Unit 9 Flashcards
Saclike body found in…
Jellyfish and flatworms
No circulatory system
Saclike body in which cells exchange materials
Fluid in coelom transports material
Fluid in coelom
Round worms and starfish
Open circulatory system
Heart pumps hemolymph via vessels into tissue spaces
Open circulatory system found in…
Molluses and Arthropods
Closed Circulatory system
Blood pumped by the heart into a system of blood vessels
Closed circulatory system found in…
Segmented worms, some molluses, chordates, and all vertebrates
Closed circulatory system aka
Cardiovascular system
Parts of the heart
Atria and ventricles
Atria
Receives blood
Ventricles
Pumps blood from heart to vessels
Vessels
Arteries
Capillaries
Veins
Arteries
Carry blood away from heart and muscles
Arterioles
Smaller artery that can constrict or dilate to regulate temperature
Capillaries
Very thin to allow for exchange of materials with tissues
Venules
Small capillaries that can constrict or dilate to regulate temperature
Veins
Carry blood to the heart, less muscle so when empty will collapse
What is larger to minimize resistance veins or arteries?
Veins
Why do veins have one way valves?
To prevent back flow
Capillary exchange
Oxygen and nutrients exit a capillary near the arterial end and carbon dioxide and waste molecules enter a capillary near the venous end
Fish circulatory pathways
Single loop circulations from heart to gills to the body with a single atrium and single ventricle
Systemic circuit
Heart to body and then back to the heart
Pulmonary circuit
Heart to lungs and back to the heart forever
Amphibians circulatory pathways
Two atria with a single ventricle and mixing of oxygenated and deoxygenated blood results
Reptiles, mammals, birds circulatory pathways
Heart divided by septum into separate sides for more efficiency
Blood composition
Plasma
Red blood cells
White blood cells
Platelets
Plasma
Liquid portion of the blood, water with dissolved molecules, such as nutrients, wastes, salts, and proteins
Red blood cells
Predominant cell type in the blood, has hemoglobin to carry oxygen, manufactured in bone marrow (erythrocytes)
White blood cells
(Leukocytes) larger and less numerous than red blood cells (1:1000 ratio) used immensely
Platelets
(Thrombocytes) cell fragments that help form blood clots
Blood pressure
The beat of the heart supplies pressure that keeps blood moving in the arteries and the skeletal muscle contraction helps push blood in the veins toward the heart
Systolic pressure
Pressure of blood pushing out on the walls of arteries during ventricular systole
Diastolic pressure
In arteries when ventricles are at rest
Heartbeat
Pacemaker generates nerve impulse that causes heart to contract and the contraction delay between atria and ventricles exists (narrow neurons) this delay is functional
Cardiovascular disorders
Hypertension
Atherosclerosis
Heart attack
Hypertension
High blood pressure
Atherosclerosis
Cumulation of fatty materials in inner linings of arteries
Heart Attack
Myocardial infraction or death of heart tissue where the coronary artery becomes partially blocked
What does the lymphatic system consist of?
Lymphatic vessels and lymphoid organs with a one way open circulatory system the fluid moved through lymphatic capillaries by skeletal muscle contraction
Three main homeostatic functions of the lymphatic system
Lymphatic capillaries take up and return excess fluid to the bloodstream
Lacteals receive lipoproteins and transport them to the bloodstream
Helps defend the body against disease
Spleen
Filters blood, if ruptures, releases impurities
Edema
Localized swelling due to accumulation of tissue fluid from lack of movement
Lymphatic system
Edema occurs then lymph flows one way from a capillary to ever-larger lymphatic vessels which drain into blood vessels in the neck and before entering back into the blood it is filtered by lymph nodes, which enlarge when sick and then enters the spleen
Lymph
Lymphatic fluid
Respiration
Exchange of gases between body cells and the environment (uptake of oxygen and disposal of a carbon dioxide)
3 steps of the respiratory system in terrestrial vertebrates
Ventilation
External respiration
Internal respiration
Ventilation
Breathing=inspiration and entrance of air into the lungs and expiration exit of air from lungs
External respiration
Gas exchange between air and blood in lungs, the blood transports oxygen from lungs to body tissues
Internal respiration
Gas exchange between blood and cells, blood transports carbon dioxide to lungs
Gas exchange takes place by…
Diffusion
For a gas exchange the surface must be…
Moist
Thin
Large in relationship to animal size
Respiratory system in aquatic invertebrates
Gastrovascular cavity. All cells are in contact with outside or with GV cavity for gas exchange (large surface area)
Respiratory system of aquatic vertebrates (fish)
Gill function and countercurrent flow
Gill function
Made up of layers of tissue called lamellar which increases surface area, while water is constantly moved over the gills either by constant swimming or movement of the gill cover
Operculum
Gill cover
Countercurrent flow
Blood moves across lamella in opposite direction of water, which maintains an oxygen gradient between the water and the blood so that oxygen will diffuse from water into blood over the entire lamella surface (85% efficient)
Terrestrial invertebrates respiratory system
Integumentary exchange or tracheal system
Tracheae
Branching tubes used in the respiratory system of invertebrates
Integumentary exchange
More primitive than the tracheal system and respiration occurs directly through skin
Tracheal system
Trachea tubes open to outside at spiracles, air sacs emptied by muscle contraction nearby
Terrestrial vertebrates respiratory system
Lungs
Birds- one way flow mechanism
Other vertebrates- two way tidal flow system
One way flow mechanism
One way flow of air through the lungs
Gas exchange efficiency is high
Oxygen rich air never mixes with used air
Human respiratory system
Two way flow involving inhalation,exhalation, and hemoglobin
Two way flow
Less efficient than one way flow system, but conserves water
Air enters nostrils and mouth, pharynx, larynx, trachea, bronchi, bronchioles, alveoli
Air is warmed and filtered in nostrils
Alveoli
Small air sacs that increase lungs surface area for gas exchange surrounded by capillaries or small blood vessels
Inhalation
Rib cage moves up and out
Diaphragm contracts and moves down
Pressure in lung decreases, air comes rushing in
Exhalation
Rib cage moves down and in
Diaphragm relaxes and moves down
Pressure in lungs increases and air is pushed out
Hemoglobin
A protein containing heme (iron) groups Found in red blood cells Binds to oxygen Comes through the body At tissues hemoglobin unloads oxygen and moves down a concentration gradient
Bohr effect
In areas with higher concentrations of carbon dioxide, hemoglobin changes shape and is more likely to unload its oxygen
Removal of carbon dioxide
Dissolved in blood (10%)
Combines with hemoglobin and is carried to lungs where it is unloaded and exhaled (30%)
Converted to bio carbonate, carried through blood plasma to lungs (60%)
CO2+H2O H2CO3 (carbonic acid) HCO3- + H+ (bicarbonate)
Autonomic Breathing Control
Chemoreceptors in medulla detect high carbon dioxide or lowered pH (from H+)
Pons sends nerve impulse to breathing muscles to correct
Chemoreceptors hear aorta detect low O2 in extreme cases (high altitude, lung disease)
Respiratory disorders
Bronchitis
Emphysema
Asthma
Bronchitis
Airways are inflamed due to infection (acute) or due to an irritant (chronic) coughing brings up mucus and pus
Emphysema
Alveoli burst and fuse into enlarged air spacer, surface area for gas exchange is reduced
Asthma
Airways are inflamed due to irritation and bronchioles construct due to muscle spasms
