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