Lecture Exam 3 Flashcards
1
Q
What are the functions of blood:
A
- Carries respiratory gases, nutrients, hormones and metabolic wastes
- Regulates pH of interstitial fluid
- Restrict fluid loss at injury sites
- Defense against toxins and pathogens
- Helps body regulate temperature
2
Q
What is plasma?
A
Straw-colored, sticky fluid portion of blood.
90% water.
3
Q
What are the components of plasma?
A
Ions nutrients wastes oxygen hormones vitamins proteins
4
Q
Types of proteins found in plasma:
A
Albumin (60%)
Globulin (30%)
Fibrinogen (5%)
Regulatory proteins (
5
Q
How is plasma different from interstitial fluid?
A
It contains proteins and different levels of gases.
6
Q
What is a hematocrit?
A
The percentage of the blood volume that consists of erythrocytes, averages 45%
(Males: 47%, Females: 42%)
7
Q
What is hematopoiesis?
A
Process by which blood cells are formed. 100 billion new blood cells formed each day.
8
Q
The 2 main stem cells that originate from the blood stem cell:
A
Lymphoid stem cells
Myeloid stem cells
9
Q
What are the functions of red blood cells?
A
Transport oxygen and carbon dioxide
10
Q
How many red blood cells do we have per mm^3?
A
4-6 million
11
Q
How is the structure of RBC related to the function?
A
Their biconcave shape provides 30% more surface area than spherical cells of the same volume, allowing rapid diffusion of oxygen into and out of erythrocytes.
12
Q
How long do red cells circulate for?
A
100-120 days
13
Q
Which organs remove old blood cells?
A
Mainly the spleen, also the liver.
14
Q
The 5 types of white blood cells:
A
Granulocytes:
- Neutrophils
- Eosinophils
- Basophils
Agranulocytes:
- Lymphocytes
- Monocytes
15
Q
Neutrophil function:
A
Destroy bacteria by phagocytosis
16
Q
Eosinophil function:
A
Turn off allergic responses and kill parasites
17
Q
Basophil function:
A
Release histamine and other mediators of inflammation
18
Q
Lymphocyte function:
A
Mount immune response by direct cell attack (T cells) or via antibodies (B cells)
19
Q
Monocyte function:
A
Phagocytosis; develop into macrophages in tissues
20
Q
Where are white blood cells formed?
A
In the bone marrow
21
Q
Platelets:
A
Not cells.
Disc-shaped, plasma membrane- enclosed fragments of cytoplasm that form by breaking off of larger cells called megakaryocytes.
Megakaryocytes are precursor of platelets.
22
Q
What type of tissue is blood?
A
A specialized type of connective tissue
23
Q
Why is the heart considered a double pump?
A
It has two sides that pump. The right side of the heart pumps blood through the pulmonary circuit. The left side of the heart pumps blood to all the body tissues via the systemic circuit.
24
Q
The 3 layers of the pericardium:
A
- Fibrous pericardium (dense C.T.)
- Serous pericardium: parietal layer and viscera layer (both C.T.)
25
Function of pericardial fluid:
Reduce friction between the beating heart and the outer wall of the pericardial sac
26
Layers of the heart wall:
- Epicardium
- Myocardium
- Endocardium
27
The 4 chambers of the heart:
Right atrium
Right ventricle
Left atrium
Left ventricle
28
Function of right atrium:
Receives blood from systemic circuit via superior vena cava, inferior vena cava, and coronary sinus
29
Function of right ventricle:
Receives blood from right atrium thru the tricuspid valve. Pumps blood into pulmonary circuit via pulmonary trunk.
30
Function of left atrium:
Receives oxygen-rich blood from lungs thru pulmonary veins.
31
Function of left ventricle:
Pumps blood thru systemic circuit via aortic semilunar valve (aortic valve).
32
Why are atrial walls thin?
The blood is pumped down to the ventricles, which are larger pumping chambers which must propel blood out of the heart so they contain more muscle tissue than the atria do.
33
Which ventricle has a thicker wall? Why?
The left ventricle has thicker walls then the right, because it needs to pump blood to most of the body, while the right ventricle fills only the lungs
34
Name the three major veins opening into the right atrium:
- Superior vena cava
- Inferior vena cava
- Coronary sinus
35
Name the two major arteries leaving the heart from the ventricles:
- Pulmonary trunk
| - Aortic valve
36
Trace blood thru all heart chambers and heart valves:
Blood coming from the body regions superior to the diaphragm (not including heart wall) enters the R atrium via the SVC; blood returning from the body regions inferior to the diaphragm enters the IVC; and blood draining from the heart wall itself is collected by and enters the R atrium thru the coronary sinus. The blood passes from the atrium thru the tricuspid valve to the R ventricle, propelled by gravity and the contraction of the R atrium. Then, the R ventricle contracts, propelling the blood thru the pulmonary semilunar valve into the pulmonary trunk and to the lungs thru the pulmonary circuit for oxygenation. The freshly oxygenated blood returns via the 4 pulmonary veins to the L atrium and passes thru the mitral valve to the L ventricle, propelled by gravity and the contraction of the L atrium. The L ventricle then contracts and propels the blood thru the aortic semilunar valve into the aorta and its branches. After delivering oxygen and nutrients to the body tissues thru the systemic capillaries, the oxygen poor blood returns thru the systemic veins to the R atrium- and the whole cycle repeats continuously.
37
Structure and location of semilunar valves:
Each has 3 pocket-like cusps shaped roughly like crescent moons. Located at the junction of the ventricles and the great arteries.
38
How do semilunar valves work to prevent the back flow of blood in the heart?
When the ventricles contract and raise the intraventricular pressure, the semilunar valves are forced open, and their cusps are flattened against the arterial walls as the blood rushes past them. When the ventricles relax, blood that tends to flow back toward the heart fills the cusps of the semilunar valve and forces them shut.
39
Structure and location of atrioventricular valves:
Located at the junctions of the atria and their respective ventricles are the atrioventricular valves: the R atrioventricular (tricuspid) valve, which has 3 cusps, and the L atrioventricular (bicuspid) valve, which has only 2 cusps (also called mitral valve).
40
How do atrioventricular valves prevent the back flow of blood into the heart?
When the ventricles start to contract, the pressure within them rises and forces the blood superiorly against the valve cusps pushing the edges of the cusps together and closing the AV valves.
41
Pectinate muscles:
A smooth-walled posterior part and an anterior part lined by horizontal ridges.
42
Chordae tendineae:
Thin strong bands (the heart strings); project superiorly from the papillary muscles to the flaps (cusps) of the tricuspid (R atrioventricular) valve.
43
Papillary muscles:
Come-shaped; project from the walls into the ventricular cavity.
44
Cardiac skeleton:
Lies in the plane between the atria and the ventricles and surrounds 4 heart valves, like handcuffs.
45
Functions of cardiac skeleton:
* Anchors valve cusps
* Prevents overdilation of valve openings as blood pulses thru them
* Point of attachment for bundles of cardiac muscle in the atria and ventricles
* Blocks the direct spread of electrical impulses from atria to the ventricles. This critical for proper coordination of atrial and ventricular contractions
46
Systole:
Contraction of a heart chamber
47
Diastole:
The time during which a heart chamber is relaxing and filling with blood.
48
Conducting system:
A series of specialized cardiac muscle cells that carries impulses throughout the heart musculature, signaling the heart chambers to contract in the proper sequence. Also initiates each contraction sequence, thereby setting basic heart rate.
49
Components of the conducting system:
- Sinoatria (SA) node
- Atrioventricular (AV) node
- AV bundle
- Bundle branches
- Subendocardial conducting network (Purkinje fibers)
50
Function of Sinoatria (SA) node:
Sets basic heart rate by generating 70-80 electrical impulses per minute.
51
Function of atrioventricular (AV) node:
Conducts the normal electrical impulse from the atria to ventricles.
52
Function of AV bundle:
Transmits impulses from the AV node, located at inferior end of interatrial septum, to ventricles of the heart.
53
Function of bundle branches:
Right bundle carries nerve impulses that cause R ventricle to contract; left bundle carries the nerves that contract the L ventricle.
54
Function of Purkinje fibers:
Carry the contraction impulse from both the left and right bundle branch to the myocardium of the ventricles.
55
Influence of parasympathetic system on heart rate:
Decrease heart rate
56
Influence of sympathetic system on heart rate:
Increases heart rate and strength of contraction
57
Name the 3 layers (or tunics) of blood vessels:
Tunica intima
Tunica media
Tunica externa
58
Composition of tunica intima:
Simple squamous epithelium and connective tissue (areolar)
59
Composition of tunica media:
Sheets of smooth muscle in loose connective tissue that anchors the media to the intima and the externa.
60
Composition of tunica externa:
Connective tissue. Vasa vasorum.
61
How is the wall of an artery different from the wall of a vein?
```
The artery has:
-A thicker wall
-A thicker tunica media
-A narrower lumen
-Thickened elastic membrane (not present in the vein)
The vein has:
-A thicker tunica externa
-A wider lumen and valves
```
62
What is the function of a valve (in which vessels do we have valves)?
Blood pressure in veins is low, so most contain valves to prevent pooling
63
How is a capillary structurally different from an arteriole?
Capillaries are smaller in diameter (8-10ūm) and are composed of only a single layer of endothelial cells surrounded by a basement membrane.
Arterioles' diameters range from 0.3mm-10ūm. Larger arterioles contain all 3 tunics; tunica media is thin (contains only 1 or 2 layers of smooth muscle cells).
64
General structure of a capillary:
A single layer of endothelial cells surrounded by a basement membrane.
65
Name the 4 routes of capillary permeability:
- Direct diffusion thru endothelial cell membranes
- Thru intercellular clefts
- Thru pinocytotic (cytoplasmic) vesicles
- Thru fenestrations
66
Structure of continuous capillaries:
Tight junctions and occasional desmosomes the capillary endothelial cells together. There are gaps in unjoined membrane called intercellular clefts. External to the endothelial cells, the capillary is strengthened and stabilized by scattered pericytes (spider-shaped cells).
67
Function of continuous capillaries:
Tight junctions of epithelium make them highly permeable to anything but the smallest molecules.
68
Where are continuous capillaries found in the human body?
Most common type of capillary.
Occurs in most organs of the body such as skeletal muscles, skin, and central nervous system.
69
Structure of fenestrated capillaries:
Endothelial cells are joined by tight junctions and contain intercellular clefts. Also have pores spanning the epithelial cells.
70
Where are fenestrated capillaries found in the human body?
Small intestine, kidney, endocrine glands, and synovial membrane of joints.
71
Structure of sinusoids:
Wide, leaky capillaries. Fenestrated, and their endothelial cells have fewer cell junctions than other capillaries.
72
Where are sinusoids found in the human body?
Bone marrow and spleen
73
Function of sinusoids:
Large diameter and twisted course ensure that blood slows when flowing thru these vessels, allowing time for exchanges that happen along their walls.
74
What are the 2 terminal branches of the abdominal aorta?
Right and left common iliac arteries
75
At what vertebral level does the branching occur?
L4 of the lumbar vertebrae
76
What are the 3 branches of the aortic arch?
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
77
What regions of the body are supplied by the 3 branches of the aortic arch?
The head and neck, upper limbs, and the superior part of the thoracic wall.
78
Name the 3 branches of the celiac trunk:
Left gastric artery
Splenic artery
Common hepatic artery
79
Which body region does the SVC receive venous blood from?
All body regions superior to the diaphragm excluding the heart wall
80
Which body regions does the IVC receive venous blood from?
All body regions inferior to the diaphragm
81
The 2 specific veins that form the SVC:
Left and right brachiocephalic veins
82
The 2 specific veins that form the IVC and at which level:
2 common iliac veins on the body of vertebrae L5
83
Name the 3 tributaries to the hepatic portal vein:
Superior mesenteric vein
Splenic vein
Inferior mesenteric vein
84
What is the functional significance of having an hepatic portal system?
It picks up digested nutrients from the stomach and intestines and delivers these nutrients to the liver for processing and storage.
85
Lymph:
The fluid that circulates throughout the lymphatic system
86
Lymphatic system:
A network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials
87
Main functions of lymphatic system:
Responsible for the removal of interstitial fluid from tissues.
Absorbs and transports fatty acids and fats as chyle from digestive system.
Transports white blood cells to and from lymph nodes into bones.
88
Lymphatic tissue:
A specialized form of reticular C.T. in the lymphatic system that contains large numbers of lymphocytes
89
Lymphatic organs:
Primary lymphoid organs
| Secondary lymphoid organs
90
Primary lymphoid organs:
Bone marrow and thymus
91
Secondary lymphoid organs:
- Lymph nodes
- Spleen
- The collections of mucosa associated lymphoid tissue (MALT) that forms the tonsils
- Aggregated lymphoid nodules in the intestine
- Appendix
92
Phagocytosis:
Process where a cell forms cytoplasmic extensions to engulf foreign particles, cells, or macromolecules and then uses lysosomes to digest these substances.
93
Macrophages:
General phagocytic cells of the body, capable of engulfing and digesting a wide variety of foreign cells, particles, and molecules; present throughout the connective tissues of the body and especially abundant in lymphoid tissues of the immune system.
94
Contrasts of the structure of the wall of arteries and veins:
- The lumens of the veins are larger than arteries of the same size.
- Veins have less elastic in their walls than arteries.
95
Comparisons of the structure of the wall of arteries and veins:
- Both consist of 3 layers (tunics)
| - Both have thin outer layers (tunica externa)
96
Hepatic veins:
Collect blood from liver and return it to the IVC
97
Inferior mesenteric vein:
Drains distal part of the colon
98
Splenic vein:
Drains the spleen, pancreas, and stomach
99
Superior mesenteric vein:
Drains blood from small intestines, proximal part of colon, pancreas, and stomach.
100
B cells:
Fight infectious microorganisms in the areolar and lymphoid CT by producing antibody-secreting plasma cells.
B cells and antibodies are best at destroying bacteria products.
101
Cytotoxic (CD8+) T cells:
Fight infectious microorganisms in the areolar and lymphoid CT by directly killing antigen-bearing cells.
Best at destroying eukaryotic cells that express surface antigens, such as virus-infected cells and grafted and tumor cells.
102
Helper (CD4+) T cells:
Stimulate the cells of the immune system by secreting chemicals called cytokines.
103
Cytokines:
Stimulate the proliferation of activated B cells, cytotoxic T cells, and macrophages and amplify and fine-tune the immune response.
104
Immune response:
If immune cells (dendritic cells) decide that a material (virus/bacteria) is dangerous, they stimulate white blood cells that cause Helper T cells to become activated. Helper T cells stimulate the cells to make antibodies that bind and immobilize the specific antigen, which prevents infection. Once activated, memory cells are produced that ensure a faster and stronger immune response that can be made upon re-exposure to the same pathogen.
105
How do vaccinations protect us?
They provide lasting protection against disease.
