Anatomy final review
contraction of skeletal muscle
-Muscle fiber contraction is "all or none" -Within a skeletal muscle, not all fibers may be stimulated during the same interval -Different combinations of muscle fiber contractions may give differing responses -Depolarisation and calcium ion release -Actin and myosin cross-bridge formation -Sliding mechanism of actin and myosin filaments
Epiglottis
A flap of tissue that seals off the windpipe and prevents food from entering.
motor unit
A motor neuron and all of the muscle fibers it innervates
skeletal muscle
A muscle that is attached to the bones of the skeleton and provides the force that moves the bones.
what is needed for contraction
ATP and calcium
Sutures
Areas where the cranial bones have joined together
appendicular skeleton
Bones of the limbs and limb girdles that are attached to the axial skeleton
role of CO2 and pH in breathing
CO2 is transported in the bloodstream to the lungs where it is ultimately removed from the body through exhalation. CO2 plays various roles in the human body including regulation of blood pH, respiratory drive, and affinity of hemoglobin for oxygen (O2)
Divisions of the Nervous System
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
tendons
Connect muscle to bone
pyloric sphincter
Controls passage of food from stomach to small intestine
gas transport for CO2
During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs. This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli
physiology of exhalation
Exhalation is a passive process because of the elastic properties of the lungs. During forced exhalation, internal intercostal muscles which lower the rib cage and decrease thoracic volume while the abdominal muscles push up on the diaphragm which causes the thoracic cavity to contract
Fontanels
Gaps between a baby's skull that slowly close up during the first 18 months of life
Peristalsis
Involuntary waves of muscle contraction keep food moving along in one direction through the digestive system.
smooth tissue
Involuntary, no striations, uninucleated. Spindle-shaped cells found in the walls of hollow structures.
Cardiac Tissue
Involuntary, straited and branched muscles, circulates, in heart
mechanical digestion
Physical breakdown of large pieces of food into smaller pieces
axial skeleton
Portion of the skeletal system that consists of the skull, rib cage, and vertebral column
chemical digestion
Process by which enzymes break down food into small molecules that the body can use
how is breathing affected at high altitudes
The air at higher altitudes is colder, less dense, and contains fewer oxygen molecules. This means that you need to take more breaths in order to get the same amount of oxygen as you would at lower altitudes. The higher the elevation, the pressure is lower making your breathing difficult
resting potential
The difference in electric charge between the inside and outside of a neuron's cell membrane
pepsinogen
The inactive form of pepsin that is first secreted by specialized (chief) cells located in gastric pits of the stomach.
Hyperpolarization
The movement of the membrane potential of a cell away from rest potential in a more negative direction.
Depolarization
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.
pepsinogen and hydrochloric acid interaction
When pepsinogen and hydrochloric acid exist together in the gastric juice, pepsin takes its active form. Through the actions of pepsin and the squeezing properties of the stomach, the food bolus enters the intestines as a liquidy mixture of partially digested food particles, called chyme
how is breathing affected during exercise
When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide. To cope with this extra demand, your breathing has to increase from about 15 times a minute when you are resting, up to about 40-60 times a minute
physiology of inhalation
When you inhale, the diaphragm and muscles between your ribs contract, creating a negative pressure—or vacuum inside your chest cavity. The negative pressure draws the air that you breathe into your lungs
multipolar neuron
a nerve cell that has many dendrites and a single axon
action potential
a neural impulse; a brief electrical charge that travels down an axon
Reuptake
a neurotransmitter's reabsorption by the sending neuron
Central Nervous System (CNS)
brain and spinal cord
digestive system function
breaks down food, absorbs nutrients and removes waste (mechanical and chemical)
Fascicles
bundles of muscle fibers
systemic capillaries
capillaries in all the body tissues where gas exchange occurs internally (internal respiration)
Neuroglia
cells that support and protect neurons
Neurotransmitters
chemical messengers that cross the synaptic gaps between neurons
Parts of a long bone
diaphysis, epiphyses, metaphyses, articular cartilage, periosteum, medullary cavity, endosteum
Neurotransmitter function
diffuse across synaptic cleft and bind to receptor proteins embedded in the membrane of a post synaptic cell
alimentary canal
digestive tube that extends from the mouth to the anus
example of reuptake
dopamine
characteristics of muscle
excitability, contractility, extensibility, elasticity
unipolar neurons
have a short single process leaving the cell body
skeletal tissue
makes up the bones of the body
Path of food through the digestive system
mouth, pharynx, esophagus, esophageal sphincter, stomach, pyloric sphincter, small intestine, cecum large intestine, rectum, anus
parts of the pharynx
nasopharynx, oropharynx, laryngopharynx
bipolar neurons
one axon and one dendrite
cell types in bone
osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts
Structures of the respiratory tree
pharynx, epiglottis, larynx, trachea, bronchi, bronchioles, alveoli
neuromuscular junction
point of contact between a motor neuron and a skeletal muscle cell
Ossification
process of bone formation
surfactant in alveoli
reduces surface tension and prevents each alveolus from collapsing during respiration
accessory glands
salivary glands, pancreas, liver, gallbladder
Muscle Fiber Structure
sarcolemma, sarcoplasm, sarcoplasmic reticulum
Nerons
send and receive messages from various parts of the cell body
muscle tissue types
skeletal, cardiac, smooth
uvula
soft tissue hanging from the middle of the soft palate
hydrochloric acid
substance produced by the stomach; necessary for digestion of food
Function of skeletal system
support, protection, movement, storage, blood cell production
pulmonary capillaries
surround the thin tissue membranes of the alveoli; site of gas exchange in blood
threshold
the level of stimulation required to trigger a neural impulse
gas transport
the process of carrying gases from the alveoli to the systemic tissues and vice versa
Peripheral Nervous System (PNS)
the sensory and motor neurons that connect the CNS to the rest of the body
upper/lower esophageal sphincters
thickened smooth muscle bands preventing bolus/stomach contents from moving superiorly
3 steps of gas exchange
ventilation, diffusion, perfusion
sarcomere structure
•Z-lines: define the boundaries of each sarcomere •M-line: located in the middle of the sarcomere •I-band: contains only thin filaments •H-zone: consists of only thick filaments •A-band: contains the thick filaments in their entirety