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405 Cards in this Set

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Name the 4 functions of the heart
1. Generating blood pressure

2. Routing blood (separates pulmonary and systemic circulation)

3. Ensures one-way blood flow

4. Regulating blood supply (adjusts to metabolic changes like exercise / rest)
Lymphatic system
body system that includes lymph, lymphatic vessels, lymphatic tissue,lymphatic nodules, lymph nodes, tonsils, the spleen, and the thymus
Encapsulated Dendritic Endings
Virtually all are mechanoreceptors.
Consists of one or more fiber terminals of sensory neurons enclosed in a connective tissue capsule.
What is the mediastinum?
heart, trachea, esophogus

midline partition structures
List three functions of the lymphatic system
1) fluid balance
2) fat absorption
3) defense
Meissner's Corpuscles
An encapsulated receptor.
Small receptors in which a few spiraling sensory terminals are surrounded by Schwann cells.
Found just beneath the epidermis in the dermal papillae
Especially numerous in sensitive and hairless skin areas (nipples, fingertips, soles of the feet)
Receptors for discriminative touch.
Also called tactile corpuscles.
Lymph
excess fluid passed from the bloodstream into bodily tissues accumulates and drains into lymphatic capillaries where it passes back into the circulatory system, this fluid is called lymph;
contains water, substances normally found in plasma, and substances derived from cells (hormones, enzymes, and waste)
Pacinian Corpuscles
Scattered deep in the dermis and in subcutaneous tissue underlying the skin.
A mechanoreceptor
Stimulated by deep pressure, but respond only when the pressure if first applied
Best suited for monitoring vibration.
The largest corpuscular receptor
What is the outer layer of the heart?
parietal pericardium
Lacteals
special lymphatic vessels that are located in the lining of the small intestine;
fats enter these vessels and pass through lymphatic vessels to the venous circulation
Ruffini endings
Located in the dermis, subcutaneous tissue, and joint capsules.
Resemble Golgi tendon organs
Respond to deep and continuous pressure.
What is the inner lining of the heart?
visceral pericardium

aka epicardium
Chyle
lymph passing through lacteals;
has a milky appearance due to its fat content
Muscle spindles
A proprioceptor
Found throughout the perimysium of a skeletal muscle.
Detect muscle stretch and initiate a reflex that resists the stretch.
Where is the pericardial cavity and what is it filled with?
between the parietal pericardium and the visceral pericardium and it's filled with pericardial fluid
Lymphatic capillaries
small dead-end tubes into which extra fluids from the body tissues enter into and becomes lymph;
differ from blood capillaries in that they lack a basement membrane and that cells of the simple squamous epithelium ovelap and are loosely connected
Golgi tendon organs
A proprioceptor.
Located in tendons, close to the skeletal muscle insertion.
When tendon fibers are stretched by muscle contraction, the nerve endings are activated by compression.
When activated, the contracting muscle is inhibited causing the muscle to relax.
What is pericarditis?
inflammation of serous membrane pericardium

pain similar to a heart attack

fluid can build up in pericardial sac
Lymphatic vessels
formed by the merging of lymphatic capillaries;
resemble small veins;
consists of three layers and contains one-way valves that keep lymph flowing in a single direciton
Joint kinesthetic receptors
A proprioceptor.
Monitor stretch in the articular capsules that enclose synovial joints.
4 receptor types contribute to this category: Pacinian corpuscles, Ruffini endings, free nerve endings, and receptors resembling Golgi tendon organs.
Together, these receptors provide info on joint position and motion.
What is cardiac tamponade?
large amount of fluid in pericardial sac.

can occur due to rupture from myocardial infarction, trauma, tumor growth or radiation therapy
What are three factors that are responsible for the movement of lymph through lymphatic vessels?
1) contraction of surrounding skeletal muscles during activity
2) periodic contraction of the smooth muscles in the lymphatic vessel walls
3) pressure changes in the thorax during respiration
Somatosensory system
Serves the body wall and limbs.
Receives input from exteroceptors, propriceptors, and interoceptors.
What are the 3 layers to the heart wall?
1. epicardium (visceral pericardium

2. myocardium (middle layer)

3. endocardium
Lymph nodes
round, oval (or bean-shaped) bodies distributed along the various lymphatic vessels;
function to filter lymph
3 main levels of somatosensory (or any sensory) system
Receptor level: sensory receptors
Circuit level: ascending pathways
Perceptual level: neuronal circuits in the cerebral cortex.

Sensory input is generally relayed toward the head, but it is also processed along the way.
Lymphatic trunks
lymphatic vessels converge to form lymphatic trunks, which drain major portions of the body;
juglar, subclavian, bronchomediastinal, intestinal, lumbar trunks
Describe the epicardium
thin serous membrane on outer surface of the heart wall
Processing at the Receptor level
For sensation to occur, a stimulus must excite a receptor and action potentials must reach the CNS.
Stimulus E must match the specificity of the receptor.
Stimulus must be applied within the receptor's field - smaller the receptive field, the greater localization.
Stimulus must be converted into the E of a generator (receptor) potential - transduction.
Lymphatic ducts
larger vessels which connect lymphatic trunks to large veins
Describe the myocardium?
thick middle layer comprised of smooth muscle cells
transduction
When stimulus E is converted into the E of a graded potential called a receptor potential.
Maybe depolarizing or hyperpolarizing
Right lymphatic duct
drains the right side of the head, right-upper limb, and right thorax
Describe the endocardium?
simple squamous epithelium over a layer of connective tissue.

allows the blood to move smoothly and easily
Generator potentials
Membrane depolarizations that summate and directly lead to generation of action potentials in an afferent fiber.
What are the pectinate muscles?
mucular ridges in both auricles and wall of right atria

(means comb shaped)
Thoracic duct
drains the right side of the body inferior to the thorax and the entire left side of the body
Sensory adaptation
A change in sensitivity and nerve impulse generation in the presence of a constant stimulus.
Phasic receptors and tonic receptors.
What is the crista terminalis?
separates the pectinate muscles from the larger, smoother portions of atrial wall
Lymphatic tissue
tissue that consists of primarily lymphocytes, but also includes macrophages, dendritic cells, reticular cells, and other cell types
Phasic receptors
Sensory adaptation
Fast adapting
Often give bursts of impulses at the beginning and at the end of the stimulus.
Act mainly to report changes in the external and internal enviroment.
Pacinian and Meissner's corpuscles
What are the trabeculae (beams) carnae (flesh)?
large muscular ridges on the inside of the ventricles
Lymphocytes
a type of white blood cell that originates from red bone marrow and carried by blood to lymphatic organs and other tissues;
divide in response to microorganisms and foreign pathogens
Tonic receptors
Sensory adaptation
Provide a sustained response w/ little or no adaptation.
Nociceptors, most proprioceptors b/c of the protective importance of their info.
What's another term for atria?
auricles
(ears)
Reticular fibers
very fine collagen fibers contained within lymphatic tissue;
produced by reticular cells;
lmphocytes and other cells attach to these fibers and forms a network that traps microorganisms and other particles in the lymph
Processing at Circuit level
Second level of integration.
Task is to deliver impulses to the appropriate region of the cerebral cortex for stimulus localization and perception.
Occurs in ascending pathways.
Nonspecific ascending pathways transmit pain, temp., and course touch-info is general and emotional.
Specific ascending pathways discriminate aspects of touch, vibration, pressure, and concious proprioception.
Typically chains of 3 neurons - 1st, 2nd, and 3rd order sensory neurons.
1st order: receptor to dorsal gray horn, link receptor and circuit levels of processing.
2nd order: to thalamus or medulla.
3rd order: to cerebral cortex
Mucosa-associated lymphoid tissue (MALT)
aggregates of nonencapsulated (no connective tissue layering) lymphatic tissue found in and beneath the mucous membranes lining the digestive, respiratory, urinary, and reproductive tracts
How many chambers are there in the heart?
4
2 atria
2 ventricles
Processing at Percpetual level
Interpretation of sensory input occurs in cerebral cortex.
Ability to identify and appreciate sensations depends on the specific location of the tg neurons in sensory cortex.
Can determine:
Stimulus has occured (perecptual detection).
Magnitude estimation - intensity.
Spatial discrimination - site of stimulation.
Feature abstraction - circuit tuned to one feature.
Quality discrimination - submodalities (sweet vs. bitter)
Pattern recognition - friends face or a melody.
What are the 2 main veins going from body into the right atrium?
superior vena cava
inferior vena cava
Diffuse lymphatic tissue
contains dispersed lymphocytes, macrophages, and other cells;
has no clear boundary and blends with surrounding tissues;
located deep to mucous membranes, around lymphatic nodules and within lymph nodes and spleen
Projection
Each sensory fiber is analogous to a "labeled line" that tells the brain "who" is calling and from where.
Brain always interprets the activity of a specific sensory receptor as a specific sensation.
The exact pt in the cortex that is activated always refers to the same "where" regardless of how it is activated.
All impulses coming to the brain are alike. The sensation depends on which part of the brain is stimulated.
Lymphatic nodules
denser arrangements of lymphoid tissue organized into compact, somewhat spherical structures;
numerous in loose connective tissue of the digestive, respiratory, urinary, and reproductive systems
How many pulmonary veins are there going from the lungs to the left atrium?
4 pulmonary veins
Pain receptors
Most pain receptors can be stimulated by more than one stimulus (extremes of pressure and temp.)
Histamine, K+, ATP, acids, adn bradykinin are potent pain producing chem.
Act on small diameter fibers.
Pain receptors adapt little if at all.
What is the main artery connected to the heart?
aorta

carries blood from the left ventricle to systemic circulation (body)
Peyer's patches
aggregations of lymphatic nodules found in the distal half of the small intestine and the appendix
Sharp pain
Carried by small myelinated A delta fibers
What's the other main artery (besides aorta) in the heart?
pulmonary trunk

carries blood from the right ventricle to the lungs
Tonsils
large groups of lymphatic nodules and diffuse lymphatic tissue located deep to the mucous membranes with the pharynx;
provide protection against bacteria and other potentially harmful material entering the pharynx from the nasal or oral cavities;
decrease in size in adults
Burning pain
Carried more slowly by small unmyelinated C fibers.
What is the Coronary sulcus?
crown /ditch

separates the atria from the ventricles
separates the right and left ventricles
Lymph nodes
small, round structures located along the course of the lymphatic vessels;
filter lymph;
sight of lymphocyte congregation, function, and proliferation
Glutamate and substance P
Neurotransmitters
Activate 2nd-order sensory neurons.
Released by pain transmitting neurons.
Where do the arteries that supply the heart with blood lie?
coronary sulcus
interventricular sulci
Germinal centers
areas of rapid lymphocyte division found in lymph nodes and especially in the lymphatic nodules of the cortex
Visceral pain
Pain receptors are the only receptors in the viscera that produce sensations.
Tends to be referred pain - feels as though it comes for elsewhere due to common nerve pathways.
Explain how the heart gets the blood it needs to pump
right and left coronary arteries exit the aorta right above where the aorta leaves the heart.

left marginal artery branches off the left coronary artery to supply left ventricle

right marginal artery branches off right coronary artery to supply the right ventricle

supplies heart with blood from these arteries that lie in the coronary sulcus

left anterior interventricular artery lies in the anterior interventricular sulcus to supply blood as well

circumflex artery covers the posterior side of the heart

posterior interventricular artery supplies the posterior and inferior heart
Afferent lymphatic vessels
vessels that carry lymph to the lymph nodes
Phantom pain
Comes from a limb that has been amputated.
May be due to stimulation of remaining nerve fibers or may be generated in the brain itself.
Can use local anasthetic w/ general for amputations so spinal cord doesnt feel the pain and learn.
what is an anastomoses?
direct connections between arterial branches
Efferent lymphatic vessels
vessels that carry lymph away from the nodes
Hyperalgesia
Pain amplification.
Pain may arise from remapping of area of the cortex previously used for sensations from amputated limb.
What are the 2 sides veins that empty into coronary sinus that flows into the right atrium?
left side - great cardiac vein

right side- small cardiac vein
Spleen
a lymphatic organ that is roughly the size of a clenched fist and is located on the left side in the extreme, superior part of the abdominal cavity;
destroys defective red blood cells, detects and responds to foreign substances in the blood, and acts as a blood reservoir
Eyebrows
Short, coarse hairs that overlie the supraorbital margins of the skull.
Help shade the eyes from sunlight and prevent sweat from reaching the eye.
Contraction of the orbicularis muscle depresses the eyebrow.
The corrugator moves the eyebrow medially.
White pulp
lymphatic tissue surrounding the arteries within the spleen
What are the 3 main openings in the right atrium?
1. superior vena cava

2. inferior vena cava

3. coronary sinus
Eyelashes
Follicles of eyelash hairs are richly innervated by nerve endings.
Tarsal glands - modified sebaceous glands that produces an oily secretion that lubricates the eyelid and the eye - prevents the eyelids froms sticking together.
Ciliary glands - modified sweat gland that lie b/t hair follicles.
What are the 4 openings of the left atrium?
4 pulmonary veins from the lungs
Red pulp
lymphatic tissue associated with the veins in the spleen;
consists of a fibrous network, filled with macrophages and red blood cells, and enlarged capillaries that connect to the veins
Olfactory sense
Sense of smell.
What is the interatrial septum?
separates the 2 atria
Periarterial lymphatic sheath
diffuse lymphatic tissue surrounding arteries and arterioles extending to lymphatic nodules
Hearing and equilibrium rely on what type of receptor?
Mechanoreceptors
What openings do the ventricles have?
opening with atria

Right ventricle opens to pulmonary trunk

Left ventricle opens to aorta
Splenic cords
a network of reticular cells within the spleen which produce reticular fibers
3 parts of the ear
Outer ear
Middle ear
Inner ear
what artery covers the posterior of the heart?
circumflex artery
Venous sinuses
enlarged capillaries between the splenic cords
External ear structure
Consists of the auricle and external acoutic meatus.
Which side is the tricuspid valve?
Right side
Thymus
a bilobed gland located in the superior mediastinum;
thought to increase in size until the first year of life;
site of maturation of T lymphocytes
Equilibrium
Balance.
Static and dynamic equilibrium.
Which side is in the bicuspid valve?
Left side
Immunity
the ability to resist damage from foreign substances such as microorganisms and harmful chemicals;
categorizes as either innate immunity and adaptive immunity
Peptides and Proteins
Chains of a.a.
TSH
Where is the coronary sulcus?

What lies in it?
between the right atrium and right ventricle

Right coronary artery
Innate (non-specific) immunity
immune response in which the body recognizes and destroys certain foreign substances, but the responses to them is the same each time the body is exposed to them
A hormonal stimulus can produce what changes?
Alters plasma memb. permeablility or memb. potential or both by opening or closing ion channels.
Stimulates synthesis of proteins or regulatory molecules w/in the cell.
Activates or deactivates enzymes.
Induces secretory activity.
Stimulates mitosis.
Where is the anterior interventricular sulcus?

What lies in it?
Between the right and left ventricles on the anterior side of heart

Great cardiac vein and anterior interventricular artery
Adaptive (specific) immunity
immune response in which the body recognizes and destroys foreign substances, but the response to them improves each time the foreign substance is encountered
Nervous system modulation
The N.S. makes adjustments to maintain homeostasis by overriding normal endocrine controls.
Incr. of blood glu. levels during periods of stress.
Where is the coronary sinus located?

Where does it empty into?
posterior in halfway part

Right atrium
Specificity
the ability of adaptive immunity to recognize a particular substance
pain receptors
nocireceptors
What are the 3 major openings of the Right Atrium?
superior vena cava

inferior vena cava

coronary sinus
Memory
the ability of adaptive immunity to "remember" previous encounters with a particular substance, resulting in a faster, stronger, and longer lasting response
Rt side of heart function
Pulmonary circulation
What are the 4 openings of the left atrium?
4 pulmonary veins from the lungs
Mechanical mechanisms
barriers that form the first line of defense against pathogens;
skin, mucous membranes;
either form barrier to prevent entry into body, or secrete chemicals that impede organisms from getting in
Left side of heart function
Systemic circulation
What's another name for the bicuspid valve?
mitral valve
Chemical mediators
molecules responsible for many aspects of innate immunity;
found on the surface of cells, in chemicals secreted by cells, etc.; lysozyme, sebum, mucus, histamine, complement
Pericardium
double layered, closed sac that encloses the heart

aka pericardial sac

tough, fibrous pericardium
and
thin serous pericardium
What are papillary muscles?
Heart strings

attached to valve cusps in each ventricle.

These muscles contract when the ventricle contracts
Complement
a group of about 20 proteins that make up approximately 10% of the globulin part of serum;
include proetins named C1-C9 and factors B, D, and P;
aid in innate immune response
Artery
Any vessel that carries blood away from the heart.
What are the semilunar valves?
aortic and pulmonary

keeps blood moving in one direction
Complement cascade
a series of reactions in which each component of the series activates the next component;
complement normally circulates in the bloodstream inactivated
Vein
Any vessel that carries blood toward the heart.
I am a little drop of blood in the coronary sinus. Explain my trip through the heart and back to this spot...
coronary artery flows into right atrium

thru the tricuspid valve into the right ventricle

thru the pulmonary semilunar valve to the pulmonary trunk

take the pulmonary arteries to the lungs

Head back to the heart via the pulmonary veins into the left atrium

thru the mitral valve into the left ventricle

thru the aortic semilunar valve to the aorta

into the body to end up in the superior or inferior vena cava OR to the heart and back to the coronary sinus

whew.
Alternative pathway
part of innate immunity and is initiated when complement protein C3 becomes spontaneously active;
activated C3 can combine with some foreign substances, become stabilized, and activate the complement cascade
Parietal pericardium
Outer fibrous layer
do veins carry Oxygen rich or CO2 blood?
veins carry oxygenated blood
Classical pathway
part of the adaptive immune system;
initiated by the constant region of antibodies;
stimulates inflammation; attracts neutrophils, monocytes, macrophages, and eosinophils to sites of infection; and kills bacteria by lysis
Parietal pericardium function
Prevent overstretching
Protection
Anchors to surrounding tissue
Membrane attack complex (MAC)
can be formed by activated complement proteins;
produces a channel through the plasma membrane of pathogen cell, causing the cell to lyse
Do arteries carry O2 blood or CO2 blood?
CO2 blood
The outer fibrous layer of the heart.
Parietal pericardium
what is a myocardial infarction?
prolonged lack of blood flow to caridac muscle resulting in cell damage and death.

arises from atherosclerotic lesions (plaque)
Interferons
proteins that protect the body against viral infection and perhaps some forms of cancer
3 layers of the heart wall.
Epicardium
Myocardium
Endocardium
What is angina pectoris?
chest pain

reduced blood supply to cardiac muscle

treated with nitroglycerin tablets which dilate vessels
Chemotactic factors
parts of microbes or chemicals released by tissue cells that act as chemical signals to attract white blood cells;
i.e., complement, leukotrienes, kinins, histamine
Muscle layer of the heart wall
Myocardium
Describe the 'skeleton' of the heart
fibrous conn. tissue forms fibrous rings around the atrioventricular and semilunar valves.

provides support, electrical insulation and muscle attachment site
Chemotaxis
the ability of some cells to detect and move from areas of low chemical concentration to areas of higher chemical conc.;
move toward the source of a chemotactic factor
Layer of heart wall that is continuous throughout the circulatory system
Endocardium
Phagocytosis
the endocytosis and destruction of particles by cells
Describe the physical characteristics of cardiac muscle cells
elongated branching cells
striated
1-2 central nuclei
actin / myosin myofilaments
Epicardium
Heart wall
Serous membrane
Neutrophils
small phagocytic cells produced in large numbers in red bone marrow that are released into the blood;
usually the first cells to enter infected tissues in large number and often die after a single phagocytic event;
release lysosomal enzymes that kill microorganisms and cause tissue damage and inflammation
Describe the Ca2+ channels and how it effects heart muscle function
smooth sarcoplasmic reticulum is in close contact with the T tubules, but the T tubules are loosely arranged and therefore there is a slower onset and prolonged contraction phase

Depolarization is less efficient and Ca2+ has further to travel to get to the actin myofilaments
Anastomoses
Collateral circulation
What provides the energy for cardiac muscle contraction?

What does that lead to?
ATP

needs O2 and so cardiac muscle cells are full of mitochondria that provide oxidative metabolism
Pus
an accumulation of dead neutrophils, dead microorganisms, debris from dead tissue, and fluid
Ischemia
Reduced blood flow
What is the conduction system of the heart consist of?
2 nodes
sinoatrial SA (pacemaker)
atrioventricular AV

atrioventricular bundle
(has right and left branches)
Macrophages
large phagocytic cells that are called monocytes when found in blood;
outlive neutrophils and ingest more and larger particles;
accumulate in tissues after neutrophils and are responsible for most phagocytic activity late in an infection;
produce interferons, prostaglandins, and complement
Hypoxia
Reduced O2 supply.
Describe an a.p. process in the heart
a.p. originates in SA node and travels to AV node

a.p. continues to atrioventricular bundle and branches into right and left

Purkinje fibers distribute a.p. to ventricular walls
Basophils
motile white blood cells that are derived from red bone marrow and can leave the blood and enter infected tissues;
can be activated through specific or non-specific immunity;
release inflammatory chemicals, histamine, leukotrienes
Angina pectoris
"strangled chest"
Where is the atrioventricular bundle located?
interventricular septum
Mast cells
nonmotile cells in connective tissue, located at potential points of entry of microorganisms into the body;
can be activated through specific or non-specific immunity;
release inflammatory chemicals, histamine, leukotrienes
Myocardial infarction
Death of an area of tissue due to interrupted blood flow.
Go thru the process of depolarization for a cardiac a.p.
DEPOLARIZATION PHASE:
Voltage gated Na+ channels open
Voltage gated K+ channels close
Voltage gated Ca2+ channels begin to open

EARLY REPOLARIZATION & PLATEAU PHASE
Voltage gated Na+ channels close
Some voltage gated K+channels open, causing early repolarization
Voltage gated Ca2+ channels are open, producing the plateau by further slowing repolarization

FINAL REPOLARIZATION PHASE
Voltage gated Ca2+ channels close
Lots of voltage gated K+ open






early repolarization where some of the Na+, Ca2+ channels close, Na+ flowing in slows and some K+ starts to go out

plateau phase Ca2+ channels open and slows the repolarization
Eosinophils
white blood cells produced in red bone marrow, leave bloodstream within a few minutes;
releases enzymes that break down chemicals released by basophils and mast cells;
contain and reduce the inflammatory response
Systole
Contraction
what does autorhythmicity mean?
cardiac muscle stimulates itself to contract in regular intervals
Natural killer (NK) cells
a type of lymphocyte produced in red bone marrow, account for 15% of lymphocytes;
recognize general classes of cells and release chemicals that cause the cells to lyse
Diastole
Relaxation
What is the prepotential and what does it do?
spontaneously developing local potential from the SA node.

small number of Na+ channels are open
voltage gated K+ channels are closing from previous a.p.'s repolarization phase
Voltage gated Ca2+ channels are beginning to open
Inflammatory resposne
a complex sequence of events involving many of the chemical mediators and cells of innate immunity;
caused by tissue injury
Sinoatrial node
Pacemaker
What is an ectopic focus?
any other part of the heart besides SA node generating a heartbeat.
Local inflammation
an inflammatory response confined to a specific area of the body;
symptoms include redness, heat, swelling, pain, and loss of function
Pacemaker
Sinoatrial node
Systemic inflammation
an inflammatory response that occurs in many parts of the body;
symptoms include redness, heat, swelling, pain, and loss of function, as well as the release of large numbers of neutrophils by red bone marrow, the release of pyrogens that stimulate fever production, and in severe cases, vaso-permeability increases dramatically
on an EKG, what does the P wave represent?
a.p. that causes depolarization of the atrial myocardium

onset of atrial contraction
Why is a prolonged refractory period a good thing in cardiac muscles?
keeps beating rhythmic and prevents tetanic contraction
Pyrogens
chemicals released by microorganisms, macrophages, neutrophils, and other cells, that stimulate fever production
What does the QRS complex on an ECG represent?
ventricular depolarization and signals the onset of ventricular contraction
Antigens
substances that stimulate adaptive or specific immunity;
usually large molecules
What does the T wave represent on an ECG?
repolarization of the ventricles

precedes ventricular relaxation
Haptens
small molecules capable of combining with larger molecules like blood proteins to stimulate an adaptive immune system response
What is the PR interval and what's happening?
0.16 seconds
atria contract and begin to relax

ventricles begin to depolarize at the end of it
Foreign antigens
antigens that are not produced by one's one body, but are introduced from outside of it
What is the QT interval and what's happening?
0.36 seconds

ventricles contract and begin to relax
Allergic reaction
an overreaction of the immune system that can be stimulated by pollen, animal dander, foods, drugs, etc.
What does a prolonged PR interval indicate?
1. delay in ap conduction thru atrial muscle because of damage (ischemia)

2. delay in ap conduction thru atrial muscle because of a dialated atrium

3. delay in ap conduction thru the AV node and bundle due to ischemia, compression or necrosis of the AV node or bundle
Self-antigens
molecules produced by the body that stimulate an adaptive immune system response;
can be beneficial or harmful
What does an unusually long QT interval indicate?
abnormal conduction of ap's thru the ventricles (from myocardial infarction or abnormally enlarged right or left ventricle)
Autoimmune disease
a condition that can result when self-antigens stimulate unwanted tissue destruction
What is atrial fibrillation?
no p waves

normal QRS

irregular timing

ventricles constantly stimulated by atria

reduced pumping effectiveness and filling time
Humoral immunity (antibody-mediated immunity)
immunity due to antibodies in serum;
effective against extracellular antigens such as bacteria, viruses, protozoans, fungi, parasites, and toxins when they are outside cells
What causes atrial fibrillation?
ectopic a.p.'s in atria
Cell-mediated immunity
immunity due to the actions of T cells and null cells
What is ventricular fibrillation?
No QRS complex wave

no rhythmic contraction of the myocardium

many patches of asynchronously contracting ventricular muscle
B cells
lymphocytes that give rise to cells that produce antibodies
What causes ventricular fibrillation?
ectopic a.p.'s in ventricles
T cells
lymphocytes that are responsible for cell-mediated immunity
What is Tachycardia?
Heart rate in excess of 100 bpm

could be caused by elevated body temp.
excessive sympathetic stimulation
toxic conditions
Effector T cells
T cells that are responsible for producing the effects of cell-mediated immunity;
i.e., cytotoxic T cells and delayed hypersensitivity T cells
What is Bradycardia?40-60
Heart rate less than 60 bpm

Elevated stroke volume in athletes
excessive vagal stimulation
carotid sinus syndrome
Regulatory T cells
T cells that promote or inhibit the activites of both antibody-medaited immunity and cell-mediated immunity
i.e., helper T cells, suppressor T cells
What is sinus arrhythmia?
Heart rate varies 5% during respiratory cycle and up to 30% in deep respiration

ischemia,
inflammation
cardiac failure
Positive selection
a process that results in the survival of pre-B and pre-T cells that are capable of an immune response
What are the corresponding bpm of:

SA Node

AV Node

AV bundle
SA 70-80

AV 40-60

AV bundle 30
Negative selection
a process that eliminates or suppresses clones acting against self-antigens, thereby preventing the destruction of self-cells;
occurs mostly during prenatal development, but continues throughout life
Primary lymphatic organs
the sites where lymphocytes mature into functional cells;
red bone marrow and thymus
Describe the cardiac cycle
SYSTOLE--isovolumic contraction

SYSTOLE--ejection

DIASTOLE--isovolumic relaxation

DIASTOLE--passive ventricular filling

DIASTOLE--active ventricular filling
What is blood pressure a measure of?
pressure in aorta rather than left ventricle

systolic average is 120 mm Hg

diastolic average is 80 mm Hg
Secondary lymphatic tissues
the sites where lymphocytes interact with each other, antigen-presenting cells, and antigens to produce an immune response;
diffuse lymphatic tissue, lymphatic nodules, tonsils, lymph nodes, spleen
What is MAP?
mean arterial blood pressure

Cardiac Output x Peripheral resistance
Antigenic determinants (Epitopes)
specific regions of a given antigen recognized by a lymphocyte;
each antigen has many different antigenic determinants
What is cardiac output CO?
amount of blood pumped by heart per minute

Heart Rate x Stroke Volume
(BPM) (end diastolic- end sys)
vol. vol.
Antigen receptors
surface proteins found on lymphocyte clones that combines with antigenic determinant;
specific to each antigen;
result is similar to the lock-and-key model for enzymes
What is Peripheral resistance PR?
total resistance against which heart beats
T-cell receptor
consists of two polypeptide chains, which are subdivided into a variable and a constant region;
variable region can bind to an antigen, different T cells have receptors with different variable regions
What does exercise do to end-diastolic volume?
It increases the volume because venous return increases
B-cell receptor
consists of four polypeptide chains with two identical variable regions, a type of antibody
What does exercise do to end systolic volume?
It decreases it because the harder contractions pump more out
Major histocompatibility complex (MHC) molecules
glycoproteins located on the surface of cells that are responsible for most lymphocyte activation;
attached to plamsa membranes and have a variable region that can attach to foreign and self-antigens
What is the approximate CO of the heart at rest?
HR= 72 bpm
SV= 70 mL

72 x 70= 5040 mL/min
MHC class I molecules
MHC molecules found on nucleated cells and function to display antigens produced inside the cells on their surfaces;
allow a way for the immune system to respond to problems within a cell, such as viruses;
viral proteins attach to these molecules and they migrate to cell surface form MHC class I/antigen complex, activating T cells;
stimulates destruction of the cell
What is the CO of the heart during exercise?
HR= 190 bpm
SV = 115 mL/min

190 x 115 = 21,850 mL/min
MHC-restricted
a process that requires both the antigen, and the organism's own MHC to be functional
What is the cardiac reserve and what does it indicate?
the difference between the resting heart CO and the maximum CO during exercise.

The greater the number of this reserve the greater is the individual's capacity for doing exercise
MHC class II molecules
found on antigen-presenting cells;
vesicles containing MHC class II molecule combine with endocytotic vesicles containing antigen, forming a complex which is transported to the cell's surface;
can bind to T-cell receptors on the surface of T-cells;
does not stimulate the destruction of the cell, but rather stimulates an immune resposne against the antigen
Which type of regulation of the heart utilizes hormones and neurons?
Extrinsic regulation
Antigen-presenting cells
include macrophages, B cells, monocytes, and dendritic cells;
can take in foreign antigens by endocytosis
What is intrinsic regulation of the heart?
Normal heart function.

No neurons or hormones involved.
Dendritic cells
large, motile cells with long cytoplasmic extensions;
scattered throughout most tissues with their highest conc. in lymphatic tissue and skin (Langerhans' cells)
What is preload?
extent to which ventricular walls stretch

think back to skeletal muscles. For the greatest contraction the muscles are stretched to the optimum length for greatest force.

cardiac muscles are different. They create stronger contractions by stretching of the ventricular walls to a big "preload" length.
Costimulation
additional stimulus that is often needed to cause an immune response, in addition to MHC class II/antigen complexes;
accomplished by molecules released from cells and by molecules attached to the surface of cells
What is Starling's law of the heart?
relationship between preload and stroke volume.

The bigger the preload stretch the larger the stroke volume.
Cytokines
proteins or peptides secreted by one cell as a regulator of neighboring cell;
promote costimulation;
involved in the regulation of immunity, inflammation, tissue repari, cell growth, etc.
What is afterload?
pressure it takes for ventricles to push the blood into the aorta.

This doesn't change very much
Lymphokines
cytokines produced by lymphocytes
What type of regulation are preload, Starlings law and afterload a part of?
Intrinsic regulation
Tolerance
a state of unresponsiveness of lymphocytes to a specific antigen;
most important funciton of tolerance is to prevent the immune system from responding to self-antigens;
can be induced by deletion of self-reactive lymphocytes, preventing activation of lymphocytes, or by activation of suppressor T cells
Do parasympathetic or sympathetic nervese play more of a role in extrinsic regulation?
Sympathetic
Anergy
"without working";
a condition of inactivity in which a B or T cell does not respond to an antigen
What is extrinsic regulation responsible for?
blood pressure

blood O2 levels

blood CO2 levels

blood pH levels
Suppressor T cells
cells with the ability to suppress immune responses;
currently not well understood;
likely that they are subpopulations of helper T cells and cytotoxic T cells
What is parasympathetic extrinsic regulation responsible for?
It plays an inhibitory role through the vagus nerve

decreases H.R.
Gamma globulins
Immunoglobulins (Ig)
other names for antibodies
Variable region
the portion of the antibody that combines with the antigenic determinant of the antigen; different antibodies have different variable regions that are specific for different antigens
How does parasympathetic extrinsic regulation decrease HR?
acetycholine binds to ligand gated channels making the cardiac membrane to become more permeable to K+ causing hyperpolarized membrane (takes longer to depolarize so action potentials are fewer)
What do the postganglionic sympathetic nerve fibers innervate to stimulate the heart?
SA and AV nodes

coronary vessels

atrial and ventricular myocardium
Constant region
portion of an antibody that is responsible for activities of antibodies like ability to activat complement or to attach the antibody to such cells as macrophages, basophils, mast cells, and eosinophils
What does stimulation of the sympathetic extrinsic regulation do?
increases the HR and force of muscular contraction
Opsonins
substances that make an antigen more susceptible to phagocytosis; IgG can act as an opsonin
What can happen if sympathetic stimulation causes the heart rate to increase too much?
stroke volume can go down because there is not enough time for ventricular filling (end diastole volume is low)

metabolites can increase and cause a decrease in strength of contractions
Primary response
results from the first exposure of a B cell to an antigen for which it is specific and includes a series of cell divisions, cell differentiation, and antibody production;
normally takes 3-14 days to produce enough antibodies to be effective against the antigen
To what degree does sympathetic stimulation effect the regulation of contraction force in a person at rest?
it provides 20% more oopmh to contraction force by stimulating the ventricular myocardium
Plasma cells
large lymphocytes produced by the mitotic division of B cells;
produces antibodies
Memory B cells
small lymphocytes that are produced when B cells undergo mitosis;
How does norepinephrine increase the heart rate and degree of cardiac muscle depolarization?
norepinephrine combines with B-adrenergic receptors, causeing a Gprotein-mediated synthesis and accumulation of cAMP in the cytoplasm of cardiac muscle cells.
Cyclic AMP increases the permeability of the plasma membrane to Ca2+
What hormones dramatically influence the pumping effectiveness of the heart?

Where do they come from? Why?
epinephrine and norepi

adrenal medulla

in response to exercise, stress, or extreme excitement
Secondary (memory) response
occurs when the immune system is exposed to an antigen against which it has already produced a primary response;
results from memory B cells, which rapidly divide to form plasma cells and large amounts of the antibody;
requires only a few hours to days to produce sufficient numbers of antibodies and produces a much larger number of antibodies than primary response
What is the Baroreceptor reflex?
detectors feeling changes to blood pressure (stretch receptors)

inside the walls of certain large arteries (aorta and internal carotid, i.e.)

They have afferent nerves that extend through the glossopharangeal nerve (IX) and vagus (X) to the cardioregulatory center (medulla oblongata)
Cytotoxic T cells
T cells that lyse cells and produce cytokines
Perforin
a protein which is similar to the complement protein C9 and is used by cytotoxic T cells to cause cell lysis;
forms a channel in the plasma membrane of the target cell through which water enters the cell
Describe the heart is regulated from baroreceptor signals
sensory neurons carry ap's from baroreceptors to cardioregulatory center

cardioregulatory center regulates parasympathetic ap's (decreases hr) thru vagus nerve

cardioregulatory center regulates sympathetic ap's thru cardiac nerves (increases hr and sv)

cardioregulatory center sends ap's thru the sympathetic neurons to adrenal medulla, which then releases epi and norepi (increase the hr and sv)
Delayed hypersensitivity T cells
T cells that respond to antigens by releasing cytokines;
promote phagocytosis and inflammation, especially in allergic reactions
Are the frequency of ap's increased or decreased when blood pressure increases in the carotid artery?
increased blood pressure causes the arteries to stretch thereby sending more frequent ap's from the baroreceptors
What does increased blood pressure do to sympathetic and parasympathetic stimulation?
increased blood pressure decreases sympathetic stimulation and increases parasympathetic stimulation
Immunotherapy
treats disease by altering immune system function or by directly attacking harmful cells
What does decreased blood pressure do to sympathetic and parasympathetic stimulation?
Decreased blood pressure decreases parasympathetic stimulation and increases sympathetic stimulation
Humanization
a process in which monoclonal antibodies are modified to resemble human antibodies;
allows monoclonal antibodies to sneak past the immune system
What are chemoreceptor reflexes?
regulate
pH
CO2
Immunization
a deliberate introduction of an antigen or antibody into the body
What happens if the medulla oblongota chemoreceptors detect a drop in blood pH and a rise in CO2?
decrease parasympathetic stimulation and increase sympathetic stimulation
Active immunity
occurs when an individual is naturally or artificially exposed to an antigen and an adaptive immune system response can occur that produces antibodies
Where are chemoreceptors sensitive to blood oxygen levels found?
carotid and aortic bodies near brain and heart

have more impact of regulating respiration and vasoconstriction than hr
Passive immunity
occurs when another person or animal develops antibodies and the antibodies are transferred to a nonimmune individual
What are the important ions for heart function?
K+, Na+, Ca2+

Na+ levels stay very constant in the heart muscles
Active natural immunity
achieved when a natural exposure to an antigen can cause an individual's immune system to mount an adaptive immune system response against the antigen
What happens if there is an excess of K+ in cardiac tissue?
HR decreases

SV decreases

only partially depolarizes membrane so ap's decrease and ectopic ap's occur causing fibrillation
Active artificial immunity
an antigen is deliberately introduced into an individual to stimulate the immune system (vaccination)
What happens if there is a decrease in extracellular K+?
HR decreases

resting membrane potential is hyperpolarized so it takes longer for the membrane to get to threshold
Passive natural immunity
results from the tranfer of antibodies from a mother to her child across the placenta before birth or through breastfeeding
What happens if there is an excess of extracellular Ca2+
cardiac contraction increases
Passive artifical immunity
a process by which an animal is injected with an antigen (vaccine) and once its immune system produces a response, antibodies are removed and injected into the individual requiring immunity
What happens if blood Ca2+ levels are low?
HR increases (more Na+ channels are opening, so more depolarizations)
Antiserum
the general term used for serum, which is plasma minus the clotting factors;
contains antibodies responsible for passive artifical immunity
What does getting old do to your heart?
hypertrophy of left ventricle due to increased aortic pressure and stiffening of cardiac muscle

decrease in maximum heart rate

tissue becomes less flexible

electric system gets a little faulty (SA nodes decrease)

coronary heart disease
Plasma
Nonliving fluid matrix of blood.
55% of whole blood.
Least dense component.
Formed elements
Living blood cells.
Suspended in plasma.
Erthrocytes - 45% of whole blood, most dense component.
Buffy coat - Leukocytes and platelets, <1% of whole blood.
Hemotacrit
% of erthrocytes.
"blood fraction".
Blood functions
Transportation/Distribution
Regulation - maintaining body temp. and pH.
Protection - preventing blood loss and infection (immunity).
Erthrocytes
No nuclei or organelles.
Bound by plasma memb.
Spectrin gives flexibility.
Over 97% hemoglobin.
Transport Oxygen.
Women typically have lower RBC count than men.
Blood thins as RBC count drops and vice versa.
Hematopoiesis
Blood cell formation.
Also hemopoiesis.
Occurs in red bone marrow.
Hemoglobin
Protein that makes RBC's red.
Binds easily and reversible w/ O2.
Composed of protein globin bound to red heme pigment.
Globin composed of 4 polypeptide chains - 2 alpha and 2 beta.
Each heme group bears an atom of iron in its center.
Hemoglobin can transport 4 molecules of O2.
Erthrocyte function
O2 loading occurs in lungs.
Transported to tissue cells.
When O2 binds to iron, hemoglobin is now oxyhemoglobin - assumes new 3 dimensional shape.
When O2 detaches - now deoxyhemoglobin, or reduced hemoglobin.
Carbaminohemoglobin
About 20-23% of CO2 transported in blood combines w/ hemoglobin.
Binds w/ globin's a.a forming carbaminohemoglobin.
CO2 loading occurs in the tissues and transported to lungs where it is eliminated.
Blood sinusoids
Network of reticular connective tissue bordering on wide blood capillaries.
W/in this network are immature blood cells, macrophages, fat cells, and reticular cells (secrete the fibers).
Hemocytoblast
Stem cell from which formed elements arise.
Once a cell is committed to a specific blood cell pathway, it can't change.
Reticulocyte count
Provides a rough index of the rate of RBC formation.
Reticulocyte
A young erythrocyte.
Still contains a reticulum, or network, of clumped ribosomes.
Bilirubin
A yellow pigment that is released to the blood and binds to albumin for transport.
Heme group is degraded to bilirubin.
Sickle-cell anemia
Caused by hemoglobin S.
RBC's become crescent shaped - rupture easily and dam up in small B.V.
Leukocytes
Only formed elements that are complete cells - have nuclei and usual organelles.
Less than 1% of blood volume.
3 cell lines: myeloid, lymphoid, and monocytic.
Granular leukocytes
Neutrophils
Eosinophils
Basophils
Agranular leukocytes
Lymphocytes
Monocytes
Eosinophils
Combat effect of histamine in allergic rxns.
Combat parasitic worms
1-3% of leukocytes.
Neutrophils
Most numerous WBC.
Phagocytes.
Our bodies bacteria slayers.
Basophils
Release heparin and histamine.
Increase in allergic rxns that intensify the inflammatory response.
Monocytes
Largest leukocyte.
Horseshoe shaped nuclei.
When leave blood and enter tissues - become macrophages.
Leukocytosis
Increase in number of WBC's.
Leukopenia
Deficiency in WBC's.
Platelets
Cytoplasmic fragments of large cells called megkaryocytes.
Essential for clotting.
Anucleated.
Formation of platelets is regulated by the hormone thrombopoietin.
Formed from megakaryocytes.
Release serotonin - contracts smooth muscle in B.V. walls.
Plasma
92% water.
8% solutes - mostly proteins.
Proteins mostly made by the liver.
Major blood carbohydrate
Glucose
Serum
Plasma w/o the clotting factors.
Includes antibodies.
Hemostasis
Stoppage of bleeding.
3 steps: Vascular spasm, Platelet Plug formation, Blood coagulation (clotting)
Also clot retraction.
Vascular Spasm (Vasospasm)
1st step of hemostasis.
Damage B.V. constricts (smooth muscle).
Decreased B.V. diameter decreases blood flow.
Last several minutes to several hours.
Platelet Plug Formation
2nd step of hemostasis.
Platelets form a plug that temporarily seals break in B.V. wall.
Platelets do not stick to each other or to smooth endothelial lining of B.V.
Instead, nitric oxide is released and prostacyclin - prevent platelet aggregation in undamaged tissue and restrict aggrgation to site of injury.
von Willebrand stabilized bound platelets.
Serotonin and thromboxane A2 enhance platelet aggregation.
Blood coagulation (clotting)
3rd step of hemostasis.
Reinforces platelet plug w/ fibrin threads that act as a glue.
Clotting factors, or procoagulants, transform blood from a liquid to a gel.
3 stages: formation of prothrombinase, conversion of prothrombin to thrombin, conversion of soluble fibrinogen to insoluble fibrin.
Fibrous Percardium function
Protect the heart
Anchor it to surrounding structures.
Prevent overfilling of the heart w/ blood.
2 layers of serous pericardium
pariteal layer - lines internal surface of fibrous pericardium

visceral layer - also epicardium, integral part of heart wall.
pericardial cavity
b/t parietal and visceral layers
contains film of serous fluid
internal partitions that divide the heart longitudinally
interatrial septum
interventricular septum
auricles func
incr the atrial volume somewhat
c shaped ridge seperating post and ant regions of the rt atrium
crista terminalis
atria function
receiving chambers for blood returning to the heart from circulation.
contribute little to the propulsive pumping activity of the heart.
blood enters the rt atrium via what 3 veins
superior vena cava
inferior vena cava
coronary sinus
how many veins enter the left atrium and what kind
4 pulmonary veins
transport blood from the lungs back to the heart
ventricle func
actual pumps of the heart
rt ventricle
pumps blood into the pulmonary trunk
routes blood to the lungs where gas exchange occurs.
lft ventricle
ejects blood into the aorta, the largest artery in the body
rt side of heart
pulmonary circuit pump - carries blood to and from lungs.
pulmonary circuit arteries
O2 poor blood
pulmonary circuit veins
O2 rich blood
lft side of heart
systemic circuit pump
systemic circuit
lft side of heart
freshly oxygenated blood is returned to lft atrium
passes into lft ventricle and pumped into aorta
from aorta to body tissues
returns via systemic veins to rt side of heart
enters rt atrium.
coronary circulation
functional blood supply of the heart
shortest circulation in the body.
av valves
located at each atrial ventricular junction
prevent backflow into the atria
tricuspid and mitral valves
chordae tendineae
heart strings
anchor cusps to papillary muscles protruding from ventricular walls
semilunar valves
aortic and pulmonary valves
guard base of large arteries issuing from the ventricles and prevent backflow into the associated ventricles.
autorhythmicity
cardiac cells can depolarize themselves and also the rest of the heart
cardiac refractory period
inexcitable period when na channels are still open or inactivated.
long in cardiac muscle
prevents tetanic contractions which would stop the hearts pumping action
events leading to contraction
depolarization opens a few na channels in sarcolemma. very brief.
transmission of this depolarization down T tubules causes sr to release ca intot he sarcoplasm.
excitation contraction coupling occurs as ca provides the siganl via troponin binding coupling the depolarization wave to the sliding of myofilaments.
plateau
though na channels have inactivated and repolarization has begun, ca surge prolongs depolarization causing a plateau.
few k channels are open preventing rapid repolarization also prolonging the plateau.
intrinsic cardiac conduction system
noncontractile cardiac cells specialized to initiate and distribute impulses throughout the heart.
allows the heart to beat as a coordinated unit
the coordinated activity of the heart is a func of what
presence of gap junctions
intrinsic cardica conduction system
autorhythmic cells
have an unstable resting potential that cont. depolarizes.
these spontaneoulsy changing memb potentials are pacemaker potentials.
what produces the rising phase of the a.p. in autorhythmic cells
influx of ca, not na that reverses memb potential.
different than contractile muscle fibers of the heart where na causes it
impulses pass across the heart in what order
sinoatrial node - av node - av bundle (bundle of his) - rt and lft bundle branches - purkinje fibers
pulmonary artery b/p
24/8
pulmonary cirulation is low pressure
cardiac cycle events
ventricular filling
ventricular systole
isovolumetric relaxation
ventricular filling
1st step of cardica cycle
mid to late diastole
pressure in the heart is low
blood returning from circulation is flowing thru atria into ventricles
atria contract propelling blood into ventricles.
then atria relax and ventricles depolarize
ventricular systole
2nd step of cardica cycle
ventricles begin contracting as atria relax
when ventricular pressure exceed pressure of large arteries, semilunar valves are forces open and blood is expelled to aorta and pulmonary trunk.
pressure in aorta reaches 120 normally.
isovolumetric relaxation
3rd step of cardiac cycle
ventricles relax
cardiac output
amt of blood pumped out by each ventricle in 1 minute
heart rate x stroke volume
stroke volume
vol of blood pumped out by 1 ventricle w/ each beat.
end diastolic vol
amt of blood that collects in a ventricle during diastole
end systolic vol
vol of blood remaining in a ventricle after it has contracted
preload
degree to which cardiac muscle is stretched just before they contract
venous return
most imp factor stretching cardiac muscle
amt of blood returning to the heart and distending its ventricles
enhanced contractility results in what
ejection of more blood from the heart so greater SV but lower ESV
afterload
pressure that must be overcome for the ventricles to eject blood
pressure is 80 in aorta and 8 in pulmonary trunk
layers of b.v
tunica intima
tunica media
tunica externa
vasa vasorum
contained in tunica externa
system of tiny blood vessels that nourish more external tissues of the b.v. wall.
vascular anastomoses
interconnections where vascular channels unite.
provide alternate pathways, collateral channels, for blood to reach a given body region.
pulse
pressure wave from the alternating expansion and recoil of arteries
2 main groups of digestive organs
organs of alimentary canal
accessory digestive organs
alimentary canal is also the what?
gastrointestinal (GI) tract
gut
alimentary canal
cont., muscular digestive tube that winds thru the body from the mouth to the anus
func. of alimentary canal
digests food
absorbs digested fragments thru its lining into the blood.
organs of the alimentary canal
mouth
pharynx
esophagus
stomach
small intestine
large intestine
accessory digestive organs
teeth, tongue, gallbladder
digestive glands - salivary glands, liver, pancreas
accessory digestive organ func.
produce a variety of secretions that help breakdown food.
digestive processes
ingestion
propulsion
mechanical digestion
chemical digestion
absorbtion
defecation
propulsion
2nd step of dig. process
includes swallowing (voluntary) and peristalsis (involuntary)
peristalsis
major means of propulsion
alternate waves of contraction/relaxation of muscles in organ walls
segmentation
in mechanical digestion, the costrictions of the small intestine, mixing food w/ digestive juices incr. absorbtion efficiency.
chemical digestion begins where and is completed where?
begins in mouth
usually complete in small intestine.
absorbtion
5th step in dig. process
the passage of digested end products from lumen of GI tract thru mucosal cells via active or passive transport into blood or lymph.
major absorbtion site in digestive process.
small intestine
splanchic circulation
includes arteries that branch off of abdominal aorta to serve digestive organs and the hepatic portal circulation.
arterial supply - hepatic, splenic, lft gastric branches off of celiac trunk
receives a/b 25% of CO
4 basic layers, or tunics, of alimentary canal
mucosa
submucosa
muscularis exeterna
serosa
mucosa
innermost layer of GI tract
moist epithelial membr. lining GI lumen.
mucosa functions
secretes mucus, dig. enzymes, hormones.
absorbs end products of dig. into the blood
protects against disease
3 sublayers of mucosa
epithilium lining
lamina propria
muscularis muscosae
epithelium sublayer of mucosa
simple columnar epithelium
rich in mucus secreteing cells
enteroendocrine glands
lamina propria
sublayer of mucosa
loose areolar connective tissue
capillaries nourish epithelium and absorb nutrients.
lymphoid follicles part of MALT - defense against bact. and other pathogens
lamina propria tissue type
loose areolar connective tissue
muscularis mucosae
sublayer of mucosa
2 layers of smooth muscle
produces local movements of mucosa
submucosa
just external to mucosa
areolar connective tissue
rich supply of BV, lymphatic vessels, nerve fibers.
glands and lymphatic tissue
submucosal plexus
submucosal plexus
in the submucosa
autonomic nerve supply to muscularis mucosae, BV, and secretory cells
muscularis externa (muscularis)
surrounds submucosa
responsible for peristalsis and segmentation
inner circular layer and outer longitudinal layer of smooth muscle cells.
circular layer thickens in some places forming sphincters - prevents backflow of food.
serosa
protective outermost layer
serous membr. - the visceral peritoneum.
areolar connective tissue covered by simple squamous epith. called the mesothelium
lubricates
splanchic circulation supplies the:
digestive organs
the cardiac sphicter is usually closed to prevent:
acidic gastric juice from entering the esophagus.
The mouth
also oral cavity
includes the cheeks, hard and soft palates, lips, tongue
walls lined w/ thick stratified squamous epi.
salivary glands function
moistens food
cleanses mouth
dissolves food chemicals so they can be tasted.
contains enzymes that begin breakdown of starchy foods (carbohydrates).
3 pairs of salivary glands
parotid, submandibular, sublingual
most saliva produced by:
extrincsic salivary glands
salivary amylase
main enzyme in saliva
digests starch and glycogen
2 sets of teeth
primary (deciduous)
permanent
how many permanent teeth?
32
2 major regions of the tooth
crown
root
dentin
bonelike substance that forms bulk of tooth
enamel
hardest substance in the body
central pulp cavity
surrounded by dentin
contains BV, nerve fibers, connective tissue.
From the mouth, food passes posteriorly into the:
oropharynx to the laryngopharynx.
what does the nasopharynx do?
it has no digestive role
after food moves thru the laryngopharynx, where does it go?
routed to esophagus
esophagus pierces diaphramn where?
esophageal hiatus
esophagus joins stomach where?
cardiac orifice.