HBS Units 9 + 10

Lymphatic System

Is the body of organs and tissues that contribute to the immune system and cardiovascular system

Interstitial fluid

surrounds tissues and blood vessels, excess fluid can return to blood via lymphatic system

Lymph

Filtered plasma that leaked from circulatory system into interstitial spaces and is picked up by the adjacent lymph vessels

contains water, white blood cells, proteins, salts, glucose, fats – no red blood cells

Lymphatic capillaries

permit excess tissue fluid to leave the tissue space

What direction is lymph flow, and what path does it take

ONE WAY: lymphatic capillaries → lymphatic veins → lymphatic ducts → blood

Lymph flowing through capillaries empty into either

1. Right lymphatic duct

2. Thoracic duct

Where does lymph in ducts go

returns to the blood through subclavian vein and internal jugular vein in neck (one way passage – back to blood just before it enters the heart)

Lymphatic capillaries are designed to

maximize capture of pathogens and debris as well as larger proteins that haven't been taken up by cells

Lymph nodes

clusters of lymphatic vessels

function to contain infection (WBCs)

filter in the lymphatic vessels, removes bacteria, foreign particles, cancer cells

where antigen processing and recognition largely occurs

Lymphadenitis

infection of lymph node with swelling and tenderness

Leukocytes

WBCs

Lymphocytes

main WBC found in the lymph system

Lymphedena

blockage of lymph flow due to surgery, tumors, or infection results in accumulation of lymph in the tissues with swelling

Elephantiasis

lymphedema caused by Filaria worm

Lymphoid tissue

where lymphocytes (types of WBCs) are made and mature or are activated

Thymus

Lobulated gland located deep to the sternum in the thorax

• Produces hormones (thymopoietins and thymosins) which makes it also part of the endocrine system

Thymopoietins and thymosins

are necessary for the white blood cell (WBC) production (T lymphocytes)

Thymus’s relation with T lymphocytes

Site of T lymphocytes maturation (T cells form in red bone marrow and then migrate to the thymus to mature), which then migrate to the spleen, tonsils, lymph nodes and other lymphatic tissues

thymus reaches maturation at ____.

Disappears by age ____.

Puberty, 80

Tonsils

First line of defense in the mouth

A protective set of lymphoid tissues under the mucous membrane in the back of the throat

types of tonsils and where

1. Palatine tonsils

2. Pharyngeal tonsils or adenoids (adenoiditis)

3. Lingual tonsils

Tonsilitis

infection of tonsils

Spleen

Largest lymphoid organ in the body

The red pulp filters out aged RBCs and salvages iron from their hemoglobin

The white pulp contains both B and T lymphocytes

A blood reservoir (red pulp) may contain more than 1 pint of blood

immune system

Interactive network of organs and cells that allow us to fight off threats

Innate immunity

• Non-specific immunity

  • Uses defenses we are born with

  • Rapid response (first responders)

Adaptive immunity

• specific immunity

  • Allows us to adapt to new threats

  • Long-term protection (memory)

  • Natural: occurs over the course of living

  • Artificial: immunizations
    

physiological innate barriers

• Skin

• Mucous membranes

• Cilia

• Body temperature

• pH

Cytokines

inflammation mediators that attract WBCS to site of injury

Phagocytes

(innate) ingest and digest foreign cells/particles, include neutrophils, monocytes, dendritic cells

Neutrophils

Abundant but short lived phagocytic cells

Found in blood

Monocytes (macrophages)

engulf bacteria

found in blood, convert into macrophages in tissues

Dendritic cells

Made in bone marrow

Released into blood stream

Migrate to tissues in contact with external environment

Antigen presenting cells

include monocytes and dendritic cells, display part of digested material (antigen) to trigger adaptive immune response

Natural killer cells

Directly kill many types of tumor cells and cells infected by viruses

Recognizes abnormal cells using different recognition receptors

Main pathway for killing = apoptosis (programmed cell death)

Adaptive immune response stimulated by

innate immune response

Immunologic synapse

naive T cells receive antigen presentation from macrophage

Types of Lymphocytes

T cells and B cells

T cells

Part of adaptive immune system

Function to destroy invading molecules

Develop in the thymus

Found in large numbers within lymphoid tissues (bone marrow, spleen, tonsils, and lymph nodes)

Activated when it comes in contact with an antigen (antigen presentation)

Activated T cells

Memory T cells: stored in lymph nodes for future use

Cytotoxic T cells: kill foreign cell directly, release substances to lyse cells

Helper T cells: kill foreign cells indirectly (by attracting macrophages) trigger activation of B cells

Regulatory T cells: help shut down immune reaction after antigens have been destroyed

B cells

Part of the adaptive immune system

Make antibodies

Originate in the bone marrow

Transform into immature B cells in liver and bone marrow (pre-birth) or in bone marrow (adults)

Mature (inactive) B cells stored in lymph nodes and spleen

Mature (active) B cells form when B cell antibody comes in contact with an antigen (also requires help from T cells)

Activated B cells

Memory cells: stored in lymph nodes until comes in contact with antigen a second time, rapid second response

Plasma cells: secrete antibodies into blood

Antibodies

Proteins (immunoglobulins) that can recognize a specific antigen to assist in clearing the foreign particle

produce humoral or antibody-mediated immunity by binding to the antigen

Antigens

may be foreign proteins, carbohydrates or lipids, most often molecules in the surface membranes of invading microorganisms or diseased cells such as cancer cells. (Antigen = antibody generator)

function of respiratory system

• Movement of air

• Exchange oxygen for carbon dioxide

• Traps pollutants/irritants

• Helps regulate acid-base balance

Bronchi end in

alveoli which are tiny terminal air sacs where oxygen and carbon dioxide diffuse across the alveolar membrane

upper respiratory tract

comprised of the nose, pharynx, and larynx

lower respiratory tract

consists of the trachea, all segments of the bronchial tree, and the lungs.

respiratory mucosa

lines nasal cavity, superior portion of pharynx, lower respiratory tract

Air flow

External nares (nostrils) to nasal cavities (L+R; separated by the nasal septum

4 paranasal sinuses

drain into nasal cavities

Lined with mucous membrane that helps to make mucus for respiratory tract

Nasolacrimal ducts

drain tears from lacrimal sacs into the nose

Conchae

protrude into the nasal cavity – increases surface over which air flows; warms & humidifies.

pharynx

passageway between nose and the larynx

nasopharynx: connected to nasal cavities

oropharynx: behind mouth

laryngopharynx: above the larynx

auditory/eustochian tubes

opens into nasopharynx

Pharyngeal tonsils/adenoids in the

nasopharynx

palantin tonsils in the

oropharynx

larynx

voice box that contains the vocal cords (muscles control tensions)

epiglottis

covers opening of larynx, prevents food from entering

Swallowing causes epiglottis to close trachea and uvula to close off nasopharynx

thyroid cartilage

Adam’s apple (connective tissue; grows during puberty)

Trachea

windpipe

lined by mucosa

Provides continuation of the air passageway from the larynx to the lungs

consists of non-collapsible C-shaped cartilage rings

Primary Bronchi

main tubes leading to the lung; off of the trachea, also lined with C-rings of cartilage

Right primary bronchi

right primary bronchi is more in line with the trachea; objects that enter

the trachea tend to lodge in the right bronchi more than the left

bronchioles

tiny tubes containing only smooth muscle

alveoli

single layer of simple squamous epithelial cells; allow for effective exchange of O2 and CO2), surrounded by capillaries

Alveoli need

large surface area; helps with gas exchange, gas only travels through capillary wall and respiratory membrane

Right lung has ___ lobes, left lung has __

3, 2

pleurae

think membrane lining the lung

Pulmonary ventilation

breathing

respiration

gas exchange between and organism and environment

external respiration

exchange of gases between air in lungs and blood

Internal respiration

exchange of gases between blood and cells of body

cellular respiration

ability to use oxygen and nutrients to make energy

Moving air in and out of the lungs requires

a change in intrathoracic pressure (air goes from high-pressure to low pressure), created by diaphragm

When lungs expand (breath in), pressure goes ___, when lungs contract (breathe out), pressure goes ___

down, up

Inspiration

Inhalation; chest cavity enlarges as the diaphragm contracts; pressure in lungs goes down and air can enter

expiration

exhalation; diaphragm muscles relax, pressure in lungs can go up and air can exit

phrenic nerves

stimulated diaphragm to contract

gas exchange enabled by___, occurs in ___

diffusion, alveoli

External respiration gas exchange

higher concentration of oxygen in alveoli moves oxygen to capillary vent

higher concentration of CO2 in capillary vents moves CO2 to alveoli

Internal respiration gas exchange

higher concentration of oxygen in oxygenated blood from capillary vents moves oxygen to cells

higher concentration of CO2 in cells moves CO2 to capillary vents —> deoxygenated blood

harder to breath at high altitude because

air pressure at high altitudes is lower, so harder for oxygen to move from high pressure to lower pressure since difference in outside pressure and lung pressure is smaller

oxygen binds to ____ via ___ in the ___

hemoglobin, iron, RBC

what happens to RBC at high altitudes

you make more red blood cells to adapt to high altitudes in order to have more hemoglobin to hold onto oxygen for longer

carbon dioxide can be ___ at high concentrations

toxic

3 ways CO2 can be transported through blood

1) dissolved in blood (10%)

2) Carboaminohemoglobin (attaches to hemoglobin (20%)

3) Bicarbonate ions (70%)

respiratory control center

Brain stem phrenic nerves found in pons and medulla

why we need oxygen

for energy, generate ATP

cellular respiration inputs and outputs

glucose + oxygen —> CO2 and water, ATP

cellular respiration occurs in

what are its parts?

cytoplasm and mitochondria

1) glycolysis

2) pyruvate oxidation

3) Krebs cycle

4) electron transport chain

glycolysis

occurs in cytoplasm

anaerobic (doesn’t need oxygen)

breaks down glucose into pyruvates, makes 2 ATP

pyruvate oxidation

occurs in intermembrane space of mitochondria

converts pyruvate to Acetyl-CoA

Krebs/Citric acid cycle

Occurs in mitochondrial matrix

Acetyl Co-A converted to carbon molecules

donated electrons (FADH2 and NADH) to electron transport chain

makes ATP, CO2 and H+ byproducts

Electron transport change

occurs in inner mitochrondrial membrane

requires oxygen (aerobic)

uses electrons and H+ from Krebs cycle and special proteins to make ATP and H2O