Transcript skeleton - El Camino College

HUMAN BODY
•Climbing the walls? Spiderman is able to
climb walls
•The explanation:
1.Hairs (called setae) on gecko’s
toes contain split ends (called
spatulae)
2. ability to “stick” to surfaces from
attractions between molecules on
the spatulae and the surface on
which the gecko is crawling
– Correlation between structure and function
– Human structure has a hierarchy:
•
•
•
•
Cell
Tissues
Organs
Organ sytems
TISSUES
• groups of cells with a common structure and function
• Main types:
– Epithelial
– Connective
– Muscle
– Nervous
Epithelial tissue
• sheets of closely packed cells
• covers the body and lines the cavities and
tubes of internal organs
• Functions in protection, secretion, and
exchange
A Simple squamous epithelium
(lining the air sacs of the lung)
D Stratified squamous epithelium
(lining the esophagus)
B Simple cuboidal epithelium
(forming a tube in the kidney)
Layers of
dead cells
Rapidly dividing
epithelial cells
C Simple columnar epithelium
(lining the intestine)
E Stratified squamous epithelium
(human skin)
Connective tissue
• binds and supports other tissues
• various types
• characterized by sparse cells in an
extracellular gel matrix
Fat
droplets
Cartilageforming
cells
C. Adipose tissue
Matrix
Cell
nucleus
D. Cartilage
(at the end of a bone)
Collagen
fibers
Central
canal
B. Fibrous connective tissue
(forming a tendon)
Cell
Collagen
fiber
White blood
cells
Matrix
Red blood
cell
Boneforming
cells
E. Bone
Plasma
A. Loose connective tissue
(under the skin)
F.Blood
Muscle tissue
• functions in movement
• Types:
– Skeletal muscle is responsible for voluntary
body movements
– Cardiac muscle pumps blood
– Smooth muscle moves the walls of internal
organs such as the stomach
Unit of
muscle
contraction
Muscle
fiber
Muscl
e
fiber
Junction between
two cells
Nucleus
Nucleus
Muscle fiber
Nucleus
B Cardiac muscle
A Skeletal muscle
C Smooth muscle
Nervous tissue
• forms a communication network
• the branching neurons transmit nerve signals that
help control body activities
Cell body
Nucleus
LM 330
Cell extensions
• Artificial tissues have medical uses: can
assist in the healing of several injuries
ORGANS
– Each organ is made of several tissues
– collectively perform specific functions
Lumen
Small intestine
(cut open)
Lumen
Epithelial tissue
(columnar epithelium)
Connective tissue
Smooth muscle
tissue (2 layers)
Connective tissue
Epithelial tissue
ORGAN SYSTEMS
• Organ systems work together to perform life
functions
1. Digestive
2. Respiratory
3. Circulatory
4. Lymphatic
5. Immune
6. excretory
7. Endocrine
8. integumentary
9. Skeletal
10.Muscular
11.reproductive
– digestive and respiratory systems:
• gather food and oxygen
Nasal cavity
Larynx
Mouth
Trachea
Esophagus
Liver
Bronchus
Stomach
Lung
Small
intestine
Large
intestine
Anus
A Digestive system
B Respiratory system
– The circulatory system, aided by the lymphatic system
• Transports the food and oxygen
– The immune system
• Protects the body from infection and cancer
Bone
marrow
Heart
D Immune system
Thymus
Spleen
E Lymphatic system
Blood
vessels
C Circulatory system
Lymph
nodes
Lymph
vessels
– The excretory system
• Disposes of certain wastes
– The endocrine and nervous systems
• Control body functions
Pituitary gland
F Excretory system
Kidney
Thyroid gland
Thymus
Adrenal gland
Ureter
Urinary
bladder
Pancreas
Testis
(male)
Urethra
Ovary
(female)
G Endocrine system
– The integumentary system
• Covers and protects the body
– Skeletal and muscular systems
• Support and move the body
Hair
Cartilage
Skin
Nails
I Integumentary system
Skeletal
muscles
Bones
J Skeletal system
K Muscular system
– The reproductive system
• Perpetuates the species
Male
Female
Prostate
gland
Vas
deferens
Oviduct
Ovary
Urethra
Penis
Uterus
Vagina
Testis
L Reproductive systems
New imaging technology
• reveals the inner body without surgery
• X-rays: used for imaging bones and teeth
• MRI, Magnetic resonance imaging: visualization
of soft tissues
• MRM, Magnetic resonance microscopy: 3-D
images of very small structures
• CT, Computed tomography scans:
excellent diagnostic tools
• PET, Positron-emission tomography:
Yields information about metabolic
processes at specific locations in the body
Skull
SKELETON
Examples
of joints
1
Shoulder
girdle
Clavicle
Scapula
Sternum
• human skeleton: 206
bones
– axial skeleton:
• Skull
• Backbone
• rib cage
– appendicular skeleton:
Ribs
2
Humerus
3
Vertebra
Radius
Ulna
Pelvic
girdle
Carpals
Phalanges
Metacarpals
Femur
• bones of the arms and legsPatella
• and the joints where they Tibia
attach to the axial skeleton
Fibula
– pectoral or shoulder joint
– pelvic or hip joint
Tarsals
Metatarsals
Phalanges
– Movable joints
• Provide the human skeleton with flexibility
Head of
humerus
Humerus
Scapula
Ulna
Ulna
Radius
1 Ball-and-socket joint
2 Hinge joint
3 Pivot joint
• Bones are complex living
organs:
– Cartilage at the ends of
bones: Cushions the joints
- Bone cells, serviced by blood
vessels and nerves
• Live in a matrix of flexible
protein fibers and hard calcium
salts
– Long bones have a central
cavity: to store yellow bone
marrow, which is mostly
stored fat
– Spongy bone contains red
marrow: blood cells are
made
Cartilage
Spongy
bone
(red
bone
marrow)
Compact
bone
Central
cavity
Yellow
bone marrow
Fibrous
connective
tissue
Blood
vessels
Cartilage
• Broken bones can heal themselves: re
realigned and immobilized
– Artificial joints: often used to repair severe
injuries
• Weak, brittle bones are a serious health
problem, even in young people
• Osteoporosis, a bone disease
characterized by weak, porous bones
• dynamic bone
“remodeling”
model: going on
all the time:
– osteoblasts
deposit bone
– osteoclasts break
bone and release
calcium
– As a person ages,
the backbone and
other bones tend
to decline in mass;
excessive bone
loss is called
osteoporosis
•The skeleton and muscles interact in
movement:
Biceps contracted,
triceps relaxed
(extended)
Triceps
contracted,
biceps relaxed
Biceps
Triceps
Tendon
Biceps
Triceps
• Muscle cells are the
motors of the body
• contractible proteins
fibers, myofilaments
• with the proteins
actin and myosin
MUSCLES
Levels of Functional
Organization in a
Skeletal Muscle Fiber
Muscle Fascicle
Muscle Fiber
Myofibril
Sacromere
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
3 types:
• Smooth muscle: walls of blood vessels
and the gut
• Skeletal muscle: move the bones of the
skeleton
• Cardiac muscle: fibers that branch and
interconnect to form a network connected,
electrical impulses passes from cell to cell
causing the heart to contract in an orderly
fashion
• Skeletal muscles move
the bones
• Tendons: connective
tissue that attach muscles
to bone
• Muscle tone: Even at
rest, some of the
motor units of
muscles are always
contracting= resting
tension
• Athletic training increases strength and
endurance: causes increases in:
- number of mitochondria
- concentration of glycolytic enzymes
- glycogen reserves
- myofibrils
Types of sports
fast or white fibers:
• Large in diameter-densely
packed myofibrils
Slow or red fibers:
• Only 1/2 the diameter of
fast fibers
• Large glycogen reserves
• few mitochondria
• Takes 3 times longer to
contract after stimulation
• Can contract in 0.01 sec
following stimulation
• abundant mitochondria
• uses a lot of ATP
• uses anerobic glycolysis:
converts stored glycogen to lactic
acid
• fatigue rapidly because glycogen
reserves are limited and lactic
acid builds up
• Uses aerobic metabolism
• Has a more extensive
capillary network
• Red color due to red
pigment of myoglobin
• Muscles only pull because myofibrils contract:
– muscles in the joints are attached in opposing pairs
called flexors and extensors
– when contracted they move the bones in different
directions
• sliding filament model: muscular
contraction
– the head of a myosin filament binds to an
actin filament
– ATP is used to flex the myosin head
– when the muscle contracts, the myosin head
returns to its original shape and pulls the actin
it is attached to along with it