Anatomy and Physiology final exam notes

Tissues and Organization of the Body

What are the 4 main types of tissue?

  1. Epithelial Tissue: Connects body surfaces and lines cavities and organs

  2. Connective tissue: Supports, binds together, and protects tissues and organs

  3. Muscle Tissue: Responsible for movement; includes skeletal, cardiac, and smooth muscle

  4. Nervous Tissue: composed of neurons and supporting cells, involved in transmission of impulses

What is the difference between cells, tissues, organs, and organs systems?

  • Cells are the smallest living units of the body. They perform basic functions needed for life.

  • Tissues are groups of similar cells working together to do a specific job.

  • Organs are structures made of different tissues working together for a larger function.
    Example: the heart, lungs, and stomach.

  • Organ systems are groups of organs that work together to carry out major body functions.
    Example: the digestive system or circulatory system.

  • Cells → Tissues → Organs → Organ Systems → The Whole body

What is homeostasis and why is it important?

Homeostasis is the body’s ability to keep internal conditions stable and balanced, even when the outside environment changes.

Examples include keeping:

  • body temperature steady,

  • blood sugar at normal levels,

  • water balance stable,

  • and proper oxygen levels.

Integumentary System

What are the functions of the integumentary system?

The integumentary system includes the skin, hair, nails, and glands. Its main functions are:

  1. Protection – Shields the body from injury, germs, and harmful UV rays.

  2. Temperature regulation – Helps control body temperature through sweating and blood flow.

  3. Sensation – Contains nerve receptors that detect touch, pain, pressure, and temperature.

  4. Prevents water loss – Keeps the body from drying out.

  5. Vitamin D production – The skin helps produce vitamin D when exposed to sunlight.

  6. Excretion – Sweat removes small amounts of waste products like salts and water.

What are the main layers of the skin?

The skin has three main layers, each with different functions:

  1. Epidermis (outer layer)

    • The thinnest layer

    • Acts as a protective barrier against germs, water loss, and damage

    • Contains cells that produce keratin (a tough protein) and melanin (gives skin color and protects from UV rays)

  2. Dermis (middle layer)

    • Thicker layer beneath the epidermis

    • Contains blood vessels, nerves, sweat glands, hair follicles, and oil glands

    • Provides strength, flexibility, and supports skin functions like sensation and temperature control

  3. Hypodermis (subcutaneous layer)

    • Deepest layer, made mostly of fat and connective tissue

    • Insulates the body, stores energy, and cushions internal organs

What structures are found in the skin?

  • Hair follicles – small sacs in the dermis where hair grows; they help with protection and sensation.

  • Hair shafts – the visible part of hair that helps protect the body and regulate temperature.

  • Sweat glands – produce sweat to cool the body and remove small amounts of waste.

  • Sebaceous (oil) glands – produce oil (sebum) that keeps skin and hair soft and helps prevent drying and infection.

  • Blood vessels – deliver oxygen and nutrients to skin cells and help regulate body temperature.

  • Nerve endings (receptors) – detect touch, pressure, pain, heat, and cold.

  • Arrector pili muscles – tiny muscles that make hair stand up (goosebumps).

Skeletal System

What are the functions of the skeletal system?

  • Support – gives the body its shape and structure

  • Protection – shields organs (skull protects brain, ribs protect heart and lungs)

  • Movement – works with muscles to allow motion

  • Blood cell production – bone marrow makes red and white blood cells

  • Mineral storage – stores calcium and phosphorus for the body

  • Energy storage – yellow bone marrow stores fat

What are the major bones of the body?

  • Skull – protects the brain

  • Mandible – lower jaw bone

  • Vertebral column (spine) – supports the body and protects the spinal cord

  • Rib cage (ribs & sternum) – protects the heart and lungs

  • Clavicle (collarbone) and scapula (shoulder blade) – connect arms to the body

  • Humerus – upper arm bone

  • Radius and ulna – forearm bones

  • Pelvis (hip bones) – supports upper body weight

  • Femur – thigh bone (strongest bone in the body)

  • Patella – kneecap

  • Tibia and fibula – lower leg bones

What are the different types of joints

  • Immovable (fibrous) joints – do not move

    • Example: skull sutures

  • Slightly movable (cartilaginous) joints – limited movement

    • Example: joints between vertebrae

  • Freely movable (synovial) joints – most movement in the body
    Common types include:

    • Hinge joints – move in one direction (elbow, knee)

    • Ball-and-socket joints – move in all directions (shoulder, hip)

    • Pivot joints – allow rotation (neck)

    • Gliding joints – bones slide past each other (wrist, ankle)

    • Saddle joints – allow movement in two directions (thumb)

Compact bone vs. Spongey bone

Compact bone

  • Dense and hard outer layer of bone

  • Makes bones strong and able to support weight

  • Contains tightly packed structures called osteons (Haversian systems)

  • Found mostly on the outer surface of all bones (especially long bones like the femur)

Spongy bone (cancellous bone)

  • Lighter, porous, and has a honeycomb-like structure

  • Found inside bones, especially at the ends of long bones and in flat bones

  • Reduces bone weight while still providing strength

  • Contains spaces that often hold bone marrow

Bone Marrow

Bone marrow is the soft tissue inside certain bones, and it has two main types:

  • Red bone marrow

    • Produces blood cells (red blood cells, white blood cells, and platelets)

    • Important for oxygen transport, immunity, and clotting

  • Yellow bone marrow

    • Stores fat (energy reserve)

    • Can convert to red marrow if the body needs more blood cell production

Muscular system

Function

The muscular system helps the body:

  • Move

  • Maintain posture and body position

  • Produce heat to help regulate body temperature

  • Support internal organs (like helping move food through the digestive system)

  • Stabilize joints to prevent injury

Muscle tissue

  • Skeletal muscle

    • Attached to bones

    • Voluntary (you control it)

    • Used for movement like walking or lifting

  • Smooth muscle

    • Found in organs (stomach, intestines, blood vessels)

    • Involuntary (works automatically)

    • Moves substances through organs

  • Cardiac muscle

    • Found only in the heart

    • Involuntary

    • Contracts continuously to pump blood

How do muscles work together?

Agonist (prime mover)

  • The muscle that does most of the work to create a movement

  • It contracts (shortens) to produce the action

  • Example: When you bend your arm, the biceps is the agonist

Antagonist

  • The muscle that opposes or reverses the movement

  • It relaxes or lengthens while the agonist contracts

  • Example: When you bend your arm, the triceps is the antagonist

Role of tendons

  • Tendons are strong connective tissues that attach muscles to bones

  • They transfer the force from muscle contraction to the bone so movement can happen

  • They also help stabilize joints

Muscle contraction

  • Muscle contraction is when a muscle shortens and becomes tighter to produce force and movement. It happens when muscle cells receive a signal from the nervous system.

Sliding Filament Model

  • Muscles are made of tiny fibers containing actin (thin filaments) and myosin (thick filaments)

  • During contraction:

    1. Myosin heads attach to actin

    2. They “pull” the actin inward

    3. The filaments slide past each other

    4. The muscle fiber shortens