SAAT Biology Section 5.1 Vocabulary (Human Biology) - تحصيلي

Number of bones in the human adult body

206

Number of bones in the human baby body

Around 300

Axial skeleton

Includes the skull, the vertebral column, the ribs, and the sternum

Appendicular skeleton

Includes the bones of the shoulders, arms, hands, hips, legs, and feet

What the outer layers of all bones are composed of

Compact or dense bones

Tubelike structures that run through the compact bones

Osteons or haversian systems

Spongy bone

Less dense found in the center of short bones or flat bones and at the end of long bones (surrounded by compact bone and does not contain haversian systems)

Short bones

Such as wrist bones

Flat bones

Bones that make up the skull

Irregular bones

Facial bones and vertebrae

Two types of bone marrow

Red and yellow

Red bone marrow

Where the red and white blood cells and platelets are produced

Yellow bone marrow

Found in many other bones, consists of stored fat

Osteoblasts

Bone-forming cells and they are used for rebuilding and repair

Osteoclasts

Cells that break down bone cells which are then replaced by new bone; they work the first in injuries’ tissues

Osteoporosis

A condition that is caused by insufficient calcium or Vitamin D (results in weak and fragile bones; the body secrets endorphins to reduce the pain)

Ball-and-socket joints

The ball-like surface of one bone fits into a cuplike depression of another bone and allows the widest range of motion of any kind of joint

Ball-and-socket joints example

Hips and shoulders (allows a person to swing their arms and legs)

Pivot joints

Primary movement is rotation; where two bones of the lower arm, the radius, and ulna meet

Pivot joints example

Elbow joint (allows a person to twist their lower arm)

Hinge joints

Convex surface of one bone fits into the concave surface of another bone

Hinge joints example

Elbows and knees (allow back and forth movements)

Gliding joints

Allow side to side and back and forth movement

Gliding joints example

Wrists and ankles (the joints of vertebrae are included as well)

Sutures joints

Joints that are in the skull and unmoveable

Sutures joints example

All skull bones except the lower jaw bone

Muscule

Consists of groups of fibers or muscle cells that are bount together

Smooth muscles

Involuntary muscles because it cannot be controlled consciously (many hollow internal organs such as the stomach, intestines, bladder, and uterus are lined with this)

Cardiac muscle

Muscle cells that are arranged in a network, or web, that allows the heart muscle to contract (only present in the heart)

Skeletal muscle

Muscles attached to bones by tendons (voluntary muscles that are consciously controlled to move bones)

Skeletal muscle alignment

Antagonistic pairs

Myofibrils

Smaller units found in muscle fibers

Myosin

Even smaller units found in myofibrils which are protein fibers (includes actin)

Sarcomeres

The arrangement of myofibrils’ sections

ATP is necessary for

Muscule contraction (when the muscle relaxes, filaments return into their original positions)

All muscle cells metabolize

Aerobically and Anaerobically

Aerobically

Processes, organisms, or exercises that require, utilize, or occur in the presence of free oxygen

Anaerobically

Processes, organisms, or activities that occur in the absence of free oxygen

Cellecular respiration process provides

ATP for energy for the contraction and relaxation of muscles

Reliance on anaerobic process of lactic acid fermentation for energy

After a period of intense exercise, when muscles might not get enough oxygen to sustain aerobic respiration (causes fatigue and cramps)

Neurons conduct

Electrical impulses that allow cells, tissues, and organs to response to stimuli

Neurons

Specialized cells that help you gather information about your environment (interprets the information and reacts to it)

Dendrites

Recieve impulses from other neurons and conduct the impulses to the cell body

Axon

Carries the nerve impulse from the cell body to other neurons

Cell body

Where organelles of the neuron and many of the cell organelles are found

Sensory neurons

Send impulses from receptors in the skin and sense organs to the brain and spinal cord

Interneurons

What the sensory neurons signal (they are found in the spinal cord and brain and carry the impulse to motor neurons)

Motor neurons

Carries impulses from the brain and spinal cord to a gland or muscue (effector)

Nerve impulse

An electrical charge travelling along a neuron

Action potential

Another name for a nerve impulse

Threshold

The minimum stimulus to cause an action potential

When a neuron is at rest

There are more sodiumm ions (Na+) outside the cell than inside it

There are more potassium ions (K+)

Inside the cell than outside it

For every two potassium ions pumped into a neuron,

Three sodium ions are pumped out

Myelin

The covering of a lipid on an axon which forms an insulating layer (myelin sheath) that increases the speed of nerve impulses

Synapse

A small gap exists between the axon of one neuron and the dendrite of another neuron or muscle

Neurotransmitter

A chemical that diffuses across a synapse and binds to receptors on the dendrite of the neighboring neuron