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BIo Exam 3 Study Guide
Movement and SupportEndoskeleton- series of levers in the body, muscles pull on them → movementHuman Skeleton
- Two Divisions- Axial Skeleton
- Cranium- Vertebral Skeleton- Rib Cage- Sternum- Sacrum- Coccyx
- Appendicular Skeleton- Hips and Shoulders- Limbs
- Vertebral (spinal) Column- 7 cervical vertebra
- Atlas (yes), allows head to move up and down- Axis (no), allows head to move side to side
- 12 Thoracic vertebra- Thoracic, more dense than cervical, lose mobility faster
- 5 Lumbar vertebra - Lumbar, DENSE, center of gravity, compressive force- Cartilage = compressed over time ---> back probs
- Sacrum - fused to form one bone- Coccyx (tail bone)
Joints- Ball and socket joint
- Almost 360 degree rotation- Hinge joint
- Almost 180 degrees of rotation- Knees, elbows
- Pivot joint- Lots of motion- Wrist, ankles, spine
- Immovable Joints- Pelvis, cranium- Move at youth so bain can grow help with birthing process- Eventually bones fuse at suture or immovable joints
Types of Bone- Flat bones
- Spongy bone only
- Shoulder, hip, sternum- Long Bones
- Dense- Handle forces (e.g. femur)- Spongy bone
- Red marrow - for making blood cells- Compact bone
- Yellow marrow - for fat storageAnatomy of a Long Bone
- Spongy bone, holes in bones = less heavy- Osteocytes = cells that make up bone- Compact bone = dense - Yellow Marrow = mostly fat
Bone is important for Ca++ regulation in the body- Calcium for muscle contraction
- Store calcium in bones- Osteoblasts (BUILD) deposit Ca++ in the bone - THICKENING AND REPAIRING
- Osteoblasts and Ca++ critical to healing of broken bones- Osteoclasts destroy bone to liberate Ca++
Interaction of Bones and Muscles- Bone → Bone = Ligament- Muscle → Bone = Tendon
Muscles- Antagonistic Pairs - muscles shorten, other muscles help pull because you can’t push
musclesThe Sarcomere
- Z line - Proteins come together- Myosin, thick with heads- Actin, thin helix, binding sites- Muscle contraction
- Z-lines get closer- Sliding filament theory- Interaction of actin and myosin depends on ATP- ATP necessary for contraction or relaxation of the muscle
Contraction of a Sarcomere 1. Impulse from a neuron (motor unit) → 2. Change in muscle cell membrane → 3. Calcium released into muscle cell (sarcoplasmic reticulum)4. Ca++ causes troponin + tropomyosin to move off the actin binding sites5. ATP attaches to myosin head → let go of actin binding sites6. ATP hydrolyzes + gives energy to myosin heads → 7. Shape change8. Myosin heads attach to actin binding sites
9. Shape change “POWER STROKE” pulls on actin10. Actin slides, moves Z lines closer together = CONTRACTION OF A SARCOMERE- Strength of contraction depends on number of motor units (neurons) activated and
number of sarcomeres activated- Not enough calcium, muscle won’t retract - Impulses from motor units increase in frequency and numbers to recruit more
sarcomeres - Too frequent = sustained (tetanic) contraction = no time to
relax → tetanus
NeuronsOrganization of the Nervous System
- 2 anatomical divisions- Central nervous system- Brain, spinal cord, process info- Peripheral nervous system- Deliver info to and from central
- 2 functional divisions- Sensory input- Collecting info- Motor output- Deliver info for action
- Somatic nervous system- Autonomic nervous system
- Parasympathetic- Calming, rest, digestion- Sympathetic- Fight or flight response
Components of Nervous System- Sensory neurons
- Collect info- Eyesight, skin, hearing
- Interneurons- Process info (integrate)- Brain, spinal cord
- Motor neurons- Action- Muscles that you can physically move
Components of a Neuron- ALWAYS travels in same direction- Dendrites- Receive info- Nerve cell body- Process info- Axon- Deliver info for action- Synaptic Knobs- Communicate with next cell
- Neurotransmitter- chemicals of communicationMyelin Aids Conduction
- Myelin sheath = fat layer- Keep signal in the axon → faster- Jump over nodes of ranvier
Neuron at Rest
- -70mV = Resting potential (ALWAYS neg)- Charge across membrane keeps nerve “readied”
- -40mV = threshold potential- Depolarization → repolarization = action potential
- Info going through axon- Neurons firing
- Stimulus → change in membrane → opens port and positive charges- Rest between firing = refractory period- Action potential is ALL OR NOTHING (hit -40 = action potential)- Control is by NUMBER of neurons firing or SPEED of firing
Synapse is key for neuron to neuron communication- Electrical synapse
- Rapid, one-to-one passing of an impulse- Really close together, pass action potential
- Chemical synapse- Uses neurotransmitter- Can recruit more neurons- Modulation of speed
Chemical Synapse- Common Neurotransmitters:
- Serotonin- well being, inhibitory- Dopamine- motor control, inhibitory- Norepinephrine- fight/flight, excitatory- Acetylcholine- motor neurons, excitatory- Anandamide- cannabinoid receptors
Modes of Drug Action- Agonist
- Increase effectiveness of neurotransmitter- Mimic - Inhibit breakdown - Inhibit reuptake (leave in synaptic gap)
- Antagonist- Decrease effectiveness of neurotransmitter- Block synthesis - Block packaging- Block release- Block binding sites
BloodPurpose of Blood
- Transport dissolved substances- Carry oxygen to cells for metabolism- Transport immune cells throughout body- Regulate body temp.
- Protect against vessel rupture- Regulate pH and water balance
Blood Components- 45% = Red Blood Cells
- Transport oxygen- No nucleus
Bags of hemoglobin- Less than 1% =
- White blood cells - Immune function- Entire cells
- Platelets- Clotting- Cell fragments
- 55% = Plasma- Extracellular matrix- 92% water- Proteins- Transporting
Formed Elements (cells or cell parts)- Flat bones → spongy → red marrow → blood stem cells- RBC = erythrocyte - WBC = leukocytes
- Immune system- Fight pathogens
- Platelets = Thrombocytes- Clotting- Cell fragments
How RBCs function- Shape = surface area- No nucleus, no organelles- Limited life span, replaced about 30 days- Full of hemoglobin
- Each hemoglobin = 4 oxygenErythropoietin (EPO) and Blood Doping
- Increases RBCs- Increases oxygen carrying capacity
Blood Types- ABO blood grouping and RH factors
- Proteins on surface of blood cells- How we type?
- Clumps/clotting = reaction, meaning the proteins are present- No reaction, no proteins present
Clotting Cascade
- Multiple steps = control- Platelets and clotting factors- Several steps of protein activation- Fibrin = contractile protein = sticky
- catch platelets + red blood cells = clotClots Go Bad
- DVT - Deep Vein Thrombosis - Clot break off and go to small vessels
- Pulmonary Embolism- Blood clot in lung
- Stroke- Heart attack
Cardiovascular System
Heart Parts- Body → Heart → Lungs → Heart → Body
deoxygenated pick up oxygen oxygenated- Arteris = AWAY- Veins = TO- BODY (right side, deoxygenated blood)
- Inferior and superior vena cava → right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary arteries → LUNGS
- LUNGS (left ride, oxygenated blood)- Pulmonary veins → left atrium → bicuspid or mitral valve → left
ventricle → aortic semilunar valve → aorta → BODYCLOSED system
- 3 Basic Layers of Vessels- Inner = Smooth/Slick- Muscle = Resist pressure from heart- Outer = Connective tissue, adds strength
- Artery- ALWAYS AWAY from heart- Under pressure- High velocity- Lots of muscle
- Arteriole- Smaller arteries- Under pressure- Higher velocity- Thinner- Resistance
- Capillary- Business- Exchange between blood and tissues- Walls = 1 cell thick- Low pressure
- Venule- Low pressure- Low velocity- Valves- Rely on skeletal muscle to get blood back to the heart
- Vein- ALWAYS GO to heart- Large returning vessels- Have valves
Blood Pressure- Systolic (contraction of heart)- Diastolic (relaxation of heart)- Usually 120/80
Cardiac Control- Heart Rhythm- Heart muscle can initiate its own contraction- Electrical impulses from nervous system alter rate of contraction- SA Node = regulatory center
Sinoatrial node = pacemaker of heart- SA → AV → Bundle of His → Purkinje Fibers
ECG (Electronic Cardiogram)- P Wave
- Atria depolarize → Contract- QRS Complex
- Ventricles depolarize → spike → contract- T Wave
- Repolarizes → Rest
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