Respiratory System

Respiratory System• Sucking chest wound

– Pleural cavity __________________– Lung collapses as air pressure difference between

pleural cavity and outside kept constant by wound (air flows in and out of wound)

Respiratory System• Boa constrictors

Respiratory System• Gas transport: overall plan

– 1) Heart pumps low oxygen blood to lungs– 2) Oxygen in, carbon dioxide out (external respiration)– 3) Blood returns to heart and is pumped to body– 4) Oxygen out of blood, carbon dioxide in (internal

respiration)

Respiratory System• Gas transport

– Oxygen non-polar: not very soluble in __________– Hemoglobin: protein that binds with oxygen.

Contains Fe in each chain, which binds oxygen.

Respiratory System• Red blood cell or rbc (ethrythrocyte) contains

300 million hemoglobin molecules. Each molecule binds to 4 oxygen molecules. 1200 million oxygen molecules on 1 rbc!

Respiratory System• Carbon dioxide transported in 3 ways:

– 1) Dissolved in plasma (67% of CO2) as bicarbonate (HCO3-).

– CO2 + H2O forms H2CO3 which forms H+ and HCO3-– This also affects pH of blood. More CO2 means lower

blood pH.

Respiratory System• Carbon dioxide transported in 3 ways:

– 2) Bound to hemoglobin (25%). Binds to amino acids, not to _______.

– 3) Dissolved in plasma as CO2 (8%).

Respiratory System• Control of breathing:

– Brain stem center monitors blood pH– If pH drops, then too ___________ CO2 in blood– Breathing rate increased in response.

Circulatory System

Circulatory System• Functions:

– 1. Transport of materials (gases, nutrients, wastes)

– 2. Temperature regulation– 3. Carries ______________

hormones– 4. Protection (immune

defense, blood clotting)

Circulatory System• Types in animals:

– None! Phylum Platyhelminthes, Nematoda, Echinodermata, etc. Circulation can occur (ex, nematodes) due to body movements.

Circulatory System• Types in animals:

– Open. Phylum Arthropoda, Mollusca. No capillaries: have sinuses into which blood flows from vessels.

Circulatory System• Types in animals:

– Closed. Phylum Annelida, Chordata. Blood always stays in vessels as it circulates.

Circulatory System• Vessels:

– Arteries (carry blood away from heart): large diameter

– Thick elastic muscular walls. Can handle high blood pressure

– Connective tissue sheath outside, _____________ inside.

Circulatory System• Vessels:

– Arterioles (carry blood away from heart): small diameter (microscopic)

– Smooth muscle controls blood flow. Vasoconstriction is contraction to cut flow down

– Vasodilation is relaxation to increase flow.

Circulatory System• Vessels:

– Precapillary sphincters: __________ muscle valves on some arterioles near capillaries. Can cut off blood flow

– Important: most capillaries not open simultaneously (blood pressure would drop critically). Parts take turns.

Circulatory System• Vessels:

– Capillaries: very small diameter (8 micrometers: rbc only 5-7 micrometers wide). Where most exchange of materials takes place

– Every cell in body within _______ micrometers of a capillary!

– 250,000 capillaries in area size of little fingernail.

Circulatory System• Vessels:

– Capillaries connect arteriole to _______________– No smooth muscle, just endothelium (note

diagram in error: capillary on upper right).

Circulatory System• Vessels:– Venules (carry blood toward heart): small diameter

(microscopic)– Smooth muscle thin. Pressure low (________% of

arteries). Connective tissue sheath outside, endothelium inside

– Veins (carry blood toward heart): large diameter

Note: labels for vein and capillary are reversed indiagram

Circulatory System• Vessels:

– Veins often have one-way valves. Muscle contractions can help move blood through valves.

Circulatory System• Vessels:

– Varicose veins: weakened valves in legs allow backflow. Small veins bulge with venous blood.

Circulatory System• Lymphatic system: open

circulatory system

Circulatory System• Blood plasma in tissues (_________________ fluid)

bathes tissues. Not all returns to capillaries• Lymphatic capillaries, vessels, nodes, organs (nodes)• Capillaries collect fluid (lymph) and pass to larger

lymph vessels

Circulatory System• Lymphatic system vessels: little smooth muscle in

walls• Have series of one-way valves. Fluid moves mainly

due to contraction of nearby __________________.

Fluid movesleft to righthere

Circulatory System• Lymph system functions

• 1) Drain excess fluid from tissues (recall elephantiasis, where nematodes clog system)

Circulatory System• Lymph system functions• 2) Involved in fat absorption from intestine

(covered).

Circulatory System• Lymph system functions• 3) Fights infection at lymph

nodes (about 100 in human body)– Bean shaped, various places.

Circulatory System• Lymph system functions• 3) Nodes produce B- and T-lymphocytes. These produce

antibodies that detect foreign materials (ex, bacteria)– Nodes become swollen in areas downstream of infection as

lymphocytes attack invaders

Heart• Major organ of circulatory system• Enclosed in membrane called

____________________• Pumps blood into arteries.

Heart• Humans have 4 chambered heart

that functions in 2 sets of 2 chambers (form 2 myocardia)

• Chambers called atria receive blood, pump it into more muscular chambers called ventricles, which send blood away from heart.

Heart• One set receives deoxygenated blood and sends it to lungs

(pulmonary circulation)– Right atrium (receives deoxygenated blood) from superior (from

head) and inferior (from lower body) vena cava– Right ventricle (pumps it to lungs) via pulmonary artery.

Heart• Second set receives oxygenated blood from lungs and

sends it to body (systemic circulation)– Pulmonary vein brings oxygenated blood to left atrium– Left ventricle pumps oxygenated blood to body via

_______.

Heart• Note valves: prevent backflow of blood when

chamber contracts• Tricuspid valve: between right atrium and ventricle• Bicuspid valve: between left atrium and ventricle.

Heart• Note valves: prevent backflow of blood when

chamber contracts• Semilunar valves (aortic and pulmonary): between

ventricles and arteries that receive blood from them.

Heart• Chordae tendinae and papillary muscles keep

bicuspid and tricuspid valves taught.

Heart• Beating controlled by special groups of cardiac muscle

cells (called nodes) that generate impulse• Other cells then transmit impulse to one another via

intercalated discs.

Heart• SA node (right atrium) originates __________• Causes atria to contract (ventricle relaxed at this time).

Heart• AV node receives stimulus• Sends to ventricle cells through specialized cardiac

muscle cells called Purkinje fibers• Ventricle cells then contract (after atria relax).

Heart• Heart sound: Lub-dub• Lub: biscuspid and tricuspid valves closing as

ventricles contract• Dub: aortic and pulmonary semilunar valves closing

as _________________ re-fill.

Heart• Autonomic nervous system influences

heartbeat rate– Sympathetic nerves: accelerate rate– Parasympathetic nerves: slow rate– Some hormones (ephinephrine = adrenalin):

accelerate rate.

Blood• Connective tissue: cells in matrix• Matrix: plasma.

Blood• Plasma components:

– 1. Water (92%)– 2. Salts (Ca, K, Na)– 3. Proteins

• globulins: large immunoglobins (antibodies)• albumins: osmoregulation (most abundant blood protein)• fibrinogen: helps clotting. Serum is plasma minus fibrinogen

– 4. Glucose (regulated by glucagon and insulin)– 5. Glycerol and fatty acids– 6. Hormones– 7. ____________ (nitrogenous waste)– 8. Carbon dioxide and bicarbonate

Blood• Cells (called formed elements)

– Erythrocytes (red blood cells: rbcs): no nucleus, biconcave disc shape, flexible. Origin: ___________ bone marrow.

Blood• Cells (called formed elements)

– Leukocytes (white blood cells: wbcs): have nucleus. <1% of blood cells.

Blood• Cells (called formed elements)

– Granular leukocytes (granulocytes)• Lobed nucleus and look grainy• Phagocytic cells. Fight infection, produced by ___________

marrow• Types: neutrophils (stain well with neutral pH dye), basophils

or mast cells (stain well with basic pH dye), eosinophils (stain well with eosin).

Blood• Cells (called formed elements)

– Agranular leukocytes• Large nucleus, no granules present• Formed in lymph nodes• Types: Monocytes (become macrophages in tissues, largest

phagocytic cells, nucleus kidney bean shaped), T-lymphocytes (phagocytes), B-lymphocytes (make ___________________)

Blood• Cells (called formed elements)

– Thrombocytes (platelets)• No _____________. Fragments of red bone marrow cells• Function in clotting of blood.

Blood Summary• Cells (called formed elements)

– Thrombocytes (platelets)• No nucleus. Fragments of red bone marrow cells• Function in clotting of blood

Blood Clotting• Blood vessel wall

broken• Platelets stick to each

other and to break. Release clotting factors.

Blood Clotting• Protein called

prothrombin converted to thrombin, which causes fibrinogen in plasma to become fibrin (protein threads)

• These threads bind together platelets and blood cells to make ____________.

How Phagocytic WBCs work• Damage to tissues• Mast cells release histamine• Causes blood vessels to dilate• Increases permeability of capillaries.

How Phagocytic WBCs work• Neutrophils and _____________ stick to lining of

capillary• Squeeze through wall into tissue• Locate and digest invading cells.