BIOL 140 Ch. 5-13

Bone functions

• Protects organs

• Stores minerals and fats

• Produces blood cells

• Provides muscle attachment

• Supports the body

Axial skeleton

Head and trunk (supports appendages)

Appendicular skeleton

Limbs

Compact bone

Dense, shaft of long bones

Spongey bone

Latticework; small flat bones like the skull

Fibrous joints

Fibrous, connective tissue; no joint cavity; mostly no movement

Cartilaginous joints

Cartilage holds bones together; some move and some don’t

Synovial joints

Most joints; freely moveable

Hinge joints

Motion in only one plane (ex. knee)

Ball and socket joints

Motion in all planes (ex. shoulder)

Flexion

Decreases the angle of a joint

Extension

Increases the angle of a joint

Adduction

Movement toward the midline

Abduction

Movement away from the midline

Circumduction

A wide circle

Rotation

Moving around its own axis (ex. turning your head)

Supination

Palm up

Pronation

Palm down

Sprain

Injury to a ligament

Bursitis

Inflammation of the bursae

Arthritis

Joint inflammation

Osteoarthritis

Degeneration of joint surfaces over time

Rhuematoid arthritis

Autoimmune condition that include inflammation of the synovial membrane

Three types of muscle

Skeletal, cardiac, smooth

Characteristics of muscles

• Excitable

• Contractile

• Elastic

• Extensible

Skeletal muscles are…

Voluntary

Smooth muscle is…

Involuntary

Cardiac muscle is…

Involuntary

Synergistic muscle

Muscles that must contract at the same time to cause movement

Antagonistic muscle

Movement is produced when one muscle of the pair contacts and the other relaxes

Tendon

Band of connective tissue that attached a muscle to a bone

Original of a muscle

The end of the muscle that is attached to the bone that remains relatively stationary during movement

Insertion of a muscle

The end of a muscle attached to the bone that moves

Fascicle

bundle of muscle cells

Myofibrils

Specialized bundles of proteins within the muscle cell

Myofilaments

Long protein filaments (actin and myosin)

Myosin

thick filament

Actin

thin filament

Sarcomere

Contractile unit of muscle

Sliding filament model

A muscle contracts when actin filaments slide past myosin filaments, shortening the sarcomere

Calcium ions are stored in…

Sarcoplasmic reticulum

Transverse tubules

Pockets in the plasma membrane of a muscle cell

Neuromuscular junction

Junction between the tip of a motor neuron and a skeletal muscle cell

Function of the nervous system

Integrate and coordinate the bodies’ activities

Central nervous system

Brain and spinal cord

Peripheral nervous system

Nervous tissue outside of the CNS

Neurons (nerve cells)

Excitable cells that generate and transmit messages

Neuroglial cells (glial cells)

Provide structural support, growth factors and insulating sheaths around axons (more numerous than neurons)

Sensory neurons

Carry information toward the central nervous system from sensory receptors

Motor neurons

Carry information away from the central nervous system to an effector (muscle or gland)

Interneurons

Found only in brain and spinal cord; between sensory and motor neurons; integrate and interpret sensory signals

Dendrites

Receive signals from other cells and carry information toward the cell body

Axon

Carries information away from the cell body to another neuron or an effector

Cell body

Maintains the neuron

Nerve

Consists of bundles of neurons with parallel axons, dendrites or both from many neurons

Myelin sheath

Provides electrical insulation that increases the rate of conduction of a nerve impulse

Schwann cells

Form myelin sheath

Saltatory conduction

Nerve impulse jumping from node of ranvier to the next

Nerve impulse (action potential)

An electrochemical signal involving sodium and potassium

Resting potential

Difference in voltage across cell membrane of the cell at rest

Threshold

Minimum charge that causes sodium gates to open

Depolarization

Reduction of the charge difference across the membrane (going up)

Repolarization

Restoration of the charge difference across the membrane (going down)

An action potential is?

All or nothing

Refractory period

The period following an action potential where the neuron can’t be stimulated again

Synapse

A junction between a neuron and another cell

Synaptic cleft

Gap between two cells

Synaptic knob

Swelling at the end of the axon of the presynaptic neuron

Summation

Combined effects of excitatory and inhibitory effects at any given moment

A meninge is formed by?

Dura mater, arachnoid, and pia meter

Blood brain barrier

Protects CNS by monitoring what goes in and out of the cerebrospinal fluid

Functions of cerebrospinal fluid

• Shock absorption

• Support

• Nourishment

• Waste removal

Cerebrum

Thinking, conscious part of the brain

Corpus callosum

Band of white matter that connects the two cerebral hemispheres

Gray matter

Outer layer, neuroglial cells, unmyelinated axons

White matter

Inner layer, myelinated axons

Four lobes of the brain

• Frontal Lobe

• Parietal Lobe

• Temporal Lobe

• Occipital Lobe

Primary somatosensory area

Receives sensory information from the body

Primary motor area

Controls skeletal muscles

Promotor complex

Coordinates learned motor skills

Prefrontal cortex

Enables us to reason and think

Thalamus

A relay station for the brain for all sensory information except smell

Hypothalamus

• Maintains homeostasis

• Coordinates nervous and endocrine systems

• Regulates emotions as part of the limbic system

Cerebellum

• Integrates information from the motor cortex and sensory pathways to produce voluntary movements

• Controls equilibrium and posture

Three parts of the brainstem

• Medulla oblongata

• Midbrain

• Pons

Medulla oblongata

The posterior part of the brain that controls the rate of breathing and other autonomic functions

Midbrain

Processes information about sights and sounds

Pons

Regulates breathing

What is the limbic system responsible for?

Emotions and memory

Spinal cord

Message transmission and reflex center

Reflex circuit

Receptor → Sensory Neuron → Interneuron → motor neuron → Effector

How many pairs of spinal nerves are there?

31 pairs

How many pairs of cranial nerves are there?

12 pairs

Sensation

The awareness of a stimulus

Perception

Conscious awareness of sensation

Sensory adaptation

Sensory receptors stop responding when continuously stimulated, leading to a decrease in the awareness of a stimulus

Mechanoreceptors

Respond to physical changes (touch, pressure, hearing, equilibrium)

Thermoreceptors

Respond to changes in temperature

Photoreceptors

Responds to changes in light intensity

Chemoreceptors

Responds to chemicals