Midterm 2 Flashcards
1
Q
Body cavities
A
- Dorsal
- cranial (head cavity- brain)
- vertebral (spinal cord) - Ventral
- thoracic (chest) - pericardial (heart), pleural (lungs)
- abdominal (digestive organs)
- pelvic (urinary bladder, reproductive organs, rectum)
2
Q
What are body cavities
A
Enclosed spaces that house and protect organs
3
Q
Organs
A
Consist of 2 or more major tissue types (some can consist of all 4)
- epithelial
- connective
- nervous
- muscle
4
Q
Membranes
A
- line cavities
- consist of 1 or 2 tissue types (connective tissue with or without attached epithelial tissue)
- line inner and outer surfaces of the body and its organs
5
Q
Mucous membranes
A
- lines cavities and organs that open directly to body exterior
- found in the digestive respiratory, urinary and reproductive systems
1. Epithelial layer - in contact with lumen of organ
- avascular
- many have goblet cells
- lots of vili
- lines digestive tract
2. Lamina propria - connective tissue layer that connects epithelial tissue to wall of organ
- loose areolar tissue
- vascular
- nourishes epithelial cells
6
Q
Serous membrane
A
- lines body cavities and organs that don’t open up to outside of body
- cover external surfaces of organs in these cavities
- double layered, layers composed of a simple epithelium bound to an areolar connective tissue
1. Parietal layer: against cavity wall
2. Visceral layer: against organ - epithelial layers secrete serous fluid into the serous cavity
- locations:
1. Pericardium (heart)
2. Pleura (lungs)
3. Peritoneum (abdominal organs)
7
Q
Synovial membrane
A
- in joints
- areolar connective tissue
- no epithelium
- only one tissue type, therefore, NOT an organ
8
Q
Cutaneous membrane
A
Skin:
- epithelium: stratified squamous (named the epidermis)
- connective tissue: areolar and dense irregular (named the dermis)
9
Q
Integumentary system
A
main function = protection
Consists of:
- skin
- nails, hair, glands
- muscles (goosebumps)
- sense receptors (nervous)
- hypodermis
10
Q
Skin
A
- Epidermis
- Dermis
- Hypodermis (below skin)
11
Q
Epidermis of skin
A
- stratified squamous epithelium
- avascular
- sub layers:
1. Stratum basale
2. Stratum spinosum
3. stratum granulosum
4. Stratum lucidum
5. Stratum corneum
12
Q
Stratum basale of epidermis
A
- single row of cells
- 2 cell types:
1. Keratinocytes (90% of skin) - undergo mitosis (shedding skin)
- makes keratin (tough protein)
- pushed towards surface as new cells are produced in basale
2. Melanocytes (10% of skin) - produce pigment for UV light protection
- skin colour (cells produce different amounts and shades of melanin)
13
Q
Stratum spinosum of epidermis
A
- low levels of mitosis
14
Q
Stratum granulosum of epidermis
A
- last layer of living cells
- no mitosis
- contains granules that help produce keratin and start to produce water proofing glycolipids to prevent water loss
15
Q
Stratum lucidum of epidermis
A
- only found in thick skin
- first layer of dead cells
- no mitosis
- flat, dead cells (too far from blood supply)
16
Q
Stratum corneum of epidermis
A
- many layers of flat, dead cells filled with keratin
- glycolipids between cells creates a waterproof layer to prevent water loss
- shed and replaced from below
17
Q
Dermis of skin
A
- contains blood vessels, nerves, glands, hair follicles, and arrest or pili muscles
- 2 sub-layers (connective tissue):
1. Papillary layer
2. Reticular layer
18
Q
Papillary layer of dermis
A
- connected to epidermis
- areolar connective tissue
- vascular
- has projection into epidermis = dermal papillae (in thick skin these form epidermal ridges like fingerprints to improve grip)
19
Q
Reticular layer of dermis
A
- between papillary layer and hypodermis
- forms most of dermis
- dense irregular connective tissue
- tears in collagen in reticular layer lead to the look of stretch marks
20
Q
Thickness of skin
A
Refers to the epidermis not the dermis
21
Q
Thin skin
A
- covers most of body
- lucidum absent
- has hair follicles, sebaceous glands and arrest or pili muscles
22
Q
Thick skin
A
- found on the palm of hand and the sole of the foot
- lucidum present
- no hair follicles, sebaceous glands or arrector pili muscles
23
Q
Epidermal derivatives
A
All derived (formed) from the epidermis
Include:
1. Hair
2. Nails
3. Skin exocrine glands
24
Q
Hair
A
- all dead cells
- root = part of hair embedded in the skin
- shaft = visible part of hair above the skin surface
- hair follicle = surrounds root
- epithelial root sheath = several epidermal layers extended into the dermis
- bulb = expanded region at base of root
- matrix = single layer of cells (site of hair growth and melanin for hair colour)
- Outer CT sheath = holds follicle in placed
- hair papilla = extends upwards beneath matrix and contains blood supply for growing hair
- root hair plexus = free nerve ending
- sebaceous gland = opens into follicle
- arrector pili muscle = causes goosebumps
25
Nails
- heavily keratinized epidermal cells
- consists of: nail root, body and free edge
26
Skin exocrine glands
1. Sebaceous gland
2. Sudoriferous gland
3. Ceruminous gland
4. Mammary gland
27
Sebaceous gland
- connected mainly to hair follicle
- secrets sebum (oil)
- softens, lubricates hair and skin, prevents drying out, antibiotic
28
Sudoriferous glands
- sweat glands
- secretory portions in dermis of thick and thin skin
- ducts open onto skin surface
- temperature regulation: cool the body
- antibiotic action: due to sweat being acidic
- waste removal: urea
29
Ceruminous glands
- modified sweat glands
- in ear canal
- produce ear wax (prevents insects, etc. from entering)
30
Mammary glands
- modified sweat glands
- produce milk
31
Sense receptors
- sensory neurons (part of nervous system)
- specialized cell that responds to stimuli
- 4 major types:
1. Touch receptors
2. Pressure receptors
3. Thermoreceptors
4. Nociceptors
32
Touch receptors
- most major
- free nerve endings (in epidermis)
- root hair plexus
- tactile (Meissner’s) corpuscles (found under epidermis: in dermal papillae, corpuscle is a CT capsule surrounding a nerve ending
33
Pressure receptors
- free nerve endings (in dermis)
- Lamellar (pacinian) corpuscles (looks like onion through microscope: deep in dermis or hypodermis
34
Thermoreceptors
Free nerve endings for temperature
35
Nociceptors
- free nerve ending for pain
- 3rd degree burns destroy Nociceptors, causing lack of pain sensation in affected areas
- 1st and 2nd degree burns hurt more because Nociceptors are still intact
36
Hypodermis
- not a part of the skin
- also called the subcutaneous layer
- also called superficial fascia (fascia: CT layers that surround and support organs)
- adipose CT below skin that stores 1/2 of body’s adipose tissue (insulation, fat)
37
Medical conditions - integumentary system
1. Albinism= lack of melanin production by melanocytes
2. Psoriasis= autoimmune disorder that causes accelerated mitosis of keratinocytes in the stratum basale
- accelerated cell cycle delays maturation and differentiation of keratinocytes
- immature keratinocytes accumulate in the epidermis and stratum corneum fails to shed, resulting in a thick, scaly area on the surface of the skin
38
Bone
- tissue AND organ
- 2 types:
1. Compact bone
2. Spongy bone
39
Compact bone
- covers external surfaces of all bones
- structure: composed of osteons (made of 3 rings)
- osteons contain:
1. Lamellae- concentric circles of matrix
2. Lacunae- between lamellae (space within matrix where osteocytes live)
3. Canaliculi- small channels that connect osteocytes to blood supply and to each other
4. Central canal- contains blood vessels and nerves, lined with endosteum
5. Perforating canal- perpendicular to central canal, carries blood and nerve supply from periosteum to canals and medullary cavity
40
Spongy bone
- No osteons
- have holes where blood cells are generated
- have trabeculae- irregularly arranged lamellae (similar to osteons)
- canaliculi connect octeocytes in lacunae
- spaces contain bone marrow (red marrow produces blood cells)
- found in:
1. Flat and irregular bone (skull, ribs, vertebrae)
2. Long bones (epiphyses- looks like an aero bar and lining medullary cavity- middle cavity)
41
Skeleton
1. Axial skeleton: bones that form from central core of body
2. Appendicular skeleton: limbs and bones that attach them to axial skeleton (girdles)
42
Articulations
- connections between bones
- region where 2 bones are connected
43
Axial skeleton
1. Skull
2. Hyoid bone
3. Vertebral column
4. Thoracic cage
44
Appendicular skeleton
1. Pectoral girdle
2. Pelvic girdle
3. Upper limb
4. Lower limb
45
Components of long bones
1. Diaphysis- shaft (body)
2. Epiphysis- proximal and distal extremities
3. Epiphyseal plate- hyaline cartilage, used for bone growth (length)
4. Epiphyseal line- replaces plate when bone growth is complete, plate/line where the diaphysis and epiphysis meet
5. Medullary cavity- red bone marrow in child, yellow bone marrow in adult
6. Periosteum- external surface, 2 layers of CT (outer= dense irregular, inner= mainly osteoblasts and osteoclasts), allows bone to grow in diameter
7. Endosteum- lines medullary cavity and canals
8. Articulated cartilage- hyaline (only at articulation points, prevents friction between bones
46
Fibrous structural joints
- no joint cavity
- fibrous CT
- ex. Sutures in skull
47
Cartilaginous structural joints
- no joint cavity
- cartilage attaches bones
- ex. Pubic symphysis, costal cartilages of ribs
48
Synovial structural joints
- articulating bones are connected by the joint capsule and ligaments
- articulating cartilage (hyaline) of bone
- space between bones is the joint cavity (contains synovial fluid)
- articular/joint capsule encloses the joint cavity (outer layer= fibrous capsule and attaches to periosteum, inner layer= synovial membrane and secretes synovial fluid
49
Types of synovial joints
- according to shape of articulating bones
1. Plane/gliding= 2 flat surfaces moving past each other (ex. Sacroiliac)
2. Hinge= concave and convex surfaces (ex. Elbow and knee)
3. Pivot= projection in ring
4. Ball and socket= great freedom of movement (ex. Humerus in glenoid fossa and femur in acetablum)
50
Functional joints
- based on degree of movement
51
Synarthrotic functional joints
- immovable
- ex. Skull sutures
52
Amphiarthrotic functional joints
- slightly moveable
- ex. Pubis bone
53
Diarthrotic functional joints
- freely moveable
- ex. Hip, shoulder
54
Muscular system
- refers to skeletal muscle system
- primarily attaches muscle to bone
- produce movement by contracting
- very important in locomotion and maintaining body posture
55
Skeletal muscle
- cells called fibres
- fascicle= group of fibres
- whole muscle= group of fascicles
56
Fascia
- CT surrounding muscles or other organs
1. Epimysium- surrounds entire skeletal muscle
2. Perimysium- surrounds fascicles within skeletal muscle
3. Endomysium- surrounds each muscle fibre (cell) within skeletal muscle
57
Tendons and aponeuroses
- extensions of epimysium, perimysium and endomysium
- anchors muscle to bone, cartilage and fascia
58
tendon
- rope like bundle of dense regular CT
- ex. Calcaneal (Achilles) tendon
59
Apineurosis
- a flat sheet of dense regular CT
- ex. Epicranial aponeurosis (scalp)
60
Sarcolemma
Skeletal muscle fibre cell membrane
61
T-tubules
- contractions of sarcolemma that extend deep into fibre (cell)
62
Sarcoplasm
Cytoplasm
63
Myofibrils
- intracellular structures
- within each fibre there are several hundreds to thousands
- composed of sarcomeres:
1. Thin myofilaments
2. Thick myofilaments
64
Sarcoplasmic reticulum
- smooth endoplasmic reticulum
- triad is formed from 2 enlarged areas of sarcoplasmic reticulum, and a t-tubule that runs in between
65
Thin microfilaments
- formed by 3 proteins involved in contraction:
1. Actin
2. Tropomyosin
3. Troponin
66
Thick myofilaments
- formed by a protein called myosin
- attached to Z-discs by titin
- myosin has rod-like tail with 2 globular heads
67
Myosin globular heads
At rest the head extends towards actin and during contraction attaches to actin to shorten the sarcomere
68
Myofilament banding pattern
- myofilaments create dark and light bands of the sarcomere
- A band: Dark band that is the length of thick myofilament
- H zone: lighter area at center of A band
- I band: light band consisting of thin myofilaments
- Z discs (in center of I band): connected to thick myofilaments (via titin) and thin myofilaments, connection point between adjacent sarcomeres
- M line: where myosin tails attach to each other
- saromeres join end to end to form a myofibril
69
lever system
- a way muscles produce movement
- bone/muscle interaction at a joint
- parts:
1. Levers= bone
2. Fulcrum= joint
- effort= contraction of agonist
- resistance= opposes movement
- effort must be greater than resistance to get movement
70
Pulling on bones when they contract
- a way muscles produce movement
- origin= attachment of tendon to stationary bone
- insertion= attachment of tendon to moveable bone
71
Using group action
- a way muscles produce movement
- agonist= major muscle producing the movement
- synergist= help the agonist action and prevent undesirable motions caused by the antagonist
- antagonist= produces opposite action of agonist
72
Flexion of forearm
- agonist= biceps brachii
- antagonist= triceps brachii
- synergist= brachialis, brachioradialis
- lever= radius
- fulcrum= elbow joint
- effort= muscle contraction
- resistance= weight of object plus forearm
73
Extension of forearm
- agonist= triceps brachii
- antagonist= biceps brachii
74
Cardivascular system components
- heart
- blood vessels
- blood
75
Cardivascular system function
- transport gases, nutrients, hormones, wastes, heat
- protect against disease
- prevents fluid loss by clotting
76
Mediastinum
- cavity containing the heart
- space between lungs within thoracic cavity
77
Structure of heart
1. Coverings (pericardium)
2. Heart wall
3. Four chambers of heart and associated blood vessels
4. Septa (separate chambers)
5. Cardiac skeleton
6. Valves (for one way flow of blood)
7. Cardiac muscle cells
78
Coverings of heart (pericardium)
- double-walled sac surrounding heart
consists of:
1. Fiberous pericardium: outermost layer= dense irregular CT
- anchors to surrounding structures (ex. Diaphragm)
2. Serous pericardium: composed of…
a) parietal pericardium (2 layers- epithelial and connective):
-connected to fibrous pericardium
- pericardial sac
b) visceral pericardium= epicardium (heart wall):
- 2 layers, epithelial and connective
- fused to heart surface, so is part of heart wall
- between pericardial layers= pericardial cavity with serous fluid
79
Heart wall
1. Epicardium= visceral pericardium
- simple squamous epithelium and CT
2. Myocardium
- cardiac muscle
- arranged in spiral/circular pattern, reinforced with CT
3. Endocardium
- simple squamous epithelium and CT
- epithelium named endothelium- lines inner surface of heart and ALL blood vessels
80
Four chambers of the heart
1. Right atrium
- 3 major veins connected to the right atrium that carry deoxygenated blood into the chamber
2. left atrium
- 4 veins carry oxygenated blood into the left atrium from the lungs
3. Right ventricle
- 1 artery, the pulmonary trunk exits the right ventricle and then divides to form 2 pulmonary arteries (left and right) these carry out deoxygenated blood towards the lungs
4. Left ventricle
- 1 artery, the aorta, exits the left ventricle and carries oxygenated blood to all organ systems
81
Major veins in the right atrium
1. Inferior vena cava: carries blood from body above heart
2. Superior vena cava: carries blood from body above heart
3. Coronary sinus: carries blood from the myocardium
82
Left atrium veins
1. Left pulmonary veins: inferior and superior
2. Right pulmonary veins: inferior and superior
83
Septa chambers
1. Interatrial septum: separates atria
2. Interventricular septum: separates ventricles
84
heart valves
1. Atrioventricular valves
2. Semilunar valves
85
cardiac skeleton
- fibrous CT separating atria and ventricles
- provides firm attachment point for cardiac muscles
- forms solid rings around heart valves , base of aorta and pulmonary trunk that provide structural support for these structures and hold them in place
- provides electrical insulation- prevents simultaneous contraction of atria and ventricles
- when heart is beating there are electrical impulses telling the heart to beat (don’t want all sections to be beating at once)
86
Atrioventricular valves
1. Bicuspid (mitral) valve:
- between left atrium and left ventricle
- has 2 sheet-like cusps composed of CT
2. Tricuspid valves:
- between right atrium and right ventricle
- has 3 sheet-like cusps composed of CT
chordae tendineae: strings of CT
- attach to atrioventricular valve cusps to papillary muscles that project from the ventricular myocardium
- prevent eversion of cusps
87
Semilunar valves
3 cup-like cusps each
1. Aortic: separates left ventricle and aorta
2. Pulmonary: separates right ventricle and pulmonary trunk
88
Cardiac muscle cells
- Cells that set the pace and tell the heart to beat
- includes 2 types of cells:
1. Contractile cells
2. Conduction system cells
89
Contractile cells
- forms majority of myocardium
- increase in pressure = increase in blood that gets pumped out
- similarities to skeletal muscle:
1. Striated: myofibrils with sarcomeres
2. Has sarcoplasmic reticulum and T-tubules (arrangement is different)
- differences to skeletal muscle
1. Branched (myofibrils with sarcomeres)
2. Uninucleated (single nucleus)
3. Intercalated discs = region where 2 fibres meet (dark bands)
4. Contain anchoring and gap junctions (for communication, atrium- ventricular contraction)
90
Conduction system cells
- forms remainder of the myocardium
- cardiac muscle cells that are modified to produce and conduct electrical impulses (DO NOT CONTRACT)
-electrical vent causes contractile vent
- have many gap junctions that help electrical signals to spread very quickly
- everything is connected through electrical signals
91
Electrical signals
Cardiac muscle cells - modified/specialized = conduction system and “normal” myocardium
modified/specialized = conduction system - generates electrical impulses and conduction
“Normal” myocardium - contraction
92
part of conduction system cells
1. Sinoatrial (SA) node: artificial pacemaker
- in right atrium at base of superior vena cave
- generates impulses the fastest (sets pace)
2. Atrioventicular (AV) node:
- base of right atrium
3. Atrioventricular bundle (bundle of his):
- superior part of interventricular septum
- electrically connects atria to ventricles
- ex. Would be like shutting down hwy 1 and trying to get E-W
4. Atrioventricular (AV) bundle branches:
- carry impulse to apex (most inferior part) of heart
5. Purkinje fibres
- terminal fibres in ventricles (not found in atria) that carry signals from apex upward to all parts of the ventricle
- NOTE: electrical signal spreads from conduction system to contractile cells then they contract
93
general structure of blood vessels (except capillaries)
1. Tunica external- CT (most external layer)
2. Tunica media- (middle layer between tunica external and tunica intima/interna)
3. Tunica intima/interna- (inner most layer)
- in direct contact with blood
- endothelium= simple squamous epithelium
- continuous with endocardium
4. Lumen- contains blood, NOT A LAYER OR A CAVITY, just a space
94
Endothelium
- name of layer, not tissue type
- not a tissue type at all
- covers inner surface as heart as well as blood vessels (makes up heart wall)
95
Blood vessel types
1. Arteries
2. Arterioles
3. Capillaries
4. Venues
5. Veins
96
Arteries
- carry blood away from heart
- does not refer to oxygenated or deoxygenated blood
- 2 types:
1. Elastic arteries: large conducting arteries exiting the heart
- elastic CT in all 3 layers
- largest artery (near heart)
- ex. Aorta
2. Muscular arteries: smaller distributing arteries
- a LOT of smooth muscle
- most arteries
- ex. Coronary artery
97
Arterioles
- little arteries
- regulate blood flow and blood pressure
98
Capillaries
- only tunica intima- one cell layer + basement membrane
- allow exchange of gases and nutrients
- most have gaps between cells that allow exchange of fluid and solutes with the interstitial fluid
- very tiny
- all epithelial tissues have basement membranes
99
Venues
- collect blood from capillaries
- intima (endothelium) with thin media/externa layers
100
Veins
- more superficial
- carry blood INTO heart (does not refer to oxygenated or deoxygenated blood)
- large lumen
- can have one-way valves that prevent backflow of blood
- thin media: more CT but less smooth muscle than arteries
101
blood vessel analogy
Think of large arteries like highways, smaller roads branching off would be the Arterioles and the driveways would be the capillaries
102
Circulatory routes
- closed = blood confined to heart and blood vessels
- double= 2 routes (pulmonary and systemic)
103
Adult circulation
1. Pulmonary circulation- for oxygenation of the blood
- Carries blood from right ventricle to lungs via pulmonary arteries (deoxygenated blood)
- picks up oxygen in lungs via capillaries
- carries blood from lungs to left atria via pulmonary veins (oxygenated blood)
2. Systemic circulation- for delivery of oxygenated blood to all other tissues
- carries blood from left ventricle to organs via aorta (oxygenated)
- organs take up oxygen form blood via capillaries
- carries blood from organs to right atrium via superior and inferior vena cava (deoxygenated)
- overall route: left ventricle to right atrium= systematic circulations
- cerebral= brain, hepatic= liver, coronary= heart, bronchial= parts of respiratory system
3. Coronary circulation (see notes for diagram)
104
Fetal circulation
- fetus gets oxygen (02), nutrients from expels wastes to mothers blood
- we rely on our mothers systems, keep us alive in utero
- Exchange cite in the placenta
- blood supplies in close together but do not mix (could have different blood types)
105
Fetal circulation differences from adult circulation
1. Umbilical vein (towards fetal heart)
- carries oxygenated blood form placenta to vena cava
2. Lungs and liver: late to develop and their functions are handled by the maternal organs
- 3 shunts allow most blood to bypass these organs (minimal blood to these organs for nourishment and growth)
- following birth all shunts normally become closed
3. Umbilical arteries (away from fetal heart)
- returns mixed blood to placenta
106
3 shunts that allow blood to bypass organs
1. Ductus venosus: bypass liver
- connects umbilical vein (oxygenated blood) to inferior vena cava (deoxygenated blood)
- permits most of the oxygenated blood coming from the placenta to bypass the liver capillaries
- oxygenated and deoxygenated blood mixes in inferior vena cava and enters fetal right atrium
2. Foramen ovale: bypass lungs
- hole in interatrial septum
- allows blood to move from the right to left atrium
- bypasses the uninflated fetal lung (fetus is not breathing, so no gas exchange takes place here)
3. Ductus arteriosus
- connects pulmonary trunk and aorta
- bypasses the uninflated fetal lung (fetus is not breathing, so no gas exchange takes place here)
107
Characteristics of blood
- higher viscosity than H2O
- pH 7.35-7.45 (not acidic)
- 4-6L in an adult (think jug of milk)
- blood is thicker than water since there are more cells in it
108
Plasma (matrix)
- makes up approximately 55-60% of blood volume (fluid portion with solutes)
- =blood minus formed elements
- composed of:
1. H2O- 90%
2. Proteins- 8%
3. Other solutes- 2%
109
Albumins in blood protein
- most plentiful plasma protein
- carries substances such as hormones, enzymes, and medicines throughout the body
- helps control tissue water balance
110
Fibrinogen in blood protein
Clot formation
111
Globulin in blood protein
Antibodies (immunity)- detect and find foreign invaders (bacteria, viruses)
112
4th thing found in blood protein
Protein based hormones and enzymes
113
Other solutes found in blood (2%)
- nutrients
- vitamins
- wastes
- electrolytes
- blood gases: oxygen and carbon dioxide
114
Red blood cells
- erythrocytes= most abundant cell type in the body
- binds and transports most of the O2 in the blood
- Hematocrit
- have a biconcave disc shape
- are anucleate (lack of nucleus and all other organelles) when mature
- life span= 120 days
- contain hemoglobin
115
Hematocrit
Is the percentage of blood volume that is made up of red blood cells (usually around 45%)
116
Hemoglobin
- hemo= means blood
- iron containing pigment protein
1. four globin chains (protein)
2. four iron (Fe) containing heme groups (gives blood its red colour)
- 1 iron per heme
- site of reversible oxygen binding (drop off O2 at lungs, pick up O2 at cells)
117
White blood cells
- nucleated
- life span varies- days to years
- defend against disease
- 2 types:
1. Granulocytes
2. Agranulocytes
118
Granulocytes in WBC
- contain visible granules
- include:
1. Neutrophils (approximately 60%)
- all phagocytic (engulf and digest invaders)
- kill bacteria
2. Eosinophils (approximately 3%)
-predominantly attack blood parasites
3. Basophils (approximately 1%)
- release chemicals involved in inflammation and reduction of blood clotting during immune responses
119
Agranulocytes in WBC
- lack of visible protein granules
- include:
1. Lymphocytes (approximately 35%)
2. monocytes (approximately 5%)
120
Lymphocytes
- only kill a couple bacteria, then die off
- for immunity (resistance to disease)
- predominantly found within lymphatic tissues
- 2 types:
1. T lymphocytes
- activate immune response
- kill tumor or virus infected/diseased cells directly
2. B lymphocytes
- become plasma cells that release antibodies that circulate in the plasma
121
Monocytes
- kill way more bacteria
- enter tissue and enlarge to become macrophages (meaning “big eaters”) phagocytic
122
Platelets
- formed element in blood
- fragments of cells called megakaroryocytes
- involved in clotting
- life span= approximately 10 days if not used for clotting
123
Hemopoiesis/hematopoiesis
- formation of blood cells
- all blood cells arise indirectly from hemocytoblast cells (which are a type of stem cells) in red bone marrow
- red marrow in an adult is located in:
1. Axial skeleton
2. Pelvic and pectoral girdles
3. Proximal ends of humerus and femur
124
Atrial septal defect
- a hole in the interatrial septum
- most common type occurs due to incomplete closure of the foramen ovale
125
Atherosclerosis
- build up of fat deposits in the tunica intima that leads to narrowing or blockages of arteries
126
Lymphatic system
- lymphoid cells, tissues and organs support the functions of the lymphatic system
- consists of:
1. One way network of lymphatic vessels that collect 10% of the extracellular fluid that leaked out from cardiovascular capillaries and return this fluid (now termed lymph) to the venous blood
2. Lymph nodes along the vessel network that cleanse lymph as it passes through them- contain T and B lymphocytes that identify and remove bacteria, viruses and cancer cells
127
Intracellular fluid
Fluid found within cells (approximately 40% of body weight)
128
Extracellular fluid
- fluid found outside of cells
1. Blood plasma
2. ISF
3. lymph
129
Blood plasma
- approximately 5% of body weight
- fluid in blood
- some exits capillaries to form ISF
130
ISF (interstitial fluid)
- approximately 15% of body weight
- fluid between cells within the body (except blood cells which are surrounded by plasma)
- some moves into lymphatic capillaries to form lymph
131
Lymph
- approximately 1% of body weight
- fluid inside lymphatic vessels
- returned to blood plasma
132
Lymphatic circulation summary
Lymph capillaries- lymphatic collecting vessels (with valves0- lymphatic ducts- subclavian veins
133
Lymph fluid is transported away from tissues to…
1. Right lymphatic duct (lymph from the right side of the head, chest and arm0
- drains into right subclavian vein re-entering circulation
2. Thoracic duct (lymph from below the ribs and the entire left side of body)
- collecting vessels form below the ribs converge to an enlarged lymph vessel= cisterns chyli (this is the most inferior portion of the thoracic duct)
- the thoracic duct drain into the left subclavian vein reentering blood circulation
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Lymphoid tissues and organs
- contain many lymphoid organs and play a key role in the body’s immune system
- includes:
1. Primary lymphoid organs and tissues
2. Secondary lymphoid organs and tissues
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primary lymphoid organs and tissues
1. Locations where lymphoid stem cells divide and mature (immuneocompetent)
2. Includes:
- red bone marrow
- thymus gland
3. Mature lymphocytes move into the blood stream and migrate to the secondary lymphoid organs/tissues
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Red bone marrow
- all lymphocytes stem cells arise here
- site of B lymphocyte proliferation (mitosis) maturation
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Thymus gland
- early in development (fetal stage) lymphocyte stem cells migrate here
- site of T lymphocyte proliferation (mitosis) and matration
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Secondary lymphoid organs and tissues
- where lymphocytes detect and remove pathogens
- locations where lymphocytes are activated and proliferate further
- includes:
1. Lymph nodes
2. Spleen
3. Mucosal associated lymphoid tissue (MALT)
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Lymph nodes
- small masses of lymphoid tissue along lymphatic collecting vessels
- high concentrations of lymph nodes are located in:
1. Cervical (neck)
2. Axillary (armpit)
3. Inguinal (groin)
4. intestinal
5. Pelvic regions
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Spleen
- located in left side abdominal cavity just below diaphragm next to stomach
- filters (cleans) blood by by removing pathogens (organisms that can cause disease like bacteria or viruses), old and defective blood cells, and cellular debris
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Mucosal associated lymphoid tissue (MALT)
- trap and remove pathogens at points of entry into the body
- include tonsils, appendix, and other lymphoid tissues on mucous membranes
- ex. Aggregated lymphoid nodules (peyer’s patches) in the small intestine
1. Pharyngeal (1)- in posterior nasopharynx (referred to adenoids when infected/swollen)
2. Palatine (2)- in oropharynx (used to be commonly removed)
3. Lingual (1)- bumpy nodules on posterior part (base) of tongue
