blg 101

Anatomy

is the study of:

• The structure of the body

• The parts of the body

• Where body parts are located

• How body structures relate to one another

examples

• Where is the heart located?

• What does the heart look like?

• What bones make up the arm?

• What tissues make up the stomach?

physiology

is the study of:

• How body parts work

• How organs perform their functions

• How the body carries out life-sustaining activities

Examples:

• How does the heart pump blood?

• How do muscles contract?

• How do kidneys produce urine?

• How does the nervous system transmit signals?

why are anatomy and physiology inseparable

bc structure determines function

Example: Teeth 🦷

Incisors

• Sharp edges

• Designed for cutting food

Molars

• Flat surfaces

• Designed for grinding food

Gross anatomy (macroscopic)

It studies structures that can be seen with the naked eye.

Examples:

• Heart

• Lungs

• Kidneys

• Bones

• Muscles

approaches to gross anatomy (3)

1. regional anatomy - studies everything in one specific region at the same time.

   • Example:

   Studying the abdomen would include:

   • Muscles

   • Blood vessels

   • Nerves

   • Organs

   • Bones

2. systemic anatomy

• studies the body one organ system at a time.

  Example:

  Studying the cardiovascular system means studying:

  • Heart

  • Blood vessels

  • Their locations throughout the body

3. surface anatomy

• studies internal structures in relation to the body's surface.

For example, nurses use knowledge of surface anatomy to locate:

• Blood vessels

• Pulses

• Muscles

• Other structures beneath the skin

microscopic anatomy

Studies structures that are too small to see with the naked eye.

Usually requires a microscope.

2 subdivisions

subdivisions of microscopic anatomy (2)

• Cytology

Study of cells

• Histology

Study of tissues

developmental anatomy

Studies how body structures change throughout life.

Embryology

A subdivision of developmental anatomy.

Studies structural changes that occur before birth.

Pathological anatomy

Studies structural changes caused by disease.

Example:

• Changes in lung tissue caused by disease

Radiographic anatomy

Studies internal structures using:

• X-rays

• CT scans

• Other imaging techniques

cardiovascular physiology

Studies:

• Heart function

• Blood vessel function

• Blood circulation

Renal physiology

Studies:

• Kidney function

• Urine production

Neurophysiology

Studies:

• Nervous system function

Muscle physiology

Studies:

Muscle contraction

Muscle function

principle of complementarity

structure determines function

Examples

Bones

• Hard mineralized structure

• → Can support and protect organs

Heart valves

• Open in one direction

• → Allow blood to flow one way and prevent backflow

Incisors

• Sharp

• → Cut food

Molars

• Flat

• → Grind food

what is the order of structural organization

Chemical → Cellular → Tissue → Organ → Organ System → Organismal

chemical level:

• Atoms

• Molecules

Atoms combine to form molecules.

Examples:

• Oxygen

• Carbon

• Water

• Proteins

cell level

cells are made from molecules and are the smallest living units.

Examples:

• Muscle cell

• Nerve cell

• Red blood cell

tissue level

A tissue is a group of similar cells working together to perform a common function.

epithelial - Covers body surfaces, Lines body cavities, Forms protective barrier

• skin surface, lining of organs

muscle - produces movements, muscles contract

connective - provides support, protection, connection

• bone

• blood

• cartiliage

• fat

nervous - allows rapid communication, uses eletrical impulses to transmit info

organ level

An organ is a structure made of at least two different tissue types that performs a specific function.

• heart, stomach, brain

Example: Stomach

The stomach contains multiple tissues:

Epithelial tissue
→ produces digestive juices

Muscle tissue
→ churns food

Connective tissue
→ strengthens the stomach wall

Nervous tissue
→ helps regulate activity

organ system level

multiple organs work together to accomplish a common purpose.

Example:

Cardiovascular system

Heart + blood vessels

Together:

→ circulate blood

organismal level

The entire human being.

All organ systems work together to keep the person alive.

organ systems (11)

1. Integumentary System

2. skeletal

3. muscular

4. nervous

5. endocrine

6. cardio

7. lymphatic/immune

8. respiratory

9. digestive

10. urinary

11. reproductive

integumentary System

Main structures:

• Skin

• Hair

• Nails

• Sweat glands

• Oil glands

Functions:

• Protects body

• Prevents injury

• Prevents excessive water loss

• Helps regulate temperature

• Produces vitamin D

• Contains sensory receptors

skeletal system

Structures:

• Bones

• Joints

Functions:

• Supports body

• Protects organs

• Provides framework for movement

• Stores minerals

• Produces blood cells in bone marrow

muscular system

Structures:

• Skeletal muscles

Functions:

• Movement

• Locomotion

• Facial expressions

• Maintains posture

• Produces heat

nervous system

Structures:

• Brain

• Spinal cord

• Nerves

Function:

fast control and communication

It responds to:

• Internal changes

• External changes

And activates:

• Muscles

• Glands

endocrine system

Structures include:

• Pituitary gland

• Thyroid gland

• Adrenal glands

• Pancreas

• Ovaries

• Testes

Function:

Produces hormones.

Hormones regulate:

• Growth

• Reproduction

• Metabolism

• Other body processes

cardio system

structures:

• Heart

• Blood vessels

• Blood

Functions:

• Transports oxygen

• Transports nutrients

• Transports hormones

• Carries carbon dioxide

• Carries wastes

• Circulates blood

lymphatic/immune system

Structures:

• Lymphatic vessels

• Lymph nodes

• Spleen

• Thymus

• Lymphocytes

Functions:

• Returns leaked fluid to blood

• Helps remove debris

• Provides immune defense

• Houses immune cells

respiratory system

structures:

• Nose/nasal cavity

• Pharynx

• Larynx

• Trachea

• Bronchi

• Lungs

Functions:

brings o2 in and removes co2

digestive system

Structures:

• Mouth

• Esophagus

• Stomach

• Small intestine

• Large intestine

• Rectum

• Anus

• Liver

• Pancreas

Functions:

• Breaks down food

• Absorbs nutrients

• Eliminates indigestible material as feces

urinary system

Structures:

• Kidneys

• Ureters

• Urinary bladder

• Urethra

Functions:

• Removes nitrogenous wastes

• Produces urine

• Regulates water

• Regulates electrolytes

• Helps regulate acid-base balance

reproductive system

Male

• Testes

• Ductus deferens

• Penis

• Prostate

• Scrotum

Functions:

• Produces sperm

• Produces male sex hormones

• Helps deliver sperm

Female

• Ovaries

• Uterine tubes

• Uterus

• Vagina

• Mammary glands

Functions:

• Produces eggs

• Produces female sex hormones

• Provides site for fertilization

• Supports fetal development

• Produces milk

requirements for life (8)

body must perform certain necessary life functions to stay alive.

1. Maintaining boundaries

2. Movement

3. Responsiveness

4. Digestion

5. Metabolism

6. Excretion

7. Reproduction

8. Growth

maintaining boundaries

The body must separate its internal environment from the outside world.

At the cellular level:

The plasma membrane separates:

Intracellular fluid
from

Extracellular fluid

movement

includes:

Whole-body movement

• Running

• Swimming

• Walking

Moving substances internally

• Blood

• Food

• Urine

Cellular movement

Muscle cells shorten. - Contractility

responsiveness

ability to detect a change and respond to it

The change is called a:

Stimulus

Example:

You touch something painful.

→ Receptors detect pain
→ Nervous system responds
→ Hand pulls away

This is a withdrawal reflex.

digestion

breaks food down into smaller molecules that can be absorbed

The digestive system breaks down food.

Then nutrients enter the blood.

The cardiovascular system distributes them to cells.

Metabolism

= all chemical reactions occurring inside body cells.

Catabolism

Breaks larger substances into smaller ones.

anabolism

Builds larger/complex substances from smaller ones.

cellular respiration

Cells use nutrients + oxygen to produce: ATP

ATP

is an energy-rich molecule used to power cellular activities.

excretion

= removal of waste from the body.

Examples:

Urinary system

Removes:

• Urea

• Nitrogenous wastes

Respiratory system

Removes:

• Carbon dioxide

Digestive system

Removes:

• Indigestible food as feces

reproduction

Cellular reproduction

A cell divides:

1 cell → 2 daughter cells

Important for:

• Growth

• Repair

Organismal reproduction

Produces a new human.

Sperm + egg → fertilized egg → developing baby

growth

increase in size.

Usually happens because: number of cells increase

But individual cells can also become larger.

survival needs (5)

1. Nutrients - chemicals for energy and cell building (macro)

2. Oxygen - essential for the release of energy from food

3. Water - Most abundant molecule in body; provides the watery environment needed for chemical reactions

4. Normal body temperature - If body temp falls below or goes above 37°C, rates of chemical reactions are affected

5. Appropriate atmospheric pressure - Specific air pressure is needed for adequate breathing and gas exchange in lungs

homeostasis

maintenance of relatively stable internal conditions despite changes in the external environment.

dynamic equilibrium - The body constantly adjusts conditions within a relatively narrow range.

law of mass balance

for a substance to remain relatively constant: amount entering = amount leaving

why is homeostasis important

our cells require a relatively stable environment.

The body must regulate things such as:

• Temperature

• Blood pressure

• Blood glucose

• Oxygen

• Carbon dioxide

• Water

• Electrolytes

• Nutrients

If these become severely abnormal:

→ cells stop functioning properly
→ disease can occur
→ potentially death

receptor

Detects a change.

eg. Temperature receptors detect that your body is getting too hot.

control center

Receives the information.

It:

• Compares the current value to the set point

• Determines what should happen

Set point: The desired level/range for a variable.

Example:

Body temperature has a normal target range.

effector

Carries out the response.

Examples:

• Sweat glands

• Muscles

• Glands

• Organs

afferent

carries information toward the control center

efferent

carries info away from the control center

negative feedback

reverses/reduces the original change

It moves the variable back toward its set point.

Pattern:

Stimulus → response → response reduces stimulus

Example: Body Temperature TOO HOT

Body temperature rises.

↓

Temperature receptors detect change.

↓

Information goes to brain.

↓

Brain activates sweat glands.

↓

Sweating occurs.

↓

Sweat evaporates.

↓

Body temperature decreases.

↓

Temperature returns toward normal.

positive feedback

amplifies the original stimulus

The response causes more of the same response.

Example: Childbirth 👶

Baby presses against cervix.

↓

Signals cause oxytocin release.

↓

Oxytocin increases uterine contractions.

↓

Stronger contractions increase stimulation.

↓

More oxytocin released.

↓

Even stronger contractions.

↓

Baby is born.

↓

Stimulus ends.

what does feedforward mean

The body responds before the change actually happens.

Anatomical Position

The standard reference position.

The person is:

• Standing upright

• Facing forward

• Feet slightly apart

• Arms at sides

• Palms facing forward

• Thumbs pointing away from body

superior (cranial)

toward the head.

Also means:

above

Example:

Head is superior to abdomen.

inferior (caudal)

Away from the head.

Also means:

below

Example:

Navel is inferior to chin.

anterior (ventral)

toward the front.

Example:

Breastbone is anterior to spine

posterior (dorsal)

Toward the back.

Example:

Heart is posterior to breastbone.

medial

Toward the midline.

Example:

Heart is medial to arm.

lateral

Away from the midline.

Example:

Arms are lateral to chest.

intermediate

Between a more medial and a more lateral structure.

Example:

The collarbone is intermediate between the breastbone and shoulder.

proximal

Closer to:

• The point of attachment of a limb

• The origin of a structure

Example:

Elbow is proximal to wrist.

distal

Farther from the point of attachment/origin.

Example:

Wrist is distal to elbow.

deep (internal)

farther from the body surface.

Example:

Muscles are deep to the skin.

superficial (external)

Superficial

Closer to the body's surface.

Example:

Skin is superficial to skeletal muscle.

what is a body planes and section

A plane is an imaginary flat surface along which the body can be sectioned.

A section is the actual cut made along a plane.

sagittal plane

Divides body into:

RIGHT + LEFT

Median/Midsagittal Plane

Divides body into:

Equal right and left portions

It passes exactly through the midline

Parasagittal Plane

Also divides: Right + left

But not equally.

It is off the midline.

Frontal / Coronal Plane

Divides body into:

ANTERIOR + POSTERIOR

Transverse Plane

Divides body into:

SUPERIOR + INFERIOR

Oblique Plane

Cuts the body:

Diagonally

Between vertical and horizontal planes.

body cavity

Body cavities protect internal organs.

dorsal body cavity

Contains the: Brain + spinal cord

It has two subdivisions:

Cranial cavity

Contains: Brain

Vertebral/spinal cavity

Contains: Spinal cord

These two cavities are continuous.

The brain and spinal cord are covered by: Meninges

ventral body cavity

The larger, more anterior cavity.

Contains many internal organs called: Viscera

It has two major subdivisions:

1. Thoracic cavity

2. Abdominopelvic cavity

thoracic cavity

Located in the chest.

Contains:

• Lungs

• Heart

• Other thoracic organs

It has:

Pleural cavities - One around each lung.

Mediastinum - Central area between the lungs. Contains many thoracic organs.

Within the mediastinum is the: Pericardial cavity which surrounds the heart.

Diaphragm

A dome-shaped muscle separating:

Thoracic cavity from Abdominopelvic cavity

It is very important for: Breathing

Abdominopelvic Cavity

Has two portions:

Abdominal cavity

Contains:

• Stomach

• Liver

• Spleen

• Intestines

• Other digestive organs

Pelvic cavity

Contains:

• Urinary bladder

• Some reproductive organs

• Rectum

Serous membranes

These are thin, double-layered membranes.

They produce: Serous fluid - which reduces friction.

Parietal serosa

Lines the: Cavity wall

Visceral serosa

Covers the: Organ

Abdominopelvic Quadrants

RUQ, LUQ, RLQ, LLQ

RUQ

• Liver

• Gallbladder

• Part of large intestine

• Small intestine

LUQ

• Stomach

• Spleen

• Liver (part)

• Intestine

RLQ

• Cecum

• Appendix

• Small intestine

LLQ

descending colon, sigmoid colon, left ureter, left ovary

what are elements

substances that cannot be broken down into simpler substances by
ordinary chemical methods

what 4 elements make up 96% of our body

carbon, o2, hydrogen, nitrogen

o2

component of organic and inorganic molecules

required as a gas for ATP production

carbon

fundamental component of all organic molecules including carbs, lipids, proteins, and nucleic acids

hydrogen

a constituent element in all organic molecules

nitrogen

a component of nucleic acids

calcium

found in bones and teeth

vital for muscle contraction, nerve impulse conduction and blood clotting