Midterm semester 2 Flashcards
What are the two primary defense mechanisms for fighting infection?
Lymphatic system
White blood cells
What are the three main parts of the lymphatic system
Lymphatic vessels
Lymph fluid
Lymph nodes
What is the primary function of the lymphatic vessels?
Transport lymph (which contains WBCs) throughout the body
Pick up and return excess interstitial fluid to the blood stream
What are the three clusters of lymph nodes and where are they located?
Cervical = in the neck
Axillary = in the armpit
Inguinal = in the groin
What is the average amount of interstitial fluid found in the interstitial spaces?
About 11 liters
In a healthy individual, how is the majority of the interstitial fluid returned to the bloodstream?
Oncontic pressure pulls the fluid back into the veins
What is the basic function of the lymph nodes?
filter /clean the lymph flowing through them prior to returning the lymph to the systemic circuit
This is done by lymphocytes
What is hydrostatic pressure?
Pressure of the blood exerted on the membrane of the capillary. Pushes fluid out of capillary into interstitial space. Pressure is greater on the arterial side than the venous side
What is oncotic pressure?
Pressure that pulls water back into the capillary and/or prevents it from leaving
What generates oncotic pressure?
Plasma proteins such as albumin which cannot cross the wall of the capillary.
What is interstitial oncotic pressure?
The pressure related to the amount of proteins in the interstitial fluid. If protein levels are increased, more fluid is pulled out of capillaries into interstitium
What is interstitial hydrostatic pressure?
Hydrostatic pressure of the fluid in the interstitium, can be thought of as “zero” which allows for fluid to pass out of capillaries and be pulled into the lymphatic vessels. If pressure increases this can result in more fluid being absorbed back into the capillaries
T/F: The distribution of lymphatic vessels throughout the lungs is ubiquitous
False. There are more lymphatic vessels on the SURFACE of the lower lobes than on the upper and middle lobes
Where does the thoracic duct drain fluid from?
From tissues inferior to the diaphragm and the left side of the body
Where does the right lymphatic duct drain fluid from?
The right lymphatic duct drains fluid from the right half of the body superior to the diaphragm
T/F: lymphatic vessel are found in the walls of the alveoli
False. Lymphatic vessels are found in the interstitial spaces to help drain fluids and foreign materials
Where does the thoracic duct drain lymph into?
The left subclavian vein
Where does the right lymphatic duct drain lymph into?
The right subclavian vein
lymph enters the lymph nodes through the efferent lymphatic vessels
False. Lymph enters the lymph nodes through the afferent lymphatic vessels
Efferent = get the “F” outta here
The cysterna chyli
The cysterna chyli marks the beginning of what?
The thoracic duct
Describe the cysterna chyli
The cysterna chyli is a dilated sac at the lower end of the thoracic duct in most mammals
Serves as a reservoir for lymph
Marks the starting point of the thoracic duct
What are the 5 types of WBCs that we care about? (at the moment)
Monocytes aka macrophages
Lymphocytes
Eosinophils
Basophils
Neutrophils
What are the 2 types of lymphocytes?
T cells
B cells
What is another name for a macrophage?
Monocyte
What is a normal WBC count?
4000-10000 (4-10 on reports)
What is the purpose of getting a WBC differential?
Can help diagnose infection
What is a leukemoid reaction?
An extreme increase in the number of white blood cells
50,000 or more
What would a WBC differential with 90% lymphocytes indicate in a patient with pneumonia?
That that the pneumonia is viral
What does a complete blood count do?
Quanitifies RBCs
Determine the number and type of WBCs
What is leukopenia?
Too few WBCs
Less than 4000
What would a WBC differential with 90% neutrophils indicate in a patient with pneumonia?
That the pneumonia is bacterial
What are bands/stabs?
Immature neutrophils
What does an increase in the number of bands or stabs indicate?
Indicates and increase in immature newly formed neutrophils which occurs in an acute inflammatory response
What are mature neutrophils referred to as?
Segs
What can an increase in the number of bands/stabs also be called?
A shift to the left
What are the first white blood cells at the site of an acute inflammatory response?
Neutrophils
What is the normal range for neutrophils in a WBC diff?
40-75%
25-80%
40-60%
Why does a shift to the left occur in acute inflammatory responses?
Bone marrow releases neutrophils
Neutrophils begin fighting infection
Neutrophils do not have a long life span
Bone marrow releases immature neutrophils to fight infection while macrophages are activated and take over as the predominant WBC at site of injury/infection/inflammation
What is the normal range for lymphocytes in a WBC diff?
20-45%
20-50%
20-40%
What is the normal range for monocytes in a WBC diff?
2-10%
2-12%
2-8%
What is the normal range for eosinophils in a WBC diff?
0-6%
0-7%
1-4%
What is the normal range for basophils in a WBC diff?
0-1%
0-2%
0.5-1%
What is the normal range for bands in a WBC diff?
0-6%
0-10%
0-3%
What is the role of the spleen?
Produces and stores WBCs
When it detects bacteria or viruses the spleen with produce lymphocytes
What are the other organs in the body responsible for fighting infection?
Tonsils
Spleen
Thymus
What is the function of the tonsils in children?
Trap inhaled viruses and bacteria
Produce lymphocytes to destroy “invaders”
This function diminishes as a child reaches the age of 3
What is the role of the thymus in fighting infections?
Produces progenitor cells which mature into T-cells
Where in the brain are the respiratory centers located?
The brainstem
The dorsal and central respiratory groups are located where?
In the medulla
The pneumotaxic center and the apneustic center are located where?
In the pons
Where is the pneumotaxic center located in the pons?
The upper portion
Where is the apneustic center located in the pons?
Lower pons
What does the apneustic center control?
Triggers inspiration only
What does the pneumotaxic center control?
Triggers inspiration
Senses lung expansion and inhibits inspiration to allow for expiration
T/F: The apneustic center fine tunes respiratory rate and depth
False. The pneumotaxic center fine tunes RR and depth
What kind of signals does the pneumotaxic center send and where does it send them?
Sends inspiratory and expiratory signals/implulses to the medullary respiratory groups
What happens if the pneumotaxic center is damaged
The Apneustic center will “take over” and without the pneumotaxic center inhibiting inspiration, the individual will take very long very deep gasping breaths called apneustic breathing
What kind of signals does the pneumotaxic center send and where does it send them?
Sends inspiratory signals/impulses to the medullary respiratory groups to trigger inspiration
Where is the DRG located in the medulla?
Bilateral groups of neurons located in the posterior medulla
Where does the DRG receive information from?
Receive information and stimuli from the pontine centers
Where is the VRG located in the medulla?
Bilateral group of neurons located in the anterior medulla