Human Body Systems and Anatomy Overview

Muscles

Deltoids

• Located on shoulders
• Composed of three parts:
  • Anterior fibers (front side)
  • Lateral fibers (top of shoulders)
  • Posterior fibers (back)

Pectorals

• Located on chest
• Two parts:
  • Pectoral minor (connected to ribs)
  • Pectoral major (enhances chest size)

Biceps

• Located on upper arm
• Helps lift heavy objects
• Two heads:
  • Long head (outside)
  • Short head (inside)

Triceps

• Located on back of arm
• Composed of three parts:
  • Lateral head
  • Long head
  • Medial head

Abdominals

• Consist of four muscles
• Include obliques:
  • Internal oblique (supports abdomen)
  • External oblique (aids side bends)

Gluteus Maximus

• Largest muscle in the human body
• Located at the rear end
• Provides upright posture and climbing ability

Quadriceps

• Located on the front of the thigh
• Composed of four muscles:
  • Rectus femoris
  • Vastus lateralis
  • Vastus intermedius
  • Vastus medialis

Hamstrings

• Located on the back of thigh
• Three muscles:
  • Biceps femoris (outer)
  • Semitendinosus (middle)
  • Semimembranosus (inner)

Gastrocnemius

• Part of the calf muscle
• Composed of medial and lateral heads

Human Body Systems

Nervous System

• Sends signals from and to the brain

Circulatory System

• Blood flow, carries oxygen and nutrients

Respiratory System

• Oxygen supply to cells

Immune System

• Fights diseases and infections

Digestive System

• Processes food, extracts nutrients

Skeletal System

• Made of bones, supported by connective tissue

Muscular System

• Composed of skeletal, smooth, and cardiac muscles

Skeletal Structure

Hand Bones

• 27 bones in total
• Distal, middle, and proximal phalanges
• Metacarpal bones at the back of the hand
• Carpal bones connect hand to arm

Spine

• Composed of vertebrae
• Cervical, thoracic, lumbar curves
• Intervertebral discs provide flexibility

Rib Cage

• Protects vital organs (heart, lungs)
• Made up of 24 ribs
• True, false, and floating ribs

Skin

Structure

• Three layers: Epidermis, Dermis, Hypodermis
• Protects body, controls temperature

Function

• Epidermis: Outer, waterproof layer
• Dermis: Contains blood vessels and glands
• Hypodermis: Stores fat, connects skin to muscles

Brain

Cerebrum

• Controls thinking, memory, and muscle movement

Cerebellum

• Coordinates balance and posture

Brain Stem

• Connects brain to spinal cord
• Controls basic life functions

Pineal Gland

• Produces melatonin
• Regulates sleep and wake cycles

Heart

body

• Four chambers: Right atrium, right ventricle, left atrium, left ventricle
• Circulates oxygenated blood to the body via aortic artery