Lymphatic System and Immunity/Integumentary System/Reproductive System Flashcards
Lymphatic Structures
- Lymphatic Vessels (Lymphatics) - Network of vessels that begin peripherally and collect in venous system vessels
- Lymp - Fluid similar to plasma that flows through lymphatic vessels
- Lymphocytes - specialized cells responsible for defending the body
- Lymphoid Tissues (nodes)
- Loose connective tissue
- groups of lymphocytes ⇒ nodules ie tonsils
- Lymphoid Organs - more complex structures that contain lymphocytes ie spleen, thymus, lymphnodes
Lymphatic Vessels (Lymphatics)
Network of vessels that begin peripherally and collect in venous system vessels
Lymph
Fluid similar to plasma that flows through lymphatic vessels
Lymphocytes
specialized cells responsible for defending the body
The three major types of lymphocyte are T cells, B cells and natural killer (NK) cells.
Lymphoid Tissues / Lymphoid Nodules
- Loose connective tissue
- Mass of lymphoid tissue not surrounded by a fibrous capsule (If had fibrous tissue surrounding = lymphoid organ)
- Increase/Decrease in size depending on # of lymphocytes present at any time
- Generally found beneath epithelial in parts of the body that have entry point from outside
- Respiratory Tract
- Urinary Tract
- Digestive Tract
- groups of lymphocytes ⇒ nodules ie tonsils, the appendix,
- If invasion is to great for tissue to manage, the body will destroy the tissue; inflammation will often lead to the removal via surgery
Lymphoid Organs
- more complex structures that contain lymphocytes ie spleen, thymus, lymphnodes
- Surrounded by fibrous connective tissue capsule
Functions of the Lymphatic System
- Production/Maintainence/Distribution of lymphocytes
- Return body fluids & solutes that have been collected in the lymphatic system from ECF/peripherial tissues to vascular system (blood)
- Distribution of nutrients, hormones, waste products to circulation
Pathogen
virus, bacteria, fungi, parasite
can be found in human body and are responsible for disease
Pathogen/Antigen/Allergen
Immunity
Body’s ability to resist or activate defenses to eliminate the pathogen
Lymphatic Vessels
Lymph vessels are a compliment to the cardiovascular system
At the begining of the Arteriole-Caplilary-Venulole Network
Begining of Capillary network
Hydrostatic pressure exceedes Osmotic pressure causing Loss of fluid out of the capillary into ECF
@ End of Capillary network
Osmotic pressure exceeds Hydrostatic pressure causing some fluid to be regained, but there is still a net loss into the Extracellular fluid.
Net loss contributes to the ECF, which inturn is sucked up into the lymphatic vessels.
Lymphatic vessels are one way transport, with ducts to prevent back flow.
Fluid is brought back centraly and dumped into subclavian veins which return fluid to SVC and systemic circulation.
*Single layer of simple squameous epithelium, important because it allows fluid to diffuse easily from the ECF into the Lymphatic Vessel
Lymphedema
A side effect of the removal of lymphnodes
Often seen with removal of axillary lympnodes in efforts to stop the metastasis of breast cancer.
Due to the loss of lymphnodes, edema presents in adjacent arm.
Thoracic Duct
&
Right Lymphatic Duct
-
Thoracic Duct -
- Patients Left side + R side below diphram
- Collects near Left subclavian
-
Right Lymphatic Duct -
- Right side above diphram
- Collects near Right subclavian
White Blood Cells
5 Types
- Lymphocytes
- Basophils
- Neutrophils
- Eosinophils
- monocytes
Lymphocytes
- Account for 25% of all WBC’s
- Three major types of lymphocytes are:
- T-Cells - Thymus Dependent Cells - account for 80% of all Lymphocytes
- B-Cells - Bone Marrow Derived Cells - account for 10-15% of all Lymphocytes
- NK Cells - Natural Killer Cells - account for 5-10% of lymphocytes
Thymus
- Located posterior to sternum in the media stinum
- Recieves Thymosin (hormone) which stimulates production and maturation of T Cells
- Has function is in pregnant females and children before they mature into adulthood; its function decreases with age.
- Functions: some endocrine; and production of Lymphocytes
T-Cells
Thymus Dependent Cells
account for 80% of all Lymphocytes
Three Types:
- Cytotoxic T-Cells - toxic to cytoplasm
- Responsible for Cell Mediated Imminity
- Attack foreign cells & cells affected by virus
- Regulatory T-Cells
- Helper T-Cells - stimulate T & B Cells
- Suppressor T-Cells - Inhibit T & B Cells
B-Cells
Bone Marrow Derived Cells
account for 10-15% of all Lymphocytes
- Differentiate into plasma cells which produce anti-bodies
- Responsible for Anti-Body Mediated Immunity
Antibody
- Soluble Protein also called Immunoglobin (Ig); its job is to bind to an antigen
Antigen
- is part of pathogen or foreign compound
Antibody and Antigens
Antibody
- Soluble Protein also called Immunoglobin (Ig); its job is to bind to an antigen
Antigen
- is part of pathogen or foreign compound
NK Cells
Natural Killer Cells
account for 5-10% of all lymphocytes
- NK cells attack
- foreign cells
- body cells infected with viruses
- normal body cells affected with cancer
- Responsible for Immunologic Survelliance
Lymphopoesis
is the synthesis and development of lymphocytes
Lymphoid Tissues / Lymphoid Nodules
- Loose connective tissue
- Mass of lymphoid tissue not surrounded by a fibrous capsule (If had fibrous tissue surrounding = lymphoid organ)
- Increase/Decrease in size depending on # of lymphocytes present at any time
- Generally found beneath epithelial in parts of the body that have entry point from outside
- Respiratory Tract
- Urinary Tract
- Digestive Tract
- groups of lymphocytes ⇒ nodules ie tonsils, the appendix,
- If invasion is to great for tissue to manage, the body will destroy the tissue; inflammation will often lead to the removal via surgery
Lymphoid Organs
- more complex structures that contain lymphocytes ie spleen, thymus, lymphnodes
- surrounded by fibrous connective tissue capsule
- Removal of Lymphoid organs is done conservatively due to the decreased ability of the body to fight infection without these organs
Lymphnodes
- Filters 99% of pathogens
- Activate B & T Cells
- Common place for cancer cells to accumulate, often used for testing to see if cancer is spreading.
- When cancer is identified in adjacent tissues, often adjacent lymphnodes will be removed as well which can cause lymphedema
Spleen
- Primary job is to filter blood and any abnormal bloodcells that pass
- Recieves a significant amount of blood, red in color due to storing Iron from recycled RBC’s
- Initiates B&T cell response
- Located on Left side of the stomach, usually hidden by stomach unless inflammed (spleenomegay - commonly a result of portal hypertension, or mono)
- Can cause rapid bleeding; treated conservatively when damaged or lacerated due to trauma due to its role in fighting infection.
Nonspecific Defenses
Vs
Specific Defenses
Nonspecific:
Deny Entry, Limit Spread of Pathogens in Body, is the same regardless of the type of pathogen
Specific:
Specific Resistance & Immunity
7 types of Nonspecific Defenses
and Primary Goals
Primary Goals:
Deny Entry
Limit Spread of Pathogens in Body
Same reaction Regardless of the type of pathogen
- Physical Barriers
- Phagocytes
- Immunological Surveillance
- Interferons
- Compliment System
- Fever
- Inflammation
Nonspecific - Physical Barriers
Two types:
-
External (Skin): Hair, Oils, Desmosomes
- Hair - prevents insects/material from sticking to surface
- Oil Secretions- coat surface to make slick and be able to be washed away
- Desmosomes - connected tightly, prevents pathogen from squeezing through
-
Internal: mucous, urine, digest
- Mucous: sweeps pathogens toward the pharanx
- Urine: flushes out of the body
- Stomach: Can digest Pathogens
Nonspecific -Phagocytes
-
First line of defense
- Remove cell debris & respond to the invasion of pathogens
- exist in many peripherial tissues
- Two types: Microphage/Macrophage
- Microphage - travel to peripherial tissues that are already dealing with infection/pathogens
-
Macrophage - derived from monocytes; can be fixed or be free to travel
- Fixed in Peripherial Tissues ie Kupfter Cells in Liver
-
Free
- Diapedesis - can squeeze through/between capillary walls
- Chemotaxis - attracted to chemicals in the ECF, draws macrophages towards them
Phagocytes - Microphages & Macrophages
- Microphage - travel to peripherial tissues that are already dealing with infection/pathogens
- Macrophage - derived from monocytes (one of the five types of WBC’s); can be fixed or be free to travel
- Monocytes & Macrophages together for Monocyte-Macrophage system
- Fixed in Peripherial Tissues ie Kupfter Cells in Liver
-
Free
- Diapedesis - can squeeze between cells in capillary walls
- Chemotaxis - attracted to chemicals in the ECF, draws macrophages towards them in presence of infection or pathogen
Nonspecific - Immunological Surveillance
NK Cells
- NK Cells Responsibility: Monitor for presence of antigens that are foreign to the body
** **Perforin - protein secreted into target cells membrane creating pores or tubules that causes the lysis of the target cell
Natural Killer Cells
Responsible for Immunologic Survelliance
account for 5-10% of all lymphocytes
- NK cells attack
- foreign cells
- body cells infected with viruses
- normal body cells affected with cancer
Nonspecific - Interferons
- small proteins released by activated lymphocytes & macrophages (due to prescence of virus, parasite, bacteria, tumor in cells)
- Named because of their capeability to interfere with viral replication in cell
- Work by second messenger to prevent replication of the virus
- they don’t destroy the virus or reverse other damages; they slow the rate of spread by the virus
- Cytokines - a class of chemical messengers that coordinate local activities; cell signaling proteins of which Interferons are a part of
Nonspecific - Compliment Cascade System
Activation occurs when a compliment protein (11 different types) attaches to an antibody (Ab)
- Causes a cascade of reactions that result in a hole in the cell membrane
- Arrival of other phagocytes and chemicals
- outcome of cascade formation of MAC (membrane attack complex)
- Holes in membrane causes cell rupture
*“complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism
**Cascade of reactions similar to clotting cascade, chain reaction of events
Nonspecific: Fever
- Rise in body temperature > 1 degree above normal (range of temperatures normal to that indiviidual)
- Pyrogens: reset body thermostat (set point) in hypothalamus
- Increased mobility of leukocytes
- Enhanced leukocytes phagocytosis
- Endotoxin effects decreased
- Increased proliferation of T cells
Nonspecific : Inflammation
- Any localized tissue response to injury presents in swelling, pain, redness, warmth and the release of chemicals
- Goals of inflammation:
- deny entry and spread of pathogens present at injury site to any other part of the body
- repair damages to injured tissues
- MAST cells are responsible for releasing histamine and heparin
- clotting factors deal with the bleeding
- compliment proteins attempt to kill any pathogens that are in that particular area
- Dying cells cause formation of Pus
- if in an enclosed area - considered an abscess
- otherwise if is considered necrosis of those tissues
Specific Defense
Cellular & Humoral
Specific defense & Immunity
- T Cells - Protect against abnormal cells & Pathogens in LIVING CELLS (Cell mediated immunity)
- B Cells - Protect against antigens & pathogens in BODY FLUIDS (Humoral/Antibody Mediated Immunity)
Specific Defense Heirarchy
Immunity
- Inate -genetically determined
-
Acquired- produced by exposure, causes production of Ab
-
Active - Produced by Ab that develop in response to Antigens
- Naturally Acquired Active Immunity - antigen in environment; exposure leads to development of Ab
- Induced Active Immunity - through administration of vaccine
-
Passive - Antibodies transfered from another source
- Natural Passive Immunity - maternal transfer to fetus
- Induced Passive - meds given to fight infection
-
Active - Produced by Ab that develop in response to Antigens
Immunity
is either acquired or inate
- **Acquired ** -
- production of Ab produced by exposure;
- can be actively or passively acquired
- Inate - genetically determined
Acquired Immunity
Active vs Passive
Actively Aquired Immunity
Production by antibodies that develop in response to Antigens
Can be Naturally Aquired Active Immunity or Induced Active Immunity
Passively Aquired Immunity
Antibodies Transfered from another source (recieving a pass ie recieving Ab from mother or recieving meds to fight existing infection)
Active acquired immunity
Produced by Ab that develop in respose to exposure to antigens
- Naturally Acquired Active Immunity - exposure to antigen in environment leads to development of antibodies
- Induced Active Immunity - Ab produced in response to administration of vaccine (ie Flu Shot)
Passive Acquired Immunity
Antibodies Transfered from another source (recieving a pass ie recieving Ab from mother or recieving meds to fight existing infection)
- Natural Passive Immunity - Maternal transfer of immunity to fetus
- Induced Passive Immunity - Meds administered to fight existing infection
4 Properties Of Immunity
- Specificity
- Versitility
- Memory
- Tolerance
Immunity Specificity
Specific Defense is activated by a specific Antigen and the subsequent result affects only that Antigen
Specific Defense: Versitility
Production of many receptors to deal with many different antigens/pathogens
Specific Defense : Memory
Remain inactive
In event of second exposure they are ready to attack
After first exposure cells are duplicated; some attack inital exposure; remainder are held in reserve for second exposure to same pathogen
They retain a memory for what the pathogen looks like and are ready to attack it on second presentation
Specific Defense: Tolerance
Will not allow own body cells to be destroyed in an imune response
If T or B cells attack body cells they are destroyed
Immune response
Produced in response to Antigen Recognition of an Antigen, Pathogen, Virus, or allergen
Communication takes place between Cell Mediated Immunity (T Cells) & Antibody Mediated Immunity (B Cells)
- T Cells attack due to direct physical or chemical contact
- B Cells attack by circulating Antibodies
Antigen Recognition
is used to generate a specific defense when activated by a specific antigen. Antigen receptors sitting on surface of the B cell are activated only by antigen that matches that receptor.
MHC Class I
vs
MHC Class II
MHC Class I proteins
are found on all nucleated cells
Work by presenting fragments of proteins from within the cell (cytosol) on cell surface for recognition by T Cells
Cytotoxic T cells are only activated by MHC Class I proteins
MHC Class II proteins
are found only on Antigen Presenting Cells (APC) and lymphocytes
Helper T cells are activated by Class II MHC proteins to coordinate specific and non-specific defenses,
Helper T’s stimulate cell and antibody mediated immunity (communication component of Immune response).
T Cells
Usually recognize antigens when they bind to receptors on body cells
- Inactive T Cells recognize Class I and II MHC (Major Histocompatibility Complex Protein)
- can also bind antigens to itself
- is looking for one specific antigen if found it will divide and differentiate into:
- Cytotoxic T Cells
- Helper T Cells
- Memory T Cells
- Supressor T Cells
Cytotoxic T Cells
- Activated only by CLASS I MHC - AKA Killer T’s or Cytotoxic T’s
- Responsible for Cell mediated immunity
- secretion of Lymphotoxins which disrupts metabolism of the cell
- secretion of Cytokines (interfere with genes) Affecting genes and causing Apoptosis (Programmed cell death)
- release of perforin - causes rupture of target cell membrane
**All three help to destoy target cell
Once cytotoxic T cells encounter an antigen bound to MHC, what subsequent steps must occur before it will attack the cell
The cytotoxic T cell will recognize an antigen bound to a class I MHC protein
then it will divide and differentiate into:
- active cytotoxic T cells which help to manage current presentation of antigen
- memory T cells which lie dormant until a second presentation of antigen.
Helper T’s
- Activated by Class II MHC*
- coordinates specific and nonspecific defenses
- Stimulates cell mediated immunity & antibody mediated immunity
Memory T Cells
- Remain in reserve for second exposure to pathogen
- can only be activated by second exposure or later
- differentiate into cytotoxic T’s and Helper T cells.
- Memory T’s help to create a rapid response in event of second exposure, increasing the effectiveness of the immune response.
- Rapid response increases effectiveness of immune response
Suppressor T Cells
Secretes Cytokines AKA supression factor
- dampens response of T and B cells
- Prevents immune response that is out of control
B Cells
Launch Chemical attack by producing antibodies
- antigen binds to B cell where it is engulfed and presented on surface
- sensitizing B cell
- Circulating Helper T’s recognize presence of antigen and secrete cytokines which
- Causes B Cell activation and differentiation.
B’s differentiate into
- Active B cells for circulation against current pathogen; Active B’s turn into plasma cells which are responsible for the production of antibodies.
- memory B’s for use against future invasions by same antigen.
Antibodies (Ab) = Immunoglobulins (Ig)
5 major classes
IgG
IgM
IgA
IgE
IgD
IgG
Largest class of Antibodies
Able to cross placental barrier - protection passed from mother to fetus
defense against viruses, bacteria, and bacterial toxins
IgM
First Ab secreted after arrival of pathogen
Ability to circulate and attack bacteria
Responsible for cross reaction with incompatible blood types (sometimes even same type)
IgA
Present iin exocrine secretions ie tears, mucous
Enables Ig to attack pathogen even before it has entered the body
IgE
Bound to MAST cells and Basophils
Stimulates release of histamine and other chemicals
Promotes inflamation
IgD
Bound to B cells
Try to eliminate pathogens in ECF
Responsible for B cell Activation
Purpose of Antibodies
Elimination of Antigens via
- Neutralization
- Agglutination and Precipitation
- Activation of Compliment Proteins
- Attraction of Phagocytes
- Enhancement of phagocytosis
- Stimulation of Inflamation
Elimination of Antigens via:
Neutralization
Ab binds to antigen/virus/bacteria so that it cannot bind to a body cell
Elimination of Antigens via:
Agglutination & Precipitation
Agglutination - Clumping resulting from Ab attaching to one or more antigens when in close proximity
Precipitation - Larger Clumps form PPT and fall out of solution (become insoluble)
*With incompatible blood ppt is in form of clots.
Elimination of Antigens via:
Activation of Compliment
Ab bind to antigen causing a change in shape of the Ab which then activates compliment cascade
Non-specific defense aimed at creating a hole in the membrane ⇒ lysis
Elimination of Antigens via:
Attraction of Phagocytes
Attraction drawn to antigen which bring it to the attention of other WBC’s
Macrophages/Neutrophils/Eosinophils which engulf antigen
Elimination of Antigens via:
Enhancement of phagocytosis
like a condiment for the Antigen covered in Antibodies which makes it easier to eat
Elimination of Antigens via:
Stimulation of Inflamation
due to stimulation of MAST cells and basophils
Responding to site of injury
Primary and Secondary Immune Response
Primary Response
The peak response to a first exposure to an antigen is about 2 weeks, where IgM is secreted in response to the presence of the antibody.
This response is delayed due to the body needing time to become sensitized to antigen, causing activation of B cells and the formation of plasma cells to make the antibodies,
meanwhile we are making memory B cells.
The first exposure takes about 4 weeks to complete.
Secondary Response
The second exposure can take place anytime after the first exposure,
this time IgG is primarily released, causing a earlier peak response with a stronger effect.
Immune Disorders Types
Auto-immune disorder - malfunction in Antigen recognition
Immunodeficency disorder - Immune System fails to develop normally or becomes blocked
Allergies - Innapropriate or Excessive Immune response to an Antigen ≈ Allergen
Auto-Immune Disorders
Malfunction in Antigen recognition
Body gets confused as to what belongs and what is foreign and attacks its own body cells
B Cells manufacture Ab against body cells (auto antibodies)
Examples: IDDM, Lutus, Mysthenia Gravis, Rheumatoid Arthritis, Pernicious Anemia, Graves Disease, Addisons, Disease, Narcolepsy, psoriasis, chronic hepatitis
Immuno-Deficency Disorders
Immune System fails to develop normally or becomes blocked
Examples:
AIDS (Acquired ImunoDeficency Syndrome) results in a destruction in Helper T Cells (which participate in both Cell and Anti-body mediated Immunity
SCID (Severe Combined Immunodeficency Disease) neonatal/infant disease where infant fails to develop any cell or antibody mediated immunity.
Allergies: Type I
Inappropriate or excessive immune response to an Antigen ≈ Allergen
Type I: Immediate Hypersensitivity/Anaphlaxis
- still follows the first exposure, second exposure rule.
- On first exposure the B cell is sensitized (pathogen engulfed) causing:
- B Cell Activation and the differentiation of:
- Activated B Cells⇒Plasma Cells⇒Production of IgE
- Memory B Cells (For second exposure Pathway)
- This process is slow and therefore it is not uncommon that upon first exposure the person may have no symptoms (no hives, swelling etc.)
- B Cell Activation and the differentiation of:
- On Second exposure: when B cells are activated:
- Memory B cells (that were created in response to first exposure are ready to go) once B cells are activated for second time make antibodies (IgE)
- Which attach to MAST and Basophil cells which then release:
- Histamine
- prostaglandin
- heparin
- cytokines
- These cause inflamatory response
Allergies: Type II
Cytotoxic reactions
Transfusions
Cross reactions
Allergies: Type III
Immune Complex Disorders ( not likely to see due to need for detailed history of patient illness)
Phagocytes fail to remove Antigen-Antibody Complex
Allergies: Type IV
Delayed Hypersensitivity
Inflamatory response is delayed
Symptoms 2-3 days after exposure
Examples: Posion Ivy/Posion Oak
Integumentary System
Two parts:
- Continuious Membrane (Skin)
- Epidermis
- Dermis
- Hypodermis
- Accessory Structures
- Hair
- Nails
- exocrine glands (sweat)
Integumentary Functions
- Protection - Loss of body fluid, impact, chemicals, and infection
- Temperature Maintenance - regulate heat loss to the environment
- Synthesis & Storage of Nutrients - ie Vitamin D3
- Sensory Reception - Touch, Pressure, Pain; Neurons stimulated by mechanical distortion that sends information to the CNS
- Excretion/Sucretion - Salts, Water, Orgainic Waste lost to the environment
Epidermis Fun Facts
Comprised of Stratified (multilayered) Squameous Epithelium
- Thin Skin - 4 Layers of strata
- Thick Skin - 5 Layers of strata - (Palms of Hands/Bottom of Feet)
- Cells grow at bottom and move towards exterior
- Is Avascular - gets its nutrient from basment layer
Epidermis Strata
5 Strata Layers & Basic Function
- Stratum Corneum - 15-30 Layers of Dead epithelium; most of barrier functions are provided by this layer
- Stratum Lucidum - Clear/Translucent layer only found in Soles and Palms; contains lots of keratin
- Stratum Granulosum - Synthesis of Keratin; cells lose their nucleus and cytoplasm looks grainy
- Stratum Spinosum - Continues process of mitosis and daughter cell creation
- Stratum Germinativum - Attached to basment layer; Contains Melancytes which are responsible for skin color
Stratum Germinativum
Base layer of Epidermis
Connects to Dermis via Epidermal ridges; attached via Hemidesmosomes - stitched to basement layer
Top side called Epidermal Ridges/Bottom side called Dermal Papillae
Epidermal Ridges function
- similar to that of microvilli in intestines; increases surface area for nutrient absorption
- create ridges that become finger prints which also increases friction and grip security
Contains:
- Stem Cells (germanitive cells) - undifferentiated cells that will become differentiated later for specific function
- Melanocytes - Melanin - partially responsible for skin color
These cells will divide via Mitosis (cell division) making more daughter cells, One stays in layer and one which will then move up into the next layer; process will continue until it reaches the surface.
Stratum Spinosa (Spiny Layer)
Recieves one daughter cell from below.
Process of Mitosis and creation of daughter cells; one of which gets sent to next layer continues
Stratum Granulosum (Grainy Layer)
Recieves daugter cell from below and continues the process
Synthesis of Kerotin - a durable, water resistant protein, coats skin (and hair) to prevent water from entry
cells lose their nucleus and cytoplasm looks grainy
Stratum Lucidum (glassy layer)
Clear/Translucent layer only found in Soles and Palms
Contains lots of keratin
Stratum Corneum (cornified layer)
15-30 Layers of flattened and Dead epithelium cells
Connected by desmosomes which is why skin layers shed in sheets vs a fine powder
Dead due to distance for diffusion too great to recieve nutrients
Cells begin to accumulate large amounts of Keratin and become Keratinized (cornified)
Takes 2-4 weeks for cells to make it into Stratum Corneum
and another 1-2 weeks for skin to begin to shed
most of barrier functions are provided by this layer; because cells are dry they don’t provide much of a breeding ground for bacteria or pathogen which prevents infection from taking root
These cells are considered expendible cells due to number, allowing cells to make sacrifices for the rest of the body
Dermis breaks into two layers
Similar; differ in type of tissues
Both contain nerves and blood capillaries as well as Hair Follicles, Sweat Glands, & Lymphatic vessels
Papillae Layer
Loose connective tissue whose function it is to support the Epidermis
Reticular Layer
Dense Irregular connective tissue
- Elastic Fibers* allow for stretch and increased flexibility
- Collagen fibers* are responsible for limiting flexibility
Subcutaneous (Hypodermis)
Not really part of the integumentary system
Primary function is to stabilize position of skin realitive to underlying organs
Permits movement of connective tissue
Contains connective tissue; including adipose cells (never lose number of adipose cells once gained; chronically high lipid levels may cause stem cells to differentiate into more adipose cells)
Skin Color
Two primary factors in pigmentaion
- Carotene - Orange-Yellow color found in vegetables; converts to Vit A ≈ good for eyes
- Melanin - derived from melanocytes; increase in color with increase in sun exposure; changes to protect sun from UV radiation
*Freckles are concentrated deposits of melanin
**UV Radiation promotes Vit D3 Synthesis which converts to Calcitrol in kidneys and promotes Ca2+/Phosphorus Absorption on the small intestines
Dermal Circulation with regard to skin color
Vasodilation = red-pink coloration
Vasoconstriction = pale-cyanotic coloration
Hair
Non-Living Structure
Present on surfaces of most of the skin
Produced in an organ called the hair follicle
Hair is divided into 3 Sections:
- Hair Papilla - type of connective tissue located at very bottom; connected to a capillary and a nerve
- Hair Root - prekaratinization; up to about 1/3 of the way up
-
Hair Shaft - remainder of hair; post-karatinization; comprised of 3 layers
- Medulla - Located in center of shaft, comprised of Soft Keratin
- Cortex - Middle layer; comprised of Hard Keratin
- Cuticle - Outermost layer; comprised of hard Keratin
- Cells reproduce like the skin; ie pushing up daughter cells to next layer
*Arrector Pilli Muscle - ennervated by sympathetic nervous system; contraction when cold will make hair stand on end
Hair Fun Facts
- Hair grows for 2-5 years; then it takes a break, falls out, and starts back up again
- Male Pattern Baldness in an X-Linked Trait; more common in males than females; ressesive, for female to have it, both mom and dad have to contribute that trait to child
- Pigment for hair is melanin (just like skin); abscence of melanin = gray hair; melanin production decreases with age
- Eyelashes and nose hair - guard pathogens from entering body
- Cushions a blow to the head
- Provides some protection from UV Light
- Insulates the skull
Nails
Present on the Dorsal Surface of fingers and toes
Function is to provide protection, limiting distortion secondary to mecanical stress
Nail Body - on surface; dead part that you can feel/see
becomes visible at surface of the skin at the cuticle
Below the skin is the nail root
Below the nail is the Nail Bed (skin underneath the nail)
Lunula - caused by blood vessels under the nail
*If nail pulls out completely, it will not grow back. If you stick a pice of nail back under cuticle while it heals it will regenerate.
Sebaceous Gland
Sebaceous = Oil
Secretes oil; present into surface of the skin and at hair folicles
Part of Function is to prevent growth of bacteria
responsible for oily residue of hair
Stimulation of Accector muscle also causes oil secretion
Sweat Glands
Two different types differentiated by where they are located
- Apocrine Gland - armpits, nipples, groin
- **Merocrine Gland - ** everywhere else
Comprised of:
- 99% - Water
- 1% - NaCl, Urea, Organic Nutrients
Primary responsibility is to cool the body
Water on surface of the skin via breeze, produces cooling of body and temperature control
Must be concious of water loss and consume more water
Reproduction
Mitosis
Somatic (Body) cell division
23 pairs = 46 chromosomes
diploid = pairs of chromosomes
Meosis
Of an organism
2 Cycles of cell division
*Goal*: To make 4 haploid cells (**Gamates**) 23 Chromosomes Total
Gamates are the reproductive cells (sperm & ova)
Gamates
&
Gonads
Gamates are the reproductive cells (sperm & ova)
Goal of Meosis is to produce 4 gamates (haploid cells 23 chomosomes)
23 gamates come from the mother and 23 come from father to produce offspring with 46 chromosomes
Gonads are the reproductive organs which produce Gamates & Hormones
Fertilization
&
Zygote
Fertilization is the uniting of sperm + ova to produce a Zygote
Zygote is a single cell that then divides into multiple cells and then many cells
typically formed by union of 2 haploid cells (23 chromosomes) to form one diploid cell (46 chromosomes)
Male Reproduction
Testis (singular) / Testes (plural) - male reproductive organ
Scrotum
- contains testes (plural), Testis (singular)
- lined by serous membrane to reduce friction
- 2°F/1.1°C cooler than the body
Sperm (spermatozoa) - Reproductive cells produced by the testes
Spermatogenesis - Series of divisions that will produce sperm cells; daughter cells move centrally w/ each cell division
- Mitosis
- Meosis I
- Meosis II
Scrotum : The parts
- Scrotum - 3 layers of skin, lined by serous membrane to reduce friction; 2°F/1°C cooler than body
- Cremaster Muscle - Its function is to raise and lower the testes in order to regulate the temperature of the testes and promote spermatogenesis.
- Spermatogenesis - Process that takes place in Seminiferous Tubules. Mitosis/Meosis 1/Meosis 2; 23 Diploid Chromosomes to 23 Haploid Chromosomes
- Seminiferous Tubules - 80cm in length (per testis); tightly coiled = .5 miles in toal length; initial location of sperm production, developing sperm move from outside toward center of tubule
- Sustentacular Cells - provide nourishment to developing sperm; located in walls of seminiferous tubules; activated by FSH.
- **Loose Connective Tissue - ** fills space around Seminiferous Tubules & Interstitial Cells - where Androgens (testosterone) is produced
- Ductus deferens - they transport sperm from the epididymis in anticipation of ejaculation
- Efferent Ductule - connect the testis with the initial section of the epididymis
- Epididymus - connecting the efferent ducts to its vas deferens (ductus deferens; storage of sperm
Mitosis (Males)
Spermatogonia (Stem Cells) - undifferentiated cells that divide by Mitosis to form into primary spermatocyte (still diploid at this point)
- divide by mitosis for entire adult life (post puberty); different than female where Mitosis - oogonia (female stem cells divide before birth and produce cells called primary oocyte)
- Goal: to make 2 duplicate daughter cells from existing parent cells = 4 diploid cells
- one stays & one daughter cell moves toward lumen (centrally) and becomes Primary Spermatocyte moves to Meiosis One
Meosis I
Primary Spermatocyte (diploid cell formed in Mitosis)
Tetrad Formation takes place
Where crossover occurs and recombination of genes recieved from parents
Primary Spermatocyte then divides into two cells each with two chromatids (chromatid = one half of a chromosome) forming secondary spermatocytes
Meosis II
2 Secondary Spermatocytes (daughter cells) formed in Meiosis I divide to produce 4 Haploid Spermatids
Each spermatid has half the genetic material originally present in the primary spermatocyte
Spermatid - haploid male gamate
Spermiogenesis final stage of spermatogenesis which sees the maturation of spermatid into Spermatozoa (Sperm)
**Spermatogenesis is the entire process, not to be confused with Spermiogenesis which is the maturation of spermatid into sperm**
Sperm cell (Spermatozoa)
Head - houses nucleus and acrosomal cap
Acrosomal Cap - contains enzymes necessary for fertilization
Nucleus - houses product of Spermatogenesis
Neck - where head meets middle piece
Middle Piece - houses Mitochondrial Spiral
Mitochondrial Spiral - important becauses it provides ATP for locomotion
Flagellum - whip like tail necessary for locomotion
Efferent ductile to epididymus
- Efferent Ductile - just a tube for transport, a travel space lined with cilia to sweep sperm cells into epididymus, due to nonfunctional locomotion.
-
Epididymis Functions
- adjust fluid concentration of seminiferous tubules
- Recycle damaged spermatazoa
- Store sperm cells
- In order for sperm to become mobile, they must undergo Capacitation
- mix with secretions from seminal vesicles
- be exposed to conditions of the female reproductive tract
From Epididymus to Ductus Deferens (Vas Deferens)
- Track toward the prostrate gland enclosed by the spermatic cord
- spermatic cord - a sheet of connective and muscle tissue containing blood, nerve, and lymphatic vessels
- Sperm propelled through passageway via peristalsis
Sperm joins Seminal Fluid
- Seminal Vessicles - 60% of semen -
- fructose for energy;
- prostaglandins for SMC contractions
- fibrinogen for forming clot in vagina
- Prostate gland - 20-30% of semen
- seminal plasma important for preventing UTI’s
- Bolbourethreal gland
- sticky mucous that is used to neutralize urinary acids
Semen
&
Ejaculate
Semen = Sperm + Secretions (Seminal, Prostrate, Bolbourethreal Fluids)
Ejaculate = 2-5ml (Sperm, fluid, enzymes).
The Penis - Structures
Root - Attachment of penis to body
Shaft - contains erectile tissue
Glands - distal portion surrounds the External urethreal meatus
Dorsal Vein
Corpora Cavernosa
External Urethreal Meatus
Corpus Spongiosum
Penis Function and innervation
- At rest, vasculature is constricted = very little blood flow
- Penile Arteries recieve parasympathetic innervation, stimulating neurons and causing the release of NO, which causes vasodilation and erection
- How Nitro works (recording)
Male Reproductive emergencies
-
Priaprism
- unopposed parasympathetic innervation due to spinal cord injury
-
Testicular Torsion-
- Twisting of Testes around spermaticord;
- impeeds blood suply leading to necrosis.
- Accute illness that is fast-tracked to surgery
Endocrine influence in Male Reproduction
- Hypothalamus releases GnRH (Gonadotropin Releasing Hormone)
- Stimulates Anterior Pituitary to produce and release FSH & LH to affect Testes (target organ)
- FSH - Folicle Stimulating Hormone
- LH - Leutinizing Hormone
- Interstitial cells in testes produce testosterone which influences
- Sex Drive
- Promotes Secondary Sex Characteristics
- Spermatogenesis
- Stimulates metabolism (growth/bone growth)
Female Reproduction
-
Ovaries - Female Reproductive Organs
- Produce - Ova (plural), Ovum (singular)
- Secrete Sex Hormones
- Oogenesis ≈ ovum production
- begins before birth
- ends @ Menopause
- Follows similar pattern to Spermiogenesis
Female - Mitosis I
- oogonia (stem cells) divide before birth produce daughter cells called primary oocyte
Meiosis I
- Begins @ 3-7 months of fetal development
- Double all chromosomes; then placed on hold until puberty
- Meiosis I is completed once monthly to form ONE secondary oocyte & ONE Polar Body (2 more produced later in meosis II) which will be destroyed later by the body
Meosis II
- Secondary oocyte is released during ovulation
- ONLY completed IF fertilization takes place, then would be called an OVUM
Follicle Development
Ovarian Follicle
- Speciallized structure within ovary that houses the development of what will be the primary oocyte growth & Meosis I
- Primordial follicle
- Primary follicle
- Secondary follicle
- Tertiary follicle
- Folllicle ruptures - releases egg into interstitial space
The cycle of the ovary and ovulation
{bracketed items are Adelson’s points}
The cycle of the ovary lasts around 28 days. It consists of two stages or phases:
- The follicular phase, the first half of the cycle, some of the eggs within the ovary complete their development. The maturation of the oocytes is under the control of the follicle-stimulating hormone (FSH), which promotes the development of a follicle, which secretes estrogen. {Formation of tertiary follicle, and allows for formation of secondary oocyte}
- The high level of estrogen in the blood causes the LH production by the anterior pituitary and ovulation (or release of the ovum into the Fallopian tube so it can be fertilized) at about the fourteenth day of a 28-day cycle.{secondary oocyte ruptures from ovary and is released into the pelvic cavity ⇒ swept into the uterine/fallopian tube}
- After ovulation and during the second half, or luteal phase, days 14-28, the cells that surrounded the ovum are transformed into a mass of yellow cells (the corpus luteum), which secretes progesterone. If fertilization does not take place, this mass of cells degenerates, menstruation occurs, and a new cycle begins.
*GnRH is a hypotalamic-releasing hormone that stimulates the anterior pituitary to secrete FSH and LH, which act on the ovaries.
**FSH promotes the development of the follicle that later, under the influence of LH, becomes the corpus luteum.
***Negative feedback controls the level of all hormones involved
Fallopian Tubes
AKA Uterine Tubes
13cm in length
moves secondary oocyte via cilia and peristalsis
ooycte + sperm = zygote if union takes place within 12-24 hours
Corpus Luteum
formed from remnants of tertiary follicle once secondary oocyte is released from ovary
secretes progesterone if fertilization does not take place within 12 days, corpus luteum degenerates, menstruation occurs, and a new cycle begins.
The cycle of the uterus and menstruation
The cycle of the uterus lasts an average of 28 days and it is the transformation of the internal wall of this organ, called the endometrium, along with the process of maturation of the ovule. Is consists of three phases:
- Menses - days 1-7, there is a low level of female hormones in the body: the endometrium, which is very thick and vascularised (i.e. has a large number of capillaries), desintegrates, detaches and is expelled through the vagina together with the blood in its capillaries. These hemorrahages are known as menstruation. {degredation of functional zone, sloughing off of tissue; loss of 35-50ml of blood each time}
- Proliferative Phase - days 7-14, the endometrium lost in menstruation regenerates itself. Increased production of estrogen by an ovarian follicle causes the endometrium to thicken and to become vascular and glandular. {surviving epithelial cells, multiply and spread across surface of endometrium, couple mm of tissue}
**Ovulation usually occurs on the fourteenth day of the 28-day cycle.
- Secrectory Phase - days 15-28, increased production of progesterone by the corpus luteum causes the endometrium to double en thickness and the uterine glands to mature. The endometrium becomes thicker and vascularises, so that, if the ovum is fertilised, the embryo can develop. If fertilization does not take place, the corpus luteum degenerates and the low level of the sex hormones in the female body causes the uterine lining to break down (i.e. the endometrium is expelled through menstruation). After, a new cycle begins. {glands enlarge; preparation for arival of embryo; persists as long as there is a corpus luteum}
*A about age 40-50, the ovaries gradually cease to respond to the anterior pituitary hormones. Eventually, no more follicles are produced. Following this occurrence, called menopause, menstruation ceases entirely.
Uterus Anatomy
Fundus - Top of Uterus; is massaged post partum to initiate cessation of bleeding
Three Layers
- Perimetrium (viseral lining) - outside
- Myometrium - muscular layer
- endometrium - innermost; divides into 3 additional layers: Functional zone (at top) only portion of lining that degrades during menstration, baslar zone (middle), myometrium (baselayer)
Cervix - lower narrow portion of the uterus; means neck of the womb
Vagina
Elastic muscular tube
- passageway for menstral fluids
- recieves penis during intercourse; and hold sperm temporarily
- forms lower portion of the birth canal, through which baby (fetus) passes during delivery
Perineum
Muscular floor of the pelvic cavity
Stretch of tissue between vagina and anus
Region that is succeptible to tearing during natural child birth due to size of baby’s head.
Clitoris
Contains erectile tissues
Engorged with blood during arousal
Mammary glands
Converge at nipple
produce and secrete milk
**Stroking from bottom of nipple by tounge stimulates let down of milk
Hormones & Female Reproduction
Estrogen
- Produced by Follicular cells in ovaries
- Increases sex drive
- Bone growth and termination
- Growth and repair of endometrium
FSH
- during Follicular phase in Ovarian cycle, FSH promotes development of the follicle ⇒ follicle cells produce estrogen
Luteal Phase
- Corpus Luteum manufacture progesterone
Uterine Cycle
- Estrogen + Progesterone decrease with the breakdown of Corpus Luteum
GnRH
- stimulates the anterior pituitary to secrete FSH and LH, which act on the ovaries.
- Negative feedback controls the level of all hormones involved.*
