Structure/Function of Circulatory SystemStructure•Heart

•Blood Vessels•Blood

Function•Transport nutrients and oxygen•Remove waste and carbon dioxide

Heart StructureStructure1.Chambers a. Right and left atria b. Right and left ventricles

2.Arteries a. Pulmonary artery b. Aorta

3.Veins a. Pulmonary vein b. Vena cava (superior/inferior

4.Four valves

5.Heart Muscle called myocardium

Blood Flow through HeartBlood Flow1.Superior/inferior vena cava returns deoxygenated blood from body to right atrium.

2. Blood moves from right atrium right ventricle pulmonary artery lungs (oxygenated) pulmonary vein left atrium left ventricle aorta

3. Aorta brings oxygenated blood to body

Circulation Types

• Heart is two separate pumps.

• Right side of heart pumps blood to lungs –pulmonary circulation.

• Left side of heart pumps blood to body- systemic circulation.

Heartbeat• Electrical Stimulation –Cardiac Action

Potential1. Heart muscles contract due to neural

impulse (action potential).2. SA (sinoatrial) Node=Pacemaker3. Electrical impulse generated by SA Node;

moves through atria; atria contract.4. Electrical impulse moves to AV

(atrioventricular) Node; impulse spreads through ventricles.

5. Ventricles contract.6. Pacemaker is the origin of the electrical

impulse; brain does not control whether or not heart beats; brains controls how fast/slow heart beats.

Checkpoint• 1. Chamber pumping blood to aorta?• 2. Vessel bringing blood to lungs?• 3. Vessel bringing blood from body to heart?• 4. Chamber pumping blood to pulmonary artery?• 5. Type of circulation pumping blood to lungs.• 6. Type of circulation pumping blood to body.• 7. Name of the pacemaker.• 8. Role of the pacemaker• 9. Spreads cardiac neural impulse to ventricles.• 10. Type of vessel which brings blood away from

heart.

Blood Vessels

Three types• Arteries – carry blood away from heart• Veins – carry blood to heart• Capillaries – connect arteries & veins.

Artery

Artery1. Made of muscle and thick

elastic wall.2. Systole(ventricle contracts);

artery stretches from the pressure of blood.

3. Diastole (ventricle relaxes); artery snaps back.

Capillary

• Capillary1.One cell thick.2.Allows for transfer of gases,

nutrients, wastes between capillary and cell by diffusion.

3.Every cell bordered by at least one capillary

Vein

• Vein1.Thin walls of muscle and

elastic tissue.2.Valves to prevent

backflow of blood.3.Skeletal muscle

movement aids in return of blood from veins to heart.

Blood Pressure• Blood Pressure1. Blood pressure= pressure of blood against artery walls.2. Pressure due to heart contraction and resistance of artery wall to blood flow.3. Normal BP 120/804. Upper number = systole=pressure when ventricles contract.5. Lower number = diastole= pressure when ventricles relax.6. Blood highest in arteries and lowest in veins.

Objectives• Compare and contrast the structure and function

of arteries, capillaries, and veins.• Describe the causes and consequences of high

blood pressure and atherosclerosis.• List some ways to prevent cardiovascular

diseases.• Describe the blood plasma fluids and proteins

(give examples).• Compare and contrast the role of red and white

blood cells in the body.

Blood

Blood is made of1.Plasma – liquid portion2.Cells

a. Red blood cellsb. White blood cellsc. Platelets

Plasma

Plasma a. Straw colored liquid

portion of blood in which cells are suspended.

b. Primarily water c. Contains proteins, amino

acids, glucose, fats, carbon dioxide, ions (electrolytes), hormones, vitamins, nitrogenous waste.

Red Blood Cells1. Red Blood Cells

(Erythrocytes) a. Non-nucleated biconcave

discs. b. 4-6 million in body; lifespan

120 days c. Made in bone marrow. d. Function: Carry oxygen via

hemoglobin molecule; concave in center for easy diffusion of gases.

White Blood Cells

6. White Blood Cells (Leukocytes)

a. 5 types; lifespan few hours to few days.

b. Make about 100 billion/day; lower numbers than RBC; made in bone marrow.

c. Function in body defense; some ingest bacteria and other pathogens, some produce antibody.

Platelets

7. Platelets (Thrombocytes)

a. Small nonucleated cell fragments; lifespan 8-12 days; made in bone marrow

b. Function in blood clotting.

Blood Clotting• Blood Clotting (Hemostasis)1. In broken blood vessel,

vessel contracts to inhibit blood loss.

2. Platelets are sticky. Stick to each other and to blood vessel to form platelet plug; controls blood loss

3. Coagulation is forming a clot; i.e. formation of fibrin threads which entangle RBC and platelets creating blood clot.

Respiratory System

• Cellular Respiration – Breakdown of glucose to create ATP in presence of oxygen.

• Respiration – Gas exchange; intake of oxygen and release of carbon dioxide.

Respiratory System

Function

Exchange oxygen & carbon dioxide between the blood, air, & tissues

Respiratory System- Structure

• Use the picture in your text on page 957.

• Label the parts of the respiratory system.

• Describe the function of each.

Gas Exchange• 150 Million alveoli/lung• Oxygen diffused from

inside alveolus to red blood cell.

• Oxygen binds to hemoglobin in RBC and is carried to cells in body.

• Carbon dioxide diffuses from the blood into the alveolus and is released from the lungs.

Breathing• Inhalation-• Air enters lungs;air

pressure inflates lungs.• Muscles attached to rib

cage pull ribs to expand.(contract)

• Diaphragm moves down (contracts).

• Exhalation –• Air is released from lungs;

lungs deflate.• Muscles attached to ribs

relax.• Diaphragm relaxes (moves

up.)

Checkpoint

• Explain how the structure of the alveoli is related to its function

• Explain how the respiratory system and the circulatory system work together to respond to your body’s needs during vigorous exercise.

objectives• Nervous System (35-2, 35-3)• Explain the function of the nervous system.• Describe, draw and label, the structure of a neuron. • Relate the functions of the three different types of neurons. • Describe the role of the myelin sheath. • Explain how a nerve impulse is transmitted using the following

terms: resting potential, action potential, threshold, synapse, and neurotransmitter.

• Discuss the overall function of the central nervous system. • Discuss the functions of the two divisions of the central nervous

system. • Compare the central nervous system to the central processing unit

of a computer.

Nervous System• Structure:

1. Central Nervous Systema. Brainb. Spinal Cord

2. Peripheral Nervous Systema. Somatic Nervous Systemb. Autonomic Nervous System

• Function1. Control/coordinate function throughout the body.2. Respond to external/internal stimuli.

Neuron

• Neural signals are transmitted by nerve cells called neurons.• Three types of neurons

1. Sensory – Impulse from sense organ to brain.2. Motor – Impulse from the brain and spinal cord to muscles & glands.3. Interneuron – connect sensory and motor neurons.

How are the functions of the three neuron types related?

Neuron

Draw and label the neuron and describe the function of each of the labeled structures.

Nerve Impulse

• Nerve impulse similar to electrical current through a metal wire.• Resting Neuron• At rest, outside of neuron has net + charge; inside neuron has net –

charge.• Difference of electrical charge across the membrane called resting

potential.

Resting Potential

• Resting potential maintained by sodium/potassium pump (active transport).

• Na+/K+ pump is a channel in cell membrane.• Uses ATP to pump 3 Na+ to outside of

membrane and 2 K+ to inside of membrane.

Action Potential• Impulse begins when neuron is

stimulated by another neuron.• Causes reversal of membrane potential.• Gated channels allow Na+ to flood into

neuron; inside of cell has + charge.• Reversal of charge called action

potential.• Gated channels then allow K+ to flow to

outside of cell; re-establishes + charge outside and – charge inside.

• Action potential is self propagating; impulse at any point on membrane causes impulse at next point on membrane.

Threshold

• Minimum level of nerve impulse (stimulus) required to activate a neuron = threshold.

• Stimulus stronger than threshold produces action potential.

• Stimulus weaker than threshold doesn’t produce action potential.

• All or none principle.

Model Resting Action Potential

• Materials – Red and white beans, tooth picks.• Create the nerve membrane with tooth picks.• Na+ = red beans, K+ = white beans• Create the resting potential by placing Na+/K+

on correct side of membrane.• Demonstrate by moving the beans across the

membrane how an action potential moves down the axon.

Synapse• End of neuron impulse reaches axon

terminal.• Neuron passes impulse to second

neuron.• Synapse – location of impulse

transfer.• Neurotransmitters (chemicals) used

to transfer impulse.• Impulse arrives at synapse;

neurotransmitters released across synaptic cleft.

• Neurotransmitters attach to receptor sites on second neuron; stimulates action potential in second neuron.

Divisions of Nervous System• Two major divisions:

1. Central Nervous System- Relays messages, processes & analyzes information.2. Peripheral Nervous System – Receives information from environment & relays commands from CNS to organs & glands.

Central Nervous System

• Central Nervous System –

1.Brain2.Spinal Cord

Central Nervous System• Skull protects brain.• Vertebrae protect spinal

cord.• Brain and spinal cord

wrapped in 3 layers of connective tissue = meninges.

• Cerebrospinal fluid bathes brain and spinal cord; acts as shock absorber & exchange medium of nutrient/waste between blood and nervous tissue.

Central Nervous System - Brain• Brain- place from which

impulses originate and flow; contains 100 billion neurons.

• 3 major parts1. Cerebrum –

voluntary/conscious activities.2. Cerebellum – Commands

muscle movement & coordinates and balances muscle actions.

3. Brain stem – Involuntary actions; heart rate, breathing, swallowing, blood pressure

Cerebrum• Cerebrum divided into left & right hemispheres.• Hemispheres connected by tissue called corpus callosum.• Each hemisphere deals with sensations on opposite side of body.• Some studies suggest right hemisphere involved in creativity; left hemisphere involved with analytical functions

• Outside of cerebrum = cerebral cortex = grey matter.• Grey matter made of nerve cell bodies; processes info from sense organs/controls body movements.• Inside of cerebrum = white matter•White matter made of axon bundles & myelin sheaths; connects grey matter to brain stem.

Cerebrum• Cerebrum contains 4 lobes• Frontal lobe - higher level cognitive functions - reasoning and judgment (executive function) ; control of voluntary muscle movement for the production of speech and swallowing.

•Parietal lobe -sensation, sense of touch, kinesthesia, perception of warmth & cold, & vibration. Involved in writing & in some aspects of reading.

•Temporal lobe - auditory processing & olfaction. Involved in word meaning.

•Occipital lobe - primary visual area

Cerebellum

• Cerebellum - involved in coordination of voluntary motor movement, balance, equilibrium & muscle tone.

Brain Stem/Limbic SystemBrain stem connects brain stem to

spinal cord.• Responsible for basic life

functions: breathing, heart rate, blood pressure.

• Three parts:1. Midbrain2. Pons3. Medulla oblongataLimbic System – Emotional brain• Contains hypothalamus &

thalamus.• Hypothalamus – hunger, thirst,

homeostasis, emotion, circadian rhythms, controls autonomic nervous system.

• Thalamus – receives all sensory information/ relays to cerebral cortex.

Spinal Cord• Spinal cord – main

communication link between brain and rest of body.

• 31 pairs of nerves branch from spinal cord.

• 8 Cervical nerves – head/neck/arms

• 12 Thoracic nerves – chest/abdominal muscles

• 5 Lumbar nerves – legs• 5 Sacral nerves –

bowel/bladder/sexual function

Peripheral Nervous System

• Nerves not part of brain & spinal cord.

• Two major divisions:1.Sensory – transmits

impulses from sensory organs to CNS.

2.Motor – transmits impulses from brain to organs/glands.

Motor Nervous System

• 2 Divisions1.Somatic – regulates primarily activities under

conscious control; wiggling toe, lifting fingers etc. Also regulates involuntary reflexes.

2.Autonomic - regulates involuntary activities; digesting food, heart rate, etc.

Somatic System – Reflex Arc

• To aid in survival, we have evolved to react to some stimuli automatically.

• Sensory information is not sent to brain.

• Sensory receptor sends impulse to spinal cord.

• Interneuron in spinal cord activate motor neurons.

• Motor neurons activate an effector (muscle).

Adult Reflex

• Some reflexes we know:

• Gag reflex• Pupillary Light reflex• Patellar (knee jerk) reflex

Newborn ReflexesSucking/ Rooting Reflex -Newborns turns head in direction of stimulus, opens mouth, and begins to suck when cheek, lip, or corner of mouth is touched with finger or nipple.

Extrusion -Newborn pushes tongue outward when tip of tongue is touched with finger or nipple

Stepping -Newborn will step with one foot and then the other in walking motion when one foot is touched to flat surface.

Newborn Reflexes

Grasping - Newborn’s finger will curl around object and hold on momentarily when finger is placed in palm of newborn’s hand.

Startle - Newborn abducts and flexes all extremities and may begin to cry when exposed to sudden movement or loud noise.

Plantar Grasp -Newborn’s toes will curl downward when a finger is placed against the base of the toes.

Autonomic Nervous System• Regulates activities that

are involuntary; speed/slow heart rate; increase/decrease blood pressure; speed/slow digestive muscles.

• Two parts of system 1. Sympathetic 2. Parasympathetic• Sympathetic/ parasympathetic systems

have opposite effect on an organ system.