Introduction to the Bodies
Cavities
Medical Biology-Unit 3
ALL students will be able to…
 Write a ½-1 page summary
describing the major cavities of the
body that includes the major organs
in the cavities and which systems
they are a part of.
Body Cavities
Ventral(Front)
Thoracic
(Chest)
Pleural
Lungs
Abdomiopelvic
(Belly)
Abdominal
stomach, intestines
liver, pancreas, spleen
Pericardial
heart
Dorsal(Back)
Cranial
(Head)
brain
Vertebral Canal
(Spine)
spinal cord
Pelvic
urinary bladder,
rectum, reproductive organs
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Cranial
cavity:
contains brain
Vertebral
cavity:
Thoracic
cavity:
contains heart,
lungs, and
esophagus
Dorsal
cavity
contains
spinal cord
diaphragm
Abdominal
cavity:
Ventral
cavity
contains stomach,
liver, spleen,
pancreas,
gallbladder,
and intestines
Pelvic
cavity:
contains
reproductive
and other
organs
a.
plurae
pericardium
Thoracic cavity:
contains esophagus,
heart, and lungs
Abdominal cavity:
peritoneum
Pelvic cavity:
contains reproductive
and other organs
b.
contains digestive
and other organs
Organization of Body Cavities
 The organs of the body are
surrounded by membranes.
 These thin tissues similar to plastic bags
serve as protective barriers for the
organs.
 Each organ is “double bagged”
 The parietal membrane is lining the wall of
the cavity
 The visceral membrane is lining the organ
itself
Dorsal Cavity
 The spinal cord and brain are
contained within their own
membranes to prevent infectious
agents from entering the body’s
control center
 “Spinal Taps” are necessary to determine
chemical nature of spinal fluid
Ventral Cavity
 The diaphragm separates the thoracic
from the abdominopelvic cavities.
 At times, due to pressure, a breakage
in the abdominal cavities wall causes
a portion of the visceral
organs(usually the intestines) to poke
out of the cavity. This is called a
hernia.
Tissues are groups of cells with a
common structure and function.
Tissues are classified into four main
categories: epithelial tissue, connective
tissue, nervous tissue, and muscle
tissue.
Epithelial Tissue
Outside of body and lines organs and
cavities; held together by tight
junctions
Epithelial Descriptions:






Squamous=flat
Cuboidal=cube shape
Columnar=column shape
Simple= 1 layer
Stratified= many layers
Pseudostratified= looks like a few
layers, but actually only one.
What is it?
Connective Tissue
 The major types of connective tissues in
vertebrates are dense (fibrous) tissue,
loose connective tissue, adipose tissue,
fibrous connective tissue, cartilage, bone,
and blood.
Each has a
structure
correlated
with its
specialized
function.
Muscle Tissue
 Muscle cells or fibers capable of
contracting when stimulated by nerve
impulses
 Long multi-nucleated cells
 3 types of Muscular tissue:
 Skeletal: voluntary movement
(striated)
 Cardiac: contractile wall of heart
(branched striated)
 Smooth: involuntary activities (no
striations)
Nervous Tissue
 Senses stimuli and transmits signals from 1
part of the animal to another
 Nervous tissues are found in the brain, spinal
cord, and nerves.
2 types of cells:
 Neurons, or nerve cells, conduct nervous
impulses
 Neuroglia, Helper cells, support and nourish
the neurons.
What do You Remember?
 For each of the following slides, wait
for Mr. Smuts to ask you what the
tissue is before you answer.
Slide 1
Slide 2
Slide 3
Slide 4
Slide 5
Slide 6
Slide 7
Slide 8
Slide 9
Slide 10
Slide 11
Slide 12
Slide 13
Slide 14
Slide 15
Slide 16
Slide 17
Slide 18
11 Organ Systems
Nervous
Integumentary
Circulatory
System
System
Skeletal
Muscular
System
System
System
Top
(from left to
right)
- Respirator
y System
- Digestive
System
- Excretory
System
Bottom
(from left to
right)
- Endocrine
System
- Reproducti
ve System
- Immune
System
Nervous System
 Central Nervous
System (CNS)
 Brain
 Spinal Cord
 Peripheral Nervous
System (PNS)
 All other nerves
 Functions?
1. Recognizes and
responds to stimulus
Integumentary System
 Skin, hair, nails, etc.
 Functions?
 Protective barrier
1. Environment
2. Sunlight
Skeletal System


1.
2.
3.
4.
Bones, cartilage, etc.
Functions?
Structure
Support
Protection
Movement
Muscular System


1.
2.
3.
Muscles
Functions?
Movement
Circulates Blood
Helps with Digestion
Circulatory System
 Heart, blood
vessels
 Functions?
1. Supplies cells
with oxygen
and nutrients
2. Removes waste
Respiratory System
 Nose, trachea, lungs,
etc.
 Functions?
1. Provides oxygen
2. Removes carbon
dioxide
Digestive System
 Mouth, stomach,
intestines, etc.
 Accessory Organs
 Liver, Pancreas, Gall
Bladder
 Functions?
1. Converts food into
nutrients the cells
can use
2. Eliminates waste
Excretory System
 Kidneys,
bladder,
urethra, etc.
 Functions?
1. Eliminates
waste
Endocrine System
 Pituitary gland,
adrenals, pancreas,
etc.
 Functions?
1. Growth
2. Development
3. Metabolism
Reproductive System
 Male

Urethra, testes, etc.
 Female

Ovary, uterus, etc.
 Functions?
1. Produce
reproductive cells
2. Nurture and protect
developing embryo
(females only)
Immune System
 White blood cells,
lymph nodes, etc.
 Functions?
1. Protect from infection
2. Helps balance fluids