Overview of the Human Body Systems

integumentary system

•Includes skin, hair, and nails
•Barrier against infection and injury
•Regulates body temperature
•Removes waste from the body
•Protection from UV light

Skin layers

epidermis, dermis, subcutaneous

epidermis

-Outer layer, mostly dead cells
-Cells make keratin protein
-Melanocytes make melanin - skin pigment

keratin protein

Long, coiled polypeptide chains, the type of protein that makes up your hair, skin, and nails

Melanocytes

a mature melanin-forming cell, typically in the skin.

Dermis

-Inner layer
-Contains blood vessels, nerve endings, glands, smooth muscles, hair follicles
-Regulates body temperature - sweat glands
-Sebaceous glands - make sebum (oil)

Sebaceous glands

secrete sebum (oil) into the hair follicles where the hair shafts pass through the dermis

Subcutaneous layer

hypodermis
-Contains mostly fat (adipose cells, connective tissue)

Hair and Nails

Appendages of the skin that are composed of strong protein called keratin

Hair

-Protects scalp from UV light
-Prevent particles from entering the body (nose, ear, eyes)

Nails

-Protects fingertips
-Contain a lot of keratin
-Grow from nail root

The Skeletal System

•Supports the body
•Protects internal organs
•Provides movement
•Stores minerals
•Site of blood cell formation

axial skeleton

Portion of the skeletal system that consists of the skull, rib cage, and "vertebrae"

appendicular skeleton

bones of the shoulder, pelvis, hips, arms and legs, and upper and lower extremities

Structure of Bones

contains living cells and protein fibers, surrounded by deposits of calcium and phosphorus salts

Osteocytes

mature bone cells

Osteoblasts

bone forming cells

Osteoclasts

break down bone

Haversian canals

contain blood vessels and nerves

Bone marrow

red marrow inside the bone that produces blood cells

Periosteum

tough layer of connective tissue, dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles.

Ossification

process of bone formation

cartilage

strong connective tissue that supports the body and is softer and more flexible than bone

ossifies

Most bone \_____ from cartilage
turns into bone

Joints

•Where two bones meet
•Classified by range of motion allowed
-Immovable (sutures in skull)
-Slightly movable (vertebrae)
-Freely movable
•Structure
- Ligaments
- Bursae

Joints Structure

ligaments and bursae

immovable joints

joint that allows little or no movement
ex. sutures in skull

Slightly movable

amphiarthrosis
ex. vertebrae

Freely movable

•Ball and socket (hip, shoulder)
•Hinge (elbow)
•Pivot (neck)
•Saddle (thumbs)

Ball and socket

shoulder and hip

Hinge

elbow and knee

Pivot

neck

Saddle

thumb

Ligaments

connective tissue that hold bones together

Bursae

small sacs with synovial fluid (lubricates joint)

Muscular System

Allows manipulation of the environment, locomotion, and facial expression. Maintains posture, and produces heat.

types of muscle tissue

skeletal, cardiac, smooth

skeletal muscle tissue

attached to bones
•voluntary and striated
•tendons- connective tissue that join muscles to bones

tendons

connective tissue that join muscles to bones

cardiac muscle tissue

specialized muscle tissue found only in the heart
•involuntary and striated

smooth muscle tissue

Involuntary muscle is found in the intestines where it pushes food along the digestive tract. Also found in arteries and veins.
-hollow organs (blood vessels, stomach)
•involuntary and nonstriated

Muscle Contraction

•Components:
-Sarcomere -
-Thick filaments
-Thin filaments
•A muscle contracts when thin filaments slide over the thick filaments (shortens the sarcomere)
•ATP is required

sarcomere

Contractile unit of muscle

thick filaments

composed of myosin

Thin filaments

actin

Digestive System

•Food passes through, is broken down, and nutrients are absorbed
•Digestion begins in the mouth

mechanical digestion

Physical breakdown of large pieces of food into smaller pieces, chewing

chemical digestion

Process by which enzymes break down food into small molecules that the body can use

Saliva contains amylase - breaks down carbohydrates

amylase

enzyme that breaks down starch

Bolus

A term used to describe food after it has been chewed and mixed with saliva travels down esophagus to stomach

peristalsis

Involuntary waves of muscle contraction of the smooth muscle in esophagus that keep food moving along in one direction through the digestive system from the bolus to stomach

Cardiac sphincter

closes esophagus once food has reached the stomach

Stomach

large muscular sac that continues the mechanical and chemical digestion of food

HCI

acid

pepsin

digests proteins

chyme

Partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach.

Mechanical digestion - churns food and fluids to produce\_____

Digestion

stomach through small intestine

pyloric valve

Chyme is pushed through the \_________________ into the small intestine which adds enzymes maltase, sucrase, lactase (carbs) and peptidase (protein)

pyloric value

between stomach and small intestine; opens to release food after about two hours

small intestine

•The part of the digestive system in which most chemical digestion takes place
•Most absorption of nutrients occurs here.

villi

Tiny finger-shaped structures that cover the inner surface of the small intestine and provide a large surface area through which digested food is absorbed

Digestive system accessory organs

salivary glands, liver, gallbladder, pancreas

Pancreas

•behind stomach
-Produces insulin and glucagon which regulate blood sugar levels
-Produces enzymes that aid in digestion:
(lipase - lipids, trypsin - protein,
amylase - disaccharides);
added into small intestine
- Sodium bicarbonate to raise pH

Sodium bicarbonate

raise pH

Liver

•above stomach
-Makes bile which dissolves lipids (emulsifier - mechanical digestion)
-Bile is stored in the gallbladder

emulsifier

An ingredient that brings two normally incompatible materials together and binds them into a uniform and fairly stable blend.

Gallbladder

stores bile

bile

A substance produced by the liver that breaks up fat particles.

colon (large intestine)

removes water from undigested material

Bacteria

\________ present help make Vitamin K

rectum

A short tube at the end of the large intestine where waste material is compressed into a solid form before being eliminated

Waste material is left, passes through \________, then eliminated from the body

respiratory system

Brings oxygen into the body. Gets rid of carbon dioxide.

pharynx

Air from nose/mouth moves to \_______(throat) - passage for both air and food

Epiglottis

covers the entrance to the trachea when swallowing

Trachea

(windpipe) - carries air to chest cavity

Larynx

contains vocal cords

Bronchi

two large passageways that lead to lungs

Bronchioles

Airways in the lungs that lead from the bronchi to the alveoli, Bronchi subdivide into smaller branches

alveoli

•are found at the end of the bronchioles
-Gas exchange occurs here - blood and air are side by side

gas exchange

•Oxygen dissolves in the alveoli, then diffuses across capillaries into the blood
•Carbon dioxide diffuses in the opposite direction

Breathing

movement of air into and out of the lungs

Diaphragm

-At the bottom of the pleural cavity
-Contracts - pulls down; causes rib cage to rise and expands volume of chest cavity when inhaling
-Relaxes - moves back up; pressure in the chest cavity is greater - air is forced out of the lungs - exhaling

pleural cavity

contains the lungs, the bottom is the diaphragm

contracts

pulls down; causes rib cage to rise and expands volume of chest cavity when inhaling

relaxes

moves back up; pressure in the chest cavity is greater - air is forced out of the lungs - exhaling

medulla oblogata

contains autonomic centers, which regulate blood pressure and respiratory rhythm, as well as coughing and sneezing centers in the brain
-Monitors carbon dioxide in blood

Circulatory System

•Transportation system of the body
•Heart

Parts of the heart

-Myocardium - thick layer of muscle
•Septum - separates right and left side of the heart
-Atria - Upper chambers that receive blood
Ventricles - Lower chambers that pump bloo

Myocardium

-thick layer of muscle
•Septum - separates right and left side of the heart

Septum

Divides the right and left chambers of the heart

Atria

upper chambers of the heart

ventricles

Lower chambers of the heart

circulation

pulmonary circulation- flow of blood from heart to the lungs and back, right side of heart pumps it

systemic circulation- flow of blood from heart to body and back, left side of heart pumps

Valves prevent back flow of blood

pulmonary circulation

-Right side of the heart pumps blood from heart to lungs
-Oxygen poor blood goes to pick up oxygen in the lungs

systemic circulation

-Left side of the heart pumps blood from the heart to the rest of the body
-Sends oxygen rich blood to the rest of the body

oxygen poor

In pulmonary circulation, \_________ \_________ blood goes to pick up oxygen in the lungs

oxygen rich

In systemic circulation sends \_________ \_______blood to the rest of the body

heartbeat

the ability to pump blood effectively throughout the body

pacemaker

special cells in the heart that set the pace by starting the wave of muscle contraction through the heart

systole and diastole

systole (contraction) and diastole (relaxation)