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.
What are the lines of defense of the immune system?
1st: physical barriers (external)
2nd: Innate immunity (interna) - cellular defense
3rd: adaptive immunity - humoral and cell-mediated response.
What are the physical and chemical barriers of the immune system?
Skin
Antimicrobial proteins (saliva and tears)
Cilia (lungs)
Gastic juice (stomach)
Symbiotic bacteria (digestive tract)
Which are the primary cells of the adaptive immune system?
Lymphocytes: B & T Cells
Where do all leukocytes derive from?
Hemapoietic stem cells in bone marrow.
Which cells are phagocytes in the innate immune system?
Neutrophils - infected tissues
Monocytes - differentiate into macrophages or dentritic cells
Macrophages - professional APC
Dendritic cells - professional APCs (antigen presenting cells)
What are eosinophils?
Cells in the innate immune system, and are effective when dealing with multicellular pathogens.
They release granules that destroy pathogens
What are mast cells?
Cells in the innate immune system that function in allegic response, inflammatory response and anyphylaxis.
They release histamine
Found in connective tissues
What are basophils?
Cells in the innate immune system that are involved in inflammatory response by releasing histamine. They circulate in the blood stream.
What are NK cells?
Cells that function in both the innate and adaptive immune system.
They circulate in the blood and attack abnormal body cells, like tumors or pathogen-infected cells.
They release chemicals to destroy cell.
What are toll-like receptors (TLRs)?
They are present on the cell surface of immune cells and are used to recognize molecular patterns present on the surface of pathogens. (e.g flagella)
What are cytokines?
Chemical signalling molecules unsed in the immune response for cell-cell communication
What are interleukins?
Type of cytokine
IL-1 involved in inflammatory reaction
IL-2 triggers adaptive immune response.
What are interferons?
Type of cytokine.
Secreted by infected cells that stimulate neighboring cells to produce proteins to defend against virus
What is the complement system?
Innate response but can be activated by the adaptive immune system.
Inactive proteins in the circulatory system that when stimulated will result in a cascade that destory cells by lysis.
What are the steps of the inflammatory response?
- Release substances that increase blood flow to area.
- Macrophages and neutrophils will be drawn to site of injury
- Mast cells release histamine + cytokines from macrophages cause vasodilation.
- Blood vessels become more permeable, which allow more immune cells and prostaglandins to enter to aid in fighting infection and repair.
- Fever and pain is a result.
What is diapedesis?
The process by which leukocytes enter tissues as part of inflammatory response.
What are the types of signalling in the body?
Endocrine - hormones are deposited in the blood stream
Exocrine - substances secreted throught ducts
Paracrine - cell signaling to a target nearby (neuromuscular junction)
Autocrine - cell signaling binding to receptors on same cell (t cells - IL - cause itself to multiply)
What are the types of hormones?
Peptide
Steroid
Tyrosin-derivative
Where are peptide hormones synthesized?
Rough ER
How do peptide hormones work?
They act on cells by binding to surface receptors and stimulating secondary messenger systems - they do not enter the cell. They move through blood since they are water soluble.
What are the secondary messengers?
They are part of the cells intercellular communication system. They allow signals from outside of cells to be transferred throughout the inside of the cell.
What are four important secondary messengers?
cAMP
Inositol trisphosphate - IP3
Diacylglycerol - DAG
Calcium
How do secondary messengers work?
- Ligand binds to a receptor
- Receptor is activated turning on its associated G-protein
- G-protein activates secondary messenger molecules
- Secondary messegners activate signaling cascade
- Signalling cascade triggers ceullular response -> transcriptional factors, gene activation
What is the cAMP pathway?
- Ligand binds to G protein receptor and activates G Protein (GDP -> GTP)
- G Protein activates Adenylyl Cyclase
- Adenyly cyclase converts ATP -> cAMP
- cAMP activates Protein Kinase A
- Protein Kinase A triggers cellular response
What is the IP3 pathway?
- Ligand binds to G protein receptor and activates G Protein (GDP -> GTP)
- G Protein activates Phospholipase C
- Phospholipase C cuts PIP3 into two separate molecules: DAG and IP2
- IP3 diffuses through cytoplasm and binds to receptors on ER
- Calcium is released from ER into cytoplasm
- Calcium binds to proteins to activate them
- Activated proteins trigger a cellular response.
What is the DAG pathway?
- Ligand binds to G protein receptor and activates G Protein (GDP -> GTP)
- G Protein activates Phospholipase C
- Phospholipase C cuts PIP3 into two separate molecules: DAG and IP2
- DAG activates Protein Kinase C
- Protein Kinase C triggers a cellular response.
Growth factors
Protein molecules (not hormones) synthesized in the rough ER. Also use secondary messenger pathways.
What are steroid hormones?
Homrones synthesized from cholesterol in smooth ER. They can pass through cell membranes and bind to intracellular receptors in the cytoplasm or nucleus.
What is direct stimulation by steroid hormones?
Hormone binds to receptor to form hormone-receptor complex.
The complex binds to activate DNA -> alter gene expression
What kind of hormones are produced by the Adrenal Cortex and what are they?
Cortisol and Aldosterone
Steroid Hormones
What kind of hormones are produced in the gonads and what are they?
Steroid hormones.
Females: Estrogen and Progesterone
Males: Testosterone
What are amino acid (tyrosine) derivative hormones?
Hormones derived from single amino acids. 2 broad categories:
1. Thyroid homrones (like steroid)
2. Catcholamines (hydrophilic and bind to extracellular receptors)
What are the thyroid hormones?
T3 - triiodothyronine
T3 - thyroxine
Hydrophobic and act like steroid hormones
Which is the primary way that the body maintains homeostasis?
The negative feedback loop which decreases the production of a process.
What are the catecholamines?
Epinephrine and norepinephrine
Hydrophilic, bind to cell surface receptors.
These are neurotransmitters as well but when they are secreted into the blood stream they act as hormones.
A common example of a positive feedback loop in the body
Milk production:
1. stimulus: baby sucking nipple
2. hypothalamus is stimulated to send signal to posterior pituitary gland
3. Posterior pituitary gland releases oxytocin
4. Oxytocin stimulates milk ejection from mammary glands
5. Milk is released and baby continues to feed.
What does the hypothalamus do?
Maintains homeostasis
Monitors internal and external environment
Links endocrine and nervous system.
Hypothalamus has what kind of connection to posterior pituitary gland?
Neuronal connection
1. hypothalaumus produce hormones in neuronal cell bodies
2. hormones are packaged into vesicles and transported down axons to PPG
What kind of connection does the hypothalamus have with the anterior pituitary gland?
Vascular connection
1. hormones synthesized in neuronal cell bodies of hypothalamus
2. hormones released into capillary network in hypothalamus
3. hyphophyseal portal veins transport to APG
What hormones are produced by the hypothalamus? (8)
ADH (stored in the PPG)
Oxytocin (stored in the PPG)
Gonadotropin-Releasing Hormone (GnRH)
Corticotropin-Releaseing Hormone (CRH)
Thryotropin-Releasing Hormone (TRH)
Growth Hormone-Releasing Hormone (GHRH)
Somatostatin (Growth Hormone-Inhibiting Hormone)
Dopamine (Prolactin-Inhibiting Hormone)
The releasing hormones stimulate APG to release hormones
Inhibing hormones inhibit release of hormones in APG
What is the difference between tropic and non-tropic hormones of the APG?
Tropic hormones act indirectly by regulating other organs to release their own hormones. Non-tropic act directly on their target tissue.
What are the nontropic hormones of the APG?
Melanocyte-Stimulating Hormone (MSH) - stimulates melanocytes to release melanin
Prolactin - stimulates milk production in the mammary gland cells
Growth hormone - stimules bone and muscle growth
What are the tropic hormones of the APG?
Thyroid-stimulating hormone (TSH) - stimulates thyroid gland to secrete T3 & T4
Adrenocorticotropic hormone (ACTH) - stimulates adrenal cortex to release glucocortioids (cortisol)
Follicle-stimulating hormone (FSH) - in males: stimulates testes to undergo spermatogenesis. in females: stimulates ovarian follicles to release estrogen.
Luteinizing hormone (LH) - in males: stimulates testes to release testosterone. in females: triggers ovulation, corpus luteum formation, progesterone release.
What kind of hormones does the APG produce?
Peptide hormones
What does ADH do?
Peptide hormone
Regulates water levels in the body by INCREASING permeoability of the collecting duct and DCT which then INCREASES reabsorption of water to INCREASE blood volume and pressure.
Released by the PPG
What is oxytocin
Peptide hormone
Secreted during childbirth to stimulate uterine contractions
Stimulates milk ejection from mammary glands.
Released by the PPG
What hormone is secreted by the pineal gland and what kind is it?
Melatonin which helps regulate the circadian rhythm and is an amino-acid derived hormone.
What hormones are produced by the Thyroid and what kind are they?
Tyrosine-derivative hormones (hydrophobic)
Triiodothyronine (T3)
Thyroxine (T4)
Increase body metabolism and heart rate
Peptide hormone
Calcitonin - tones down calcium in blood, and builds up calcium in bones (inhibits osteclast activity and promotes osteoblast activity)
Iodine is critical to making T3 & T4
What is a goiter?
Enlargement of the thyroid gland caused by hyper- and hypothyroidism
What hormone is produced by the parathyroid and what kind is it?
Peptide hormone
Parathryoid Hormone (PTH) - raises calcium levles in the blood by stimulating osteoclast activity. Increases kidney reabsorption of calcium. Converts Vitamin D to active form which increases calcium absorption.
Lowers phosphate leverls (increase phosphate excretion)
Opposite calcitonin
What hormone is produced by the thymus and what kind is it?
Peptide hormone
Thymosin - stimulates naive T-lymphocytes to mature and differentiate into functional T-cells
What hormones are produced by the adrenal cortex (outer portion) and what kind are they?
Steroid hormone
Glucocorticoids
Mineralocorticoids
Cortical androgens (male & female sex hormones in small amounts)
What hormones are produced by the Adrenal medulla and what kind are they?
Tyrosine-derivative hormones
Epinephrine & Norepinephrine
* stimulate sympathetic nervous system - fight or flight
What are the glucocorticoids produced in the adrenal cortex?
Cortisol and Cortisone (stress hormones)
* Stimulate gluconeogenesis in liver increasing blood glucose levels
* Break down proteins and fats for energy
* Suppress functions like immune system and growth
What is the mineralocorticoid hormone produced in the adrenal cortex?
Aldosterone
* Causes body to reabsorb of Na+ and excretion of K+
* Increases water retention and blood pressure
What are the hormones produced by the pancreas and what kind are they?
Peptide hormones
Glucagon - secreted by alpha cells and increases blood glucose levels by stimulated glycogenolysys and gluconeogenesis in liver
Insulin - secreted by beta cells and lowers blood glucose levels by inhibiting glycogenolysis and glyconeogenesis and stimulating glycogenesis.
Somatostain - (also released by hypothalamus) secreted by delta cells which inhibits insulin and glucagon, supresses GI hormones and gastric motility
What are prostaglandins?
Not a hormone.
Found in semen to contract uterine walls to help sperm reach egg
Placenta releases to exite uterus to induce labor
Enhances sensitivity to pain (aspirin blocks synthesis)
What are the layers of the oocyte superficial to deep?
Corona radiata - protective layer
Zone Pellucida (vitelline membrane in non mammals) - glycoproteins ZP1, ZP2, ZP3, ZP4
Perivitelline Space - prevents polyspermy
Plasma Membrane
ZP3 prevents cross species fertilization
What is capacitation of sperm?
- Glycoprotein coat removal
- Destabilization apical plasma membrane to expose acrosome
- Hyperactivation
Stimulated by enzymes of uterus
What is the fast block to polyspermy?
When the sperm fuses with the egg, sodium channels open and depolarize the egg from -70mV to +20mV
What is hololastic cleavage?
Cells divide into equal part same sized blastomeres.
Happens in mammals since we don’t depend on yolk for nutrients
Cell undergoes only partiual unequal cleave resulting in different sized blastomeres
Happens in birds and reptiles since all their nutrients come from yolk
Protostomes undergo what kind of cleavage?
Determinant and spiral
Deuterostomes undergo what kind of cleavage?
Indeterminant and radial
