Test 2 (Chapters 5-7) Flashcards
What are the 6 functions of bone?
- support
- protection
- movement
- blood cell formation
- mineral storage (calcium and phosphate)
- fat storage
What are the three types of connective tissue?
- bones
- ligaments
- cartilage
What is compact bone?
Forms the shaft and ends; contains marrow space
What is spongy bone?
Trabecular
What are the bone cells?
- osteoblasts
- osteocytes
- osteoclasts
What are the types of bone?
- long
- flat
- irregular
What does the osteon/Haversian system perform?
Cellular arrangement
What is the shaft called?
Diaphysis
What is the function of cartilage?
Support
What are the types of cartilage?
- fibrocartilage (spinal cord)
- Hyaline cartilage (connects ribs)
- elastic cartilage (ears)
What is the function of ligaments?
Attach bone to bone
What are ligaments made of?
Dense fibrous connective tissue
What do babies have in early fetal development in regards to bones?
Cartilage model of their bones (formed by chondroblasts/cartilage forming cells)
What occurs with bones in later fetal development?
Osteoblasts replace cartilage with bone
What happens with bones in childhood?
Primary and secondary ossification sites formed
What occurs with bones in adolescence?
Elongation at growth plates
What are hormones doing to bones in preadolescence?
Growth hormones stimulate bone lengthening
What are hormones doing to bones in early adolescence?
Estrogen and testosterone stimulate bone lengthening
What do hormones do to bones in late adolescence?
Estrogen and testosterone cause replacement of cartilage growth plates with bone
What are chondroblasts?
Cartilage forming cells
What are osteoblasts?
Young bone-forming cells
What are osteocytes?
Mature bone cells
What are osteoclasts?
Dissolving cells
Changes in shape, size, and strength of bone depend on what?
- diet
- exercise
- age
Bone cells are regulated by what hormones?
- parathyroid hormone (PTH): removes calcium from bone
- calcitonin: adds calcium to bone
How does a bone repair?
By a hematoma and callus formation
How many bones are in the human body?
206
What bones make up the appendicular skeleton?
- skull
- vertebral column
- sternum
What bones make up the axial skeleton?
- pectoral girdle
- pelvic girdle
- limbs
What are the C1 and C2 vertebrae called?
- C1: atlas
- C2: axis
What bones makes up the pectoral girdle (shoulder)?
- clavicle
- scapula
What bones makes up the pelvic girdle (hips)?
- coxal bones
- sacrum
- public symphysis
What bones make up the arms?
- humerus
- radius
- ulna
- wrist
- hand bones
What bones make up the legs?
- femur
- tibia
- fibula
- ankle
- foot bones
What are joints classified by?
Degree of movement
What are fibrous joints?
Immovable joints (fontanels)
What are cartilaginous joints?
Slightly moveable joints (cartilage connection: backbone)
What are synovial joints?
Freely moveable joints
What are joint capsules made of?
- synovial membrane
- hyaline cartilage
What does the synovial membrane secrete?
Synovial fluid
What does hyaline cartilage act as?
A cushion for bones
What are the types of synovial joints?
- hinge joint
- ball and socket joint
What are the functions of tendons?
Connect muscle to bone
What is a leg sprain?
Stretches or torn ligaments
What is bursitis and tendonitis?
Inflammation
What is arthritis?
Inflammation of the joints (osteoarthritis and rheumatoid arthritis)
What is osteoporosis?
Excessive bone loss
What is the principal function of muscle?
Contraction: shortens distance between bones (moves bones)
What are the two muscle groups?
- synergistic (work together)
- antagonistic (groups appose each other)
What are muscle fascicles?
Bundles of muscle fibers wrapped with connective tissue
How is muscle fibers described?
- long, tube shaped
- multinucleate
- packed with myofibrils
What do myofibrils contain?
- actin
- myosin
What is a sarcomere?
Contractive unit
What does myosin form?
Thick filaments
What does actin form?
Thin filaments
What are Z lines?
Attachment points for sarcomeres
What does the arrangement of filaments give rise to?
Striated appearance of skeletal muscle
Where is acetylcholine released from during muscle contraction?
It’s released from the motor neuron at the neuromuscular junction
Where are electrical impulses transmitted along during muscle contraction?
Transmitted along T tubules
Where is calcium released from during muscle contraction?
Sarcoplasmic reticulum
What is muscle contraction?
Formation of cross bridges between thin and thick filaments
What does calcium bind with during muscle contraction?
Troponin
What does troponin cause during muscle contraction?
The tropomyosin complex shifts position exposing myosin binding cites
What do the now exposed myosin heads form cross-bridges with?
Actin
What are the actin filaments pulled toward?
Center of the sarcomere
What occurs during muscle relaxation?
Nerve activation ends and contraction ends
During muscle relaxation what is pumped back into the SR?
Calcium
What happens during muscle relaxation after calcium is pumped back into the SR?
Calcium is removed from the troponin which then covers the myosin binding sites (no calcium=no cross bridge)
What is the principle source of energy?
ATP
What is ATP require for?
- muscle contraction
- muscle relaxation
How is ATP restored?
- creatine phosphate
- stored glycogen
- aerobic metabolism of glucose, fatty acids, and other high energy molecules
What happens in isotonic contractions?
- muscle shortens
- movement occurs
What happens in an isometric contraction?
- muscle does not shorten
- no movement
What influences force?
The degree of nerve activation
What is a motor unit (smallest functional unit of muscle contraction)?
The motor neurons and all the muscle cells it controls
What is muscle tension?
Mechanical force that muscles generate when they contract
What is muscle tension determined by?
- motor unit size
- number of active motor units
- frequency of stimulation
What is the all-or-none principal?
Individual muscle cells are always contracted or relaxed
What is muscle tone?
Whole muscles maintain intermediate level of force
What is recruitment?
Activation of additional motor units increases muscle tone
What is a muscle twitch?
A complete cycle of contraction and relaxation in response to stimulus
How can a muscle twitch be observed
By a myogram (lab recording of muscle activity)
What are the different periods of muscle twitch?
- latent period
- contraction
- relaxation
- summation
- tetanic contraction
What are the two types of muscle fibers?
- slow twitch: endurance, long duration contraction, contain myoglobin
- fast twitch: strength, white muscle, short duration contractions
What happens during strength training?
It is short and intense and builds fast-twitch myofibrils (resistance training)
What happens during aerobic training?
- builds endurance
- increases blood supply to muscle cells
How do cardiac and smooth muscle work?
- involuntary (can contract on their own without nerve stimulation)
- respond to stimulation from the autonomic nervous system (can modify degree of contraction)
What is the speed of the 3 muscles (cardiac, skeletal, and smooth)?
- skeletal: fastest
- cardiac: moderate
- smooth: very slow (partially contracted at all times; can never wear out)
How does cardiac muscle appear?
Striated because of the sarcomere arrangement of thick and thin filaments
How does smooth muscle appear?
No striations because the filaments are arranged in a criss-cross bundles (not sarcomeres)
What are common diseases and disorders of the muscular system?
- tetanus
- muscle cramps
- pulled muscles
- fasciitis
What are the functions of blood?
- transportation (nutrients, waste, hormones)
- regulation (temp, water volume, pH)
- defense (against infections and bleeding
What does plasma (55%) in the blood consist of?
- water
- proteins (albumins, globulins, clotting proteins)
- hormones
- nutrients and wastes
What do formed elements (45%) in the blood consist of?
- RBCs
- WBCs
- Platelets
What is the function of RBCs?
Transport oxygen and carbon dioxide
What is the measurement of RBCs?
- hematocrit
- hemoglobin
What is the origin of RBCs?
Stem cells in the bone marrow
What is the life span of RBCs?
120 days
What controls the production of RBCs?
Erythropoietin
What are the functions of WBCs?
- protection from infection
- regulation of inflammatory reaction
What are the two types of WBCs?
- Granular (neutrophils, eosinophils, and basophils)
- Agranular (lymphocytes and monocytes)
How are neutrophils described?
- 60% of circulating WBCs
- first on scene to fight infections by engulfing microorganisms
How are eosinophils described?
- 2 to 4% of circulating WBCs
- defends against large parasites (worms)
- moderate severity of allergic reactions
How are basophils described?
- 0.5% of circulating WBCs
- Histamine in granules (role in inflammation)
How are monocytes described?
- 5% of circulating WBCs
- leave the blood and transform into macrophages
How are lymphocytes described?
- 30% of circulating WBCs
- play large role in immune response
- two types (B and T)
What are platelets?
- small cell fragments derived from megaharyocytes
- Important role in hemostasis (blood clotting)
What are the three stages of hemostasis?
- vascular spasm
- platelet plug formation
- coagulation
What happens during the vascular spasm step in hemostasis?
Blood vessels constrict to reduce blood flow
What happens during the platelet plug formation step of hemostasis?
Ruptured blood vessel seals
What happens during the coagulation step of hemostasis?
Formation of a blood clot
- complicated series of reactions
- fibrinogen to fibrin
What do A and B antigens have?
Surface markers on RBCs
What are antibodies?
- immune system protein
- directed against antigens
What is anemia?
Reduction in oxygen-carrying capacity due to inadequate number of RBCs or inadequate hemoglobin
What is iron deficiency anemia?
Anemia caused by inadequate intake or malabsorption of dietary iron
What is hemorrhagic anemia?
Anemia caused by blood loss
What is pernicious anemia?
Anemia caused by a B12 deficiency
What is hemolytic anemia?
Anemia caused by the destruction of blood cells
What is Leukemia?
A type of cancer caused by proliferation of WBCs
What is multiple myeloma?
Form of cancer involving the proliferation of plasma cells in bone marrow
What is mononucleosis?
Contagious Epstein-Barr virus infection of lymphocytes
What is septicemia (blood poisoning)?
Bacteria proliferate in blood overwhelming the body’s defenses
What is thrombocytopenia?
- reduction in platelet number
- unusual bruising and bleeding
