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The Circulatory and Immune Systems (Ch.42-43) - Coggle Diagram
The Circulatory and Immune Systems (Ch.42-43)
Circulation & Gas Exchange
Why Circulation Exists
Diffusion Limits( slow over long distances)
Needs for transport systems (moves nutrients, gases, and eliminates waste)
A circulatory system includes:
circulatory fluid.
interconnecting vessels
a muscular pump, heart
Types of Circulatory Systems
Open:
Hemolymph fluid; low pressure, in smaller organisms, less energy(
ex:
Arthropods, mostly molluscs)
Closed
: Blood confined to vessels; high pressure, larger organisms, more energy.(
ex
: Vertebreas)
Evolution of Vertebrate Circulation
Fish:
2‑chambered heart and Single circulation.
Amphibians
: 3 chambers and Double circulation (mixed blood)
Reptiles
: 3 chambers + partial septum
Mammals & Birds:
4 chambers and Complete separation of O2-rich/O2-poor blood
Heart Anatomy & Cardiac Cycle
**
Heart Structure
Atria
(receive blood)
Ventricles
(pump blood)
Valves
: AV valves( seperates atrium and ventricle) and Semilunar valves( control blood flow)
Blood Flow Pathway
Vena cava → RA → RV → Pulmonary artery → Lungs→ Pulmonary veins → LA → LV → Aorta → Body
Cardiac Cycle
Systole:
Contraction and Blood ejected
Diastole
: Relaxation and Chambers fill
Electrical Conduction
SA node (pacemaker) → AV node→ Bundle branches→ Purkinje fibers
Blood Vessels & Blood Pressure
Types of Vessels
Arteries
:Thick, elastic, and high pressure
Arterioles
:Control flow via smooth muscle
Capillaries
: Thin walls and Exchange site
Venules & Veins
: Low pressure and Valves prevent backflow
Blood Pressure Patterns
:
Highest in arteries
Drops in arterioles
Lowest in veins
Capillary Exchange
Diffusion
Pressure-driven flow
Osmotic pressure
Blood Components
Plasma
: Water, Ions, and Proteins (albumin, antibodies, fibrinogen)
Cellular Elements
Erythrocytes (RBCs)
: Hemoglobin and Gas transport(
ex
; sickle cell disease: cased by abnormal hemoglobin proteins
Leukocytes (WBCs)
:Immune defense
Platelets
: Clotting
Blood Clotting
Platelet plug
Fibrin clot
Clotting factors
Gas Exchange Surfaces
: take place by diffusion
Requirements
:
Moist
Thin
Large surface area
Types of Respiratory Surfaces
Skin (earthworms, amphibians)
Gills (fish)→ Counter current exchnage: blood flows opposite direction to H2O
Tracheal systems (insects): Network of branching tubes throughout body.
Lungs (vertebrates): infolding of the body surface
Gas Exchange:
uptake of O2 from the enviroment and the discharge of CO2 to the enviroment
Breathing Mechanisms
Positive pressure:
: forces air down trachea(ex: amphibians)
Negative pressure:
: pulls air into the lungs
Bird Ventilation
Air sacs
One‑way airflow
Crosscurrent exchange
Control of Breathing
Medulla oblongata
CO₂ levels regulate rate
Respiratory Pigments
Hemoglobin
-Binds O₂ cooperatively
-Bohr shift (↓pH → ↓affinity)
Myoglobin
-Higher O₂ affinity
-Muscle storage
Other Pigments
Hemocyanin (copper-based, arthropods/molluscs)
The Immune System
: enable animals to avoid or limit many infections.
Innate Immunity
: defense active upon infection
Physical Barriers
Skin
Mucus
Cilia
Chemical Barriers
Lysozyme: breaks down bacterial cell walls
Low pH
Antimicrobial peptides
Cellular Defenses
Phagocytes
Neutrophils:
Circulate in the blood
Macrophages:
migrate through body
Dendritic Cells:
: stimulate development of adaptive immunity
Eosinophils:
: discharge destructive enzymes
Natural killer cells:
circulate and proctect
Inflammatory Response
Histamine
: triggers BV(BLOOD VESSELS) to dialate.
Vasodilation
:
Increased permeability
Recruitment of phagocytes
Adaptive immunity:
activated after innate response
Key Features
Specificity
Memory
Self vs. non-self recognition
Lymphocytes
B cells
-Mature in bone marrow
-Produce antibodies
T cells
Mature in thymus
Helper T cells (activate others)
Cytotoxic T cells (kill infected cells)
Antigen Recognition
Antigen receptors:
specific part of 1 molecule
Epitopes
: binds to anitigen recptor
MHC presentation:
bind and transport antigen fragments
Clonal Selection
-Effector cells
-Memory cells
Types of Immunity
Humoral Immunity
-B cells
-Antibodies in body fluids
Cell-Mediated Immunity
-T cells
-Killing infected cells
Active vs. Passive Immunity
-Active: infection or vaccination
-Passive: maternal antibodies, antibody injections
Immune System Disruptions
Allergies
:IgE and Histamine release
Autoimmune Diseases
Lupus
Type 1 diabetes
Multiple sclerosis
Immunodeficiency
:HIV, SCID
Stress & Immune Function
:Chronic stress → suppressed immunity
