Human Anatomy

lecture 1
Dr Bilal Houshaymi

bhoushaymi@gmail.com
Subdivisions of Anatomy

a) Microscopic Anatomy

(1) Cytology (study of cells)

(2) Histology (microscopic study of cells)

b) Gross Anatomy
(1) regional anatomy
(2) systemic anatomy
(3) surface anatomy

c) Other Branches of Anatomy

(1) Neuroanatomy, Developmental anatomy, Pathology
Levels of
structural
organization of
the human
Gross Anatomy
A.Hierarchy of Structural Organization (Fig 1.4)
B.Anatomical Position (Fig 1.4)
1.“left” and “right” – important!
C.Organ Systems
1.Integumentary (Fig 1.6a)
2.Skeletal (Fig 1.6b)
3.Muscular (Fig 1.6c)
4.Nervous (Fig 1.6d)
5.Endocrine (Fig 1.6e)
6.Cardiovascular (Fig 1.6f)
7.Lymphatic (Fig 1.6g)
8.Respiratory (Fig 1.6h)
9.Digestive (Fig 1.6i)
10.Urinary (Fig 1.6j)
11.Reproductive ♂ (Fig 1.6k)
12.Reproductive ♀ (Fig 1.6l)
D.Regional Terms (Fig 1.8a, Fig 1.8b)
E.Abdominal Regions and Quadrants (Fig 1.9)
F.Directional Terms (Fig 1.10a, Fig 1.10b)
1.Superior / inferior
2.Anterior (ventral) / Posterior (dorsal)
3.Medial / lateral
4.Intermediate
5.Proximal / distal
6.Superficial / deep
G.Body Planes and Sections (Figs 1.11a, 1.11b)
1.Sagittal, Frontal, Transverse, Oblique planes
1.Section views (Fig 1.12)
H.Body Cavities and Membranes (Fig 1.14a-c, 1.14d)
1.Dorsal Body Cavity
2.Ventral Body Cavity
a)Thoracic, Abdominal, Pelvic Cavities
b)Membranes in Ventral Body Cavity
3.Serous cavities: pericardial, pleural & peritoneal
1.Other Cavities: oral, nasal, orbital, middle ear, synovial
ANATOMICAL POSITION, DIRECTIONAL TERMS, PLANES AND BODY
CAVITIES STRUCTURAL PLAN OF THE HUMAN BODY:

 Humans are BILATERALLY SYMMETRICAL; in other words, the right and

left sides of the body are mirror images of each other.

 The human body's organization is a TUBE-WITHIN-A-TUBE construction.

The outer tube is the body wall. The inside tube is the gastrointestinal
(digestive) tract, which passes through the body from the mouth to the anus.

 Humans have a VERTEBRAL COLUMN (backbone) and a CRANIUM

(braincase). These characteristics put humans in the category of
VERTEBRATES. Vertebrates include fish, amphibians, reptiles, birds, and
mammals.
.
ANATOMICAL POSITION:

 The anatomical reference point is a standard body position called the

ANATOMICAL POSITION. Always assume that the body is in the anatomical
position when describing where body parts are located.

 In the anatomical position, the body is standing upright, facing the observer.
The feet are flat on the floor. The arms are hanging at the sides of the body.
The palms face forward and the thumbs are pointed away from the body.

The man facing you in FIG. 1.5 is in the anatomical position.

DIRECTIONAL TERMS: (FIG. 1.5 and 1.6)

1. SUPERIOR: toward the head or the upper part of the body or structure; "above".
Example: The nose is superior to the chin.

2. INFERIOR: toward the lower part of the body or structure; "below". Example: The
mouth is inferior to the nose.

3. ANTERIOR (VENTRAL): toward or at the front of the body; "in front of". Example: The
breastbone is anterior to the spine.

4. POSTERIOR (DORSAL): toward or at the back of the body; "behind". Example: The
heart is posterior to the breastbone.

5. MEDIAL: toward or at the midline of the body or structure. (The midline is an imaginary
vertical line that divides the body into equal right and left sides.) Example: The heart is
medial to the lungs.

6. LATERAL: away from the midline of the body or structure. Example: The eyes are lateral
to the bridge of the nose.
DIRECTIONAL TERMS: (FIG. 1.5 and 1.6)

7. IPSILATERAL: on the same side of the body. Example: The left arm & left leg are
ipsilateral.

8. CONTRALATERAL: on the opposite side of the body. Example: The left arm & right
leg are contralateral.

9. PROXIMAL: closer to the point of attachment of a limb to the body trunk. Example:
The elbow is proximal to the hand.

10. DISTAL: farther from the point of attachment of a limb to the body trunk.
Example: The knee is distal to the thigh.

11. SUPERFICIAL: toward or at the body surface. Example: The skin is superficial to
the skeleton.

12. DEEP: away from the body surface; more internal. Example: The lungs are deep to
the ribs.
PLANES AND SECTIONS:

The study of anatomy often involves dissection, in which the body or its organs are
SECTIONED (cut) along an imaginary flat surface called a PLANE. A SECTION is the
exposed flat surface that results from the cut made through the body or organ.
The most frequently used planes are the:
1. SAGITTAL, FRONTAL and TRANSVERSE planes. These planes lie at right angles to
each other.
See FIGS. 1.7 and 1.8 for examples of planes and sections:
1. A SAGITTAL PLANE is a vertical plane that divides the body or organ into right and
left portions. A cut along a sagittal plane produces a SAGITTAL SECTION (a
MIDSAGITTAL SECTION or a PARASAGITTAL SECTION ).
A. A MIDSAGITTAL PLANE is exactly at the midline of the body or organ, and
divides the body or organ into equal right and left sides.

B. A vertical plane that divides the body or organ into unequal right and left
sides is a PARASAGITTAL PLANE.

2. A vertical plane that divides the body or organ into anterior and posterior portions is a
FRONTAL (CORONAL) PLANE. A cut made along a frontal plane produces a FRONTAL
SECTION.

3. A TRANSVERSE (HORIZONTAL) PLANE runs parallel to the ground and divides the
body into superior and inferior portions. A cut made along a horizontal plane produces a
TRANSVERSE (HORIZONTAL) SECTION. The transverse section is also sometimes called
a CROSS-SECTION.
BODY CAVITIES

Spaces within the body that contain internal organs are called BODY CAVITIES.
See FIG. 1.9
The two principal body cavities are the DORSAL and VENTRAL body cavities.
1. The DORSAL BODY CAVITY is located near the posterior surface of the body. It is
further subdivided into a CRANIAL CAVITY and a VERTEBRAL CANAL.
A. The CRANIAL CAVITY is a bony cavity formed by the skull. It contains the brain.
B. The VERTEBRAL CANAL is also called the SPINAL CANAL. It is a bony cavity formed by
the vertebrae of the backbone. It contains the spinal cord. Since the spinal cord emerges
from the brain, the cranial and vertebral cavities are continuous with one another.
2. The VENTRAL BODY CAVITY is located in the anterior part of the body. The ventral body
cavity walls are made of skin, connective tissue, bone, and muscles. The organs inside the
ventral body cavity are called the VISCERA.
The ventral body cavity is further subdivided into the THORACIC and ABDOMINOPELVIC
CAVITIES by the DIAPHRAGM, a large, dome-shaped muscle used in breathing.
A. The THORACIC CAVITY (FIG. 1.10) is surrounded by the ribs and muscles of the
chest. It is further subdivided into the two PLEURAL CAVITIES and the MEDIASTINUM.
Each PLEURAL CAVITY contains one lung. The MEDIASTINUM is medial to the pleural
cavities. The mediastinum is not a cavity. It is defined as a region or mass of tissue that
extends from the breastbone (sternum) to the vertebral column. The mediastinum contains
the PERICARDIAL CAVITY, which encloses the heart. The mediastinum also
contains other thoracic organs and structures (for example: the thymus, aorta and
esophagus).
B. The ABDOMINOPELVIC CAVITY (FIG. 1.11) is inferior to the thoracic
cavity and the diaphragm. The abdominopelvic cavity is subdivided into
two portions, which are not separated by any physical partition.

•The superior portion is the ABDOMINAL CAVITY, which contains the

stomach, small intestine, part of the large intestine, spleen, liver, gall
bladder, and pancreas.

•The inferior part is the PELVIC CAVITY, which contains the urinary
bladder, the internal male and female reproductive organs, and the lower
part of the large intestine.
ABDOMINOPELVIC CAVITY REGIONS - FIG. 1.12

1. The UMBILICAL REGION is deep to and surrounding the navel.

2. The EPIGASTRIC REGION is superior to the umbilical region.

3. The HYPOGASTRIC (pubic) REGION is inferior to the umbilical region.

4. The RIGHT and LEFT HYPOCHONDRIAC REGIONS are lateral to the

epigastric region.

5. The RIGHT and LEFT LUMBAR REGIONS are lateral to the umbilical
region.

6. The RIGHT and LEFT ILIAC (inguinal) REGIONS are lateral to the
hypogastric region.
SEROUS MEMBRANE (FIG. 1.10)

The walls of the VENTRAL BODY CAVITY and the outer surfaces of the
organs inside it are covered with an extremely thin tissue membrane called the
SEROSA or SEROUS MEMBRANE.

The serous membrane is an EPITHELIAL TISSUE MEMBRANE.

The serous membrane in the pleural (lung) cavity is called PLEURA.

The serous membrane in the pericardial (heart) cavity is called

PERICARDIUM.

The serous membrane in the abdominopelvic cavity is called PERITONEUM.

The part of the serous membrane that lines the ventral body cavity walls is
called the PARIETAL SEROSA. The parietal serosa is continuous with the
VISCERAL SEROSA, which covers the organs (VISCERA) within the cavity.

The POTENTIAL SPACE between the parietal and visceral serosa contains a
thin lubricating fluid, called SEROUS FLUID, which reduces friction between
organs within the body cavity.