Exam 3 Flashcards
1
Q
Primary & Secondary Lymphnoid organs
A
Primary: Thymus and bone marrow (because they produce T & B cells)
Secondary: spleen, appendix, tonsils, lymphnodes
2
Q
T & B cells
A
T-cells: born in bone marrow, educated (immunocompetence) in the **Thalmus. ** Then gather mainly in the spleen and lymphnodes. Only mature when they actually fight.
B-cells: Born and educated in the bone marrow. Travel to fight infection.
3
Q
Lymphnode
A
Germinal center is where T & B cells are dividing.
cancer spreads and is trapped in lymphnodes
4
Q
Spleen
A
Largest of all lymph organs. During fetal development its the site on hematopoises.
Cleansing function: removal and destruction of pathogens and old blood cells.
Pulps:
** white-** concentration of WBC (immunity)
**red:** concentration of RBC
5
Q
Tonsils
A
Simplest lymphoid organs
Four groups of tonsils:
Palatine, lingual, pharyngeal, and tubal (opening of auditory tube) tonsils
Arranged in a ring (crypt) to gather and remove pathogens
Underlying lamina propria consists of MALT
6
Q
Function of Lymphatic system
A
- Return excess tissue fluid back to blood pool (if not, we would have 2-4L in our interstitial spaces)
- Return leaked proteins (maintains osmotic pressure)
- Return fat (chyle)
- Fight disease (pathogens are agents/microorganisms that can cause disease)
7
Q
Lymph & Tissue fluid
A
- Lymph - blood filtered through capillary walls; contains plasma, water, ions, sugars, proteins, gases, amino acids - is colorless, but low in protein compared to blood plasma
- Tissue fluid - Watery fluid that, along with the molecules of ground substance, occupies the extracellular matrix of connective tissue; it is a filtrate of the blood containing all the small molecules of blood plasma; also called interstitial fluid.
8
Q
order of lymph vessels
A
- Lymphatic capillaries are the smallest and first to receive lymph.
- Lymphatic collecting vessels collect from lymph capillaries.
- Lymph nodes are located along these collecting vessels.
- Lymph Trunks
- Lymph Ducts empty in the veins of the neck.
9
Q
Lymphatic trunks
A
- Lumbar trunks – receives lymph from lower limbs and lumbar region
- Intestinal trunk – receives chyle from digestive organs
- Bronchomediastinal trunks – collects lymph from thoracic viscera
- Subclavian trunks – receive lymph from upper limbs
- Jugular trunks – drain lymph from the head and neck
10
Q
Lymphatic Ducts
A
• Thoracic duct – ascends along vertebral bodies
o Empties into venous circulation
o Junction of left internal jugular and left subclavian veins
o Drains three quarters of the body
o Body parts they drain – the left side of the head, neck, and thorax; the left upper limb; and the body’s entire lower half
• Right lymphatic duct
o Empties into right internal jugular and subclavian veins
o Body parts they drain – right jugular, subclavian, and bronchomediastinal trunks
Cisterna chyli – located at the base of the Thoraciic duct at the union of lumbar and intestinal trunks
11
Q
Regional nodes
A
Axillary, cervical, and inguinal
12
Q
** What is an antigen/pathogen?**
A
- Antigen - A molecule that is recognized as foreign by the immune system, activates the immune system, and reacts with immune cells or antibodies.
- Pathogen - a bacterium, virus, or other microorganism that can cause disease.
13
Q
Edema
A
Abnormal accumulation of tissue fluid in the loose connective tissue; causes the affected body region to swell.
-Standing for long times at work my develop it
14
Q
** Elephantiasis**
A
a condition in which a limb or other part of the body becomes grossly enlarged due to obstruction of the lymphatic vessels, typically by the nematode parasites that cause filariasis.
o Lymph nodes become swollen usually from bacterial or viral infections.
15
Q
T cells
A
bind to antigens that are present by special proteins that occur only on the membranes of eukaryotic cells. Only responds to foreign antigens. Anything with altered (antigenic) proteins on their surface.
16
Q
B cells
A
differentiate into plasma cells that secrete antibodies. Antibodies are proteins that bind to specific antigens and mark them for destruction by, making them more recognizable to phagocytic cells
17
Q
** Monocytes**
A
transforms into macrophages, phagocytic cells that move by amoeboid motion through connective tissue and ingest a wide variety of foreign cells, molecules, and tiny particles of debris
18
Q
How do lymphatic vessels differ from those of the CV system in structure/ how are they similar?
A
- Both of these systems work in a similar manner. They both produce liquid substances — blood and lymph — that move through their networks of vessels and ducts to various parts of the body. Each of these liquid substances carries nutrients or removes waste. As such, both could be considered circulatory in nature.
- The circulatory system is primarily responsible for transporting blood throughout the body. It’s made up of the heart, the organ that pumps blood, and the veins and arteries that move blood to and away from body tissues. Blood transport is crucial because this substance carries many nutrients and fluids that the body needs for sustenance, such as oxygen.
- The lymphatic system acts as a waste removal system for the body. When unneeded material is absorbed by the muscles, lymph picks up this material and transports it to the lymph nodes, where it is ingested. Old and unusable red blood cells are eliminated in this way, meaning that the circulatory system uses the lymphatic system as a means of disposal.
- The blood plays a major role in creating lymph. Blood plasma becomes a substance known as interstitial fluid when it comes into contact with body tissues. Some of this fluid enters lymphatic vessels, where it is then transformed into lymph. In fact, one of the primary responsibilities of the lymphatic system is to drain interstitial fluid from tissues.
19
Q
MALT
A
mucosa associated lymphoid tissue
20
Q
Lymphatic Collecting Vessels
A
Accompany blood vessels (arteries and veins)
Composed of the same three tunics as blood vessels (tunica intima, media and externa)
Contain more valves (one way)
Helps direct the flow of lymph
Lymph propelled by:
Bulging of skeletal muscles
Pulsing of nearby arteries (lymph vessels share a common connective tissue sheath)
Tunica media of the lymph vessels
21
Q
Lymph Capillaries
A
Located near blood capillaries, but closed at one end
High permeability allows:
Uptake of tissue fluid from connective tissue due to high pressure
Entrance of bacteria, viruses, and cancer cells
22
Q
characteristics of lymph nodes
A
• Medulla
o The medullary cords are cords of lymphatic tissue, and include plasma cells, macrophages, and B cells
o The medullary sinuses are vessel-like spaces separating the medullary cords. Lymph flows into the medullary sinuses from cortical sinuses, and into efferent lymphatic vessels.
• Hilus – lymph exits from this indented region
• Afferent vessels – enters the node through this and has a valve
• Efferent vessels – exits after hilum
• Capsule – dense connective tissue that surrounds the node
• Trabeculae – invaginations of capsule
23
Q
What is lymphoid tissue, what does it do and where do you find it?
A
• The main/important tissue of the immune system; a reticular connective tissue that houses and activates many lymphocytes.
• Macrophages on the fiber network kill invading microorganisms by phagocytosis and, along with dendritic cells, activate nearby lymphocytes by presenting them with antigens.
Found in
• Infected mucous membranes of the digestive, respiratory, urinary, and reproductive tracts.
• All lymphoid organs except the thymus
24
Q
Lymphnodes
A
Function
Lymph percolates through lymph sinuses
Have afferent and efferent vessels with node acting as a “bottleneck” to slow the flow to allow time for cleaning.
Antigens destroyed – and activate B and T lymphocytes
approximately 500
organized in clusters
Bean-shaped
Situated along collecting vessels
NOT glands
25
**Heart Location**
* *Base**- inferior border of second rib
* *Apex**- rests on diaphragm and in between 5th and 6th rib
* *Tilts** to the left and anteriorly
26
**heart chambers, valves, septa and blood vessels leading to and away from the heart.**
**Heart chambers** (4)
• Right and left atria
• Right and left ventricles
**Valves** (4)
• Right atrioventricular (tricuspid) valve
• Left atrioventricular (bicuspid) valve
• Aortic (semilunar) valve
• Pulmonary (semilunar) valve
**Septa**
• Interventricular septum
• Interatrial septum – tissue between L and R atria
**Blood vessels**
• Arteries take blood away from the heart
• Veins take blood toward heart
27
**pericardial membranes and layers of the heart wall.**
**3 Pericardial membranes**
• Fibrous pericardium (provides anchoring, structural support and electrical insulation)
• Parietal layer of serous pericardium
• Epicardium (visceral layer of serous pericardium)
**Heart Wall**
• Epicardium
• Myocardium
• Endocardium
28
**chordae tendinae & papillary muscles**
• Papillary muscles (anchor chordae tendinae, which prevent AV valves from opening during ventricular contraction)
29
**nodes and bundles for conduction and the path of the impulse through the heart**
* Sinoatrial (SA) node: pacemaker
* Internodal bundles
* Atrioventricular (AV) node
* Atrioventricular bundles (bundle of His)
* Bundle branches
* Purkinje fibers
30
**angioplasty & bypass**
* **Angioplasty** - involves inserting a catheter into the patient’s arm or leg and threading it through the arteries until it enters the blocked coronary artery. When the catheter reaches the blockage, a balloon located on the tip of the catheter is inflated to exert pressure on the plaque-filled wall of the vessel. This pressure compresses the plaque and increases the diameter of the vessel lumen, thus improving blood flow to the myocardium.
* **Bypass** - vessels from another part of the body are used to reroute blood to the heart. A portion of a vessel is removed from its original location and grafted between the aorta and the heart wall, thus supplying an alternate route for blood to the heart muscle
31
**Systole vs Diastole**
* Systole - ventricles or the atria of the heart contract.
* Diastole - ventricles or atria of the heart relax.
32
**Innervation , Parasympathetic (Vagus), & Sympathetic**
* **Innervation** alters rate of contraction (chronotropy) and force of contraction (inotropy) – it does not cause the contraction
* **Parasympathetic (Vagus)** - slow down (20bpm or even stop; Ach binds to mACh receptors) - SA would normally beat at 100bpm, but vagal tone slows it down. Mostly affect chronotropy (innervate SA and AV nodes)
* **Sympathetic** – speed up (230bpm; epinephrine binds to β1 receptors). Affect chronotrophy and inotrophy (innervate SA node, AV node, and ventricles)
33
**systemic / pulmonary/ cardiac circulations**
• **Pulmonary circulations** - carries blood to and from the lungs for the uptake of oxygen and the removal of carbon dioxide
• **Systemic circulations** - carries oxygenated blood throughout the body and picks up carbon dioxide from body tissues
**• Cardiac circulations** - brings blood from the heart to the muscular layer of the heart wall. This gives the muscles the oxygen necessary to be able to pump blood. It also carries away carbon dioxide waste.
34
**functions of the heart**
* (1) Its **right side** receives oxygen-poor blood from the body tissues and then pumps this blood to the lungs to pick up oxygen and dispel carbon dioxide
* (2) its **left side** receives the oxygenated blood returning from the lungs and pumps this blood throughout the body to supply oxygen and nutrients to the body tissues
35
**coronary sulcus and the coronary vessels**
* **R and L coronary arteries** are the only branches of the ascending aorta; both travel in **coronary sulcus** to supply blood to heart wall. Their openings are immediately superior to the aortic semilunar valve (behind the cusps)
* **R coronary artery** branches into R marginal artery “small cardiac vein” (supply right border of heart) and posterior interventricular artery (supply both ventricles)
* **L coronary artery** branches into **anterior interventricular artery** (supply anterior surface of both ventricles and most of interventricular septum) and **circumflex artery** (supplies left atria and ventricle)
36
**anterior and posterior interventricular sulcus and the vessels you find there.**
* **Anterior interventricular sulcus**-Anterior interventricular artery/Great cardiac vein
* **Posterior interventricular sulcus**-Posterior interventricular artery/middle cardiac vein
37
**right and left atria
structures**
**Right atrium**
• **Auricles** – flaps projecting anteriorly
• Posterior part has smooth wall, anterior part lined with pectinate muscles
• **Crista terminalis** – ridge between anterior and posterior parts
• **Fossa ovalis** – depression in the interatrial septum that marks spot from opening in fetal heart (foramen ovale)
• Openings to coronary sinus, inferior vena cava and superior vena cava.
**• Right AV valve (= tricuspid)**
**Left atrium**
• Mostly smooth with pectinate muscle in auricle
• Openings to left pulmonary veins
• **Left AV valve (= bicuspid = mitral)**
38
**Ventricles structure**
* **Interventricular septum**
* **Trabeculae carneae** (irregular, muscular ridges)
* **Papillary muscles (**anchor chordae tendinae, which prevent AV valves from everting and flipping into atria during ventricular contraction)
* **Pulmonary semilunar valve** – between right ventricle and entrance of pulmonary trunk (which then divides into R and L pulmonary arteries)
* Left ventricle has thicker myocardium
* **Aortic semilunar valve** – between left ventricle and aorta
39
**Heart valve function**
• Valves open and close as a result of differences in blood pressure between chambers (NOT a result of muscle contraction)
**Function**
• Blood returning to the heart fills atria, putting pressure against **atrioventricular valves**; they are forced open.
* Atria contract, forcing additional blood into ventricles
* Ventricles contract, forcing blood against atrioventricular valve forcing them close.
* **Papillary muscles** contract and **chordae tendineae** tighten, preventing valve flaps from opening into atria
* As ventricles contract and intraventricular pressure rises, blood is pushed up against **semilunar valves**, forcing them open
* As ventricles relax and intraventricular pressure flows back from arteries, filling the cusps of semilunar valves and forcing them to close.
40
**Heart Valves**
**Atria**
**R- atrioventricular- AKA Tricuspid**
**L-atrioventricular- AKA Bicuspid, AKA Mitral**
**Ventricle**
**R-Pulmonary semilunar valve**
**L-Aortic semilunar valve**
41
**pacemaker**
* **Sinoatrial (SA) node**: pacemaker-sends out action potentials
* **Atrioventricular (AV) node**-pauses and then forwards AC to ventricles
* **Bundle branches**- conduct impulses at the interventricular septum
* **Purkinje fibers**-stimulates contraction
42
**Fetal heart defects**
* *Foramen ovale**- Intra-atrial septum. Most of the blood goes through here from right to left This is because the baby isnt getting oxygen from the lungs, but rather the placenta. It closes to become **fossa ovalis**
* *Ductus arteriosus**- right to left shunt from pulomary trunk to Aorta. Keeps blood from going to the lungs. When it closes it is then **ligamentum arteriosum.**
43
**Heart sounds**
**Lub**- AV valves close
**Dub-** Semilunar valves closing
44
**Coronary artery disease**
**Myocardial infarction**
**Congestive heart failure**
* **Coronary artery disease** – the arteries supplying the heart wall are narrowed or blocked
* **Myocardial infarction** – if the blockage of a coronary artery is more complete or prolonged, the oxygen-starved cardiac muscle cells die, also called heart attack.
* **Congestive heart failure** – the heart enlarges greatly while its pumping, efficiency progressively declines.
45
**Resistance vessels**
**Capacitance vessels**
**Exchange vessels**
* **Resistance vessels** - Arteries are also referred to as "resistance vessels" due to their strong, muscular nature and ability to withstand high blood pressure. Arteries, unlike veins, are able to remain rounded even when empty.
* **Capacitance vessels** - Veins are also referred to as "capacitance vessels" due to their flaccid nature and ability to expand significantly to accommodate higher volumes of blood.
* **Exchange vessels** - capillary walls are thin, the diffusion distances are small, so exchange can occur quickly. Blood flows through capillaries relatively slowly, allowing sufficient time for the diffusion or active transport of materials across the capillary walls.
46
**varicose veins**
• When the valves in veins weaken and fail, the veins twist and swell with pooled blood, and venous drainage slows considerably
47
**Blood Circulation**
Powered by the pumping action of the heart
Heart
**Arteries**-**Elastic**, then **muscular**
**Arterioles-** (small arteries )resistance vessels
**Metarterioles-** intermediate between arterioles and capillaries (getting smaller)
**Capillaries
Thoroughfare channel
Venules
veins**
48
**Arteries**
Branch and diverge
Blood away from heart
Generally oxygen rich
-Pulmonary arteries and umbilical arteries are the exceptions!
**Walls have 3 tunics**
**Tunica intima**-simple squamous endothelium
**Tunica media**-circular sheets of smooth muscle (vasomotion- diameter controlled by local factors and sympathetic NS)
**Tunica adventitia**(externa)- connective tissue with collagen and elastin in longitudinal arrangement
49
**Types of Arteries**
**Elastic**- largest arteries near heart
Low resistance
More elastin interspersed with the tunica media
Internal and external elastic lamina are not visible.
Can dissipate pressure and recoil back to pump blood
**Muscular**-
Supply organs
Can regulate diameter of artery to control blood supply to organ
Internal and external elastic lamina (unique feature)
50
**arterioles**
Smallest arteries- “resistance arteries”
**Tunica media** only has 1-2 layers of smooth muscle
Diameter controlled by local factors and sympathetic division
**Metarterioles**- just upstream of capillary beds. Can shunt blood directly to thoroughfare channel
51
**Capillaries**
Smallest blood vessels
Single layer of endothelial cells and basal lamina
Renew and interstitial fluid- pick up wastes, drop off nutrients, etc.
Walls have intercellular clefts
Stabilized by pericytes
Most cells only 60-80 µm away
Over a billion of them
52
**Types of capillaries**
(from least to most leaky)
* *Continuous capillaries**- (most common type)- skin, skeletal tissue, etc.
* *Fenestrated**- intestines to absorb nutrients into capilaries, synovial joints, and kidneys to filter blood.
* *Sinusoids**- (hella leaky)- bone marrow-new blood cells hop in, spleen-grave yard of blood cells.
53
**• Anastomoses**
vessels joining together; gives redundancy (heart artery can be 90% occluded)
54
**vasa vasorum**
“vessels for (large) vessels” Small blood vessels located in the tunica externa of large arteries that supply oxygen and nutrients to the outer layers of the vessel wall
55
Veins & Venules
**Venules**-Just endothelium and pericytes
Leukocytes initiate diapedesis (white blood cells coming out of circulation) here.
**Veins**
Tunica adventitia is larger than tunica media, less elastin
(Venous sinuses)- large veins with thin walls and large lumens- not capable of vasomotion (Dural sinuses and coronary sinus)
56
**Sympathetic innervation of vessels**
```
Medulla Oblongata
Causes vasoconstriction (increased vasomotor tone)
Most of the time (skeletal muscle and brain are exceptions)
Increases blood pressure
Increases venous return
```
57
**Respiritory System**
Supplies body with oxygen
Disposes of carbon dioxide
Speech
Sense of smell
Helps control pH of body (removes carbon dioxide)
Help regulate blood pressure (angiotensin II synthesis)
Special movements: Valsalva maneuver and lymph movements
58
**Organs of the Respiratory System**
Divided into:
* *Conducting zone**- From nose to terminal bronchioles. Carry air to site of gas exchange, filter, humidify, and warm air
* *Respiratory zone**- actual site of gas exchange in lungs. Includes respiratory bronchioles, alveolar ducts, and alveolar sacs
* *Upper respiratory tract**: nose to larynx
* *Lower respiratory tract**: trachea through the lungs.
• **External nares** – nostrils
• Divided by – **nasal septum** (perpendicular plate of ethmoid bone, vomer and septal cartilage)
• **Hard palate** (palatine and maxillary bones “anterior”) and **soft palate** (muscular “posterior”)
• **Vestibule** (Keisselbach’s area )- sebaceous and sweat glands + vibrissae (nose hair)
• **Nasal conchae/turbines** and swell bodies (blood vessels; alternate sides on warming air vs. allowing air in)
• Continuous with **nasopharynx**
o Posterior nasal apertures – **choanae** (internal nares)
59
**Nose**
Moistens and warms air
Filters inhaled air
Provides an airway for respiration
Resonating chamber for speech
The Paranasal Sinuses (FEMS)
Houses olfactory receptors
Size variation due to differences in nasal cartilages
Skin is thin – contains many sebaceous glands
Bones: frontal, nasal, maxillary, and hyaline cartilage
60
**The Nasal cavity**
**External nares** – nostrils
Divided by – **nasal septum** (perpendicular plate of ethmoid bone, vomer and septal cartilage)
**Hard palate** (palatine and maxillary bones) and soft palate (muscular)
**Vestibule** (Keisselbach’s area)- sebaceous, sweat glands, and vibrissae
**Nasal Conchae** and swell body
Continuous with **nasopharynx**
Posterior nasal apertures – **choanae**
61
**Respiratory conditions**
* **Cystic fibrosis** - an inherited disease in which the functions of exocrine glands are disrupted throughout the body.
* **Pulmonary edema** - Pulmonary edema is an abnormal buildup of fluid in the air sacs of the lungs, which leads to shortness of breath.
* **Respiratory distress syndrome** - In such infants, the alveoli collapse during exhalation and must be completely reinflated during each inspiration, an effort that requires a tremendous expenditure of energy that can lead to exhaustion and respiratory failure.
* **Bronchitis** - inhaled irritants lead to a prolonged secretion of excess mucus by the mucosa of the lower respiratory passages and to inflammation and fibrosis (formation of scar tissue) of this mucosa.
* **Asthma** - a respiratory condition marked by spasms in the bronchi of the lungs, causing difficulty in breathing. It usually results from an allergic reaction or other forms of hypersensitivity.
* **Emphysema** - a permanent enlargement of the alveoli caused by a deterioration of the alveolar walls
* **Pneumothorax** - A lung will collapse if air enters the pleural cavity (holds the lung to the thoracic wall)
* **Restrictive disorders** - decrease in the total volume of air that the lungs are able to hold, is often due to a decrease in the elasticity of the lungs themselves or caused by a problem related to the expansion of the chest wall during inhalation.
* **Chronic obstructive pulmonary disease** (COPD) - category of disorders in which the flow of air into and out of the lungs is difficult or obstructed
* **Pleurisy** - Lung infections such as pneumonia produce inflammation of the pleura
62
**Four processes in respiration**
* *Pulmonary ventilation**- air must be moved in and out of lungs
* *External respiration**-gas exchange between blood and air at the lung alveoli
* *Transport of respiratory gases**-Blood (gases) must be transported from lungs to body cells.
* *Internal respiration**-gas exchange between capillaries and body tissues
* *Inspiration** – inhalation
* *Expiration** – exhalation
63
**conductive vs. respiratory airways**
* **Conductive zone** - From nose to terminal bronchioles. Carry air to site of gas exchange. Filter, humidify, and warm air the incoming air
* **Respiratory zone** - actual site of gas exchange in lungs. Includes respiratory bronchioles, alveolar ducts, and alveolar sacs
64
**functional unit of the lung**
• **Alveoli** (They are small round sacs. Red blood cells have oxygen exchanged with them from the alveoli when the heart sends its signal.)
65
**molecule of oxygen from the external environment all the way to a red blood cell in the capillary near an alveolus
pathway **
**a molecule of carbon dioxide from the internal environment out the nares**
• External Nares (Nostrils) --\> Nasal Cavity --\> Inferior, Superior, & Middle Nasal Conchae --\> Pharynx --\> Larynx --\> Trachea --\> Primary Bronchi (Left & Right) --\> Hilus --\> Bronchioles --\> Respiratory Bronchioles --\> Alveolar Ducts --\> Alveoli (the grape-like sacs) --\> the the "spider web" of Pulmonary Capillaries.
The complete path out of the body is:
• Inferior Vena Cava-Right Atrium-Right Atrioventricular valve-Right Ventricle-Pulmonary Semilunar valve-Pulmonary Artery-Pulmonary arteriole-Pulmonary capillaries-alveolar sacs-tertiary bronchioles-secondary bronchioles-primary bronchioles-bronchus-trachea-larynx-pharynx-epiglottis- nostrils
66
**mucous membranes**
**and cells found there**
• **2 types of mucous membranes**
**olfactory mucosa** receptors for smell (Cranial nerve I endings)
**respiratory mucosa**, a mucous membrane that lines the vast majority of the nasal cavity.
• **Goblet cells** within epithelium
o **Mucous cells** secrete mucous
o **Serous cells** secrete digestive enzymes (destroys bacteria)
67
**The Pharynx**
Funnel-shaped passageway
Connects nasal cavity and mouth to larynx and esophagus
Divided into three locations
o **Nasopharynx** (from superior nasal cavity to uvula)
o **Oropharynx** (from uvula to hyoid bone)
o **Laryngopharynx** (from hyoid bone to cricoid cavity)
Type of mucosal lining varies along its length
68
**cartilages do you find in the larynx**
• 9 Cartilages (elastic and hyaline)
o **Thyroid** (laryngeal prominence; Adam’s apple)
o **Cricoid** – only to form complete ring
o **Arytenoid** (2) - anchor vocal chords
o **Corniculate** (2) - pulled on by intrinsic muscles
o **Cuneiform** (2) – “wedge-shaped”
o **Epiglottis** - is “guardian of air ways”
69
**functions of the larynx**
• Air passageway; prevents food from entering lower respiratory tract
** glottis**- the opening between the two vocal cords in the larynx.
70
**true and false vocal cords**
* **True vocal chords** - elastic fibers and white because are avascular. Air exhaled from lungs causes the folds to vibrate in a wave motion and to clap together, producing basic sound of speech
* **False vocal chords** (vestibular folds) - no part of sound production but can accentuate high pitch (Valsalva maneuver)
71
**gross anatomy of the trachea**
• Descends into the mediastinum (roughly from clavicles; hence “lower” respiratory tract)
• Divides into two main bronchi
• C-shaped cartilage rings (16-20 and made of hyaline cartilage) keep airway open despite changes in pressure during breathing
• Carina - marks beginning of bronchi
**3 microscopic layers**
• **Mucous membrane** - pseudostratified ciliated columnar epithelium (lamina propria has elastic fibers, separated from submucosa by sheet of elastin – enables trachea to stretch)
• **Submucosal layer** - glands, serous and mucous cells
• **Adventitia** - most external layer and contains the tracheal cartilages
72
**the “branches” of the bronchial tree**
• **Secondary** (lobar) bronchi
o Three on the right
o Two on the left
• **Tertiary** (segmental) bronchi
o Branch into each lung segment (bronchopulmonary segments)
• **Bronchioles** – little bronchi, less than 1 mm in diameter
• **Terminal bronchioles** – less than 0.5 mm in diameter (ends conducting zone)
73
**alveoli and the two types of cells**
• Alveoli are air exchange chambers and provide great surface area
• Alveoli consist of type I cells (simple squamous epithelia cells) and basal laminae
• Scattered among type I cells: Cuboidal epithelial cells – type II cells
o **Secrete surfactant** – phospholipids and protein. Reduces surface tensions within the alveoli, without it the inner walls of an alveolus would stick during exhalation.
o Repair damaged alveolar squamous cells
74
**respiratory membrane**
the alveolar and capillary walls and their fused basal laminae form the respiratory membrane, where oxygen and carbon dioxide are exchanged between the alveolus and the blood. Air is present on the alveolar side of the membrane, and blood flows past on the capillary side. Gases pass easily through this thin membrane: Oxygen diffuses from the alveolus into the blood, and carbon dioxide diffuses from the blood to enter the air-filled alveolus
75
**pleural cavity and membranes**
• **Pleura membranes**
o **Parietal pleura** – outer layer of the sac
o **Visceral pleura** – inner layer of the sac (directly on the lung)
• **Pleural cavity**
o Potential space
o Lubricating fluid reduces friction
o The fluid also holds the parietal and visceral pleurae together, just as a film of oil or water would hold two glass plates together.
76
**gross anatomy of the lungs**
* **Hilum** (indentation on medial surface for entry of blood vessels, bronchi, lymphatic vessels and nerves)
* The anterior, lateral, and posterior surfaces of a lung contact the ribs and form a continuously curving costal surface.
* **Root** – attaches the lung to the mediastinum
* **Base** - concave inferior surface that rests on the diaphragm
* **Apex** - rounded, superior tip of the lung
* **Right lung** - Oblique fissure and horizontal fissure gives the lung 3 lobes: superior, middle, and inferior lobes.
* **Left lung** - has cardiac notch (deviation In its anterior border that accommodates the heart). It’s smaller to right lung. Divided into 2 lobes: superior and inferior lobe, by the oblique fissure.
* **Lobule** - hexagons on surface
* **Stroma** – (The balance of the lung tissue), a framework of connective tissue containing many elastic fibers.
77
**body’s mechanisms for ventilation, respiratory centers and chemoreceptors for control of breathing**
• Inspiration (Quiet)
o Volume of thoracic cavity increases
o Decreases internal gas pressure
o Action of the diaphragm – diaphragm flattens (phrenic nerve)
o Action of external intercostal muscles – contraction raises the ribs
o Deep inspiration requires (Forced)
• Rib cage elevated by scalenes, sternocleidomastoid, and pectoralis minor
• Erector spinae – extends the back
• Quiet expiration – chiefly a passive process
o Inspiratory muscles relax
o Diaphragm moves superiorly
o Volume of thoracic cavity decreases
• Forced expiration – an active process
o Produced by contraction of:
• The oblique and transversus abdominis muscles
• Internal intercostals
• Respiratory center – generates baseline respiratory rate
o Has input from pons (hypothalamus, limbic and cerebral cortex)
• Chemoreceptors – sensitive to rising and falling oxygen, pH and carbon dioxide levels
o Central chemoreceptors – located in medulla
o Peripheral chemoreceptors -help modify heart rate
• Aortic bodies –in aortic arch to medulla via vagus
• Carotid bodies-fork of carotid, to medulla via CN IX and vagus
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**Sympathetic vs. parasympathetic effects on lung function**
* Parasympathetic – constrict airways
* Sympathetic – dilate airways
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**The Nasopharynx**
Superior to the point where food enters (from soft palate upward)
Only an air passageway
Uvula Closes off during swallowing- usually
Ciliated pseudostratified columnar epithelium
90 turn- large particles (pathogens) can’t make it and become trapped in mucosa.
Pharyngeal tonsil (adenoids)
Located on posterior wall
Destroys entering pathogens
Contains the opening to the pharyngotympanic (auditory) tube
**Tubal Tonsil**- protects middle ear from infection
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**The Oropharynx**
Arch-like entranceway – fauces
Extends from soft palate to the hyoid bone
Carries food and air
Epithelium is stratified squamous epithelium-more friction here, need more layers
Two types of tonsils in the oropharynx
Palatine tonsils – in the lateral walls of the fauces
Lingual tonsils – covers the posterior surface of the tongue
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**The Laryngopharynx**
Passageway for both food and air
Lined with stratified squamous epithelium
Continuous with the esophagus and larynx- ends at level of cricoid cartilage.
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Coronary arteries – capillary beds – great cardiac vein – middle cardiac vein – small cardiac vein - Coronary sinus drains blood from heart wall – right atrium
Aorta – artery – arteriole –metarterioles - capillary bed – thoroughfare channel - venule – vein – inferior vena cava – right atrium – right ventricles – pulmonary trunk – pulmonary arteries – lung capillary beds – gas exchanges at the alveoli in the respiratory membrane (CO2 is removed and goes in alveoli, and O2 is entered in capillaries) – pushed back by diaphragm
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**components of blood**
* **Plasma** – 55% of whole blood, least dense component
* **Buffy coat** – Leukocytes and platelets, \<1% of whole blood
* **Erythrocytes** (hematocrit) – 45% of whole blood, most dense component**t**
**hematocrit**-
• The ratio of the volume of red blood cells to the total volume of blood
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**plasma, serum and whole blood**
* **Plasma** - the extra cellular fluid, consists of water and dissolved glucose, plasma proteins, amino acids, fatty acids, hormones, electrolytes and waste products.
* **Serum** – fluid that exudes from the clotted blood plasma as it shrinks and then no longer contains clotting factors.
* **whole blood** - consists of extracellular fluid in the form of plasma and intracellular fluid with respect to the fluid within the red blood cells, platelets, and white blood cells suspended in the plasma. Whole blood is considered to be a fluid connective tissue.
* Blood is the oxidizing element of our body. Its function is to carry out oxygen throughout the body with the help of hemoglobin.
* Plasma is the liquid part of blood. Its function is to keep the Red Blood Cells together, in the form of a liquid, which we call as blood.
* Serum is a yellowish liquid that comes out of a healed wound. When our skin gets cut at some point, White Blood Cells come over immediately to that part of the body and start killing the entering germs. Finally, when the work is completed, all the dead White Blood Cells, dead germs and lot of plasma ooze out of the wound in the form of serum.
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** solutes found in plasma**
• Ions, nutrients, wastes and proteins (Albumin, globulins, fibrinogen)
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**Differentiate between granulocytes and agranulocytes**
* **Granulocytes** (neutrophils, eosinophils, and basophils)(aka polymorphonuclear cells) contain many obvious granules. They have nonspherical nuclei with purple-staining lobes joined by bandlike constrictions. Functionally, all granulocytes are phagocytic; that is, they engulf and digest foreign cells or molecules.
* **Agranulocytes** (lymphocytes and monocytes) lack obvious granules.
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**WBC's in order of most to least abundant in blood**
• Neutrophils
• Lymphocytes
• Monocytes
• Eosinophils
• Basophils
o “Never Let Monkeys Eat Bananas”
* **Basophil** – Release histamine and other mediators of inflammation; contains heparin. (S or U shape nucleus)
* **Eosinophil** – (nucleus is bi-lobed) Turn off allergic responses and kill parasites
* **Neutrophil** – (Nucleus multi-lobed) Destroy bacteria by phagocytosis
* **Monocyte** – (U-shaped) phagocytosis; develop into macrophages in tissues
* **Lymphocytes** – (spherical) Mount immune response by direct cell attack (T cells) or via antibodies (B cells)
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**important structural features of RBC’s (erythrocytes) and their function**
i
• its unique biconcave disc structure allows respiratory gases to be loaded and unloaded rapidly as the biconcave shape gives much surface area for gas diffusion. Allows them to line up and more flexible through a capillary bed, while resisting tearing. 30% more surface area
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**structure of platelets and their role in clotting**
* **Platelets** - Discoid cytoplasmic fragments containing granules; stain deep purple; diameter 2-4 μm.
* Platelets plug small tears in the walls of blood vessels.
* They release thromboplastin that helps initiate clotting, a sequence of chemical reactions in blood plasma that ultimately generates a network of tough fibrin strands among the accumulated platelets. It provides a strong seal across the tear, then after the platelets within it contract in a muscle-like way, pulling the edges of the tear together.
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**red vs. yellow bone marrow**
* Red marrow – only one to actively generates blood cells
* Yellow marrow – is dormant; it makes blood cells only in emergencies that demand increased hematopoiesis. (Yellow because it reflects the many fat cells in it)
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**What is hematopoiesis? What is a hematopoietic stem cell? How do the various types of blood cells form and differentiate?**
* **Hematopoiesis** – Red blood cell formation (occurs in red bone marrow)
* The process starts with hemopoietic stem cells called hemocytoblasts. Hemocytoblasts are considered to be multipotent cells, which means they can differentiate and develop into many different kinds of blood cells.
* Thus, they are committed, or determined, but not differentiated. Put this in another way, it means the hemocytoblast is determined to generate daughter cells that will then differentiate into specific types of blood cells. Hemocytoblasts produce two lines for blood cell development: the myeloid stem cells forms erythrocytes (RBCs), megakaryocytes (these generate platelets), and all leukocytes except lymphocytes. The lymphoid stem cells forms the lymphocytes. A number of hormones and growth factors influence the maturation and division of the blood stem cells.
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**a thrombus? An embolus?**
* **Thrombus** - A clot that develops and persists in an intact blood vessel. If it becomes too large it can block the flow of blood and cause death
* **Embolus** - If a thrombus or a piece of a thrombus breaks off of a vessel wall and floats freely in the bloodstream. Becomes dangerous when it obstructs a vessel that is too narrow to pass through
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**disorders of blood**
* **Polycythemia** – abnormal excess of erythrocytes in the blood. Severe polycythemia causes an increase in the viscosity of the blood, which slows or blocks the flow of blood through the smallest vessels
* **Anemia** – any condition in which erythrocyte levels or hemoglobin concentrations are low, such that the blood’s capacity for carrying oxygen is diminished. Anemic individuals are constantly tired and often pale, short of breath, and chilly because their tis- sues are receiving low amounts of oxygen.
* **Leukemia** – a form of cancer resulting from the uncontrolled proliferation of a leukocyte-forming cell line in the bone marrow. the cancer cells take over the bone marrow, crowding out the nor- mal blood cell lines and slowing the production of normal blood cells.
* **Thrombocytopenia** – “lack of platelets” an abnormally low concentration of platelets in the blood. Characterized by diminished clot formation and by internal bleeding from small vessels.
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