A&P Systems of Homeostasis Exam 2

Afferent

towards structure

Efferent

away from structure

Lymphoedema

accumulation of interstitial fluid due to interference with lymphatic drainage

Cortex

outer region of a structure

Medulla

inner region of a structure

Hilum

involuted portion (exit/entry point)

Trabeculae

dense connective tissue capsule

Acute tolsillitis

inflammation and infection of tonsils

Apoptosis

regulated cell death (causes shriveling rather than lysis)

T-cells

lymphocytes that mature in the thymus

B-cells

lymphocytes that mature in the bone marrow

Antigen

substance that can elicit a response from a B or T cell

Pleura

serous membrane lining the lung surface and the thoracic wall

Pleural fluid

acts as a lubricant and helps hold the two membranes close together (adhesion)

Inspiration

breathing in (diaphragm, external intercostals)

Expiration

breathing out —> muscles that depress ribs and sternum (abdominal muscles and internal intercostals)

Spirometer

device that directly records changes in lung volume during respiration

Tidal volume (TV)

volume of air inspired and expired during quiet breathing

Inspiratory reserve volume (IRV)

maximum volume above tidal volume that we can inspire into our lungs

Residual volume (RV)

volume of air remaining in the lungs after a full expiration

Spirogram

graph visualizing the changes in lung volume over time

Spirometry

measurement of airflow and corresponding changes in lung volume

Boyle’s Law

pressure exerted by a constant # of gas molecules is inversely proportional to the volume of the contianer

Airflow

the amount of air moving in and out of the lungs with each breath

Pressure gradient

difference between atmospheric pressure and intrapulmonary pressure

Resistance

factors that increase the difficulty of moving air

Apnea

absence of breathing

Atmospheric pressure

pressure of air in the environment

Alveolar volume

collective volume of alveoli

Intrapleural pressure

pressure in the pleural cavity

Transport maximum (Tm)

maximum rate of substance that can be reabsorbed (or secreted) across tubule epithelium per a certain amount of time

Paracellular transport

between cells

Transcellular transport

through water transporter proteins —> aquaporins

Lymphatic system order

lymphatic capillaries —> lymphatic vessels —> lymphatic trunk —> lymphatic ducts —> blood

Lymphatic capillaries

lacteal: specialized lymphatic capillaries in GI tract —> absorbs lipids & lipid soluble substances from GI tract

Lymphatic vessels

have all 3 vessel tunics: intimastinum (innermost), mediastinum (middle), externastinum (outermost)

adjacent to arteries and veins

Lymphatic trunks

jugular trunk, subclavian trunk, bronchomediastinal trunk, intestinal trunk, lumbar trunk

Lymphatic ducts

largest type of lymphatic vessel

returns lymph to venous blood circulation

there are 2: right lymphatic duct (drains upper right quadrant of body), and thoracic duct (receives lipid-rich lymph from GI tract & drains lymph from left side of body and both legs)

Lymph

water, solutes, and pathogens are here

Primary lymphoid structures

produce lymphocytes

a) red bone marrow

b) thymus (especially in kids)

Secondary lymphoid structures

house lymphocytes & immune cells

a) lymphoid organs (made of dense tissue)

b) lymph nodes (filter antigens from lymph —> initiate immune response; small, oval and encapsulated; occur in clusters)

c) tonsils (3 pairs; pharyngeal, palatine, lingual)

• immune surveillance

• structure: tonsillar crypts, lymphoid nodules (forms mucosa-associated lymphoid tissue (MALT), located in gastrointestinal, respiratory, genital, and urinary tracts)

Macrophages

remove foreign debris from lymph through proliferation

Immune system functions

• defend against pathogens

• remove old/damaged cells

• identify & destroy cancer cells

Innate immunity

Present at birth

Nonspecific & responds immediately

skin (epidermis and dermis), mucosal membranes (produce mucus and release antimicrobial substances), nonspecific cellular and molecular internal defenses (immune cells, antimicrobial proteins, inflammation, fever)

neutrophils, macrophages, eosinophils, basophils, NK cells

chemicals like interferon & complement

Adaptive immunity

Acquired over lifetime

Specific & takes several days to take affect

T-lymphocytes & B-lymphocytes

targeted response

Phagocytic cells —> neutrophils & macrophages

engulf unwanted substances by phagocytosis

intake vesicle fuses with the lysosome, forming phagolysosome

digestive enzymes break down unwanted substances

the remaining residue is released by exocytosis

Proinflammatory chemical-secreting substances —> basophils

promote inflammation

circulate in blood

releases granules that contain various chemicals

• increases fluid movement from blood to injured tissue

• serve as chemotaxis chemicals —> attract immune cells

• histamines

• heparin

• eicosanoids

Histamine

increases vasodilation and capillary permeability

Heparin

acts as an anticoagulant

Eicosanoids

are released from the plasma membrane to increase inflammation

Apoptosis-initiating cells —> NK cells

destroy unwanted, unhealthy cells

form in bone marrow, circulate in blood, and accumulate in secondary lymphoid structures

• perform immune surveillance

• destroy virus infected cells

Eosiniphils

attack multicellular parasites