Foundation 3B: Organ Systems

lymphatic system's role in immunity

- B and T cells of the adaptive immune system react to specific invaders (bacteria, viruses, etc.) and are located in the lymph nodes - bacteria, viruses, and macrophages carrying invaders can enter lymphatic vessels and travel to the lymph nodes which filter the fluid before it re-enters the blood • blood infections are way more severe than local, tissue infections - lymph nodes are very small (1-25mm) and dispersed through the body (~600) • b/w thigh and abdomen • neck, clavicles, face, and jaw • arms - all lymph will pass through at least one lymph node to be filtered before re-entering the bloodstream

activating angiotensin II

- angiotensinogen is made by liver cells and dumped into blood vessels • large inactive molecule made of 450+ amino acids - when angiotensinogen meets with renin (released by JG/granular cells) it cuts off a large chunk of angiotensinogen, leaving only 10 amino acids called angiotensin 1 - angiotensin 1 flows through blood vessel endothelial cells which have angiotensin-converting enzymes (ACE) that cut off two amino acids creating angiotensin 2 - angiotensin 2 contains eight amino acids and is very active

regulation of muscle contraction

- availability of myosin-binding sites on actin is regulated by troponin and tropomyosin to avoid continuous muscle contraction - tropomyosin coils around actin to block myosin-binding sites - troponin holds tropomyosin in place on actin - nerve impulse triggers the release of Ca²⁺ which causes conformational changes to tropomyosin-troponin complex exposing myosin-binding sites - Ca²⁺ binds to troponin to change its conformation, causing tropomyosin to move, allowing myosin to bind to actin > muscle contraction • low Ca²⁺ concentration = Ca²⁺ released from troponin and tropomyosin blocks myosin from binding > muscle relaxation

the Haversian system

- cancellous bone: spongy bone that's a porous network of spikes surrounding the innermost portion of bone marrow • serves to make the bone lighter • structure gives it a large surface area - compact bone: denser layer that surrounds spongy bone • made of osteons or the haversian system osteons: shaped like a cylinder and contains multiple layers of bone called a lamellae - haversian canal: center of lamellae that blood vessels, lymph vessels, and nerves travel through • a direct way for things like medication to reach the bone (ex for treating osteoporosis) - canaliculi: b/w lamella and surround lacunae - lacunae: empty space for osteocytes or bone cells - osteocytes: bone cells with long processes that branch through canaliculi to contact other osteocytes for communication - Volkmann's canals: run perpendicular to Haversian canals • connect osteons to one another - carry small blood vessels - periosteum: outermost layer of bone

smooth muscle

- innervated by the autonomic nervous system, meaning that it is not under voluntary control - found throughout the body, including the digestive tract, where it is responsible for peristalsis, as well as blood vessel walls, the bladder, the uterus, and other locations - non-striated because it does not contain well-organized, linear myofibrils (although it does contain actin and myosin filaments that engage in contraction) - smooth muscle cells contain only one nucleus, which is found towards the center of the cell

skeletal muscle

- innervated by the somatic nervous system, meaning that it is under conscious control - striated, which means that it has extensive linear myofibrils that form striations when viewed with a microscope - myocytes in skeletal muscles have multiple nuclei on the periphery of the cell, as they are formed via the fusion of multiple precursor cells - two different types of fibers within skeletal muscles: red fibers (slow-twitch fibers) and white fibers (fast-twitch fibers) • red fibers obtain their color from the presence of abundant reserves of myoglobin, and are also rich in mitochondria; prefer oxidative metabolism, and therefore are present in large quantities in muscles that specialize in performing less intense actions over a longer period of time • white fibers tend to mobilize glycogen for quick bursts of intense action followed by fatigue

ligaments, tendons and joints

- ligaments: extra strong, dense connective tissue that connect bones to other bones - tendons: extra strong, dense connective tissue that connect muscles to bone - joint: place where a bone articulates/meets up with another bone • bones lined by articular cartilage, a special type of hyaline cartilage, which is avascular which makes it hard to overcome damage from infection/overuse • overuse of joints can lead to arthritis (inflammation of joints) and permanent destruction of articular cartilage - types of joints: 1. synarthroses: immovable joints; bones are fused together - found in skull; separate during development, fuse during growth 2. amphiarthroses: stiff, but slightly moveable - ex: vertebral joints 3. diarthroses/synovial joints: lubricated by synovial fluid contained in the synovial capsule that surrounds the joint - ball and socket: have many degrees of motion • found in shoulder and hips - hinge joint: moves in one plane, like a door hinge • elbow and knee

functions of the colon

- mainly absorbs water • too little absorption = diarrhea • too much absorption = constipation - absorbs inorganic ions like Na⁺ and K⁺ - rich source of microorganisms like bacteria that assist in the digestion of nutrients that we aren't able to bc we don't have the enzymes • often carbs which result in CH₄ and H₂S (smell) by-products

teeth and digestion

- mandible = lower jaw bone - maxilla = upper jaw bone - gingiva = gums - central incisor (4): mainly used for cutting food - lateral incisor (4): also used for cutting food - canines (4): aka fangs; sharpest and longest teeth we have used for gripping food - premolars (8): used to grind food - molars (12): also used to grind food • 3rd molars = wisdom teeth - only 28% of people have wisdom teeth; 72% of ppl have them removed bc they cause gingiva pain that can lead to inflammation or infection

motor nerves and muscle groups controlled by respiratory center

- motor nerves C1-C3 control the accessory muscles around the neck area - motor nerves C3-C5 control the diaphragm - motor nerves T1-T11 control intercostal muscles which expand the ribs - motor nerves T6-L1 control abdominal muscles

how do WBCs/leukocytes move through the body?

- neutrophils (phagocytes) circulate in the bloodstream - macrophages (phagocytes) circulate in the tissue phagocytize pathogens and release chemicals that alert the endothelial cells lining the blood vessels - endothelial cells express proteins that attract neutrophils so they can squeeze through the blood vessels to the tissues to help phagocytize the pathogens • phagocytized pathogens become puss - neutrophils only ever travel from the bloodstream to the tissues, not from tissues to bloodstream - macrophages and neutrophils from the tissues will travel through lymph vessels to the lymph nodes to present antigens to B and T cells • B and T cells are made in the Bone marrow and Thymus and travel straight to lymph nodes; don't normally hang out in tissues - once filtered, lymph will dump back into the blood and the process will start over

kidney anatomy

- renal cortex: shell of the kidney - renal medulla: middle of the kidney - nephron: functional unit of the kidney responsible for filtration and collection; located in both the renal cortex and medulla - renal calyx/ces: collects urine and brings it to the renal pelvis - ureter: sends urine away from the kidneys into the bladder - hilum: where the renal vein, artery and ureters exit the kidney

lung contraction and recoil

- sternum attaches 7 of the 12 pairs of ribs (14 of 24) - intercostal muscles in between each rib that contain nerves allowing them to contract causing the ribs to move outward when we inhale - diaphragm muscle contracts, causing it to flatten from a dome to a floor-like structure, allowing the heart and lungs to move down - alveoli expand and stretch by their elastin proteins or are recoiled, shrinking them when exhaling - muscle contraction requires energy from ATP and recoil requires elastic potential energy from elastin proteins

angiotensin II target organs/glands

1. blood vessels - causes smooth muscles to constrict; vasoconstriction - "angio" (blood vessel) "tensin" (tense) - increases resistance; ΔP = Q x R (Pₐ - Pᵥ = (SV x HR) x R) • increase in resistance = increase in pressure - this is done rapidly 2. kidneys - causes sodium reabsorption, which also causes the kidney to absorb water - concentrated urine and sodium/water to the bloodstream which increases stroke volume - ΔP = Q x R (Pₐ - Pᵥ = (SV x HR) x R) • increase in stroke volume (SV) = increase in pressure - this is done slowly 3. posterior pituitary gland - causes it to release ADH (antidiuretic hormone) which causes vasoconstriction from water reabsorption in the kidney • water channel/aquaporin approach; works in areas of kidney that are not permeable to water - having the same effect as sodium absorption; increased stroke volume 4. adrenal cortex - causes it to release aldosterone which causes sodium reabsorption in the kidney as well all of these things increase blood pressure

clonal selection

1. cell division - B cells divide into daughter cells with DIFFERENT receptors in the Bone marrow due to shuffling of DNA • receptors bind to specific pathogens - T cells divide into daughter cells with DIFFERENT receptors in the Thymus due to shuffling of DNA • these receptors bind antigens by APCs 2. B and T cells migrate to lymph nodes; infection occurs and the correct B and T cells are alerted and activated 3. clonal selection: activated B and T cells begin replicating - some will become effector cells that are immediately ready to fight and some will become memory cells - creates an army of specific B and T cells that travel from the bone marrow or thymus to the lymph nodes

types of bones

1. flat bones - serve to protect organs and as a site of hematopoiesis - made of inner spongy (cancellous) bone and an outer shell of compact bone - ex: skull, ribs, pelvis 2. long bones - serve as a framework for movement and a site of hematopoiesis - made of inner spongy (cancellous) bone and an outer shell of compact bone - diaphysis: long, middle portion - epiphysis: end portion - metaphysis: part between the diaphysis and epiphysis that contains growth plates in children - ex: femur and humerus

anatomy of nephron (6)

1. glomerulus: coiled structure of capillaries that receives afferent arterioles from the renal artery - filters blood; makes filtrate and lets the rest (RBC, WBC, big proteins) pass through the efferent arteriole 2. proximal convoluted tubule: part of the nephron that connects the glomerulus and loop of Henle - important for reabsorbing ions like Na⁺, Cl⁻, and other nutrients: amino acids, Glc, and water 3. loop of Henle - descending limb: dives deep to the salty renal medulla • reabsorbs water; impermeable to ions - ascending limb: rises back up to the renal cortex • reabsorbs Na⁺, Cl⁻, K⁺; impermeable to H₂O - countercurrent multiplication: descending and ascending limb flow in opposite directions; specific permeability of each limb allows renal medulla to become salty to then absorb water passively 4. distal convoluted tubule: responsible for reabsorption of ions like Na⁺, Cl⁻ that we don't want to pee away - juxtaglomerular apparatus: where the distal convoluted tubule meets the glomerulus; controls BP 5. collecting tubule: collects leftover products in the lumen of the nephron to create urine - several distal convoluted tubules feed into one collecting tubule - reabsorbs water and urea (sometimes to maintain osmolarity) 6. peritubular capillaries: tiny blood vessels that run parallel to and surround the proximal and distal tubules of the nephron, as well as the lopps of Henle, where they're called the vasa recta - vasa recta is important for countercurrent exchange, the process that concentrates urine - connects afferent arterioles to renal vein average adult human kidney contains 1,000,000 nephrons

how does lymph re-enter the high-pressure circulatory system?

1. location of re-entry: re-enters at the end of the venous circulation which is very low in pressure (5 mmHg) compared to the arteries (120 mmHg) and even capillaries - subclavian veins (2) > superior vena cava > heart 2. valves: structures within the lymph vessels that prevent fluid from moving backward - fluid can move forward, not back - same principle used in the heart and veins 3. smooth muscle: surrounds lymphatic vessels and contracts to cause movement of fluid forward 4. skeletal muscle: random squeezing of certain parts of the body which starts motion by chance

functions of the liver (5)

1. metabolism (catabolism and anabolism) 2. storage (mainly of carbs and fats) - carbs stored as glycogen - carbs/fats can be stored as lipoproteins - fats stored as triglycerides 3. processes proteins into molecules that are sent to the bloodstream to carry out other functions until they need to be retrieved by the liver 4. detoxification by cytochrome p450 enzymes (don't bind a specific substrate; bind to multiple!) - decreases drug efficacy bc the enzymes recognize the foreign substance and break it down; specific does given to counteract 5. production of bile which is needed for the absorption of fat from food

diabetes mellitus

A condition in which the body is unable to produce enough insulin, the hormone required for the metabolism of sugar - eye, nerve, and kidney disease: excess glucose causes vision problems, nerves (most commonly in feet) unable to sense sensations, and kidneys can stop working leading to dialysis - two types: 1. type 1 diabetes: caused by absence of insulin production - not able to store glucose into glycogen at all 2. type 2 diabetes: insulin receptors are broken

self vs non-self immunity

B and T cell receptors that will become antibodies are generated at random, which makes it possible for them to attack our own cells - no way to prevent this from occurring since the process of B and T cell differentiation is completely random - solution 1: when B/T cells recognize human molecules by binding to a protein like insulin or hemoglobin, they will self-destruct in the bone marrow/thymus before traveling to the lymph nodes • central tolerance: lymphocytes that do not receive survival signals undergo apoptosis - solution 2: occurs if solution 1 fails; B cells require T cells to activate them, so you'd need both a B and T cell to travel to the lymph node for the body to attack itself - autoimmune disease: immune system attacks itself; when solutions 1 and 2 fail

Fick's Law of Diffusion

V = ((P₁ - P₂) A • D) / T - V = rate of particles moving • amount (moles) or volume - (P₁ - P₂) = bigger pressure difference = more molecules moving - A = surface area - D = diffusion constant ( solubility / √MW ) - T = thickness - diffusion through a membrane is directly proportional to the surface area and concentration gradient and inversely proportional to the thickness of the membrane and its resistance V/A = ((P₁ - P₂) / T) • D - V/A = flux: NET rate of particles moving through an area - ((P₁ - P₂) / T) • D = gradient: change in pressure (particles in a volume) over a distance how to maximize amt of particles over time: - decrease the thickness of the wall - reduce MW (Graham's law) • smaller MW molecules have a faster diffusion rate - increase pressure of particles (∆P), area (A) or diffusion constant (D)

immune system

a complex response system that protects the body from bacteria, viruses, and other pathogens 1. nonspecific/innate immunity: - first line of defense (barriers): skin, hair, mucous membranes, stomach acid, etc. - second line of defense: inflammatory response and phagocytes 2. specific/adaptive immunity: - lymphocytes • B cells: humoral response • T cells: cell-mediated response

tonicity

ability of a solution surrounding a cell to cause that cell to gain or lose water - capability of a solution to modify the volume of cells by altering their water content - movement of water into a cell can lead to hypotonicity - movement of water out of a cell can lead to hypertonicity - isotonic = equal movement of H₂O into and out of a cell

thorax

air (specifically oxygen) travels through the mouth or nose to the Adam's apple (voice box), through the trachea then to the right and left lungs - right lung has 3 lobes: upper, middle, lower - left lung has 2 lobes (upper and lower) and a cardiac notch where the heart pushes it over - ribs and rib muscles surround the lungs and heart (walls) - diaphragm makes the floor that the heart and lungs sit on - thorax = heart, lungs, ribs, rib muscles, and diaphragm

mouth and digestion

aka oral cavity or buccal cavity - overall goal is to convert food to a bolus or a sphere of food that is easier for us to digest - two main steps: 1. chewing/mastication: physical breakdown by the teeth and tongue - tongue/lingula: made of two types of muscles; extrinsic and intrinsic • extrinsic muscles are located around the outside and allow us to elevate or depress the tip of our tongue, protrude it out and retract it in our mouth • intrinsic muscles are located interiorly allowing us to shorten and widen, lengthen and narrow our tongue 2. hydrolysis: enzymatic breakdown - enzymes come from glands that contribute components to our saliva and allow us to taste - glands can release: • serous content: things rich in enzymes that cut food • mucinous content: contain mucin that wet the food

anatomy of the colon

aka the large intestine - begins after the ileocecal valve at the end of the small intestine called the cecum - cecum contains the appendix - right/ascending colon - transverse colon: runs transversely; connects ascending and descending - descending colon: descends to the sigmoid colon - sigmoid colon: 's' shape before reaching the rectum - rectum: end of the colon that functions to store stool until before it's expelled through the anus

aldosterone and ADH on blood volume and osmolarity

aldosterone - works on part of the nephron that are permeable to H₂O - pulls Na⁺ into blood and pushing K⁺ into urine - Na⁺ is not permeable to membranes; contributes to tonicity - K⁺ can slightly cross membranes - sodium-potassium pumps activated by aldosterone increases tonicity allowing H₂O to follow Na⁺ and cross the membrane - increases osmoles and volume, although osmolarity is not affected bc osmolarity = osmoles/volume • if both are increased, the ratio remains the same - use if you want to increase volume, but maintain osmolarity ADH - acts on parts of the nephron that are NOT permeable to H₂O; relies on aquaporins - increases volume and decreases osmolarity bc osmolarity = osmoles/volume - use if you want to increase volume, regardless of osmolarity - use is you want to decrease osmolarity, regardless of volume must increase ADH and decrease aldosterone if you want to decrease blood osmolarity and maintain blood volume - work together to maintain osmolarity and volume

blood cell lineages

all blood cells come from bone marrow and share the same pluripotent hematopoietic stem cell - pluripotent stem cell: capable of giving rise to several different cell types two main lineages: 1. myeloid lineage - RBC and megakaryocytes (buds off platelets) - immune cells: monocytes, mast cells (release histamine), granulocytes (neutrophils, eosinophils, and basophils) • monocytes circulate in the blood before differentiating into macrophages or dendritic cells that live in the tissue 2. lymphoid lineage (immune cells) - B cells, T cells, and natural killer (NK) cells - dendritic cells

micturition

another term for urination - concentrated urine in nephron goes from the renal calyx to the renal pelvis which leaves the kidney through the ureter - ureters from both kidneys connect at the bladder • have valves that prevent backflow of urine - bladder is lined with transitional epithelium; in between squamous (flat) and columnar (tall) epithelial cells which allow the bladder to expand - bladder leads to the urethra • internal urethral sphincter: smooth muscle that makes sure the bladder doesn't leak out urine; don't have control of it (involuntary = smooth muscle) - prostatic urethra: only males have this; passes through the prostate - external urethral sphincter: membranous urethra made of skeletal muscle which we voluntarily control (after potty training); males and females have this - spongy urethra: part of the urethra in the penis; only males have - women are more likely to get UTIs bc we have a shorter urethra which functions to expel bacteria

ADH secretion and triggers

antidiuretic hormone - supraoptic nucleus in the hypothalamus is a collection of nerve somas that extend through the infundibulum to the posterior pituitary gland - ADH sent from the supraoptic nucleus to the posterior pituitary - ADH is a 9 amino acid peptide hormone triggers to release ADH to capillaries in the posterior pituitary 1. high blood concentration; high osmolarity (salty) - osmolarity: measured in osm/L - osmoreceptors range from 260-320 osm/L - want to be b/w 280-300; below 280 = dilute blood; above 300 = salty - most important/major function! 2. low blood volume - nerve endings in the superior and inferior vena cava recognize when blood volume is low - venous system detects information about blood volume by nerve endings detecting stretch or slack in veins 3. decrease in BP - baroreceptors in aortic arch and carotid sinuses detect low BP 4. presence of angiotensin 2 - signal to nerves that BP is low

respiratory center

areas of the brain that control breathing brain stem: - central chemoreceptors: located in the brain and gather information about CO₂ and pH levels - peripheral chemoreceptors: located outside the brain and send info through neurons that extend through the brain • detect O₂, CO₂ and pH levels • aortic body extends through neurons to the vagus nerve (CN (cranial nerve) 10) • carotid body extends through neurons to the glossopharyngeal nerve (CN 9) - mechanoreceptors: send information ab pressure from nose, lunges, GI tract, etc to the brain through the vagus or trigeminal nerve (CN 5) hypothalamus: - changes breathing pattern based on anxiety, fear or pain cerebrum: - controls voluntary actions like: singing, yelling, screaming

biliary tree

bile is composed of two things 1. pigments that give it its color, not important for function 2. bile salts: how we emulsify fats into micelles which can then be absorbed in the ileum once bile is produced it leaves through the common hepatic duct to the cystic duct which temporarily stores it in the gallbladder - only purpose of the gallbladder is to store bile - the hormone cholecystokinin (CCK) causes the gallbladder to contract, squeezing the bile out and through the cystic duct to the common bile duct before it reaches the duodenum of the small intestine - bile emulsifies fat in the duodenum and the bile salts travel to the ileum to be absorbed - then bile salts are circulated back to the liver to be recycled

bronchial tree

branched airways that lead from the trachea to the microscopic air sacs called alveoli - different branches serve different lobes (upper, middle, lower) - air reaches the alveoli, O₂ enters the blood, CO₂ exits the blood and enters the alveoli to exit through exhaling

creatinine

breakdown product of creatine phosphate from muscle and protein metabolism - nitrogenous waste excreted in the urine - removed from the body entirely by the kidneys - rate of urinary excretion should equal the rate of glomerular filtration for molecules that the body does not want to reabsorb under any circumstance (waste products like creatinine)

Henry's Law

concentration = P • Kₕ -Kₕ: constant that represents the likelihood of molecules exiting a liquid - partial pressure (P): likelihood of molecules entering a liquid - concentration: solubility of the gas - relationship between p and concentration within a liquid

conducting vs respiratory zone

conducting zone: - series of tubes through which gases travel - nose, pharynx, larynx, trachea, bronchi, and bronchioles - provide a route for incoming and outgoing air, remove debris and pathogens from the incoming air, and warm and humidify the incoming air respiratory zone: - areas that directly participate in gas exchange - found deep inside the lungs and is made up of the respiratory bronchioles, alveolar ducts, and alveoli - thin-walled structures allow inhaled O₂ to diffuse into the lung capillaries in exchange for CO₂

mechanism of myosin and actin

contractile and motor proteins that interact to produce mechanical force - myosin uses ATP to crawl along actin 1. ATP binds to myosin head causing myosin to release from actin 2. ATP hydrolyzes to ADP + Pi releasing energy to change to a high-energy conformation of myosin ready to move along actin 3. ADP and Pi released from myosin, causing a power stroke 4. ATP binds to myosin, causing a detachment from actin

absorption in the small intestine

digestion = polymers > monomers - most likely occurs in the jejunum 1. amino acids shuttled into enterocytes (intestinal cells) using primary (ATP) active transport - next AA will leave the enterocyte and enter a capillary so it can be sent through the bloodstream 2. monosaccharides shuttled into enterocytes using secondary active transport using an ion gradient - sodium ion flows into an enterocyte, down its concentration gradient - next MS will leave the enterocyte and enter a capillary so it can be sent through the bloodstream 3. nucleotides shuttled into enterocytes using primary (ATP) active transport - next they leave the enterocyte and enter a capillary so it can be sent through the bloodstream 4. fatty acids are able to passively diffuse across the membrane into enterocytes - once they enter, they're reorganized into chylomicrons which are too big to fit in capillaries - instead, they're absorbed in lymphatic capillaries, or lacteals, where they're further digested until they reach the veins and enter circulation

renin production

distal convoluted tubule contains maxilla densa cells - smooth muscle cells, juxtaglomerular (JG) cells, and mesangial cells surround the afferent arteriole • JG cells are specialized smooth muscle cells full of granules, so they're sometimes called granule cells • mesangial cells provide support and structure juxtaglomerular apparatus = goal is to release renin; made of maxilla densa cells, smooth muscle cells, juxtaglomerular cells, and mesangial cells - granules of JG cells contain renin which travels to the afferent arteriole, through the glomerulus to the efferent arteriole (A comes before E) - triggers for renin release: 1. low BP directly sensed by JG cells 2. sympathetic nerve endings that sit on JG cells; cause renin to be released when fired 3. macula densa cells that sense sodium - low sodium = low BP in glomerulus - send prostaglandins to JG cells

aldosterone effects

effects the principle cells of the late distal convoluted tubule and collecting duct of kidneys (alDosterone > Distal tubule and collecting Duct) - principle cells: line the distal convoluted tubule and collecting duct; peritubular capillaries sit next to them • basolateral surface: space between principle cells and peritubular capillaries • apical surface: separation b/w principle cells and urine - principle cells contain a lot of K⁺, and blood contains a lot of Na⁺ (main ions, not only ions) - sodium-potassium pumps on the basolateral surface which uses ATP to pump 3 Na⁺ to the peritubular capillaries and 2 K⁺ to the principle cells effects: 1. drives sodium-potassium pump to work harder; more Na⁺ in blood & more K⁺ in principle cells 2. inserts potassium channels on the apical surface allowing K⁺ to leave the principle cells and enter the urine - makes the blood lose potassium; trigger for aldosterone production = excess potassium 3. inserts sodium channels on the apical surface allowing Na⁺ from urine to enter principle cells and then be pumped into the blood by sodium-potassium pumps on the basolateral surface - makes the blood gain Na⁺ which then causes water to enter the blood, leading to increased stroke volume and increased BP

CD4 and CD8 proteins

either can be located on T cells - CD4 proteins are attracted to MHC-II complexes, so most CD4⁺ T cells are helper T cells • MHC-II is mostly expressed by antigen-presenting cells such as monocytes, macrophages, and dendritic cells - CD8 proteins are attracted to MHC-I complexes, so most CD8⁺ T cells are cytotoxic T cells • every nucleated cell has MHC-I

oral cavity glands (4) and functions

enzymes come from glands that contribute components to our saliva and allow us to taste - glands can release: • serous content: things rich in enzymes that cut food • mucinous content: contain mucin that wet the food 1. parotid: serous glands that makes up 25% saliva; releases ⍺-amylase that breaks down starch to smaller carbs 2. submandibular: serous glands that makes up 70% saliva; releases ⍺-amylase that breaks down starch to smaller carbs 3. sublingual: mucinous gland that makes up 5% of saliva; releases mucin 4. Von Ebner's: serous gland that makes up <5% saliva; releases lingual lipase that breakdown triglycerides into FFA, DG, and MG

cartilage and types (3)

extracellular connective tissue found throughout the body secreted by chondrocytes - chondrocytes are derived from fibroblasts, the same precursor cells as bones - chondrocytes make collagen (fibrous protein) and elastin (elastic protein); building blocks of cartilage that give it strength and flexibility - not innervated and avascular; instead receives nutrition and immunity from the surrounding fluid - three main types: 1. hyaline cartilage: - reduce friction and absorb shocks - found in the larynx, trachea, other parts of throat and joints (specifically called articular cartilage) 2. elastic cartilage: - provides shape and support - found in outer ear and epiglottis (protects airway when swallowing food) 3. fibrous cartilage: - provide rigidity and absorb shocks - found in intervertebral discs and pubic symphysis

lymph

extracellular fluid squeezed through capillaries to the lymphatic vessels - made of: water, small proteins (albumin), WBCs (lymphocytes) - does not contain RBCs or large proteins (immunoglobulin) - less protein in lymph than in blood which is important for blood's osmotic pressure that draws some lymph back into the venules - produce ab 3 L of lymph per day

duodenum

first and busiest part of the small intestine - most digestion occurs here compared to all other parts of the GI tract 1. receives chyme and HCl from stomach 2. receives bile from liver and gallbladder 3. receives enzymes from the pancreas 4. contains brush-border enzymes that are important for digestion of nutrients - villi/us: infoldings on the wall of the duodenum, increasing it's surface area allowing for more digestion - microvilli/us: infoldings on villi that further increase surface area - villi + microvilli = brush border that contains enzymes that aid with digestion

movement of O₂ from alveoli to capillaries

gas > fluid layer > epithelial > BM > connective tissue > BM > endothelial > plasma > RBC > hemoglobin - alveolus is surrounded by a basement membrane, epithelial cells, and a layer of fluid - air diffuses through these layers (fluid > epithelial > BM) to the connective tissue to the capillary - capillary is surrounded by basement membrane and endothelial cells • interior contains plasma that RBCs flow through with hemoglobin for O₂ to bind • RBC carries O₂ throughout the body where it's needed formulas: - alveolar gas equation; partial pressure O₂ - Fick's law; amt of O₂ diffusing over time

glomerular filtration in the nephron

glomerulus: coiled structure that receives afferent arterioles from the renal artery • makes filtrate from products (ions, aa, glc) in blood and lets the rest (RBC, WBC, big proteins) pass through the efferent arteriole • glomerulus endothelial cells are fenestrated (have holes) allowing nutrients to flow through • basement membrane: makes sure only small things pass through the glomerulus - efferent arteriole becomes a capillary > venules > renal vein - Bowman's capsule/space: collects filtrate from the glomerulus • have tubule/epithelial cells and specialized podocytes that hug the glomerulus ensuring they're close

type 1 and type 2 muscle fibers

golden rule: m1tochondria are present in greater quantities in type 1 muscle fibers type 1: - color: red bc of oxidative phosphorylation - contraction speed: slow; takes time for mitochondria to make energy - conduction velocity (time to receive nerve signal): slow twitch - activity: aerobic respiration - duration of contraction: long (able to make more energy w/ mitochondria) • ex: leg and back muscles that allow us to stand for long periods of time - fatigue: resistant - power: strong - storage: triglycerides type 2: - color: white - contraction speed: fast - conduction velocity: fast twitch - activity: anaerobic respiration (no mitochondria) - duration of contraction: short • ex: finger muscles that allow us to flick something - fatigue: easily - power: weak - storage: raw ATP or creatine phosphate

major histocompatibility complex

group of genes that code for cell surface proteins essential for acquired immune system to recognize foreign cells - every nucleated cell has MHC-I • CD8⁺ cytotoxic T cells bind to MHC-I to divide into effector Tₕ cells - MHC-II is mostly expressed by antigen-presenting cells such as monocytes, macrophages, and dendritic cells • CD4⁺ T helper cells bind to MHC-II

granulocytes

group of leukocytes from the myeloid lineage containing granules in their cytoplasm that have enzymes that are released during allergic rxns or in the presence of pathogens - function in nonspecific/innate immunity 1. neutrophils: most common granulocyte 2. eosinophils: target multicellular parasites (protists/worms) 3. basophils: least common; release histamine during allergic rxns - mast cells: found in mucous membranes and connective tissue; contain basophil granules that release histamine and cytokines during inflammatory and allergic reactions.

small intestine

has three parts: 1. duodenum: most digestion occurs here compared to all other parts of the GI tract - busiest part of small intestine: • receives chyme and HCl from stomach • receives bile from liver and gallbladder • receives enzymes from the pancreas • contains brush-border enzymes that are important for digestion of nutrients 2. jejunum: most absorption occurs here compared to all other parts of the GI tract 3. ileum: absorbs important vitamins (B-12, A, D, K)

liver blood supply

has two separate blood supplies - portal vein supplies nutrient-rich blood from food that is absorbed in the intestinal tract so it can be metabolized by the liver (input) - proper hepatic artery supplies oxygen-rich RBC's (input) - hepatic vein is nutrient and oxygen-deficient (output) - common hepatic duct is where bile leaves the liver (output)

aldosterone production

hormone produced by the adrenal cortex of the adrenal gland - cholesterol sits inside adrenal cortex cells and is a precursor to aldosterone triggers for aldosterone production: 1. when adrenal cortex cells encounter angiotensin 2 2. when adrenal cortex cells encounter excess K⁺

skeletal endocrine control

hormones that regulate amt of calcium absorbed from gut or reabsorbed from kidneys as well as the ratio of activity of osteoclasts to osteoblasts 1. parathyroid hormone (PTH) - increase calcium and phosphate in the blood - increases osteoClast activity - decreases osteoBlast activity - increases intestinal/renal Ca²⁺ absorption 2. calcitonin - decreases calcium and phosphate in the blood - calciTONin tones down calcium/phosphate in blood - decreases osteoClast activity - increases osteoBlast activity - decreases intestinal/renal Ca²⁺ absorption 3. calcitriol (active form of vitamin D) - increase calcium and phosphate in the blood - increases osteoClast activity - decreases osteoBlast activity - increases intestinal/renal Ca²⁺ absorption * if calcium increases, phosphate will increase and vice versa * as calcium or phosphate increases in the blood, it must be decreasing in the bone and vice versa

professional antigen presenting cells (APCs)

immune cells that specialize in presenting an antigen to a T-cell - takes up an antigen, processes it, and returns part of it to its surface on a class II major histocompatibility complex (MHC-II) - T helper cells have variable receptors that bind with the MHC-II complex, activating it, causing it to proliferate into effector Tₕ and memory Tₕ - main types of APC's: dendritic cells, macrophages, B cells

zymogen

inactive precursor of an enzyme that needs to be activated to complete its function - contains an extra bond that needs to be broken - activated by various methods (acid hydrolysis, cleavage by another enzyme, etc)

inhaling and exhaling

inhalation: - intercostal muscles contract, lungs expand, alveoli stretch, volume increases and pressure decreases to 757 mmHg ("negative" pressure) - air molecules enter (N₂ and O₂) causing the pressure to increase back to normal 760 mmHg (atmospheric pressure) exhalation: - intercostal muscles relax, lungs contract, alveoli recoil, volume decreases and pressure increases to 763 mmHg ("positive" pressure) - air molecules exit lungs causing pressure to call to 760 mmHg - more collisions happening inside lungs = more air molecules exiting the lungs and vice versa

Renin-Angiotensin-Aldosterone System (RAAS) in kidney

juxtaglomerular smooth muscle cells in the blood vessels of the kidney that releases a long-distance hormone called renin that raises BP - triggers: 1. low blood pressure 2. neighboring sympathetic nerve firing causes juxtaglomerular cells to release renin - SNS = fight or flight 3. macula densa cells in the distal tubule of the nephron that sense Na⁺ - low BP = low Na⁺ - send messages to juxtaglomerular cells through prostaglandins (lipids with hormone-like action) local messengers

lipid and protein transport in the lymphatic system

lipids: - fatty acids packaged into chylomicrons before exiting the intestine - chylomicrons are too large to enter directly into capillaries, so they diffuse through the pores of the lymphatic vessels (lacteals) which carry them to the blood to be dispersed t/o the body - lacteals: lymphatic vessels in the small intestine that uptake chylomicrons proteins (hormones) and wastes: - may be too large to enter capillaries, so also enter through the pores of the lymphatic vessels which carry them to the blood to be dispersed t/o the body (liver, kidney, etc)

Renin-Angiotensin-Aldosterone System (RAAS) in liver

liver makes angiotensinogen that meets with renin - angiotensinogen is inactive until it meets with renin which cuts it forming moderately active angiotensin 1 - angiotensin 1 floats through endothelial cells lining the inside of blood vessels which convert it to a very active angiotensin 2 - angiotensin 2 goes to: 1. smooth muscle cells: in blood vessels all over body causing vasoconstriction, increasing resistance 2. kidney cells: causing them to hold on to more water; increasing stroke volume 3. posterior pituitary gland: causing it to release antidiuretic hormone (ADH) which causes vasoconstriction and increases stroke volume as well (kidney and smooth muscle) 4. adrenal gland: causing it to release aldosterone which increases stroke volume (kidney)

cellular structure of bone

made up of the bone matrix and the cells that form the matrix 1. bone matrix: made of two building blocks - osteoids: forms the organic portion - organic portion: consists of a soft, highly-ordered structure of proteins and type I collagen • helps give bone its tensile strength; how rubber can "give" but holds its shape - hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂]: forms the inorganic portion - inorganic portion: calcium phosphate crystals that give bone its rigid strength and density 2. four cells that make up matrix - osteoprogenitor: precursor to osteoblasts • immature version of osteoblasts that differentiate into them by growth factors - osteoblasts: responsible for synthesizing collagen and osteoid (composed of osteocalcin and osteopontin proteins) • also make up alkaline phosphatase, the enzyme responsible for forming hydroxyapatite • mature into an osteocyte after forming the organic and inorganic structures of the bony matrix - osteocytes: occupy lacunae (empty space w/i bone) • contain branches that allow them to communicate with other cells (like dendrites) - osteoclasts: derived from monocytes (WBC phagocyte) • responsible for bone resorption; break bone down by an enzyme called tartrate-resistant acid phosphatase • form Howship's lacunae (empty spaces of bone) *osteoBlasts Build bone up; osteoClasts Crash bone down

aldosterone and alpha-intercalated cells

main job of alpha-intercalated cells is to get rid of protons; reduce acidity - peritubular capillaries sit next to them on the basolateral surface - all cells are making CO₂ and H₂O by breaking down sugars; carbonic anhydrase enzyme helps them become H⁺ and HCO₃⁻ - antiporter in basolateral surface that sends bicarb (HCO₃⁻) across the basolateral surface to the blood to bind to H⁺ and become H₂O and CO₂ to reduce the acidity and moves Cl⁻ from blood to alpha-intercalated cells - for every H⁺ that becomes H₂O and CO₂ in the blood, 1 H⁺ is formed in the alpha-intercalated cells; transporters driven by aldosterone on the apical surface use energy to send H⁺ from the alpha-intercalated cells to the urine - antiporter on the apical surface uses a concentration gradient that transports H⁺ to the urine and Na⁺ in the alpha-intercalated cells; also driven by aldosterone - another antiporter on the apical surface that requires energy to move H⁺ to the urine and pump K⁺ into the cell - sodium-potassium pumps on the basolateral surface to maintain the sodium-potassium gradient • more Na⁺ in the blood, more K⁺ in the cells

tubular reabsorption

mechanisms in the nephron that allow the movement of water and solutes from the tubular fluid back into the blood and extracellular fluid - called REabsorption bc it is the second time the products have been absorbed; the first time was when they were absorbed into the bloodstream from the digestive tract after a meal - nephrons are also able to do the opposite; secrete unwanted substances from the blood to the filtrate which will become urine - two-step process: 1. passive or active movement of water and dissolved substances from the filtrate, across the tubule wall, to the space outside 2. passive or active movement of water and dissolved substances through capillary walls to the bloodstream

types of muscles

muscles = movement 1. skeletal: mostly attached to bones by tendons - some are attached to aponeurosis or flat tendons - voluntary movement - fastest movement - straight cells with several peripheral nuclei - striated 2. cardiac: heart muscles - help heartbeat - automatic or involuntary movement - some are branched with one to two nuclei near the middle of the cell - striated 3. smooth: found mainly in the walls of hollow organs (like the stomach) and blood vessels - help movement of food, etc - automatic or involuntary movement - slowest movement - shaped like an eye or almond; spindle-shaped with one nucleus in the middle of the cell

anatomy of skeletal muscles

muscles attached to bones by tendons which is a type of connective tissue - epimysium: outer layer of muscle, continuous with the tendon, that helps protect muscle - perimysium: layer beneath the epimysium that covers multiple subunits of muscle or fascicles • contains nerves and blood vessels that can conduct neuronal signals/blood - fascicle/fasciculus: contains another connective tissue layer called the endomysium - endomysium: covers individual muscle cells called myofibers; contains nerves and blood vessels that can conduct neuronal signals/blood to cells bone > tendon > epimysium > perimysium > multiple fascicles > endomysium > myofibers

anus

muscular opening at the end of the rectum through which waste material is eliminated from the body - composed of two sphincters 1. internal anal sphincter (IAS): composed of smooth muscle (involuntary control) 2. external anal sphincter (EAS): composed of skeletal muscle (voluntary control)

esophagus

muscular tube that connects the mouth to the stomach - contains sphincters (circular localization of muscles) that ensure food flows one way • composed of skeletal muscle under voluntary control 1. upper esophageal sphincter 2. lower esophageal "sphincter": no ring of muscle; instead a sheet of muscle that lines the connection between the thoracic cavity (heart and lungs) and abdominal cavity - surrounded by the respiratory diaphragm (also a muscle) - two muscle layers prevent stomach contents from flowing upward (refluxing) into the esophagus peristalsis: wave-like propulsion of food caused by upward contraction of muscles and downward relaxation of muscles that serve to push boluses down the esophagus to the stomach - top 1/3 esophagus contains skeletal muscle (voluntary) - middle 1/3 contains skeletal and smooth muscle - bottom 1/3 contains smooth muscle (involuntary)

motor neurons

nerve cells that send signals to muscle cells - upper motor neuron (UMN) in the brain sends a signal to a lower motor neuron (LMN) which tells a muscle to start contracting • UMN tells LMN when to start and when to stop - signal from UMN lands on dendrite, travels to soma, and moves down the axon to eventually reach the axon terminal causing the muscle to contract - Schwann cells (myelin sheath of the PNS) help insulate axons so signals can travel long distances without dying off • nodes of Ranvier: empty space b/w Schwann cells

inflammatory response

nonspecific defense against infection, characterized by redness, heat, swelling, and pain - mast cells release histamine and skin cells release chemokines (hormone-like chemical messengers) and prostaglandins (lipids made at sites of tissue damage or infection) that signal an inflammatory response - vasodilation of capillaries causes swelling and gaps in capillary endothelial cells allowing phagocytes, specifically neutrophils to squeeze through and start engulfing harmful materials

anatomy of myofibers

nuclei that sit on the edges of muscle cells cause small bumps along the edges of the sarcolemma (cell membrane) - myo = muscle ; sarco = flesh - sarcoplasm: cytoplasm of muscle cells - contain smaller units called myofibrils where muscle contraction occurs • contain striations or z-lines where actin attaches • sarcomere: space b/w two z-lines where actin and myosin interact - sarcomere • I-band: part that only contains actin (no myosin); I looks like 1 • A-band: part that consists of both myosin and actin • H-zone: contains only myosin • Z-lines: sarcomere boundaries - T-tubules: allow action potentials to travel deep into myofibers causing sarcoplasmic reticulum to release Ca²⁺, bind to troponin, and allow myosin to bind and pull actin toward the center, decreasing the length of the I band • A band does not change, only I band

thermoregulation in the lungs

one way we regulate body temperature - function of the respiratory system - inhale cool air and exhale warm air - increase in O₂ and decrease in heat by breathing heavily - dogs cannot sweat, so they rely solely on this process

sarcoplasmic reticulum

organelle of the muscle cells that stores calcium and controls its concentration within muscle cells - contain Ca²⁺ pumps on its membrane that use ATP to pump Ca²⁺ in and out - resting muscles have a high concentration of Ca²⁺ inside the sarcoplasmic reticulum; contracting muscles - synapse b/w a motor neuron and a muscle cell releases the neurotransmitter acetylcholine which binds to receptors on the sarcolemma (membrane of a muscle cell) to open sodium channels allowing it to enter the cell creating an action potential - action potential travels down the T-tubule (hole in the sarcolemma) to trigger the release of Ca²⁺ from the sarcoplasmic reticulum to the cytoplasm - Ca²⁺ released into the cytoplasm bind to troponin, allowing myosin to bind to actin when muscles need to contract

alveolar gas equation

pO₂ = FiO₂ (Pₐₜₘ - Pₕ₂ₒ) - pCO₂/RQ - O₂ entering alveolus = FiO₂ (Pₐₜₘ - Pₕ₂ₒ) - O₂ exiting alveolus = pCO₂/RQ - partial pressure of O₂ = pO₂

ADH effects on blood pressure

peptide hormone made of 9 amino acids 1. targets smooth muscles of blood vessels causing vasoconstriction; vessels become tight and small to increase resistance which increases BP - ΔP = Q x R • Pₐ - Pᵥ = (SV x HR) x R 2. targets collecting duct of the kidney to cause increased reabsorption of water which increases stroke volume - collecting duct cells contain aquaporins that merge with apical surface of the collecting duct when ADH is present • allows water to exit urine, flow through aquaporins into collecting duct cells, and enter the blood = increased stroke volume

neuromuscular junction

point of contact between the axon terminal of a motor neuron and a skeletal muscle cell - signal cast from a motor neuron in the form of an influx of Na⁺ and Ca²⁺ ions - Ca²⁺ binds to vesicles that contain acetylcholine (Ach) causing it to fuse to the membrane of the axon terminal, releasing Ach to the synaptic cleft through exocytosis - Ach binds to nicotinic-acetylcholine receptors on Na⁺ channels of muscle cells causing it to open, allowing Na⁺ to influx into the cell • muscle cells contain multiple sodium and calcium channels - once the cell is depolarized by Na⁺, voltage-gated Ca²⁺ channels open causing Ca²⁺ to enter as well - sarcoplasmic reticulum holds excess Ca²⁺ that is released when a Ca²⁺ ion that entered through a voltage-gated Ca²⁺ channel binds to it; a process called calcium-induced calcium release - gap junctions: proteins that attach myofibers and allow cations to flow through allowing calcium-induced calcium release in neighboring cells • syncytium: when one muscle cell contracts, its neighbors contract as well *Ach indirectly causes calcium release by opening voltage-gated ion channels

portal triad

portal vein, proper hepatic artery, and common hepatic duct - liver is split into units called hepatic lobules that contain several hepatocytes (liver cells) in the center surrounded by 6 portal triads forming a hexagon - how hepatocytes are able to extract nutrients for metabolism or storage of macromolecules - hepatocytes receive oxygen from the proper hepatic artery - all the blood collects at the central vein in the center of the hepatic lobule to send the nutrient and oxygen-deficient blood through the hepatic vein > heart > lungs > intestines > liver

stomach digestion

primarily responsible for three steps: 1. churning the bolus using the muscular walls of the stomach 2. hydrolysis of bolus through enzymes - parietal cells secrete hydrochloric acid (HCl) - chief cells secrete pepsinogen, the inactive form of pepsin • pepsinogen + HCl = pepsin > hydrolysis of peptide bonds - mucus cells secrete mucin, a coating that surrounds and protects stomach from degrading - ultimately create chyme: mixture of bolus and gastric enzymes/juices 3. storage of chyme until it is released to the duodenum - can store 2-4 L of food at a time

endochondral ossification

process of transforming cartilage into long bone through the ossification of cartilage - ossification, or osteogenesis, is the process of bone formation

complement system

proteins in the blood that are normally inactive in circulating blood, but are activated when the body is infected to help antibodies kill their target - complements innate or adaptive immune systems - ex: 1. opsonization: tagging pathogens with antibodies to be picked up by phagocytes 2. chemotaxis: releasing cytokines and chemokines to attract macrophages and neutrophils 3. cell lysis: puncturing the membranes of foreign cells 4. agglutination: uses antibodies (adaptive) to round up pathogens to one area for destruction; clustering

diabetes insipidus

rare disorder that causes one to feel thirsty, despite drinking a lot, and produce large amounts of urine - usually caused by a malfunction in the production of ADH, a hormone that prevents the production of dilute urine (meaning it retains water in the body)

glomerular filtration rate

rate at which kidneys filter blood; - main driving force is BP entering the glomerulus, aka outward pressure which is counteracted by inward pressure - inward pressure is due to hydrostatic pressure of the fluid within the urinary space - net filtration pressure = outward pressure - inward pressure - think of it as a race - larger afferent arteriole diameter = more blood = increased filtration - smaller afferent arteriole diameter = less blood = decreased filtration - larger efferent arteriole diameter = less time in glomerulus = decreased filtration - smaller efferent arteriole diameter = back up = more time in glomerulus = increased filtration

kidneys

receive blood from the heart through the renal arteries, filter it, and release the waste as urine - Na⁺, amino acids, glucose, O₂, and urea flow through the arteries to the kidneys - nutrients flow back to the heart from the renal veins while waste products remain in the kidney - maintains homeostasis of pH, BP, and osmolarity - kidneys have 2 capillary beds that work together to deliver O₂ to kidney tissue and recollect nutrients so the vein can have them • vasa recta: mainly deliver O₂ to kidney • peritubular capillaries: mainly collect nutrients for renal vein

endocrine pancreas

releases hormones to the bloodstream - many islet cells (islets of Langerhans) that sit on islands - three types of islet cells: 1. alpha islet cells: release glucagon - glucagon breaks down macromolecules - ex: glycogen into glucose 2. beta islet cells: release insulin - insulin builds up/stores macromolecules - ex: glucose to glycogen 3. delta islet cells: release somatostatin - somatostatin's main job is to stop the effects of all other active hormones like glucagon, insulin, cholecystokinin, etc

exocrine pancreas

releases salts and enzymes into the duodenum 1. bicarbonate (HCO₃⁻) to neutralize gastric acid (HCl) in the duodenum 2. amylase which breaks down starch into smaller carbs 3. lipase which breaks down triglycerides into DG, MG, glycerol and FFA's 4. proteolytic enzymes which break down proteins - trypsinogen (zymogen): inactive form of trypsin, activated by enteropeptidase located in the membrane of the duodenum - chymotrypsinogen (zymogen): inactive form of chymotrypsin, activated by trypsin

enzymes that help with digestion

send these to the duodenum 1. proteins - brush border peptidases that break peptide bonds - pancreas sends trypsinogen and chymotrypsinogen • "gen" = not functional/active yet • enteropeptidase (brush-border enzymes) convert them to trypsin and chymotrypsin (active) 2. carbohydrates - brush border contains lactase, sucrase, etc. - pancreas sends amylase which breaks glycosidic linkages to form monosaccharides 3. nucleotides - brush border nucleosidases that break nucleotides at carbon 1 (b/w the sugar and base) • nucleoside = sugar + base • nucleotide = phosphate + sugar + base 4. fats - liver and gallbladder send bile to the duodenum which helps emulsify (organize) fat, not necessarily break them down - pancreas released lipase which cleaves triglycerides at the ester bond leaving 3 FA tails and a glycerol backbone

cardiac muscle

shares some features of skeletal and smooth muscle, while having unique features of its own - like smooth muscle, it is not under voluntary control and their cells tend to only have one nucleus, although some cells may have two or more - like skeletal muscle, cardiac muscle is striated - unique feature: cardiac muscle cells are connected by structures known as intercalated discs, which connect the cytoplasm of adjacent cardiac muscle cells, allowing ions to pass from cell to cell • these connections are known as gap junctions, and they allow action potentials to pass rapidly from one cardiac muscle cell to another

pancreas

sits in the retroperitoneum - peritoneum = abdomen (stomach, liver, intestines) - retroperitoneum = back of abdomen (pancreas, abdominal aorta, inferior vena cava) - arises from the endoderm embryonic germ layer - releases powerful enzymes that digest macromolecules - un-incapsulated: different from liver and kidneys • the lion of the abdomen; very important w/ powerful enzymes - two main components: 1. exocrine pancreas: excretes salts and enzymes into the duodenum 2. endocrine pancreas: releases hormones to the bloodstream

skeletal structure and function

skeleton supports body and provides a framework for movement - protects most vital organs (brain, heart, lungs) - performs physiological roles; storage of calcium and hematopoisis • hematopoiesis: production of RBC, WBC and platelets in the bone marrow - axial skeleton: skull, ribcage and vertebral column • central - appendicular skeleton: formed from appendages (arms and legs) that attach to the axial skeleton

appendix

small, finger-shaped pouch of intestinal tissue located between the small intestine (cecum) and large intestine (colon) - sits in lower, right abdomen - acts as a safe house for good bacteria; after intense diarrhea, the appendix repopulates and reboots the intestine with good bacteria before harmful bacteria find a home there - other experts believe the appendix is just a useless remnant from our evolutionary past

secondary active transport in the nephron

sodium-potassium pumps between all parts of the nephron and the peritubular capillary which uses energy from ATP to power the movement of other materials - countercurrent multiplication: descending and ascending limb flow in opposite directions; specific permeability of each limb allows renal medulla to become salty to then absorb water passively - symporters in the proximal convoluted tubule allow glucose to travel with Na⁺ to the blood - ascending loop of Henle has sodium-potassium-chlorine cotransporters allowing Cl to enter making the medulla saltier - distal convoluted tubule has antiports allowing Na⁺ to enter and Ca²⁺ to exit to the capillary

bone marrow

soft connective tissue within the medullary cavity of bones - two types: 1. red bone marrow - primary site of hematopoiesis - RBC make it look red - found in flat bones and epiphyses of long bones 2. yellow bone marrow - primary site of fat storage - made of adipocytes (fat cells) - found in diaphysis of long bones

enteric nervous system

the nervous system of the digestive tract that acts independently of the CNS - gastrocolic reflex: presence of food in the stomach signals the colon to make way for food, so colon pushes food further along toward the rectum hormonal control: 1. gastrin: hormone released from mucosal cells in the stomach when food is present - stimulates secretion of digestive juices (HCl and pepsinogen) - increases stomach motility (churning) - results in chyme - when stomach pH = 3, gastrin release is decreased (inhibition) 2. acidity of stomach acid causes secretin to be released - secretin travels to the pancreas to cause the release of bicarbonate to neutralize the acid - also travels to the stomach to cause the inhibition of stomach motility, HCl release, and pepsinogen release - serves to neutralize acidity of stomach acid 3. presence of lipids in chyme causes cholecystokinin (CCK) to be released - CCK released from intestinal mucosa > bloodstream > pancreas to stimulate release of pancreatic enzymes (lipase) > digestion - CCK released from intestinal mucosa > bloodstream > gallbladder > gallbladder contraction > pumps bile into cystic duct > common bile duct > duodenum > emulsify fat - also decreases stomach motility to make time to process what is already in duodenum 4. insulin and glucagon

gastrointestinal tract

the path food takes from the mouth to the anus 1. mouth: - chewing (physical breakdown) - hydrolysis (enzymatic breakdown) - forms a bolus (sphere of food that can be swallowed) 2. esophagus: propels the bolus to the stomach 3. stomach: responsible for churning, hydrolysis (enzymatic breakdown), storage - overall goal is to make chyme (bolus > fluid chyme) 4. intestine - duodenum: first part of the small intestine that connects to the stomach - small intestine: hydrolysis and absorption of nutrients - large intestine/colon: absorption of water, ions, vitamins, not necessarily nutrients 5. rectum: storage of processed food until time to expel through the anus 6. anus: expulsion of processed food

calcium homeostasis and importance

the regulated flow of Ca²⁺ between the bloodstream and bone - under endocrine or hormonal control - hormones alter the ratio of osteoclast to osteoblast activity • PTH, calcitonin and calcitriol - as osteoclast activity increases, movement of (Ca²⁺ + PO₄²⁻) from bone to the bloodstream increases • osteoClasts Crash bone down - as osteoblast activity increases, movement of (Ca²⁺ + PO₄²⁻) from bloodstream to bone increases • osteoBlasts Build bone up why does it matter? - regulation has important physiological effects - excess calcium leads to hypo-excitable cell membranes, leading to lethargy, fatigue, and memory loss - too little calcium leads to muscle cramps and convulsions (involuntary muscle contractions)

lymphatic system

there is high pressure in the heart and blood vessels which pushes fluid (lymph) out from the capillaries to the porous lymphatic vessels - lymphatic vessels return fluid from the tissues to be recirculated; don't form a closed loop like the circulatory system - lymph and small proteins pass through endothelial cells that line the capillary; RBC and larger proteins are too big to squeeze through • increased concentration of RBC and large proteins causes a decrease in pressure in the venules (what was once pushing lymph out) causing some lymph to reenter • net movement of lymph out of the arterioles and capillaries functions: 1. collects fluid and returns back to the circulatory system 2. immunity and filtering of invaders through lymph nodes 3. indirectly transports lipids, proteins, and wastes to the blood

troponin complex

troponin complex: composed of three proteins; troponin C, I, and T - calcium binds to troponin C and moves tropomyosin out of the way so myosin can bind to actin - inotropy: more myosin heads "working" or binding to actin • increase calcium • increase sensitivity of troponin C (bind calcium more easily)

phagocytes

type of WBC/leukocyte capable of engulfing and absorbing pathogens to create a phagosome - lysosomes and ROS break down the contents in phagosomes into fats and peptides that can be used to create an antigen to be presented on a major histocompatibility complex (MHC) - aka antigen-presenting cells that trigger the specific immune system - function in nonspecific/innate immunity - three major types: 1. neutrophils: fast and abundant 2. macrophages: versatile and hang out in tissues waiting for invaders 3. dendritic cells: located in tissues; antigen-presenting cells that are the bridge b/w innate and adaptive immunity

lymphocytes

type of WBC/leukocyte that make antibodies to fight off infections (specific/adaptive immunity) 1. B cells/B lymphocytes: produced in Bone marrow - humoral response: response to pathogens floating in humoral fluid before infiltrating cells; mediated by antibodies - contain membrane-bound antibody proteins (immunoglobulins) with specific variable portions that bind to the epitope of pathogens to become activated and replicate - memory B cells: hold memory of the pathogen - effector B cells: immediately ready to fight invader - plasma cells: antiBody factories • opsonization: tagging pathogens with antibodies to be picked up by phagocytes 2. T cells/T lymphocytes: mature in the Thymus - cell-mediated response - helper T cells (Tₕ): alarm other cells; have variable and specific T cell receptors that bind to antigens to become activated • effector Tₕ cells: immediately start releasing cytokines (chemical messengers/alarms) • memory Tₕ cells: last longer - cytotoxic T cells (Tc): attack and kill infected cells • bind to MHC-I to divide into effector Tₕ cells forcing the infected cell to die by releasing different proteins • cell-mediated response

voluntary vs involuntary control of muscles

voluntary - striated, skeletal muscle - CNS: Cerebral cortex and spinal Cord • you Control it - somatic nervous system: controls voluntary muscles • neurotransmitter: acetylcholine (Ach) involuntary - cardiac and smooth muscle - CNS: Brainstem, sympathetic ganglia (sit Beside the spinal cord) • control that is Beyond me - autonomic nervous system 1. sympathetic: fight or flight - neurotransmitter: norepinephrine (noradrenaline) 2. parasympathetic: rest and digest - neurotransmitter: Ach