Physiology Flashcards
What is the role of histamine?
triggers inflammatory response and dilates blood vessels to increase blood flow and immune cells to damaged tissue
What are the roles of cytokines?
- fever rsponse
- activate B lymphocytes –> immunoglobin
Which cells are involved in allergic response?
basophils and eosinophils (granulocytes)
- also involved with parasites
What cells do MHCII and MHC I bind to?
- helper T cells (MHC I)
- cytotoxic T cells (MHC II)
What cells can produce a memory-driven response?
- B cells and T cells
Where does an antigen bind the antibody?
- N terminus of antibody
What structure focuses light in the eye on the retina?
Lens
- shape and focal length controlled by cilliary muscles
- focus image onto retina
What does the cornea do?
- focuses light rays
- at the front of the eye!
What are chondrocytes?
cells that synthesize cartilage
Differentiate osteoblasts and osteoclasts.
Osteoblasts: secretion of organic constituents of bone matrix. Mature into osteocytes
Osteoclasts: bone reabsorption, bone breaks down, Ca2+ release to blood
What are two methods of bone formation?
- endochondral ossification: chondro - cartilage - cartilage to bone
- intramembranous ossification: undifferentiated mesenchymal cells to bone
Yellow marrow vs Red Marrow
- yellow is inactive and infliltrated in adipose
- red blood formation
What are the circles of bony matrix called
lamellae
Osteon vs osteocye
Osteon is the concentric circle of bony matrix (lamellae) + the haversian canal
Osteocyte: bone cells - osteoblasts and osteocytes
Tetanus vs tonus
Tetanus: contractions of a muscle combine and are very strong and become continuous when stimuli so frequent, muscle cannot relax
Tonus: state of partial contraction; never fully relaxed
What is the point of attachment of a muscle to a stationary bone?
- origin
- proximal end of the muscle
What is the point of attachment of a muscle to the bone that moves?
- insertion
- distal end of muscle
What are chylomicrons?
lipid droplets
- transported from small intestine to blood (circulatory) via lymphatic system
Is osmosis active or passive process?
passive. (diffusion of water…)
In which system do hormones travel? circulatory/lymphatic
Circulatory
What are the 2 functions of the lymphatic system?
- collect excess interstitial fluid and return to circulatory to maintain balance of fluids
- absorb chylomicrons from small intestine and deliver to cardiovascular circulation
Is gas exhange a passive or active process?
passive
What is extracellular digestion?
molecules broken down outside of the cell
i.e. stomach churning; HCl acidic conditions to secrete pepsinogen
Where are carbs digested?
- mouth: salivary amylase
- stomach: NOPE (mechanical breakdown only)
- small intestine: pancreatic amylase, sucrase, lactase
What enzyme is involved in digestion of starch?
- amylase (salivary and pancreatic)
- starch to maltose
What are the stages of spermatogenesis?
spermatogonia 1 spermatocyte 2 spermatocyte spermatid spermatozoa
During ovulation, where is the egg released into from the ovary?
abdominal cavity (before fallopian tube)
Which embryonic germ layer is the reproductive system a part of?
Mesoderm
Which embryonic germ layer are nerves a part of?
Ectoderm
Which embryonic germ layer is the thyroid a part of?
Endoderm
At what stage does the embryo’s development become to differentiate into germ layers?
Gastrula - gastrulation
What are the four extra-embryonic membranes?
- amnion: amniotic fluid
- chorion: surrounds amnion (sac)
- allantois: blood vessels –> umbilical cord
- yolk: blood vessels
What are the parts of the adrenal gland and what do they produce?
- Cortex: mineral corticoids; sex hormones; corticol steroids
- Medulla: catecholamines (norepinephrines, a.a.)
Differentiate the anterior pituitary to the posterior pituitary
Anterior pituitary: stimulated by the hypothalamus to produce direct hormones
Posterior pituitary: hypothalamus produces hormones and stores it in the posterior. Oxytocin, ADH
How are plasma calcium levels affected?
- Calcitonin: thyroid -> decrease Ca2+ concentration; inhibit Ca2+ release from blood
- PTH: parathyroid –> raises Ca2+ concentration in blood; release Ca2+ in bone and decrease Ca2+ excretion out of blood in kidneys
antagonistic !!
What is the role of bile and where is it formed?
- bile emulsifies fats
- bile is synthesized in the liver
- released in the gall bladder
- therefore, gall stones - would inhibit digestion of fats
What is the main site of digestion?
small intestine:
- chemical digestion
- proteins, disaccharids, starch, fats/lipids all in small intestine
What digestion occurs in the stomach?
- protein digestion via pepsin
What digestion occurs in the mouth?
- salivary amylase
- starch to maltose (disaccharide)
What are some functions of the liver?
- breakdown a.a. to urea
- regulation of blood sugar levels
- detoxification of poisons
- storage of glycogen
- ## synthesis of angiotensinogen
Where are red blood cells formed?
red bone marrow
Where is erythropoietin mainly formed?
kidneys
What does bilirubin do?
- used in formation of bile salts
- formed in breakdown of rbc
- liver removes it from bloodstream
Endocrine vs exocrine glands.
Endocrine: hormones into bloodstream
Exocrine: chemical substances through ducts
Is glucagon a pancreatic exocrine or endocrine secretion?
- endocrine
- it helps increase blood glucose levels in response to low blood glucose
- degrades glycogen, decreases uptake by muscles
What are lacteals?
- part of small intestine villi
- villi have capillaries and lacteals
- lymphatic vessels
- large fatty acids and glycerol pass into lacteals (reconverted to fats) later empty into central circulatory system
- amino acids and glucose go into the bloodstream
What is the role of vitamin k in the digestive system and where?
- vitamin K is absorbed in the large intestine
Where is kidney filtrate produced?
- glomerulus from the blood (capillaries)
- enters the bowman’s capsule
What is the direction of reabsorption of water or solutes?
- filtrate in the nephron to the blood
Ascending limb _____ to water and ____ solutes
impermeable to water
absorb solutes
What happens if the the ascending limb is inhibited in the reabsorption of solutes?
- more solute will remain in the filtrate once in the DCT and collecting duct
- more solute = more water remains in filtrate; compensate to have same osmolarity
- more volume!
If protein is lost in the glomerulus, what is the consequence of the change in osmolarity?
- filtrate will have higher osmolarity, blood will have lower osmolarity.
- tissues in the body will have higher osmolarity than blood
- water/fluid moves from low osmolarity to high osmolarity (in terms of solute it moves from high osmolarity to low)
- therefore fluid moves to tissues - edema
What is another name for vasopressin? Where is it produced/stored?
- ADH
- produced in hypothalamus
- stored in posterior pituitary
- increases water reabsoprtion
Where is aldosterone produced? What is the role of aldosterone?
- adrenal cortex
- acts on DCT and collecting duct
- conserve sodium
- secrete potasium
- conserve water
- increase blood pressure
What hormones does the adrenal cortex produce?
- mineralcorticoids: aldosterone
- glucocoticoids: cortisol
- androgens: testosterone
What does vitamin D do?
- converted into active form by PTH, increases blood Ca2+ levels
- stimulates intestinal a2+ absorption
What does cortisol do?
- raise blood glucose levels
- gluconeogenesis
- deccrease protein synthesis
- reduce immune and inflammatory response
PTH increases/decreases blood calcium levels?
- increases blood calcium levels
- calcium in bone - osteoporosis ; via osteoClasts
- vitamin D; calcium absorption
Calcitonin increases/decreases blood calcium levels?
- decreases blood calcium levels
- deposits blood calcium to bone matrix
What part of the brain regulates temperature?
- hypothalamus
What happens to ACh in the synaptic cleft?
acetylcholinesterase inactivates acetylcholine by breaking it down in the synaptic cleft after it is released off the receptors of the post synaptic cleft
Ligaments vs tendons
- ligaments: bone to bone
- tendons: muscle to bone
Are action potentials intercellular or intracellular?
- intracellular
- action potentials cannot pass from one muscle fibre to the next
- it is intracellular with respecto to the release of Ca2+ in the SR to initiate the sliding of actin and myosin filaments = contraction
T- tubule? What happens here?
ACh enters and depolarizes t-tubule - signals SR release calcium
- nonfunctioning ACh receptor means no ACh received by t-tubule and therefore no muscular contraction
Where do B cells remain dormant?
- lymph nodes
- until activated by antigen - lymphocytes are specific to
What is the main function of activated B cells?
- produce antibodies to be secreted
- antibodies (4 protein subunits) - therefore more RER (secretory proteins)
Where do lymphocytes orginate?
- bone marrow! all blood cells originate in bone marrow!!
- lymphocytes can be found in spleen and lymph nodes but do not originate here
B cell vs T cell specific functions
- B cells: release antigen specific antibodies (humoral); surface antigens
- T cells: cell mediated (adaptive immunity) ; viral antigens outside infected cell (foreign); activates macrophages or directly attack
Hydrostatic pressure vs osmotic pressure
What happens in the capillary?
- high hydrostatic pressure pushes out solute
- high osmotic pressure pushes water out
- in the capillary: arteriole end: high hydrostatic pressure (solute out) (low osmotic pressure)
venule end: low hydrostatic pressure; high osmotic pressure: pushes water in
What is Starling’s hypothesis?
- capillary physiology
- hydrostatic/osmotic pressures
- not all fluid can be returned to vessel; fluid travels through interstitial spaces, picked up by lymphatic system, filtered through lymph nodes, returned to circulatory via thoracic duct
Which hormone, secreted only by fertilized embryo, functions to maintain the corpus luteum?
human chorionic gonadotropin maintains the corpus luteum. Previously, the corpus luteum is maintained by LH
External fertilization is asexual or sexual reproduction?
asexual reproduction
- fusion of female and male gametes when female deposits her eggs and male gametes fertilize somewhere in the environment
What does the pancreas produce? (digestive enzymes)
carboxypeptidase trypsin chymotrypsin lipase pancreatic amylase
Between the medulla and the loop of henle what has a higher concentration of salt? Which way does salt flow passively/actively?
loop of henle = low salt conc.
medulla = high salt conc.
- salt flows passively from high to low (medulla to henle)
- active transport of salt out of the loop of henle to the medulla
