Exam 2

Question 1

What are the deviations from normal mean arterial pressure?

Answer 1

Less than normal:
Systolic/Diastolic 90/60 or less = hypotension: inadequate blood flow to tissues
More than normal:
140/90+ = hypertension: stresses cardiovascular system (chambers and vessels) increasing the risk of aneurism and breaking blood vessels

Question 2

What is Mean Arterial Pressure (MAP) proportional to?

Answer 2

Cardiac output (CO) and Total peripheral resistance (TPR)
CO: amount of blood pumped from a ventricle in a minute (SV x HR)
TPR: resistance to flow in arterioles.

Question 3

How does cardiac output affect mean arterial pressure?

Answer 3

Increasing the cardiac output increases the amount of volume into the arteries this increases the MAP because blood fills the artery faster than it can get out,

Question 4

Why is total peripheral resistance variable and how does it affect mean arterial pressure?

Answer 4

Variable because arterioles have a lot of smooth muscle for vasoconstriction/dialation
Increased TPR means that the arterioles are constricted decreasing the space in them blood backs up into the arteries increasing MAP

Question 5

How does the nervous system respond to high blood pressure? What is this called?

Answer 5

Baroreceptor reflex:
1) high blood pressure
2) arteries stretched more than normal
3) baroreceptors, stretch receptors in the carotid artery and aorta, are activated
4) sensory neurons are stimulated
5) stimulates cardiovascular control center of the medulla (cardioinhibitory)
6) excite parasympathetic neurons in CN X, vagus nerve
7) Stimulate the heart through the SA & AV nodes hyperpolarizing them with ACh
8) decreases heart rate because the cells do not signal as fast
9) decreases cardiac output decreasing the blood pressure

Question 6

How does the nervous system respond to low blood pressure? What is this called?

Answer 6

Baroreceptor reflex:
1) low blood pressure
2) arteries stretched low than normal
3) baroreceptors, stretch receptors in the carotid artery and aorta, are activated
4) sensory neurons are stimulated
5) stimulates cardiovascular control center of the medulla (cardioexcitatory)
6) excite sympathetic neurons in spinal cord –> sympathetic chain ganglia
7) Stimulate the SA, AV, ventricles, arterioles and veins
8) SA AV increases heart rate b/c cells signal faster
ventricles: increase stroke volume
arterioles & veins: vasoconstrict
9) increased Cardiac output, increased total peripheral resistance, increased venous return (increasing stroke volume, increasing CO) increasing blood pressure

Question 7

What are the three aspects of the lymphatic system?

Answer 7

Lymphatic vessels: run parallel to veins and arteries
Lymphoid tissue & organs: stroma- abundant reticular CT in lymphatic tissue & organs, involved in removing damaged cells and debris, get nutrients, immune response
Lymph: fluid CT, comes from interstitial fluid (between cells) when it enters L. vessel called lymph

Question 8

What are the functions of the lymphatic system?

Answer 8

1) bring fluid back into circulation from interstitial spaces preventing edema (from fluid build up b/c cancerous cell blockages, parasitic infections “elephantiasis”
2) Absorb digested fat: in intestinal mucosa lymph capillaries called lacteals b/c have milky appearance because contain lots of fat
3) Cleanse lymph and fight infection
-macrophages and lymphocytes

Question 9

Where are lymphatic capillaries found?

Answer 9

In the same areas we find cardiovascular capillaries. In almost all cells in the body except the skeletal system.

Question 10

What makes lymphatic capillaries so different than other capillaries and what do they absorb?

Answer 10

Lymph capillaries are much more permeable due to endothelial flaps (flaps in between cells) allowing large molecules to pass through
Absorb: cells pathogens (things that cause infection), cancer cells, proteins, chylomicrons (fat-containing particles)
Why lymph nodes are checked for cancer. Cancer cells get into lymphatic vessels and collect in the nodes

Question 11

How are lymphatic vessels similar and different to cardiovascular vessels?

Answer 11

They both have the same three tunics and similar composition of the tunics. Both large versions of these vessels get nutrients from vasa vasorum.
Lymphatic vessels have thinner walls with more internal valves because nothing is giving it pressure to flow. They are also more interconnected.

Question 12

Where are lymphatic vessels found?

Answer 12

Collecting vessels in the skin travel with superficial veins.
Deep vessels travel with the arteries

Question 13

What is special about the right and left lymphatic vessels?

Answer 13

They are not symmetrical.
Right lymphatic duct drains right thoracic, arm, and head regions into the right subclavian vein.
Thoracic duct drains the left head, arm, and thoracic regions as well as the legs, abdominal and pelvic regions into the left subclavian vein.
this is how interstitial fluid is brought back into circulation

Question 14

How is lymph moved?

Answer 14

There is no pump so lymph uses:
1) muscular pump and pulsations of nearby arteries
2) Respiratory pump
3) Contractions of smooth muscle in the walls of lymphatic vessels.

Question 15

What are the lymphoid cells?

Answer 15

Macrophages: engulf worn-out cells, cell debris, sometimes while wandering encounters something, phagocatizes it then warns the T-cell that something is up
Lymphocytes: involved in immune response, protects body against cells expressing non-native antigens (other organisms have antigens)
T cells, Natural Killer cells, b cells, plasma cells

Question 16

What do T cells do?

Answer 16

Start immune response, activated by weird cells (these are the cells destroyed by HIV).
immune response cannot start without T cells

Question 17

What do Natural Killer cells do?

Answer 17

innate immune system: wander and kill what does not have MHC I antigen
-all body cells with nuclei have MHC I
-cancer cells, foreign cells, & cells with a viral infection do not have MHC I

Question 18

What do B cells do?

Answer 18

Start the antibody production by producing plasma cells that pump out tons of antibodies

Question 19

What are the primary and secondary lymphoid organs?

Answer 19

Primary:
bone marrow
thymus: lymphocyte maturation
Secondary:
lymph nodes, spleen, MALT, and GALT

Question 20

What does the bone marrow do for the lymphatic system?

Answer 20

It produces blood cells including lymphocytes, particularly B-cells & T-cells

Question 21

What role does the thymus play in the lymphatic system?

Answer 21

Most active in the neonatal to pre-adolescent period the thymus allows the T cells to mature and become immunocompetent (able to recognize non-self antigens) and self tolerant (does not attack normal body antigens)
Thymus slowly atrophies after puberty and is replaced with fat

Question 22

What are the lymph nodes?

Answer 22

Lymph nodes are hundreds of balls of lymphoid cells and proteins that cluster along a lymph vessel each with a size of a few millimeters to 1-2 cm. They can be felt where they are highly concentrated (armpit, groin, neck)

Question 23

What role do lymph nodes play in the lymphatic system?

Answer 23

Lymph nodes use macrophages to filter out and destroy microorganisms and debris in the lymph.
They also activate the immune system by monitoring for antigens and notifying T-cells to mount an attack against them.

Question 24

What is the spleen and what is its structure?

Answer 24

It is the largest lymphoid organ. In the spleen the strong fibrous capsule is missing (unlike other lymphoid organs). It has lymphocytes and macrophages and has two areas: white pulp and red pulp

Question 25

What role does the spleen play in the lymphatic system?

Answer 25

1. Lymphocytes: this is where some B cells hand out for the immune system 2. Blood cleansing: macrophages remove old erythrocytes, platelets, and debris in the blood 3. Erythrocyte and Hb breakdown and iron storage 4. Platelet and RBC storage 5. Fetal erythrocyte production

Question 26

What is MALT and what is its role in the lymphatic system?

Answer 26

Mucosa-associated lymphatic tissue Functions to protect the digestive and respiratory systems Examples: tonsils, Peyer's patches, the appendix, and lymphoid nodules in the walls of the bronchi

Question 27

What are the tonsils and what are their role in the lymphatic system?

Answer 27

Tubal (medial top), adenoid (center top), palantine (lateral), lingual (under tongue) Functions to form a ring of lymphoid tissue around the pharynx to trap pathogens from the air and food

Question 28

What is GALT and what is its role in the immune system?

Answer 28

gastrointestinal-associated lymphatic tissue Peyer's patches and appendix function to destroy bacteria, preventing them from breaching the intestinal wall

Question 29

What are Peyer's patches?

Answer 29

Peyer's patches: isolated clusters of lymphoid tissue similar to tonsils found in the wall of the distal portion of the small intestine (ileum) similar to structures found in appendix

Question 30

What is the function of the immune system and what are the two divisions?

Answer 30

Functions to distinguish between self and non-self and then destroyed non-self. Innate immune response and adaptive/acquired immune response *these divisions are intertwined and are not completely separate responses*

Question 31

What are the general aspects of the innate immune response?

Answer 31

Non-specific (general), fast, short terms, present from birth, centers around inflammation, uses the same strategies no matter what it is fighting

Question 32

What are the general aspects of the acquired immune response?

Answer 32

Specific, slow (but powerful, this is how you get over something), long-term: it keeps a memory of pathogens (so it is built over time)

Question 33

What are the surface barriers of the immune system?

Answer 33

Physical and chemical barriers of the cutaneous and mucous membranes provide a barrier to most microorganisms

Question 34

What are the chemical barriers of cutaneous and mucous membranes?

Answer 34

Acid: acidity of skin, stomach acid, urinary tract & vagina inhibits the growth of microorganisms Enzymes: in saliva, respiratory mucus, and lacrimal fluid (tears) kill some microorganisms Mucin: Sticky mucus that lines digestive and respiratory tract traps microorganism

Question 35

What are the physical barriers of cutaneous and mucous membranes?

Answer 35

Stratified squamous epithelium produces physical barrier to abrasion and infection Nose-hairs trap inhaled particles Cilia of respiratory tract sweeps mucus containing microorganisms away from lungs

Question 36

When is the innate immune system needed and what does it use?

Answer 36

Necessary if microorganisms invade deeper tissue: uses inflammatory response, fever, phagocytes, natural killer (NK) cells, and antimicrobial proteins (interferons and complete proteins)

Question 37

What causes inflammation?

Answer 37

Chemical messengers called inflammatory cytokines--a term that can include local and distant control, but it associated with the immune system. Cytokines are released by any time of cell for different purposes. Released by tissue damage and as a response to pathogens (cause vasodilation of local arterioles, make capillaries leaky, and attract phagocytes)

Question 38

What is the purpose of inflammation?

Answer 38

To create a barrier to prevent the spread of a pathogen/ damaging agent, to bring in WBCs, disposes of cell debris and pathogens, alerts adaptive immune system, and sets the stage for repair

Question 39

What are the signs of inflammation and what causes these signs?

Answer 39

Redness, heat, swelling, and pain Cytokines cause vasodilation to bring in WBC and provide a barrier (redness & heat) & cause leaky capillaries by increasing the spaces between endothelial cells to allow fluid, blood cells and proteins to leak out. WBC after diapedesis follow chemotoxins to site (chemotaxis). The leakage of antibodies and cytokines lead to a decrease in osmotic pressure causing swelling and then pain

Question 40

What is a fever?

Answer 40

An abnormally high body temperature. a systemic (whole body) response to invading microorganisms

Question 41

What causes a fever?

Answer 41

Specific cytokine called pyrogen secreted by leukocytes & macrophages when they are exposed to a foreign substance. When released into the bloodstream pyrogens travel to the hypothalamus (temperature regulation center) and resets the set point from ~98.7 to 102

Question 42

What are the benefits of a fever?

Answer 42

Increases the functioning of some immune cells decreases the functioning of the pathogen causes liver and spleen to sequester iron and zinc (needed by microorganisms) increases metabolic rate (increases the rate of repair)

Question 43

What are the potential costs of a fever?

Answer 43

A fever above 106 leads to brain damage (and you just don't feel good)

Question 44

Which immune response are phagocytes part of, what are they, what do they do, and what are the different types?

Answer 44

The innate response. Cells that are involved in phagocytosis: they engulf pathogens and cell debris. Neutrophils, macrophages, and dendritic cell.

Question 45

How are neutrophils involved in phagocytosis?

Answer 45

Neutrophils are the most abundant phagocyte, they become phagocytic on exposure and die fighting. Neutrophils phagocytize bacteria.

Question 46

What are macrophages and how are they involved in phagocytosis?

Answer 46

Macrophages are specialized monocytes. They are the chief phagocytic cell and the most robust (b/c they're dedicated) phagocytic cell. Macrophages locate infection through chemotaxis, they follow the trail because they must be right on scene to be effective.

Question 47

How are dendritic cells involved in phagocytosis?

Answer 47

Dendritic cells are found in body tissues such as the epidermis and not in the blood stream. They can alert other immune cells to the presence of a pathogen. Due to their location in the body dendritic cells may be the first to contact a pathogen.

Question 48

What is phagocytosis and what are the steps?

Answer 48

Phagocytosis is a type of endocytosis. 1) Recognize and sticks to pathogen's antigens 2) Cytoplasmic extensions--pseudopods-- extend around the pathogen until it is completely enclosed in a vesicle called a phagosome "eat" "body" 3) The phagosome fuses with a lysosome "cut/break" forming a phago-lysosome that will expose the bacteria to digestive enzymes and destroy it 4) Phgolysosome is acidified and the lysosomal enzymes digest the particles 5) All indigestible and residual waste is released via exocytosis.

Question 49

What is MHC?

Answer 49

Major Histological Complex is a protein displayed by all nucleate cells. There are two types.

Question 50

What are NK cells and what is there role in the immune response?

Answer 50

Natural Killer cells play a role in innate immunity. They are non-phagocytotic large lymphocytes that patrol the blood and lymph. Function: destroy cancer and virus-infected cells before the adaptive immune response is activated. It attacks cells that lack MHC I by secreting a chemical that causes apoptosis (programmed cell death) and by punching holes in cell membranes.

Question 51

What is the complement cascade?

Answer 51

~25 blood proteins that circulate inactivated until they are activated by antibodies or chemicals on pathogens similar to the coagulation cascade except for the fact that the goal of this cascade is to create a response that will kill a pathogen.

Question 52

What is the result of activating the proteins in the complement cascade?

Answer 52

Trigger inflammation, produces opsonins that stimulate phagocytosis of a pathogen and generate MAC: membrane attack complex that rupture the pathogens membrane (like NK hole punching) Enhancing the adaptive (by increasing chemotaxis for T-cells to promote antibody production) and innate immune responses

Question 53

What are the characteristics of adaptive immunity and what are the two main branches?

Answer 53

Specific: recognizes & targets specific antigens Memory: mounts and even stronger attack to "known" antigens during second and subsequent exposures Slow: requires time to be set up Two main branches: 1) Humoral (antibody-mediated) immunity [in plasma and involves chemicals] 2) Cellular (cell-mediated) immunity

Question 54

What are the cells of the acquired immune response?

Answer 54

B lymphocytes (B Cells), T lymphocytes (T Cells), and Antigen-Presenting Cells (APCs)

Question 55

What do B Cells do for acquired immunity?

Answer 55

B cells never directly attack. They stay in the lymphatic system and do not wander. They help to produce humoral immunity as they produce antibodies on a large scale

Question 56

What do T Cells do for acquired immunity?

Answer 56

T cells are involved in cellular immunity. They directly attack pathogens as they wander around.

Question 57

What are APCs and what do they do for acquired immunity?

Answer 57

Antigen-presenting cells. Cells, both dendritic and macrophages, that present antigens on MHC II membrane protein platforms alerting T cells to the presence of a pathogen. These cells really move around and are likely to be the first to encounter a pathogen.

Question 58

Where does T cell maturation occur and what are the steps?

Answer 58

T cell maturation occurs in the thymus. A positive and negative selection. T cells must be able to find to MHC and to the pathogen antigen to initiate immune response. T cells are sensitive to a specific antigen. Positive selection: Immunocompetent: T-cells must recognize MHC Negative selection: self tolerant: T-cells must not bind to self antigens Fail a selection? Apoptosis Only 2% of T cells pass and are released into circulation and lymphatic organs. At first they are naive (not activated)

Question 59

Where does B cell maturation occur and what are the steps?

Answer 59

B cells mature in the bone marrow. Each cell expresses a different type of antibody that is embedded in plasma membrane (looks like Y antigen). Cells must become self-tolerant: antibodies must not bind to self antigens (negative selection) Fail: apoptosis Pass: released into circulation and congregate in lymphatic organ. At first Naive (not activated)

Question 60

What are the steps of the primary response of humoral immunity?

Answer 60

1) Naive B cell is presented with an antigen 2) If the antigen matches the B cell's antibody the B cell engulfs the pathogen 3) The cell expresses the pathogen antigen on MHC II 4) Helper T cell is activated by the same antigen and seeks out the B cell and binds to it activating it (Tells it that antigen is bad) 5) The activated B cell proliferates (mitosis) making many clones 6) Most of the clones will become plasma cells that will generate thousands of antibodies 7) The rest of the clones will become memory cells that will remember being exposed and will cause a faster response if the body is reexposed to the pathogens

Question 61

What are the steps of the secondary response of humoral immunity?

Answer 61

(This may be years after first exposure) 1) Memory B cell binds with pathogen antigen activating the B cell 2) Activated B cell makes clones 3) Nearly all the clones become plasma cells **more plasma cells are produced in this response** 4) Thousands of antibodies are made **more** 5) Some activated B cells will become memory cells

Question 62

What are the differences between the primary and secondary responses of humoral immunity?

Answer 62

Primary: time- 3-6 days before any antibodies are made, antibody levels peaks around 10 days and then declines Secondary: (faster & more antibodies) Time: hours before antibodies production Peak: 2-3 days and at much higher levels Antibodies: bind with greater affinity (they stick better) and levels remain high for weeks to months (the decline is not as sharp)

Question 63

What do vaccines do?

Answer 63

Vaccines mimic primary infection so the body produces the secondary response if it is exposed to the pathogen. Some vaccines must be repeated because memory cells are not immortal

Question 64

What is active humoral immunity and what are the two types?

Answer 64

Your B cells make antibodies 1) Naturally acquired: you were exposed to the pathogen 2) Artificially acquired: you were given a vaccine (dead or attenuated pathogen or pathogen antigen (mRNA))

Question 65

What does an mRNA vaccine do?

Answer 65

mRNA is a recipe for 1 protein (in the case of a vaccine this is one pathogen antigen). Ribosomes read the mRNA and makes the antigen which is then expressed on the cell surface.

Question 66

What is passive humoral immunity and what are the two types?

Answer 66

Your B cells did not make the antibodies 1) Naturally acquired: from mother to baby (placenta or breast milk) 2) Artificially acquired: injection of exogenous (made outside of body) antigens. (made synthetically in a lab or made in another organism) *Protection is immediate but antibodies will degrade over time

Question 67

What does the cellular immunity activate?

Answer 67

Humoral and cellular because it activates both types of T-cells.

Question 68

How is a T cell activated in cellular immunity?

Answer 68

APC presents an antigen on a MHC-II to Naive T cell that binds to the MHC II & antigen. Some naive T cells become Helper T cells while some will become Cytotoxic Killer T cells

Question 69

What do Helper T Cells do?

Answer 69

Helper T cells activate B cells in the humoral immunity and work with dendritic cells to stimulate some activated T cells to form Cytotoxic Killer T cells

Question 70

What do Cytotoxic Killer T cells do?

Answer 70

Cytotoxic Killer T cells seek out body cells presenting abnormal antigens on MHC-I and stimulates the cell to undergo apoptosis.

Question 71

What is the function of the respiratory system?

Answer 71

Gas exchange: Conditioning of Air Speech Olfaction Protection

Question 72

Why does the body need gas exchange?

Answer 72

O2 in (for mitochondria for ATP production) & CO2 out (byproduct from pyruvic acid in Krebs cycle in mitochondria)

Question 73

Why does the body need to condition air?

Answer 73

Cold/dry dries out mucus membranes so respiratory system warms and humidifies air to make gas exchange process better

Question 74

How does the respiratory system protect the body?

Answer 74

The respiratory system is lines with mucus membranes that trap or attack and destroy infectious agents.

Question 75

How does the respiratory system allow for speech and olfaction?

Answer 75

Speech (vocal cords in larynx) Olfaction (Top of nasal cavity containing olfactory bipolar neurons)

Question 76

What is the job and the structures of the upper respiratory system?

Answer 76

Brings air into the body, begins to condition the air, and protection Nostrils, nasal cavity, oral cavity, and pharynx.

Question 77

What is the job and the structures of the lower respiratory system?

Answer 77

Brings air to the gas exchange in lungs (smaller and smaller tubes) Larynx, trachea, carina of trachea, left and right main (primary) bronchus, bronchi, alveoli, right and left lung, parietal pleura, and diaphragm.

Question 78

What is the major respiratory epithelium?

Answer 78

Pseudostratified ciliated columnar epithelium, stratified squamous epithelium, simple squamous epithelium.

Question 79

Where is the pseudostratified ciliated columnar epithelium found and what notable structures are found on/in it?

Answer 79

Found throughout respiratory tract except the lower pharynx (near the voice box), in the bronchioles and alveoli Goblet cells: produce mucus that is slippery and sticky to coat the surface where air interacts with epithelium that can trap pathogens in the air. Cilia: pushes mucus away from lungs in rowing movement (like crowd wave) "mucus escalator" to where mucus can be coughed out of the body or swallowed and digested.

Question 80

What is the structure, location, and function of stratified squamous epithelium?

Answer 80

Structure: stacks of squamous epithelium Location: Oropharynx & laryngopharynx (areas shared with the digestive tract) Function: protect against abrasion and chemicals (from food & water)

Question 81

What is the structure, location, and function of simple squamous epithelium?

Answer 81

Structure: single layer of flat cells for diffusion Location: alveoli Function: diffusion of gases

Question 82

What is the zone of the respiratory tract and what is the function of this zone?

Answer 82

Conduction zone: carries air to gas exchange, warms, humidifies, and filters air. (All upper respiratory and some lower respiratory)

Question 83

What are the structures **before** the nasal cavity?

Answer 83

Nostrils (external nares) permits entry of air to nasal cavity Nose hairs (vibrissae) filters large particles (and traps some)

Question 84

What are the structures of the nasal cavity?

Answer 84

Paranasal sinuses: cavities in the skull lined with mucus membrane. Mucus drains into nasal cavity through openings in the bone around the nasal cavity (sphenoid, olfactory, cribriform, frontal, ethmoid) Nasal conchae: bumps that create turbulents. This swirling warms, humidifies, filters the air Olfactory epithelium (top of NC below ethmoid bone) chemicals dissolve in mucus stimulating chemoreceptors that sense them as oderents.

Question 85

What is another name for the pharynx and what are the sections?

Answer 85

The throat. Nasopharynx, oropharynx, and laryngopharynx

Question 86

What is the tissue, location, and the structures of the nasopharynx?

Answer 86

Tissue: pseudostratified ciliated columnar epithelium Location: begin at the end of the nasal cavity and end at the soft palate Pharyngeal (adenoid) tonsil: posterior superior region of NP Eustachian tube: linked to middle ear to relive pressure build up Soft palate & uvula: helps to direct food & drink down. Uvula pushed up while swallowing closing the entrance to the NP.

Question 87

What is the tissue, location, and the structures of the oropharynx?

Answer 87

Tissue: stratified squamous epithelium

Question 88

What is the tissue, location, and the structures of the oropharynx?

Answer 88

Tissue: stratified squamous epithelium Location: Inferior to Npharynx: soft palate - epiglottis Connects to oral cavity at fauces (space between oral cavity and throat). Palatine tonsils: lateral walls of fauces Lingual tonsils: posterior surface of tongue

Question 89

What is the location and function of the laryngopharynx?

Answer 89

Location: Area from the glottis to the esophagus (parallel to the larynx) Function: for the passage of food and air

Question 90

What are the zones of the lower respiratory tract?

Answer 90

Conducting zone (same as upper tract) Respiratory zone: functions as an are of gas exchange structures: microscopic- bronchioles, alveolar ducts, and alveoli

Question 91

What is another name for the larynx and what are its structures?

Answer 91

Voice box Structures: epiglottis, hyaline cartilage, glottis, and vestibular folds

Question 92

What is the epiglottis?

Answer 92

Flap made of elastic cartilage that covers the opening to the trachea (glottis) during swallowing

Question 93

What is the hyaline cartilage of the larynx?

Answer 93

Thyroid cartilage: large, inferior to hyoid bone anterior & lateral Cricoid cartilage: continual ring superior to tracheal cartilage to stabilize area around the glottis Arytenoid cartilage: moves because of a muscle to change tension in vocal cords (folds) (pitch of sound depends on length & tension of folds)

Question 94

What is the glottis and the vestibular folds?

Answer 94

Glottis: opening between/ below the vocal folds Vestibular folds: stimulate cough reflex- big fat areas of tissue

Question 95

What are the structures of the trachea?

Answer 95

Tracheal cartilage: C-shaped rings (anterior & lateral) for support. Holds the trachea open so it does not collapse while allowing esophagus to expand. Trachealis: smooth muscle connecting "C" controlling diameter of trachea Tissue: pseudostratified columnar epithelium Carina: end of trachea where it bifurcates (splits in two to form two new structures)

Question 96

What are the structures of the bronchial tree?

Answer 96

Primary bronchi splits many times into secondary bronchi splits many times into tertiary bronchi that branches into bronchioles (0.3-0.5mm) the structure where the hyaline cartilage plates disappear but still has smooth muscles and elastin and tissue changes from pseudostratified columnar to simple cuboidal.

Question 97

What are the alveoli?

Answer 97

Round gas exchange areas that group into alveolar sacs. Singular is alveolus. Sacs are surrounded by capillaries and elastic tissue. (~150 million alveoli per lung)

Question 98

What are the types of alveolar cells?

Answer 98

Type 1: simple squamous epithelium for gas exchange Type 2: cuboidal epithelium secrete substances that act as surfactant Alveolar macrophages: live in cells eat dust, debri, particulates (anything that does not belong) then climb up bronchial tree to be coughed out or swallowed

Question 99

What does a surfactant do?

Answer 99

decrease surface tension helping to keep alveoli open (keep from collapsing)

Question 100

What are the structures of the lung?

Answer 100

Pleura: serous membrane, parietal, pleural cavity, visceral Right: 3 lobes Left: 2 lobes because of a cardiac notch.

Question 101

What are in the red and white pulp of the spleen?

Answer 101

Red: Erythrocytes and macrophages White: Lymphocytes

Question 102

What cells are in the lymph nodes?

Answer 102

T cell, B cells, and Phagocytes