BIO 101: Body Systems

Review of Nervous, Skeletal, Muscular Systems, and Special Senese, key functions, organs, and other related vocabulary terms

Nervous System

communication network that organizes and coordinates all the body’s functions

2 Divisions of the Nervous System

Central Nervous Systems (CNS) and Peripheral Nervous System (PNS)

Central Nervous System

made up of the brain and spinal cord where the brain communicates via electrical and chemical signals

Peripheral Nervous System

includes all the nerves that connect the CNS to the rest of the body and controls involuntary functions like heart rate, digestion, and breathing

2 Divisions of Peripheral Nervous System

Sympathetic Nervous System and Parasympathetic Nervous System

Sympathetic Nervous System

speeds up body’s functions, activates fight or flight response, affects smooth involuntary muscles

Parasympathetic Nervous System

slows down the body’s functions, promotes rest and digest activities, and reverses the effects of the sympathetic system

neuron

nerve cells that send messages all over body to allow you to carry out activities like breathing, walking, talking, etc.

sensory neurons

takes sensory information from environment and sends the signal to the brain

motor neuron

communicate information from brain to tissues and organs throughout the body, allowing for movement

interneuron

neurons that make up the majority of neurons in the body; they act as the “middle man”, transferring information between sensory and motor neurons which helps with learning, memory, and planning

stimulus

anything the body can detect by means of its receptors

sclera

outside, white tissue of eye and helps eye maintain shape

retina

converts light into electrical signals that are sent to the brain

iris

controls the amount of light entering the eye

ear

capable of receiving vibrations in the air and translating them into sounds

nose

olfactory organ at the top of the nasal cavity, chemoreceptors detect odors dissolved in mucus

tongue

taste buds contain chemoreceptors that are located on the tip, sides, and back, to help your taste things

skin

largest organ in the body; touch is administered through receptors in fingertips

5 Important Functions of Skin

1) protection

• acts as a barrier against bacteria

2) temperature control

• regulates body temperature which is important for blood circulation

3) absorption

• absorbs things through hair follicles and glands

4) perception

• works with nervous system to create the feeling of touch

5) excretion

• eliminates water, salt, and other waste products

3 Layers of Skin

epidermis, dermis, subcutaneous

Epidermis

top layer of skin that contains melanocytes (melanin)

Dermis

middle layer of skin that contains the blood vessels, nerves, glands, and hair follicles

Subcutaneous

bottom layer of skin which provides insulation and stores fat

4 Appendages of Skin

1) Sweat glands

• tiny coil tubes deep in the dermis and corkscrew tubules leading to the surface

2) Oil glands

• located in or near hair follicles over the entire skin surface besides palms or soles of feet

3) Hairs

• have a root that is located inside the follicle (shaft) that extends deep inside the dermal layer

4) Nails

• composed of hard keratin

Erythema

when skin is exposed to the sun for too long, causing it to become reddened because of dilation of superficial blood vessels

Skeletal System

consists of organs called bones that work to support the body and provide protection to the body’s vital organs

2 Sections of the Skeleton

axial skeleton and appendicular skeleton

Axial Skeleton

includes the spinal column, skull, and rib cage

Appendicular Skeleton

bones of the arms, hands, legs, feet, shoulders, and pelvis

Bone Structure

made up of 20% water, with the main minerals being calcium, phosphorus, magnesium, and collagen

Spinal Column

stack of vertebrae that supports the head and keeps the truck erect; protection for the spinal cord

Names for vertebrae in spinal column

cervical (neck), thoracic (chest), lumbar (back), sacral (posterior pelvic girdle), and coccygeal (tailbone)

Bones of the Ribcage

sternum (breast bone), clavicle (collar bone), scapula (shoulder blade), xiphoid (inferior portion of the sternum)

Long Bones

femur (thigh bone), tibia (shin bone), fibula

Bones of Hands and Feet

carpais (wrist bones), tarsals (ankle bones), metacarpais, metatarsais, phalanges (finger bones)

joint

the place where two or more bony parts join

ligament

strong flexible bands of connective tissue

Diarthoses or Synovial Joints

movable joints (elbow, knees)

Amphiarthrosis or Cartilaginous

partially movable joints (between the vertebrae)

Synarthrosis or Fibrous Joints

immovable joints (cranial structure)

Bone Healing Process

fracture —> callus (calcium accumulates) —> cartilage (5-6 weeks) —> bone (4-10 months)

Muscular System

muscles provide heat, ability to move, helps to keep body upright, and protective padding to shield delicate internal organs

Skeletal Muscle

muscle attached to bones to permit movement

Smooth Muscle

involuntary muscle found throughout the internal organs of the body, except for the heart

Myocardial Muscle

muscle found in the heart; the muscle contracts to produce a heartbeat

Skeletal Muscle Action

when muscles contract, they become shorter and thicker

Flexor

skeletal muscle that bends a joint

Abduction

muscles that contract to move extremities away from the body’s center line

Extensor

muscle that performs the action of straightening the joint (e.g. triceps)

Adduction

muscle towards the center line

Sphincters

ring-shaped smooth muscles in digestive track and blood vessels

Neck/Upper Back Sternocleidomastoid & Trapezius

holds head up and allows movement

Chest Pectoralis Major

main upper chest muscle

Intercoastal Muscles

under the pectoralis, assists with breathing

Diaphragm

key breathing muscle; aids in coughing, sneezing, and laughing

Back & Shoulder Latissimus Dorsi

extends and abduct arm

Back & Shoulder Deltoid

triangle shaped shoulder muscle that abducts arm

Gluteus Maximus

largest muscles in the buttocks, support much of the body’s weight and enables us to stand erect

Gluteus Medius

located at the back of the iliac crest and stretches downward toward the femur

Sartorius

front of thigh which is the longest muscle in the body

Quadriceps Femoris

makes up the bulk of the anterior of the thigh

Tibialis Anterior

the front of the leg

Hamstring

the posterior of the thigh; function is to flex the knee by pulling insertion at the fibula and tibia