Midterm!!!!!! Flashcards
anatomy
the study of structure and shape of the body and body parts and their relationships to one another
physiology
the study of how the body and its parts work or function
structural levels of organization in order
1) chemical level
2) cellular level
3) tissue level
4) organ level
5) organ system level
6) organism level
what is the chemical level
where atoms combine to form molecules such as water, sugar, and proteins
what is the cellular level
where the cells are made up of molecules. it is the smallest unit of living things.
what is the tissue level
where the tissues consist of similar types of cells
what is the organ level
where organs are made up of different types of tissues
what is the organ system level
where organ systems consist of different organs that work together closely
what is the organism level
where human organisms are made up of many organ systems
integumentary system overview
- the external covering of the body, or the skin
- waterproofs the body and cushions and protects deeper tissues from injury
- excretes salt and urea to help regulate temperature
- made up of skin, sweat/oil glands, hairs, and nails
skeletal system overview
- consists of bones, cartilages, ligaments, and joints
- supports the body and provides framework that the skeletal muscles use to cause movement
- has a protective function
- storehouse for minerals
hematopoiesis
formation of blood cells
muscular system overview
- they have only one function and it is to contract (or shorten) when this happens movement occurs
- made up of skeletal muscles
nervous system overview
- body’s fast-acting control system
- consists of the brain, spinal cord, nerves, and sensory receptors
- body must be able to respond to stimuli outside and inside of the body
endocrine system overview
- controls the bodies activities
- produces chemical molecules called hormones and release them into the blood
- includes the pituitary, thyroid, parathyroid, adrenals, thymus, pancreas, pineal, ovaries (in F) and testes (in M)
cardiovascular system overview
- consists of heart and blood vessels
- using blood as the transporting fluid it carries oxygen, nutrients, hormones, and other substances to and from the tissue cells where exchanges are made
- heart pumps blood throughout the body
lymphatic system overview
- includes lymphatic vessels, lymph nodes, and other lymphoid organs such as the spleen and tonsils
- vessels return fluid leaked from the blood to the blood vessels so that blood can be kept continuously circulating throughout the body
- help to cleanse the body and house the cells involved in immunity
respiratory system overview
- to keep the body supplied with oxygen and to remove carbon dioxide
- consists of nasal passages, pharynx, larynx, trachea, bronchi, and lungs
digestive system overview
- a tube that runs through the body from mouth to anus
- includes the oral cavity (mouth), esophagus, stomach, small intestine, large intestine, and rectum
- role is to break down food for dispersal to the body cells
- after the small intestine the role is to reclaim water
urinary system overview
- removes the nitrogen-containing wastes from the blood and flushes them from the body in urine
- composed of the kidneys, ureters, bladder, and urethra
- maintaining the bodies water and salt balance
- regulates the acid-base balance of the blood
what are the functional unit of life
cells
reproductive system overview
- exists to produce offspring
- sperm produces by the testes of the male
- other male structures: scrotum, penis, accessory glands, and the duct system
- ovary in the female produces eggs
- other female structures: uterine tubes, uterus, and vagina (uterus provides site of development for fetus)
homeostasis
-describes the body’s ability to maintain relatively stable internal conditions even though the outside world is continuously changing
negative feedback
neteffectofresponseistoshutofftheoriginalstimulusor reducetheintensity
Ex: bodytemp,heartrate,bloodpressure,breathingrate,
bloodlevelsofglucose,oxygen,carbondioxide,
minerals
-effects all of the organ systems
positive feeback
neteffectincreasestheoriginalstimulusandpushesthe variable fartherfromtheoriginalvalue
Ex.bloodclotting,labor
-effects all of the organ systems
positive/negative feedback order of elements pathway (pg 10)
step 1: stimulus: produces change in variable
step 2: change detected by receptor
step 3: input: information sent along afferent pathway to
step 4: output: information sent along efferent pathway to activate
step 5: response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
homeostaticimbalance
causesillness,diseaseordeath
anatomical position
bodyiserectwithfeetparallelandarms
hangingdownbysideswithpalmsfacingforward
superior (directional term)
toward the head end or upper part of a structure or the body; above
Inferior (directional term)
away from the head end or lower part of a structure or the body; below
anterior (directional term)
toward or at the front of the body; in front of
posterior (directional term)
toward or at the backside of the body; behind
medial (directional term)
toward or at the midline of the body; on the inner side of
lateral (directional term)
away from the midline of the body; on the outer side of
intermediate (directional term)
between a more medial and a more lateral structure
proximal (directional term)
close to the origin of the body part or the point of attachment of a limb to the body trunk
distal (directional term)
farther from the origin of a body part or the point of attachment of a limb to the body trunk
superficial (directional term)
toward or at the body surface
deep (directional term)
away from the body surface; more internal
directional terms
used by medical personal and anatomists allow them to explain exactly where one body structure is in relation to another
abdominal (body region)
- anterior body trunk
- inferior to ribs
acromial (body region)
- point of should
- anterior
antecubital (body region)
-anterior surface of elbow
axillary (body region)
- anterior
- armpit
brachial (body region)
- arm
- anterior
buccal (body region)
- cheek area
- anterior
carpal (body region)
- wrist
- anterior
cervical (body region)
- neck region
- anterior
coxal (body region)
- hip
- anterior
crural (body region)
- leg
- anterior
digital (body region)
- fingers, toes
- anterior
femoral (body region)
- thigh
- anterior
fibular (body region)
- lateral part of the leg
- anterior
inguinal (body region)
- area where thigh meets body truck; groin
- anterior
nasal (body region)
- nose area
- anterior
oral (body region)
- mouth
- anterior
orbital (body region)
- eye area
- anterior
patellar (body region)
- anterior knee
- anterior
pelvic (body region)
- area overlying the pelvis anteriorly
- anterior
pubic (body region)
- genital region
- anterior
sternal (body region)
- breastbone are
- anterior
tarsal (body region)
- ankle region
- anterior
thoracic (body region)
- chest
- anterior
umbilical (body region)
- navel
- anterior
cephalic (body region)
- head
- posterior
deltoid (body region)
- curve of the shoulder formed by large deltoid muscle
- posterior
gluteal (body region)
- buttock
- posterior
lumbar (body region)
- area of back between ribs and hips
- posterior
occipital (body region)
- posterior surface of head
- posterior
popliteal (body region)
- posterior knee area
- posterior
sacral (body region)
- area between hips
- posterior
scapular (body region)
- shoulder blade region
- posterior
sural (body region)
- area between hips
- posterior
vertebral (body region)
- area of spine
- posterior
section
cut
plane
when the section is made through the body wall or through an organ with an imaginary line
sagittal section
a cut made along the lengthwise, or longitudial, plane of the body, dividing the body into right and left parts
midsagittal (median) section
a cut fown the median plane of the body and the right and left parts are equal in size
frontal (coronal) section
a cut made along a lengthwise plane that divides the body or organ into anterior and posterior parts
transverse (cross) section
a cut made along a horizontal plane, dividing the body or organ into superior and inferior parts
dorsal body cavity (body cavity)
two subdivisions
- cranial cavity: space inside the bony skull
- spinal cavity: extends from the cranial cavity nearly to the end of the vertebral column
ventral body cavity (body cavity)
-contains all structures within the chest and abdomen
-subdivided:
~thoracic cavity
~diaphragm
~abdominopelvic cavity
-abdominal cavity
-pelvic cavity
thoracic cavity (body cavity)
- separated from the rest of the ventral cavity by the diaphragm
- contains the lungs, heart, and other organs protected by the rib cage
abdominopelvic cavity (body cavity)
subdivided into two:
- abdominal cavity (superior)
- pelvic cavity (inferior)
abdominal cavity (body cavity)
-contains the stomach, liver, intestines and other organs
pelvic cavity (body cavity)
-reproductive organs, bladder, and rectum
umbilical region (abdominal region)
-centermost region, deep to and surrounding the umbilicus (navel)
epigastric region (abdominal region)
-located superior to the umbilical region
hypogastric (pubic) region (abdominal region)
-inferior to the umbilical region
right and left iliac regions (abdominal region)
-lateral to the hypogastric region
right and left lumber regions (abdominal region)
-lie lateral to the umbilical region
right and left hypochondriac regions (abdominal region)
-flank the epigastric region and contain the lower ribs
what elements is the body mostly made of
- Oxygen (O): 65.0%
- Carbon (C): 18.5%
- Hydrogen (H): 9.5%
- Nitrogen (N): 3.2%
role of calcium in the body
- found as a salt in bones and teeth
- an ionic form required for muscle contraction, neural transmission, stregthen bones, and blood clotting
protons
- positive charge
- found in nucleus
neutron
- neutral charge
- found in nucleas
electron
- neutral charge
- found in orbitals outside nucleus
Magnetic Resonance Imaging (MRI)
- gives off magnetic field and radio waves to make a detailed image of organs/tissues
- magnets force protons to align in the field, radio frequency is pulsed
- used to find problems such as tumors, bleeding, etc… and can look at bones and joints, blood vessels, abdomen and pelvis, head, chest, etc…
X-Ray
- form of electromagnetic radiation
- travels throughout the body and is absorbed in different amounts in different tissues
- used when there is pain in an area of the body
- specifically for broken bones or sprains
Positron Emission Tomography Scan (PET Scan)
-injects patient with small amounts of radioactive substance, organs/tissues that pick it up need high amounts of energy (specifically tumors) and the 3D picture is formed
Ultrasonography
- small probe creates waves and can show direction of blood flow, sounds information on a baby in the uterus, etc…
- used for pain (swelling of organs), during surgeries, or for pregnancies
Computerized Tomography Scan (CT Scan)
- moves in a spiralized fashion and takes pictures while the patient is lying down
- look for things in the body that should not be there like tumors, to guide surgery, biopsy and radiation therapy, can detect cancer, etc…
Fluoroscopy
- person lies down and can get pictures with or without contrast
- multiple pictures taken in multiple places
- used for blood, lumbar puncture, digestive system, etc…
what is the plasma membrane
-a fragile, transparent barrier that contains the cell contents and separates them from the surrounding environment
what does the plasma membrane do
- defines the limits of the cell
- controls what goes in and out of the cell
what is the plasma membrane made up of
- consists of two lipid (fat) layers arranged “tail to tail” in which protein molecules float
- lipid portion are phospholipids
- polar heads of the phospholipids are hydrophilic (“water loving”) while the tails are hydrophobic
active transport
-the cell provides the metabolic energy (ATP) that drives the transport process
passive transport
substances are transported across the membrane without any energy input from the cell
diffusion
-the process by which molecules and ions tend to scatter themselves throughout the available space (passive transport)
osmosis
-diffusion of water through a selectively permeable membrane such as the plasma membrane (passive transport)
filtration
-the process by which water and solutes are forced through a membrane by fluid (hydrostatic) pressure (passive transport)
solute pumping
-requires protein carriers that combine reversibly with the substances to be transported across the membrane and ATP is used to energize its protein carriers called solute pumps (active transport)
exocytosis
-moves substances out of cells by packaging it in a vesicle(active transport)
endocytosis
-it takes up or engulfs extracellular substances by enclosing them into a small membranous vesicle (active transport)
phagocytosis
-a term that means “cell eating”. Certain white blood cells and other “professional” phagocytes of the body act as scavenger cells that police and protect the body by ingesting bacteria and other foreign debris as well as dead body cells
pinocytosis
-a term that means “cell drinking”. The plasma membrane invaginates to form a tiny pit and then its edges fuse around the droplet of fluid
four types of tissues
- epithelial tissue
- connective tissue
- muscle tissue
- nervous tissue
examples of epithelial tissue
- forms various glands in the body
- covering and lining all free body surfaces
- forms outer layer of the skin
- lines respiratory tract
- lines some digestive organs (stomach and small intestine)
- in the kidneys
function of epithelial tissue
- protection
- absorption
- filtration
- secretion
classification of epithelial tissue
two ways:
-first by the relative number of cell layers it has
~simple epithelium (one layer of cells)
~stratified epithelium (more than one cell layer)
-second describes the shape of the cells
~squamous cells (flattened)
~cuboidal (cube-shaped)
~columnar (column-shaped)
special characteristics of epithelial tissue
- cells fit closely together to form continuous sheets
- has an apical surface (the membrane always has one free surface or edge)
- has a basement membrane (a structureless material sereted by the cells)
- have no blood supply of their own (avascular)
- if well nourished they can regenerate easily
epithelial tissue
the lining, covering, and glandular tissue of the body
connective tissue
connects body parts
examples of connective tissue
- bone
- cartilage
- dense connective tissue
- loose connective tissue
- blood
function of connective tissue
connects body parts
characteristics of connective tissue
- variations in blood supply
- extracellular matrix
muscle tissues
-highly specialized to contract, or shorten, to produce movement
examples of muscle tissue (3)
- smooth muscle
- skeletal muscle
- cardiac muscle
skeletal muscle tissue
- attached to the skeleton
- voluntarily controlled
- striated
- multinuceate
cardiac muscle tissue
- found only in the heart
- it contracts=helping to pump blood
- striated
- uninucleate
- fit together with intercalated disks
- involuntarily controlled
smooth muscle tissue
- no striations
- single nucleus
- spindle shaped (pointed at both ends)
- involuntary
- found in digestive system, bladder, uterus, and blood vessels
function of muscle tissue
to contract and shorten to produce involuntary and voluntary movement
nervous tissue
neurons and supporting cells form the brain, spinal cord and nerves
examples of nervous tissue
neurons, supporting cells
function of nervous tissue
- to receive and conduct electrochemical impulses from one part of the body to another
- tissue repair
characteristics of the nervous tissue`
- irritability
- conductivity
main structure of epithelium tissue
- basement membrane and apical surface
- lies over connective tissue
main structure of connective tissue
-extracellular matrix
main structure of nervous tissue
-unique shape
-cytoplasm is drawn out into long extensions
~allowing a single neuron to conduct an impulse over long distances in the body
main structure of skeletal muscle tissue
- connect to bones
- long, cylindrical, with striations
main structure of cardiac muscle tissue
-striated branching cells that fit together with intercalated disks
main structure of smooth muscle
- no striations
- spindle shaped (pointed at each end)
where is epithelial tissue found
- forming various glands in the body
- outer layer of skin
- lines respiratory tract
- lines some digestive system organs
- in the kidneys
where is connective tissue found
- found everywhere in the body
- most abundant/widely distributed
where is muscle tissue found
- attached to the skeleton (skeletal)
- in the heart (skeleton)
- in the walls of hollow organs (smooth)
what tissue lines the oral cavity?
smooth muscle
endocrine gland
- one of the major glands developed from epithelial sheets
- lose their connection to the surface (duct); thus they are ca ductless glands.
- secretions diffuse directly into blood vessels that weave through the glands
- ex: thyroid, adrenals and pituitary gland
exocrine glands
- retain their ducts
- secretions empty through the ducts to the epithelial surface
- ex: sweat and oil glands, liver, and pancreas
what type of membrane is the skin
-epithelial cutaneous membrane
what does keratin do for the skin
it hardens and toughens the skin
what type of tissue is the skin made out of
- epidermis=epithelial tissue
- dermis=dense connective tissue
- hypodermis= adipose tissue
layers of the epidermis
-top: stratum corneum
stratum lucidum
stratum granulosum
stratum spinosum
-bottom: stratum basalewhy do we tan? what is the purpose of it?
we tan because the melanin in the skin is produce more when in the sun causing the skin to turn darker trying to protect your skin from the sun
how do nutrients get to the surface of the skin
-they are diffused from the dermis
what type of tissue is the epithelium
stratified squamous epithelium
what type of tissue of the hypodermis made of
adipose tissue
is the epidermis avascular or vascular
avascular (no blood supply)
is the dermis avascular or vascular
vascular (has blood supply)
what is acne
an active infection of the sebaceous glands on the skin
eccrine glands
- produce sweat
- important and highly efficient part of the body’s heat-regulating equipment
apocrine glands
- confined to the axillary and genital areas
- ducts empty into hair follicles
- secretion contains fatty aids and proteins
- precise function is not yet known
sebaceous glands
- oil glands
- normally dump into hair follicles but some open directly onto the skin
sudoriferous glands
-sweat glands
two types= eccrine and apocrine gland
cyanosis
when the skin appears blue when hemoglobin poorly oxygenated
erythema
-reddened skin may indicate embarrassment (blushing), fever, hypertension, inflammation, or allergy
pallor/blanching
-becoming pale under emotional stress (fear, anger, etc..), anemia, low blood pressure, or impaired blood flow into the area
jaundice
-a yellow cast signifying a liver disorder in which excess bile pigments are absorbed into the blood, circulated throughout the body, and deposited in body tissues
bruises/black and blue
-reveal sites where blood has escaped from the circulation and has clotted in the tissue spaces (hematoma)
impetigo
- pink, water filled raised lesions that develop a yellow crust and eventually rupture
- commonly around mouth and nose
- caused by a highly contagious staphylococcus
alopecia
- hair thinning and baldness
- by age 50 the number of hair follicles dropped by 1/3 and continues to decline
contact dermatitis
- skin inflammation
- happens over time because of the skins contact with irritants, pollutants, and bacteria
burn
tissue damage and cell death caused by intense heat, electricity, UV radiation (sunburn), or certain chemicals (ex: acids)
first degree burn
- only epidermis is damaged
- area becomes red and swollen
- temporary discomfort
- no usually serious and generally heal in two to three days
- partial thickness burn
- ex: mild sunburn
second degree burn
- epidermis and upper dermis
- skin is red, painful, and blisters appear
- regrowth/regeneration can occur
- partial thickness burn
third degree burn
- destroy the entire thickness of the skin
- full thickness burn
- appears blanched (gray-white) or blackened
- not painful: nerve endings=dead
- regeneration=not possible
- skin grafting is needed
burns are considered critical when:
1) over 25% of the body has second degree burns
2) over 10% of the body has third degree burns
3) third degree burns on the face, hands, or feet
rule of nines
-the volume of fluid lost can be estimated indirectly by determining how much of the body surface is burned
regions and percentages for rule of nines
- anterior/posterior head/neck: 9%
- anterior/posterior upper limbs: 18%
- anterior/posterior trunk: 36
- perineum: 1%
- anterior/posterior lower limbs: 36%
two major concerns with burns
- facial burns because of the possible burned respiratory passageways can cause swelling and suffocation
- joint injuries are hard because scar tissue that eventually forms can severely limit joint mobility
three skin cancers
- basal cell carcinoma
- squamous cell carcinoma
- malignant melanoma
basal cell carcinoma
- least malignant and most common
- cells are altered and cannot form keratin
- they proliferate, invading the dermis and subcutaneous tissue
- lesions occur on sun-exposed areas
- appear as tiny, dome-shaped nodules
- slow-growing and metastasis slowly
- full cure 99% of the time
squamous cell carcinoma
- arises from cells of the stratum spinosum
- appears as a scaly, reddened papule and gradually forms a shallow ulcer with a firm, raised border
- grows rapidly and metastasizes to adjacent lymph nodes if not removed
- sun-induced
- complete cure is likely if caught early
malignant melanoma
- 5% of skin cancers
- increases rapidly and is often deadly
- can begin wherever pigment is present
- appears as a spreading brown to black patch to surrounding lymph and blood vessels
- survival=50/50
ABCD Rule
helps to recognize melanoma
- A: Asymmetry of the two sides of the pigmented sport or mole do not match
- B: Border Irregularity the borders of the lesion are not smooth but exhibit indentations
- C: Color contains area of different colors such as: blacks, browns, tans, blues, and reds
- D: Diameter the spot is larger than 6mm
functions of the skeletal system
- support
- framework
- protection
- movement
- storage
- blood cell formation
how many bones in the adult skeleton
206
classification of bones
- long bones
- short bones
- flat bones
- irregular bones
long bones
- longer than they are wide
- have a shaft with heads at both ends
- mostly compact bone
- EX: humerus, femur
short bones
- generally cube-shaped
- contain mostly spongy bone
- EX: sesamoid bone, patella, carpals
flat bones
- thin, flattened, usually curved
- two thin layers of compact bone sandwiching spongy bone
- EX: skull, ribs, sternum
irregular bones
- do not fit in any other category
- vertebrae, hip
gross anatomy of long bone
- diaphysis
- periosteum
- epiphyses
- articular cartilage
- epiphyseal line
- epiphyseal plate
- medullary cavity
- sharpey’s fibers
-diaphysis
shaft
periosteum
fibrous connective tissue covering the diaphysis
epiphyses
end of the bones (heads)
articular cartilage
covers the external surface on the head of the bone
epiphyseal line
remanant of the epiphyseal plate
epiphyseal plate
a flate plate of hyaline cartilage
medullary cavity
cavity of the shaft primarily a storage area for fat tissue
sharpey’s fibers
connective tissue fibers securing the periosteum to the bone
red marrow
area in the shaft that forms blood cells
yellow marrow
area in the shaft that adipose (fat) tissue is stored
what does it mean if the epiphyseal plate is present
that it was a bone of a young person whose bones were still growing
microscopic structure of the bone
- osteocytes
- lacunae
- lamellae
- central (haversian) system
- canaliculi
- perforating (volkmann’s) cavity
osteocytes
mature bone cells
lacunae
tiny cavities within the matrix
lamellae
concentric circles the lacunae are arranged in
central (haversian) system
a canal for blood vessels and nerves in the bony matrix
perforating (volkmann’s) cavity
communication pathway from the outside of the bone that run into the compact bone at right angles
stages of bone fracture healing
1) hematoma (blood filled swelling) is formed
2) break is splinted by fibrocartilage to form a callus
3) fibrocartilage callus is replaced by a bony callus
4) bony callus is remodeled to form a permanent patch
comminuted fracture
bone breaks into many fragments
compression fracture
bone is crushed
depressed fracture
broken bone portion is pressed inward
impacted fracture
broken bone ends are forced into each other
spiral fracture
ragged break occurs when excessive twisting forces are applied to a bone
greenstick fracture
bone breaks incompletely; like a green twig breaks
closed (simple) fracture
when the bone breaks cleanly but does not penetrate the skin
open (compound) fracture
when the bone breaks cleanly and penetrates through the skin
what bones make up the axial skeleton
- skull
- vertebral column (spine)
- bony thorax
- ribs
what bones make up the appendicular skeleton
- bones of the shoulder girdle
- bones of the upper limbs
- bones of the pelvic girdle
- bones of the lower limbs
location of the coronal suture of the skull
between the parietal bone and the frontal bone
location of the lambdoid suture of the skull
between the occipital bone and parietal bone
location of the squamous suture of the skull
between the temporal bone and the occipital/parietal bones
what is the foramen magnum and where is it located
- a large opening in the base of the occipital bone
- allows the spinal cord connect to the brain
where is the mastoid process located
-a rough projection both posterior and inferior to the external auditory meatus providing an attachment site for some muscles of the neck
regions of the vertebral column
(superior) cervical curvature thoracic curvature lumbar curvature sacrum coccyx (inferior)
cervical curvature
first 7 vertebrae
thoracic curvature
vertebrae 8-19
lumbar curvature
vertebrae 20-24
sacrum
5 fused vertebrae after the lumbar curvature
coccyx
4 fused vertebrae after the sacrum
parts of the ribs
- true ribs
- false ribs
- floating ribs
- sternum
- costal cartilage
true ribs
ribs 1-7
false ribs
ribs 8-12
floating ribs
ribs 11 and 12
what bone does not articulate with any other bone in the body?
hyoid bone
arthritis
inflammation of the joints
osteoarthritis
- most common form of arthritis
- a chronic degenerative condition that typically affects the aged
- affects the articular cartilages
rheumatoid arthiritis
- a chronic inflammatory disorder
- occurs between ages of 40-50yrs old
- autoimmune disease
gouty arthritis
- disease in which uric acid accumulates in the blood and may be deposited as needle-shaped crystals in the soft tissues of joints
- agonizingly painful attack
what does it mean to have a dislocated or separated shoulder? How would a doctor take care of it? How might the skeletal, muscular, and integumentary systems be involved in the injury?
- a dislocated shoulder is when the top of your arm bone pops out of the shoulder socket
- a separated shoulder is when there are tears in one of the ligaments that connects the collarbone to the shoulder blade
- a doctor will move the arm bone back into the shoulder socket and advise you to take painkillers, ice, and strengthen your shoulder
- the skeletal muscle is affected because the bone comes out of the joint
- the muscluar system is affected because there is a tear in the ligament
- the integumentary system is affected because it swells, you might get scratches, bruising may occur, etc
skeletal muscle
- attached to bones
- single, very long, cylindrical, multinucleate cells with obvious striations
- voluntary; via nervous system controls
- speed of contraction: slow to fast
- no rhythmic contraction
cardiac muscle
- found in walls of the heart
- branching chains of cells; uninucleate, striations
- involuntary
- speed of contraction: slow
- there is rhythmic contraction
smooth muscle
- mostly in walls of hollow visceral organs (other than heart)
- single, fusiform, uninucleate; no striations
- involuntary
- speed of contraction: very slow
- yes, some rhythmic contraction
perimysium
connective tissue enveloping bundles of muscle fibers
epimysium
the sheath of fibrous connective tissue surrounding a muscle
endomysium
the thin connective tissue surrounding each muscle cell
functions of the muscular system
- producing movement
- maintaining posture
- stabilizing joints
- generating heat
motor unit
a motor neuron and all the muscle cells it supplies
acetylcholine
(ATP) a chemical transmitter substance released by certain nerve endings
how a muscle contraction occurs
-when muscle fibers are activated by the nervous system the cross bridges attach to myosin binding sites on the thin filaments, and the sliding begins. Energized by ATP, each cross bridge attaches and detaches several times during a contraction. The attachment of myosin cross bridges to actin requires calcium ions, and the action potential leading to contraction causes the sarcoplasmic reticulum to release stored calcium calcium ions into the sarcoplasm. when action potential ends, calcium ions are absorbed.
muscle twitches
- single, brief, jerky contractions
- sometimes a result of a nervous system problem
tectonic contraction
a smooth, continuous contraction with no relaxation
frontalis muscle
- covers the frontal bone
- allows you to raise your eyebrows and wrinkle your forehead
buccinator muscle
- runs horizontally across the cheek and inserts into the orbicularis oris
- flattens the cheek, helps in chewing
masseter muscle
- covers the angle of the lower jaw running from the zygomatic process of the temporal bone to the mandible
- closes the jaw by elevating the mandible
temporalis
- overlying the temporal bone
- acts as a synergist of the masseter in closing the jaw
zygomaticus
- extends from the corner of the mouth to the cheek-bone
- raises corners of the mouth upward (smile)
platysma
- covers the anterolateral neck
- action is to pull the corners of the mouth inferiorly, producing a downward sag of the mouth
orbicularis oris
- circular muscle of the lips
- closes the mouth and protrudes the lips
latissimus dorsi
- covers the lower back
- extends and adducts the humerus
triceps brachii
- fleshing out the posterior humerus
- primer mover of elbow extension
deltoid
- form the round shape of our shoulder
- injection site
- prime movers of arm abduction
pectoralis major
- covers the upper chest
- forms the anterior wall of the axilla
- acts to adduct and flex the arm
biceps brachii
- located on the forearm
- prime mover for flexion of the forearm and acts to supinate the forearm
hamstring
-muscles forming the muscle mass of the posterior thigh (biceps formoris, semimembranosus, and semitendinosus)
sartorius
- runs obliquely across the thigh from the anterior iliac crest to the medial side of the tibia
- acts as a synergist to bring about the cross-legged position
gastrocnemius
- two bellied muscle that forms the curved calf of the posterior leg
- prime mover for plantar flexion of the foot
gluteus medius
- runs from the ilium to the femur
- hip abductor and important in steadying the pelvis
- injection site
quadriceps group
-consist of four muscles (the rectus femoris and three vastus muscles)
-flesh out the anterior thigh
(the lateral vastus and rectus femoris are injection sites)
