spike in luteinizing hormone.
Cortical reaction
“Slow block” component of polyspermy (multiple sperm fertilize one egg -> inviable zygote). Ca+ is released into the egg’s plasma membrane. The ions causes the releases of cortical granules which inactivate the zone pellucida and render it impenetrable. The granules also separate the zone pellucida from the plasma membrane which prevents other sperm from reaching the egg’s plasma membrane. This is the longer-lasting polyspermy prevention mechanism.
What part of the brain controls respiration? How?
The medulla oblongata. It is sensitive to H+ and increased levels stimulate contraction of the diaphragm.
When the diaphragm contracts, what happens to the volume and pressure in the lungs?
Volume increases, pressure decreases.
What are the factors that cause a shift to the right in the hemoglobin cooperativity curve?
Increase in CO2, Acid, 2,3 DPG, Exercise and temperature.
“CADET, face Right!”
What is the formula Cardiac Output (CO)?
It is the volume of blood discharged from both ventricles each minute. Stroke Volume (SV) x Heart Rate (HR)
What is the formula for Stroke Volume?
End diastolic volume (EDV) - End systolic volume (ESV)
What is the formula for Blood Pressure?
Cardia output (CO) x systemic vascular resistance (SVR)
What are lacteals?
Lymph vessels weaved in the capillary beds of the villi in the small instestine that absorb digested fat.
What is the chemical environment in the small intestine?
Less acidic due to bicarbonate ions secreted by the pancreas.
What are the two movements of the small intestine?
Peristalsis and segmentation
What enzymes does the pancreas secrete?
Proteases: Trypsin + Chymotrypsin (zymogens)
Carbs: Amylase
Lipids: Lipase
Nucleic acids: Nucleases
Enterokinases activate trypsin -> activates other enzymes
Where do fats primarily get digested?
The small intestine by pancreatic lipase as well as bile emulsification from the liver.
Bile breaks up fat spheres into droplets so that there is more surface area for lipases to work on
Where do nucleic acids initially get digested?
- Duodenum by pancreatic nucleases, and they get broken down to nucleotides
- the small intestine by nucleotidases to nucleosides
- Nucleosidases & Phosphatases to nitrogenous bases, sugars and phosphates
Where do proteins get broken down?
- Stomach by pepsin
- Duodenum by pancreatic trypsin and chymotrypsin
- Small intestine by depeptidase, carboxypeptidase, & aminopeptidase
Where do sugars get broken down in the digestive tract?
- Mouth by salivary amylase (polysacc. to disacc)
- Duodenum by pancreatic amylase (small polysacc. to disacc.)
- Small intestine by disaccharidases (disacc. to mono sacc.).
Liver functions?
Bile Release
Detox & filtration of blood
Vitamin & mineral storage
Erythorcyte destruction
Carb metabolism
Fat metabolism
Protein metabolism (deaminates proteins to form urea)
What is the main function in the colon?
Reabsorption of water and elctrolytes, as well as vitamin B12 and K through synthesis by gut flora.
Extended use of abx can lead to vitamin deficiency
What is gastrin?
Secreted by stomach epithelial cells that stimulates secretion of HCL.
What is secretin?
Secreted by duodenum which stimulates release of bicarbonate from pancreas
What is cholecystokinin (CCK)?
Also secreted by cells in duodenum, stimulated by fatty acids which then stimulates gall bladder to contract, pancreas to release enzymes, and slows stomach down so that duodenum isn’t overwhelmed.
What is gastric inhibitory peptide
Produced in response to glucose, fats and proteins in the small intestine.
Stimulates insulin release.
Mildly inhibits gastric secretion
What is somatostatin?
Secreted by the pancreas.
Inhibits secretion of digestive hormones
Decreases gastic motility.
What hormones stimulate hunger?
Ghrelin
What hormones suppress hunger?
Leptin, PYY, Insulin, and epinenphrine.
What is saltatory conduction?
A fast depolarization of a neuron through the nodes of ranvier (unmyelinated segments of axons)
What glial cells produce the myelin sheathe present within the CNS?
Ogliodendrocytes
What glial cell produces the myelin sheath present with the PNS?
Schwann cells
What are the types of channels that stimulate action potential
Voltage-gated (electrical), ligand-gates (AcH), mechanically-gated (physical changes)
What are the values of action potential?
Resting potential: -70mV
Threshold: -55mV
Depolarization: +30mV
Hyperpolarization: -90mV
If a second stimulus is applied to generate an action potential, an action potential will not occur if the neuron is in which stage?
Absolute refractory period
A second stimulus can only generate an AP in the relative refractory period.
What happens when there is an influx of Ca2+ into a cell?
Causes vesicles to merge with membrane and release contents.
Seen in synaptic cleft as well as cortical reaction in embryology
What is the Excitatory Post Synaptic Potential?
Post-synaptic membrane depolarizes by opening Na+ gates
What is the Inhibitory Post Synaptic Potential?
When post-synaptic membrane hyperpolarizes by opening K+ gates letting K+ ions out and possibly Cl- ion in.
What are the inhibitory neuotransmitters and where do they act?
GABA in brain
Glycine in spinal cord
What are the layers of the epidermis (superficial to deep)?
Corneum - Lucidum (only on palms and soles) - Granulosum - Spinosum - Basal
What are Langerhans cells?
Found in deep layer of epidermis, interact with helper T-cells.
What are Merkel cells?
Attached to sensory neurons and work as mechanoreceptors.
What is collagen?
Fibrous protein present in tissue as a triple helix. Provides strength.
Most Abundant protein in the dermis for all mammals
Glycine is present in every 3rd amino acid.
What are the corpuscles present in the dermis?
Tactile (meissner) - sensitive to light touch
Lamellar (pacinian) - responds to deep pressure and vibration.