Exam 3 Flashcards
Lymphatics
Functions (3)
Location?
- Immune surveillance
- Absorb large molecules. e.g. fats in small intestine
- Reclaim fluids from interstitial space back into circulation
*location: throughout the body but not in bones, teeth, CNS
Lymphatics
Tubes caring lymph (in order)- one way flow to heart
- Lymphatic capillaries
- Lymphatic vessels
- Lymphatic trunks
- Lymphatic ducts (two)
Lymphatics: Tubes caring lymph (in order)- one way flow to heart
Lymphatic capillaries
-small, dead end tubes
-mini valves between walls cells let fluid in
–collagen filaments attach them to nearby tissue cells
-lacteals: lymph capillaries of small intestine that pick up the chyle
Lymphatics: Tubes caring lymph (in order)- one way flow to heart
Lymphatic Vessels
-resemble veins with thin walls (but do have 3 tunics)
–have valves to ensure flow of lymph towards heart; flow aided by skeletal muscle pump and respiratory pump that enhance pressure gradient, flow also aided by arterial pulse, also aided by smooth muscle contraction in wall of lymph vessel
Lymphatic capillaries: LACTEALS
lymph capillaries of small intestine that pick up the chyle
what helps flow occur in lymphatic vessels
-have valves to ensure flow of lymph towards heart;
-flow aided by skeletal muscle pump and respiratory pump that enhance pressure gradient
-flow also aided by arterial pulse
-also aided by smooth muscle contraction in wall of lymph vessel
Lymphatics: Tubes caring lymph (in order)- one way flow to heart
Lymphatic Trunks
-jugular, subclavian, brachiomediastinal lumbar, intestinal
Lymphatics: Tubes caring lymph (in order)- one way flow to heart
Lymphatic Ducts (two)
a) thoracic duct (most of the bodies lymph)
-in front of vertebrae
-starts with cisterna chyli
b) right lymphatic duct (lymph from R head, R chest, R upper extremity
*both ducts drain into subclavian veins
Lymphatic Ducts: Right Lymphatic Duct
(lymph from R head, R chest, R upper extremity
Lymphatic Ducts
thoracic duct
(location, what does it begin with)
(most of the bodies lymph)
-in front of vertebrae
-starts with cisterna chyli
Lymphatic Organs
Nodes
(where are they, fed and drained?, what type of tissue)
-concentrated in inguinal, cervical, axillary regions
-pea-sized
-hilum=indentation
–fed lymph by multiple different afferent vessels
–drained by few efferent vessels at hilum
-reticular connective with many lymphocytes, macrophages
-follicles produce b-cells that can become plasma cells that make antibodies
nodes: Follicles produce…
follicles produce b-cells that can become plasma cells that make antibodies
Lymphatic Organs
Spleen
-size of the heart (fist)
-on L side of the body
-hilum faces medially
-Red Pulp: RBC recycling iron storage, platelet storage
-White Pulp: Lymphocyte surveilling blood for pathogen
Spleen
-Red Pulp
RBC recycling iron storage, platelet storage
SPLEEN
White Pulp
Lymphocyte surveilling blood for pathogen
Lymphatic Organs
Thymus
Location+ what does it do?
-Near Trachea+ Heart
-Larger in kids than seniors
-Helps development of immune cells
–Proliferation, specialization of T cells
Lymphatic Organs
Tonsils
-MALT: Mucosa Associated lymphatic tissue
–MALT is also in the intestine wall and the appendix
-surround pharynx to surville air and food that come in; have crypt
–palatine tonsils: mouth
–pharyngeal (nasopharynx) tonsils: adenoids
–lingual tonsils: base of tongue
–tubal tonsils: near opening of auditory tube
–palatine tonsils:
mouth
–pharyngeal (nasopharynx) tonsils:
adenoids
–lingual tonsils:
base of tongue
–tubal tonsils:
near opening of auditory tube
Respiratory Anatomy
External Nose
(what is the root, bridge, type of cartilages)
-root: frontal bone
-bridge: nasal bones
-cartilage: hyline
–septal cartilage
–lateral cartilage
–alar cartillage
Respiratory Anatomy
Internal Nose
(whats the linings, what bones)
-External Nares: Nostril
-Vestibule: has vibrissae
-Nasal Septum: Midline
–Septal cartilage, vomer bone, ethmoid bone’s perpendicular plate
-nasal conchae: turbinates: superior, middle, inferior, help warm. moisten. filter
–superior, middle, inferior meatus
-lining: Pseudo stratified mucosa, olfactory mucosa (superior part of cavity)
-internal nares: posterior nasal aerture
-lining:
a) in the nasal cavity
b) superior part of cavity
a)Pseudo Stratified mucosa
B) olfactory mucosa
Nasal Conchae (turbinates)
turbinates: superior, middle, inferior, help warm. moisten. filter
Respiratory Anatomy
Paranasal Sinuses
What are they, their names, their function
-cavities in skull bones lined w/ mucosa
-maxillary sinus, sphenoid, ethmoid, frontal
-Function: Lighten skull, voice resonance, warm+ moisten air
Respiratory Anatomy
Pharynx: Throat
Location+ what surrounds it?
-skull to C6
-surrounded by skeletal muscle
Respiratory Anatomy
Nasopharynx
Location, whats it for, what is it lined with, what is here
-above+behind palate
-for air
- pseudo stratified epithelial
-adenoids, tubal tonsils (auditory tubes opening) live here
Respiratory Anatomy
Oropharynx
location, whats it for, its lining, what is here
-From uvula to epiglottis
-for air+food so has stratified squamous
-home to palatine and linguinal tonsils
Respiratory Anatomy
Laryngopharynx
Loc and lining?
-Behind Larynx
-for air+ food so has stratified squamous lining
-continues inferiorly to esophagus
Larynx Extent (location)
c4-c6: between pharynx and trachea
Larynx cartilage
-made of hyaline cartalige
a) thyroid: anterior, laryngeal prominence
b) cricoid: ring at bottom of larynx
c) arytenoid: pyramid shaped on back of larynx, attached to vocal chord
d) corniculate: small cartilage pieces on top of arytenoids
elastic cartillage
e) epiglottis: cover opening to larynx when swallowing
epiglottis (cartilage)
cover opening to larynx when swallowing
*made of elastic cartilage
corniculate cartilage
small cartilage pieces on top of arytenoids
arytenoid cartilage
pyramid shaped on back of larynx, attached to vocal chord
cartilage
thyroid
anterior, laryngeal prominence
cartilage
cricoid
ring at bottom of larynx
Larynx
Vocal Folds
-true vocal cords
-glottis: vocal folds+ space between them
-ridges in larynx below vestibule
Larynx
Vestibular Folds
-False vocal cords
-Help close off airway when swallowing
Trachea location
between larynx and bronchi
Trachea inner wall
whats there + lining
Inner= musosa
-pseudo stratified ciliated epithelium
-lamina propria- loose connective t
Trachea Middle wall
-Trachea cartilage (Hyaline)
-Trachealis muscle (smooth muscle)
Trachea Outer wall
-adventitia
Trachea Carina
-ridge of cartilage and epithelium (sensory neuron rich) at bottom of trachea; helps start cough reflex
Bronchial Tree
Conducting Zone (Ventilating Zone) is the
The anatomical dead space
Bronchial Tree Conducting Zone (Ventilating Zone)
A) Primary Bronchi (2) R Primary Bronchus is wider and more vertically oriented than L primary bronchus
B) Secondary Bronchi (5): Lobar Bronchii 2 on left and 3 on right
C) Tertiary Bronchi: Segmental Bronchii
D) Many more splits
E) bronchioles: 1mm or smaller diameter
F) Terminal bronchiole: end of conducting zone (Have no alveoli)
Primary Bronchi
R Primary Bronchus is wider and more vertically oriented than L primary bronchus
(2)
Bronchial Tree Respiratory Zone
a) Respiratory Bronchioles
b) alveolar ducts
c) alveolar sacs: clumps of alveoli
d) alveoli/ alveolus= 1 bubble
i) type 1 cells- squamous
ii) type 2 cells- cuboidal, secrete surfacant
iii) macrophages: engulf foreign particles
type 1 cells:
types 2 cells
i) type 1 cells- squamous
ii) type 2 cells- cuboidal, secrete surfacant
Secondary Bronchii
Lobar Bronchii 2 on left and 3 on right
(5)
Gross Anatomy: Lungs
Each lung has
hilum+ pleurae
Gross Anatomy: Lungs
Hilum
Here does the indentation, base, and apex point/ faces to
roots are what and where
-indentation (faces medially)
-Apex: Points up
-Base- Faces interiorly
-Root- tubes (blood vessel, broncus) at hilum
Gross Anatomy: Lungs
Pleurae
-separate sac for each lung
-visceral pleurae: inner
+ pleural space/ cavity with fluid
-parietal pleura: superficial
Gross Anatomy: Lungs
Lobes In each lung
L lung has 2 lobes
R lung has 3 lobes
-lobes separated by fissures
Mechanics Of Breathing: Pressure relationships in the thoracic cavity
Intrapulmonary pressure is the pressure in the
-the lungs (the alveoli)
-Rises and falls during breathing but equalizes with atmospheric pressure
(If airway is open)
Mechanics Of Breathing: Pressure relationships in the thoracic cavity
Intraplueral pressure is the pressure in the
-the pleural cavity
-rises and falls with breathing but lower than the intrapulmonary pressure
-it varies inversely with chest volume
What is pulmonary ventilation
INSPIRATION AND EXPIRATION
-a mechanical process causing gas flow in and out of the lungs according to volume changes in the thoracic cavity
Boyles Law States
pressure is inversely related to volume in a closed container
During Quiet Inspiration…
-Diaphragm and external intercostals contract
-causes increased chest volume so chest pressure decreases and air flows in
During Forced Inspiration
-Also contracts sterenocleidomastoid muscle and scalane muscles and pec. minor muscles
-increases chest volume further so more air flows into lungs
Quiet expiration is a _ process
passive
Quiet expiration relies on
-eslastic recoil of chest muscles and lung tissue decreases thoracic volume
-pressure increases so air flows out
Forced expiration is an _ process
active
Forced expiration
what intercostals contract?
-internal intercostals contract
-abdomincal muscles contract and push abdominal organs toward chest so chest volume decreases and pressure increases: air flows out
Airway resistance is the _ encountered by air in the airway; gas flow is _ as airway resistance increases
Friction
Decreased
Alveolar surface tension due to water in the alveoli…
-draws alveolar walls closer together
-makes inspiration tougher
-surfactant lowers surface tension; premature babies don’t make enough surfacant
lung complience is determined by
3
distendability of lung tissue and the surrounding thoracic cage, and alveolar surface tension
it is important for lung complience to be ___…
HIGH. for lung inflation during inspiration
Tidal Volume
The amount of air that moves in and out of the lungs during each relaxed breath
The inspiratory reserve volume (IRV) is
the amount of air that can be inspired above TV
The expiratory reserve volume (ERV) is
The amount of air that can be expired beyond TV
Residual Volume (RV) is the amount of air
remaining in the lungs after forced expiration
Inspiratory Capacity (IC) is the sum of
max amount of air someone can take in after a tidal inhalation TV+IRV
Vital Capacity is
Its equation
The total amount of exchangeable air
VC=IRV+TV+ERV
The Total lung capacity is
Equation
the sum of all lung volumes
TLC= Vital capacity+ Residual Volume
The anatomical dead space is the
volume of the conducting zones- External nares to terminal bronchioles
Anatomical dead space (in terms of gas exchange)
-does not contribute to gas exchange: It has no alveoli
Alveolar ventilation rate (AVR) equals
respiratory rate times (tidal volume minus dead space)
AVR= RR* (TV-DS)
Pulmonary Function tests evaluate
respiratory function using a spirometer to distinguish between obstructive (blockage-cant ventilate quickly) and restrictive (lungs can’t expand for full inspiraton) pulmonary disorders
Obstructive Pulmonary Disorders
Blockage: Can’t ventilate Quickly
Restrictive pulmonary disorders
lungs cant expand for full inspirartation
Spirometer shows decreased vital capacity with ____
Restrictive Disorders (e.g. fibrosis from TB, scoliosis, obesity)
Obstuctive disorders are best measured with
Flow meters:
Decreased flow with increased resistancem (e.g. bronchitis, asthma, enphysema)
External Respiration Involves
Pulmonary gas exchange
External Expiration Involves
O2 loading of blood in pulmonary capillaries when CO2 is being unloaded
A steep partial pressure gradient exists between blood in the pulmonary arteries and the alveoli, and O2 diffused rapidly from
O2 in alveolar air towards blood in the pulmonary capillaries (CO2 goes in the other direction)
Ventilation-Profusion Coupling ensures a close match between the amount of
if O2 levels in the air are high:
O2 levels are low:
Fresh air and blood going into a section of the lung
-e.g. if O2 levels in the air are high: dialate pulmonary arterioles
-if O2 levels are low: Constrict pulmonary arterioles
The respiratory membrane is usually
-very thin to allow for easy diffusion
-has large surface area
Internal Respiration Involves
Capillary Gas exchange in the body tissues
Internal Respiration
- The diffusion Gradients for oxygen and carbon dioxide are reversed from those for external respiration and pulmonary gas exchange
- The partial pressure of oxygen in body tissues is lower than it is in blood and so O2 diffuses out of the blood (it is “unloaded”) to body tissue cells
Oxygen Transport
Since molecular oxygen is poorly soluable in water, it needs help to be transported through the blood
-only 1.5% Of the O2 disolves in plasma
-98.5% of O2 binds to hemoglobin
How many O2 molecules can be bound to hemoglobin
Up to four oxygen molecules can be reversibly bound to a molecule of hemoglobin-one oxygen on each iron
The affinity of hemoglobin for oxygen changes with each sucessive oxgen that is bound or released so that
-when more O2 is bound, Hb has more affinity to O2
-when less O2 is bound, Hb affinity for O2 is low
-makes loading and unloading efficient
What happens to the amount of oxygen Hb unloads when…
There are high partial plasma pressures of oxygen:
When plasma pressure drops dramatically (eg vigorous excersise):
There are high partial plasma pressures of oxygen: Hb unloads little oxygen
When plasma pressure drops dramatically (eg vigorous excersise): more more oxygen can be unloaded
Temperature, blood pH, PCO2 influence hB affinity (“grip on o2”) for oxygen
-high T, high CO2 and low pH lower hB affinity for O2
Carbon Dioxide is transported in blood in three ways
-7% of CO2 dissolves in plasma
-23% of CO2 binds to hB
-70% of CO2 is converted by carbonic anhydrase into carbonic acid which gives rise to bicarbonate ions
the haldane effect encourages CO2 exchange between lungs and tissues
-when O2 is low Hb easily binds CO2 but when O2 high Hb releases CO2 easily
the carbonic acid bicarbonate buffer system of the blood is formed when
carbonic anhyrase is present and it catalyzes combination of CO2 and H2O
Neural Mechanisms and Breathing rhythm
normal RR
15breaths/min
The medulla oblongata contains respiratory control areas called
VRG, DRG
Respiratory control areas
VRG of medulla
-front
-generates rhythm of breathing
-its inspiratory neurons excite cervical motor neurons (C3-C5) that are attached to phrenic nerve to diaphragm
DRG of medulla
what does it get input from
-posterior
-influence activity in the VRG
-get input from peripheral proprioceptors and other brain areas as well as chemoreceptors
The pontine respitatory group (within the pons) provide….By modifying…
provide fine tuning of respiratory patterns (e.g. when speaking) by modifying activity of medullary respiratory neurons
The pontine respiratory group
-recieves PNS and CNS inputs during speech and excersise
-Influences DRG and VRG of medulla to smooth inspiration and expiration transitions
Factors influencing breathing rate and depth
Influence of higher brain centers
-the limbic system, strong emotions, pain activate the hypothalamus, which mods rr and depth
-the cerebral cortex can exert voulentary control over respiration by bypassing the medulary centers and directly stimulating the respiratory centers
Chemical Factors influencing breathing rate and depth
what are the strongest stimuli influencing respiration
-plasma and cerebrospinal fluid levels of pCO2
Chemical Factors influencing breathing rate and depth
Evevated pCO2
=hypercapnia= lowers pH
Chemical factors influencing breathing rate and depth
(what detects)
-central chemoreceptors in brainstem excite the respiratory neurons nearby
-peripheral chemoreceptors in aorta+ carotid also sensitive to chemistry (including decreased O2)
blood PCO2 affects breathing ___ through___
affects breathing indirectly through peripheral chemoreceptors
peripheral chemoreceptors monitor
plasma Po2 and stimulate an increase in ventilation when PO2 drops below 60mmHg
as arterial pH declines.. the respiratory system attempts to compensate by
-causing an increase in rate and depth of breathing
-then increase in ventilation brings PCO2 and PH back to normal
Respiratory adjustments during exercise
during vigorous exercise, deeper and more vigorous respirations, called ___, ensure that….
hyperpnea ensure that tissue demands for oxygen are being met
three neural factors contribute to the change of respiration with exercise
-conscious anticipation
-motor cortex and muscle proprioceptors excites brainstem respiratory neurons
homeostatic imbalances of the respiratory system
COPD causes
Emphysema
Bronchitis
-cause dyspnea; increases infections
- emphysema: alveoli breakdown
- bronchitis: bronchial mucosa inflamed
asthma is characterized by…
-coughing, dyspnea, wheezing, and chest tightness brought on by active inflammation of the airways
-sporadically obstructive
-environmental+ genetic risk factors
TB is an infecious disease caused by….
-the bacterium Mycobaterium TB and spread by coughing and inhalation
-causes fibourus nodules in lungs
-restrictive
Two main groups of the digestive system organs
alimentary canal and accessory organs
Alimentary canal or GI tract
-mouth, pharynx, esophagus, stomach, small intestine, large intestine
accessory digestive organs aid digestion but are not
the tubes that food passes through
Accessory Digestive Organs
(3 are in mouth)
-teeth, tongue, salivary gland, pancreas, liver, gallbladder
6 Steps of digestion
- Ingestion
- Propulsion
- Mechanical Breakdown
- Chemical Digestion
- Absorption
- Defecation
- Ingestion
-put food in mouth
- Propulsion
-Swallowing by skeletal muscle
-Peristalsis by smooth muscle
- Mechanical Breakdown
-Chewing
-Swallowing
-Segmention
- Chemical Digestion
-hydrolysis: add water+enzyme to split large molecule
- Absorption
-Takes small molecules into blood or lymph
- Defecation
-Elimination of solid waste
Digestive Activity within the small intestine is triggered by
mechanical and chemical stimuli
Controls of digestive activity are both extrinsic and intrinsic
Extrinsic: Long reflexes, involve neurons and glands outside of the GI tract
Intrinsic: short reflexes occurring within the GI tract
Peritoneum
Visceral vs parietal
sheets of membrane w fluid that reduce friction
visceral=inner
parietal=outer
Mesentery is a _ That_
mesentery is a double layer of peritoneum that suspends organs and blood vessels
Retroperitoneal
sits behind the parietal peritoneum
Histology Of the Alimentary Canal
Muscosa
What is it? its function and what is there?
slick, inner lining
function: Absorption, mucus secretion, protection, hormone secretion
epithelial layer, lamina propria, muscularis mucosa
Mucosa: Epithelial Layer (lining)
-mostly simple columnar but is stratified squamous in mouth and anus (top+bottom)
Muscosa: Lamina Propria
Loose C.T.
Muscosa: Muscularis Mucosa
what type of m?
smooth m. to cause inner lining
Histology Of the Alimentary Canal
Submucosa (3)
-connective tissue
-submucosal glands
-sibmucosal plexus: network of neurons
Histology Of the Alimentary Canal
Muscularis Externa
function+whats there
Function: segmentation and peristalsis
-thick layer of smooth M
–Circular layer (inner)
–longitudinal layer (outer)
-mesenteric plexus or neurons
Histology Of the Alimentary Canal
Serosa
other name+ function
-visceral peritoneum
-hold things together while lowering friction
Mouth
- another name
- what is it between
- lining?
-Buccal cavity
-vestibule: between gums+ lips and cheeks
-lined by stratified squamous
Lips: Labia
-red margins
-skin orbicularis oris m.
-labial frenula connects lips to gums
Cheeks
-musocsa
-buccinator m.
-skin covering
Palate
Roof of mouth
-hard palate+ soft palate
Hard palate
-bony: anterior
-palatine process of maxillae
-palatine bones
Soft Palate
-posterior
-mucosa w skeletal m.
-uvula
-palatoglossal arch, fauces, palato-pharageal arch
TONGUE
-mostly skeletal M.
-intrinsic and extrinsic
-lingual frenulum connects to floor of mouth
PAPILLAE: Filiform=smallest
House taste buds:
fungiform
foliate
circumvallate: big row at back of tongue (in front of terminal sulcus)
Salivary gland function
Make and secrete saliva
-moisten food
-cleanse mouth
-break down complex carbs
Extrinsic Glands
Parotid g.
-Near ear
-Duct opens near upper 2nd molar
Extrinsic Glands
sublingual gland
-under tongue
Extrinsic Glands
submandibular g.
-under jaw
-duct opens to lingual frenulum
Extrinsic Glands (3)
-submandibular
-sublingual
-parotid
intrinsic gland
Salivary Gland
-small, numerous glands in mouth
Teeth= Dentitions
a) decidous
-baby teeth
-20 total
-erupt by 3yr, lost 6-12 yr
Teeth= Dentitions
b) permanent
-32 (28+ 4 wisdom)
-start coming in at 6yr
Teeth= Dentitions
c) classes of teeth (4)
- inscisors (8) chisels
- canines (4) fangs for tearing
- premolars (8) grind teeth
- molars (12) grind teeth (include wisdom: 3rd molars)
Tooth structure
- Crown
-visible portion
-enamel cover
-Ca++ Rich
Tooth structure
- Neck
-Constriction
-Surrounded by gums
Tooth structure
- Root
-embedded in jaw bone connected by periodontal ligaments
-cementum covering
-1-4 roots
Tooth structure
- Tissues
-enamal, dentin, cementum care ca++ rich, hard
-pulp is blood vessels+ nerves
Pharynx
-oropharynx+ laryngopharyx
-lines with stratified squamous
-wall contains skeletal m.
esophagus
lined
type of m. in sup and inf
lined w stratified squam
-tube from throat to stomach
-lined w stratified squamous
-superior part has mostly skeletal m in wall
-inferior part has mostly smooth ,
stomach
a) Regions
-cardia: near cardiac/ gastroesophageal sphincter
-fundus: dome
-body: main part
-pyloric region: has valve (sphincter) at exit
stomach regions
carida
near cardiac/ gastroespohageal sphincter
stomach regions
fundus
dome
stomach regioms
body
main part
stomach regions
pyloric region
has valve (sphincter) at exit
stomach
b) surface curves
-greater curvature: convex L+down
–greater omentum: mesentary off greater curvature
-lessercurvature: concave R+ UP
–lesser omentum: mesentrary off lesser curvature (toward liver)
stomach surface. curves
greater curvature:
greater omentum
curvature: convex L+ down
omentum: mesentary off greater curvature
stomach surface
lesser curvature
lesser omentum
curvature: concave R+ up
omentum: mesentary off lesser curvature (toward liver)
stomach
c) rugae
-ridges of mucosa folds within empty stomach
stomach
d) microscopic anatomy
lining + glands?
-simple columnar epithelial lining
-gastric glands (deep to pits) secrete gastric juice
stomach
e) physiological processes
-gastrin stimulates parietal cells to secrete HCL
-cheif cells secrete pepsinogen which will become pepsin inside stomachs lumen
-secrete intrinsic factor for vitamin B12
-churning: mechanical breakdown of food
stomach
e) physiological processes
gastrin stimulates
parital cells to secrete HCL
stomach
e) physiological processes
cheif cells secrete
pepsinogen which will become pepsin inside stomachs lumen
stomach
e) physiological processes
secretes instrinsic factor for
vitamin b12
stomach
e) physiological processes
churning
mechanical breakdown of food
small intestine
a) functions
-segmentation+chemical digestion+absorption of nutrients
-release CCK in response to arrival of fatty foods
-CCK stimulates gallbladder+ pancrease to secrete chemicals into small intestin
small intestine
b) divisions
1) Duodenum: recieves hepatopancreatic ampulla of major papilla
2) jejunum
3) ilium: ends at iliocecal valve
small intestine
c) features that increase surface area
-circular folds- 1cm tall
-villi- 1mm tall
-microvilli- 1 um tall
Liver
4 lobes: R lobe (largest), L lobe, quadrate lobe, caudate lobe
-falciform ligament: anterior
-round ligamnt (teres): scar of umbilical V
Gall bladder
where is it+ what goes after it lol
-back of livers R lobe
-gallbladder-> cystic duct-> common bile duct->hepatopancreatic ampulla-> sends bile into deuodemum when CCK is present
Pancreas
-is a retroperitoneal accessory gland
-has a main pancreatic duct
-pancreatic juice; basic PH, many ezymes
-also makes hormones (eg insulin)
Large intestine aborbs __ from food and ___feces
also absorbs
absorbs water from food and eliminates feces
-also absorbs some B vitamins and + Vitamin K
Large intestine segments
-cecum
-ascending colon-> R hepatic flexture
-transverse colon-> L splenic flexture
-decending colon
-sigmoid colon
-rectum
-anal canal- anal sphincter; external sphincter is skeletal m.
-tenia coli- smooth m. -> haustra
Chemical Digestion is
catabolism to make food molecules small enough for absorption
Catabolism is acomplished by
-hydrolysis: splitting with water (reactant)
-breaks a polymer into monomers by adding water using an enzyme
Carbohydrates
Monosachharides
simple sugars (eg glucose and fructose) directly absorbed
-no digestion needed
Carbohydrates
Disacharides: which will be
-Broken down+ products are absorbed
Carbohydrates
Starch is a
-digestable polysacharide
-broken down by amalayse
(cellulose is a non-degestible polysach)
chem digestion begins in the__ with\
resumes in the
begins in the mouth with salivary amylase
-resumes in the small intestine with pancreatic amylase and with brush border enzymes such as lactase
proteins come from
-food but also digestive secretions in the tract
pepsin
what is it secreted by
-is secreted by chief cells in the stomach as pepsinogen
-pepsinogen becomes pepsin in stomach lumen
Pancreatic enzymes:
trypsin and chymotrypsin
-released as inactive precursors that are activated in duodenum; break peptides down
Brush Border Enzymes
-carboxypeptidase, aminopepsidase, dipepsidase
-break down small peptides so that amino acids can be absorbed
Lipids are
elumsified and digested
bile emulsifies lipid glob
-reduces attrations between the lipids within the glob
-disperses globs into droplets
lipase chemically digests lipids
chem equation
H2O+tryglycerides—-lipase—->monoglyceride+ 2 F.A.
Nucleic Acids (both DNA and RNA) are hydrolyzed to their
nucleotide monomers by pancreatic nucleases from pancreatic juice
-brush border nucleases finish digestion
absorption occurs throughout the
small intestine but most is completed before chyme reaches the ilium
Absorption of specific nutrients
Glucose
absorbed by ___ into___ ___ exports by
-glucose is absorbed by secondary active transport into epitheliel cell of intestine lining; the cell exports the glucose by facilitated diffusion
Absorption of specific nutrients
Amino Acids
-are absorbed by secondary active transport
-the cell exports the a.a. by facilitated diffusion
Absorption of specific nutrients
Monoglyerides and free fatty acids combine with other molecules to form..
exocytosis removes…
-Micelles (fats+bile)
-Lipids of micelles diffuse passivly into cell
-exocytosis removes chylomicrons to go into lymph of lacteals
the small intestine absorbs…
the large intestine absorbs…
small: dietary vitamins
large: vitamin B and K
electrolytes are actively absorbed throughout…. except for
the entire small intestine
except for calcium and iron which are absorbed in the duodenum
Most abundent substance in chyme
-Water: 95% of it is absorbed in the small intestine by osmosis
Malabsorption of nutrients can result from anything that
interferes with delievery of bile or pancreatic juices, as well as factors that damage intestinal mucosa
-
dz causing poor absorption
celiac
