A&P II: Exam 2 | Lymphatics, Respiratory, Digestion, and Metabolism

nonspecific (innate) immunity

no specific recognition of invaders, no memory component. This is the first and second lines of defense

specific (adaptive) immunity

specific recognition of invaders with a memory component

lymphatic vessels

begin as lymphatic capillaries and they are closed at one end. They then unite to form large lymphatic vessels. These vessels then pass through the lymph nodes. The lymph nodes are located in areas with encapsulated organs with masses and B and T cells. These function as lymph filters.

myeloid tissue

bone marrow: site for the production of blood cells in the medullary cavities. is also known as red bone marrow

how lymphatics differ and compare to the circulatory system

Lymph vessels travel one-way, back to the heart, venous route; has similar structure to veins including tunics and valves (?); structural difference includes the lymph vessel's need to diffuse bigger molecules; lymph transport slower and has lower pressure and speed than veins

Blood and nutrients travel through blood vessels (arteries, veins, and capillaries). The lymphatic system is responsible for draining excess fluid from the tissues and returning it to the circulatory system.

distribution of lymphatic vessels

lymphatic capillaries

have a larger diameter than blood capillaries. They have a unique one-way structure in order to permit interstitial fluid to flow in but not out.

how veins and vessels are similar

These large lymphatic vessels resemble veins in structure, but the vessels have thinner walls and more valves than veins.

LEUKOCYTES

F. LEUKOCYTES [WBCs] Myeloid derived

1. Monocyte-Macrophages - fixed and free big eaters [Reticuloendothelial System]

Fixed: Langerhan Cells, Kupffer Cells, Microglea, Osteoclasts etc. Present

antigens; Clean up after microphage battles

2. Microphages - kamikaze little eaters

a. Neutrophils - invading bacteria & cellular debris

b. Eosinophils - target foreign cpds or pathogens coated with antibodies

3. Basophils and Mast Cells - Inflammatory response Histamine, Heparin,

Prostaglandins

primary lymphatic organs

sites where stem cells divide and become immunocompetent (the ability of the body to produce a normal immune response following exposure to an antigen). These are formed in the red bone marrow and thymus.

secondary lymphatic organs

sites where most immune response occurs. These are the lymph nodes, spleen, and lymphatic nodules.

Major Histocompatibility Complex

The function of MHC molecules is to bind peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate T cells.

Major histocompatibility complex (MHC), group of genes that code for proteins found on the surfaces of cells that help the immune system recognize foreign substances. MHC proteins are found in all higher vertebrates. In human beings the complex is also called the human leukocyte antigen (HLA) system.

MHC Class I

- found on all nucleated cells

- built into all body cells except RBCs

MHC Class II

- found on antigen presenting cells and lymphocytes

- only on antigen presenting cells

immune system response

an antigen triggers an immune response -> activates t cells and b cells -> t cells attack the antigen and stimulate the b cells -> activated b cells mature and produce antibodies -> antibodies attack the antigen

origins of t-cells , how they develop, competent or not

t-cells migrate to the thymus from red bone marrow. dendritic cells and specialized epithelial cells help educated and mature t-cells. after the negative/positive selection process, immunocompetent t-cells go to the inner medulla.

interleukin

- a type of cytokine

- interleukin 1 is released by active macrophages

>> triggers the release of ACTH resulting in glucocorticoid release, moderates the immune response, lowers resistance to disease

- interleukin 2 is needed for virtually all immune responses

b-cells, how they develop, competent or not

Produced in the bone marrow, B cells migrate to the spleen and other secondary lymphoid tissues where they mature and differentiate into immunocompetent B cells. Part of the adaptive immune system, B cells are responsible for generating antibodies to specific antigens, which they bind via B cell receptors (BCR).

properties of immunity

1) specificity: activated by and responds to a specific antigen

2) versatility: is ready to confront any antigen at any time

3) memory: "remember" any antigen it has encountered

4) tolerance: responds to foreign substances but ignores normal tissues

exogenous antigens

present in fluid outside body cells

Antigen-presenting cells (APCs) include dendritic cells, macrophages and B cells

Ingest antigen, process, place next to MHC-II molecule in plasma membrane, and present to T cells

endogenous antigens

antigens inside body cells

Infected cell displays antigen next to MHC-I

cell mediated (cellular)

- lymphocytes act against target cell

>> DIRECTLY - by killing infected cells

>> INDIRECTLY - by releasing chemicals that enhance inflammatory response

- Cellular immunity has cellular targets

T LYMPHOCYTES

cytotoxic t-cells directly attack invading antigens. particularly effective against intracellular pathogens, some cancer cells and foreign tissue transplants.

antibody mediated (humoral)

- antibodies, produced by lymphocytes, circulating freely in body fluids

- bind temporarily to target cell

>> temporarily inactive

>> mark for destruction by phagocytes or complement

B LYMPHOCYTES

b-cells transform into plasma cells making antibodies (Abs) or immunoglobulins. work against extracellular pathogens in fluids outside cells.

cell mediated and antibody mediated both...

- have helper t-cells aid in both processes

- both types work together to defend the body

innate immunity

- genetically determined

- present at birth

acquired immunity

- not present at birth

- achieved by exposure to antigen

active immunity

natural active example: exposure to chicken pox

artificial active example: immunization against polio

passive immunity

natural passive example:

maternal antibodies crossing the placenta

artificial passive example:

vaccination against the effects of a snake bite

suppressor t-cells

(Ts) inhibit the activation of t cells and b cells

helper t-cells

(Th) activate other t cells and b cells

memory t-cells

have previously encountered and responded to their related antigen

b-cell differentiation

A single B cell or a clone of cells with shared specificity, upon encountering its specific antigen, divides to produce many B cells. Most of such B cells differentiate into plasma cells that secrete antibodies into blood that bind the same epitope that elicited proliferation in the first place.

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delayed hypersinsitivity

Delayed hypersensitivity is a major mechanism of defense against various intracellular pathogens, including mycobacteria, fungi, and certain parasites, and it occurs in transplant rejection and tumor immunity.

it is not antibody mediated but rather is a type of cell-mediated response. CD4+ helper T cells recognize antigen in a complex with Class 2 major histocompatibility complex.

autoimmune disorders

immune response mistakenly targets normal cells

immunodeficiency diseases

immune system does not develop properly or is blocked

upper respiratory vs lower respiratory

the upper respiratory consists of the: nose, pharynx, and associated structures

the lower respiratory system consists of the: larynx, trachea, bronchi, and lungs

anatomy of the respiratory system

conducting zone vs respiratory zone

the conducting zone conducts air to the lungs - while the respiratory zone is the main site of gas exchange

respiratory tree order

1. trachea

2. primary bronchi

3. secondary bronchi

4. tertiary bronchi

5. bronchioles

6. terminal bronchioles

differences between the right and left lung

left lung:

>two lobes; superior & inferior.

>It is longer and lighter than the right lung

> has a cardiac notch at its mediastinal/anterior border.

right lung:

>is divided into three lobes; superior, middle, and inferior.

chronic pulmonary diseases

bronchitis and emphysema

Boyle's Law

pressure of a gas in a closed container is inversely proportional to the volume of the container

example: if the pressure is 2 atm, then the volume is 0.5 liters

Henry's Law

The more pressure that is put on a solution, the more gas that can be dissolved in a liquid. Lessening the pressure causes that gas to come out of the liquid.

Bohr Effect

As acidity increases (pH decreases), affinity of Hb for O2 decreases

Decreased Attraction of Hb to O2, Right shift caused by an increase in PCO2.

Hb loads more O2 in lungs where pH is high and unloads more in tissues where pH is low

quiet vs active respiration

Inhalation (always active) and exhalation (passive or active); 2 types of inhalation = quiet and forced; 2 types of exhalation = quiet and forced

how respiratory chemical regulation works

Homeostasis is maintained by the respiratory system in two ways: gas exchange and regulation of blood pH. Gas exchange is performed by the lungs by eliminating carbon dioxide, a waste product given off by cellular respiration.

Oxygen-Hemoglobin Dissociation Curve

Other factors affecting affinity of hemoglobin for oxygen

Each makes sense if you keep in mind that metabolically active tissues need O2, and produce acids, CO2, and heat as wastes

Acidity

PCO2

Temperature

This curve is an important tool for understanding how our blood carries and releases oxygen.

"hemoglobin affinity for oxygen"; that is, how readily hemoglobin acquires and releases oxygen molecules into the fluid that surrounds it.

chloride shift

HCO3- accumulates inside RBCs as they pick up carbon dioxide

Some diffuses out into plasma

To balance the loss of negative ions, chloride (Cl-) moves into RBCs from plasma

Reverse happens in lungs - Cl- moves out as moves back into RBCs

anatomy of the digestive system

gastrointestinal (GI) tract organs

mouth, most of pharynx, esophagus, stomach, small intestine, and large intestine

accessory digestive organs

teeth, tongue, salivary glands, liver, gallbladder, and pancreas

digestive processes

ingestion, secretion, mixing + propulsion, digestion, absorption, and defecation

layers of the GI tract

from in to out

mucosa, submucosa, muscularis, serosa

mucosa

inner lining of the GI tract, MALT, contains muscularis mucosae which is a thin layer of smooth muscle making folds to increase surface area

submucosa

connective tissue that binds the mucosa to the muscularis, contains many blood and lymphatic vessels, and the submucosal plexus

muscularis

voluntary skeletal muscle found in mouth, pharynx, upper esophagus, and anal sphincter

serosa

outermost covering of organs in the abdominal cavity, also called visceral peritoneum

peritoneum

- largest serous membrane of the body

- parietal and visceral peritoneum

- major peritoneal folds: greater omentum, falciform ligament, lesser omentum, mesentery, and mesocolon

--- weave between the viscera and bind organs together

peritoneum

layers of the gastrointestinal tract

oral/buccal cavity

- formed by cheeks, hard and soft palates, and the tongue

- a space that extends from gums and teeth to fauces

- in this cavity, the salivary glands will release saliva

salivary glands

- release saliva

- when food enters the mouth, secretion increases to: lubricate, dissolve, and begin chemical digestion

- parotid, submandibular, and sublingual

what are the three pairs of major salivary glands that secrete most of the saliva?

parotid, submandibular, and sublingual

tongue

accessory digestive organ, maneuvers food for chewing, and lingual glands secrete salivary lipase

teeth/dentes

accessory digestive organ, emulsify food with mechanical digestion

adult dentition

4 incisors, 2 canines (cuspids), 4 premolars (bicuspids), and 4 molars

child dentition

2 incisors, 1 canine (cuspid), 2 molars. have no premolars, but 'first' molars.

saliva

- mostly water 99.5%, the rest 0.5% are ions, dissolved gases, urea, uric acid, muscus, etc

- not all salivary glands produce the same saliva

- salivation is controlled by the ANS

>> parasympathetic: promotes secretion of saliva

>> sympathetic: decreases salivation

mechanical digestion in the mouth

chewing/mastication, food manipulated by tongue->ground by teeth->mixed with saliva, and forms a bolus

chemical digestion in the mouth

the release of salivary amylase (acts on starches) and lingual lipase (acts on triglycerides)

pharynx

passes from nasal cavity into esophagus

> the nasopharynx only functions in respiration. the oropharynx and laryngopharynx participate in digestive and respiratory functions.

-- consists of the: nasopharynx, oropharynx, and laryngopharynx

esophagus

function: secretes mucous, transports food. does not produce any enzymes or participate in absorption.

- made of mucosa to protect against wear and tear. contains two sphincters to regulate movement into the esophagus (UES) and movement into the stomach (LES). contains adventitia.

stomach

function: serves as a mixing chamber and holding reservoir. contains the gastric pits. rugae moves food along. peristaltic movements with rugae.

cells in the gastric pits

Goblet, parietal, chief, and entero-endocrine cells (G-Cells)

gastric pits

These structures are lined with cells that produce chemicals that help the stomach digest food.

what do the gastric pits produce

contain many exocrine cells that secrete digestive enzymes and hydrochloric acid into the lumen, or hollow region, of the stomach. Mucous cells found throughout the stomach lining and gastric pits secrete mucus to protect the stomach from its own digestive secretions.

mechanical digestion

- mixing waves

- gentle, ripping peristaltic movements

- creates chyme

chemical digestion

salivary amylase: digestion continues until inactivated by acidic gastric juice

lingual lipase: acidic gastric juice activates lingual lipase. digest triglycerides into fatty acids and diglycerides.

pepsin

- secreted by cheif cells

- secreted as inactive pepsinogen

- digests proteins

what are the phases of gastric secretion?

cephalic, gastric, and intestinal

the gastric phase

function: enhance secretion started in cephalic stage, acidify chyme, initiate digestion of proteins by PEPSIN

duration: long (3-4) hours

actions: increased acid and pepsinogen production; increased motility and initiation of mixing waves

the intestinal phase

function: control rate of chyme entry into duodenum

duration: long (hours)

actions: feedback inhibition of gastric acid and pepsinogen production; reduction in gastric motility

the cephalic phase

function: prepares stomach for the arrival of food.

duration: short

actions: stimulation of mucus, enzyme, and acid production which leads to an increased volume of gastric juice ---> stimulation of gastrin released by G cells

nutrient pool

fuels the cell's metabolic activities both catabolic and anabolic

pancreas

gland that secretes pancreatic juice into the duodenum, where it mixes with bile to digest food

pancreatic juice

- mostly water

- sodium bicarbonate: buffers acidic stomach chyme

- ENZYMES: pancreatic amylase, proteolytic enzymes-- trypsin, chymotrypsin, carboxypeptidase, elastase--- pancreatic lipase, ribonuclease and deoxyribonuclease

exogenous and endogenous cells in the pancreas

exogenous: in pancreatic acini

endogenous: in pancreatic islet

liver

- is the heaviest gland of the body

- composed of: hepatocytes, bile canaliculi, and hepatic sinusoids

liver products

Processing of hemoglobin for use of its iron content (the liver stores iron) Conversion of poisonous ammonia to urea (urea is an end product of protein metabolism and is excreted in the urine) Clearing the blood of drugs and other poisonous substances. Regulating blood clotting.

gallbladder

function: to store and concentrate bile produced by the liver until it is needed in the small intestine

- absorbs water and ions to concentrate bile up to ten-fold

divisions of the small intestine

regions: duodenum, jejunum, and ileum

histology: Absorptive cells (digest and absorb), goblet cells (mucus), intestinal glands (intestinal juice), Paneth cells (lysozyme), and enteroendocrine cells

Abundance of MALT

small intestine structure for larger surface area

> circular folds: permanent ridges of mucosa and submucosa, cause chyme to spiral

> villi: fingerlike projections of mucosa

> microvilli: fingerlike projections of apical membrane of absorptive cells -- brush border with brush border enzymes

small intestine anatomy

intestinal juice

provides itself as a liquid medium for aiding in absorption

brush border enzymes

enzymatic digestion occurring on the surface rather than just in lumen -- breaks down enzymes into glucoses

alpha enzymes include: sucrase, lactase, and maltase

large intestine anatomy

large intestine

to complete absorption, produce certain vitamins, and form/expel feces

digestion in the large intestine

mechanical: haustral churning, peristalsis, mass peristalsis (drives contents) of colon toward rectum

chemical: final stage of digestion through bacterial action, fermentation of carbohydrates, produce some B/K vitamins, mucus but no enzymes

remaining water absorbed along with ions and some vitamins

zymogen cascade

trypsinogen ---(enteropeptidase)---> tripsin --->

procarboxypeptidase ---> carboxypeptidase --->

chymotrypsinogen --> chymotrypsin

zymogen

inactive form of an enzyme