Anatomy Lecture-8/23

What is the general strategy for this class?

-regional approach to anatomy of the dog (thoracic limb, thorax, head and neck, abdomen, urogneital and pelvic limb

What order is each section presented in?

1. Skeleton, 2. Joint, 3. Muscle, 4. Nerves, 5. Vasculature

What is the skeleton made of?

Bone and cartilage

What are functions of skeleton?

1. Support the body
2. Provide the system of levers used in locomotion
3. Protect soft tissues
4. Storage house for minerals
5. Site for fat storage
6. Site of blood cell formation

How are bones grouped and classified?

1. Shape
2. Structure
3. Function
4. Origin
5. Position

What are the 5 shape classifications?

1. Long bones
2. Short b
3. Sesamoid b
4. Flat bone
5. Irregular b

Name parts of long bones x 7

1. Epiphysis-ends of bone
2. Epiphysis plate-growth plate
3. Metaphysis-part after growth plate
4. Diaphysis-body of bone (long part)
5. Medulla- inside cavity (hollow)
6. Cortex- surround medulla
7. Articulation cartilage-over epiphysis that articulates

Define physis

Segment of bone responsible for lengthening bone

Name 3 topographic classifications of bones and what each includes

1. appendicular skeleton (thoracic limb and pelvic limbs)
2.Axial skeleton (vertebra, rib, sternum, skull)
3. Spanchnic or visceral skeleton ( os penis, os cordis)

List functions of muscles

Most movement of the body and its parts are due to muscular contraction
-activated by voluntary and involuntary nerve impulses or by humoral substances
-generate heat by shivering (involuntary)

Muscle classified by 3 types, name and describe

1. Cardiac muscle- (involuntary) contract heat, branching with inter calculated discs, striated with few (1-2) nucleus
2. Smooth muscle (Involuntary) muscle of blood vessels and viscera, contract. Spindle shape, no striations (1 nucleus)
3. Skeletal muscl

Define joints

Formed when 2 or more bones are united by fibrous, elastic or cartilaginous tissue or by a combo of these.

Joints are divided into 3 groups according to their structural features, name them

1. Fibrous joints ( fixed/immovable)
-united by fibrous connective tissues (skull sutures)
2. Cartilaginous joints ( slightly movable)
-untied by cartilage tissue and sometimes fibrous tissue (vertebral bodies, pelvic symphysis,mandibular symphysis)
3. Sy

Name 4 characteristics of synovial joint

1. Inner, synovial membrane
2. Outer fibrous layer
3 . Joint capsule
4. Articular cartilage

What do nerves do?

Receive stimuli from both external and internal environments, then produce an appropriate response in various effector organs.

Nerves are divided Anatomically into 2 groups

1. Central NS-brain and spinal cord
2. Peripheral NS- spinal nerves

Nerves are divided functionally into 2 groups

1. Somatic NS- Voluntary function ( muscle contract)
2 Autonomic NS- Involuntary function response to unfavorable conditions and restore normal condition

cardiovascular system consists of

The Heart (central organ)
Blood vessels
Lymphatic vessels

Cardiovascular system functions x5

1. Supply's the cells and tissues of body with nutrients required for their function
2. Transport surplus metabolites to storage organs
3. Remove waste products and convey to organs for excretion
4. Regulate water/electrolyte balance
5. Maintain body temp

Blood Vessels consist of

Arteries, capillaries and veins
-continuous system lined by unbroken low friction endothelium
- outer walls VARY greatly in construction and thickness, due to different functions

Arteries

Wide, thick, relatively ridged walls and empty lumina

Veins

Thinner walls, frequently collapsed appearance and capacity, More varied
-have VALVES, repeated at intervals along length, to ensure unidirectional flow and prevent reflux of blood.

Lymphatic system ( 2 components)

1. A system of lymphatic capillaries and larger vessels that return interstitial fluid to the blood stream (veins), such as thoracic duct, lymph vessels
2. A widely scattered aggregations of lymphoid tissues, including many lymph nodes, less discreet lymp

How do you spell professors name?

Dr. Nong Inpanbutr

Functions of thoracic limb x 2

1. Weight bearing ( clinical consequences, lameness more obvious because 60% of weight in front legs (30/30) vs rear (40% or 20/20)
2. Propulsion

Topographical region vs osteology/bones
1. Thoracic girdle
2. Arm/brachium
3. Forearm/antebrachium
4. Forepaw/Manus

1. Scapula, clavicle
2. Humerus
3. Radius and ulna
4. Carpal bones and metacarpal bones and phalanges

Scapula ( border vs angles). TRIANGLE

1. Cranial��Cranial
2. Caudal �Caudal
3. Dorsal�Ventral

Name muscle that attaches to Supraspinous fossa

Supraspinatus m

Infraspinous fossa

Infraspinatus m

Acrominon

Deltoideus m

Supraglenoid tubercle

Biceps brachii m

Coracoid process

Coracobrachialis m

Glenoid cavity

Head of humerous

Subscapular fossa

Subscapularis m

Humerus proximal end includes

1. Head,
2. Greater tubercle
3. Lesser tubercle
3. Deltoid tuberosity
4. Intertubercular groove

intertubercular groove what goes there?

Biceps brachii tendon sites there

body of humerus

Long part or shaft

Distal end of humerus, what is it called

Humeral condyle

medial epicondyle of humerus function

-LARGER
Fxn : provide origins for FLEXER muscles of carpus and digits

lateral epicondyle of humerus function

-smaller
-fxn : provides origin for EXTENSOR muscles of carpus and digits

Supratrochlear foramen vs. supracondylar foramen ( what runs there?)

Dog Only�supratrochlear foramen
Cat only - Surpracondylar foramen ( for brachial artery and median nerve)

Trochlea of humerus function

Medial, articulates with Radius and Ulna

Capitulum of humerus function

Lateral, articulates with RADIUS ONLY!! Weight bearing

Radius describe parts x 3 FXN

( Weight support)
1. Head-flat top, proximal
2. Trochlea- entire distal end
3. Styloid process- projection on medial surface on distal end

Ulna describe parts and fxn x 5

(Muscular attachments)
1. Olecranon- Most proximal part ( long projection)
2. Anconeal process - proximal, prone to fracture, below olecranon
3. Medial and lateral Coronoid process- prone to fracture, below trochlear notch
4. Trochlear notch-below anconea

Manus describe location and parts

Carpus down
1. Carpus, ( wrist) 2. Metacarpus (palm), 3. Digits ( 5 of them, each has 3 parts ( Proximal,middle and distal) **except digit I (P/P) 4. Sesamoid bones

Carpal bones, how many rows and name them

1. Proximal row (3)
Medial to latteral ( thumb�>pinky)
1. Radial carpal bone (intermedioradial)
2. Ulnar carpal bone
3. Accessory bone
2. Distal row (4)
M�L
First, second, third, fourth ) or (I, II, III , IV)

Metacarpal ( palm)

5 of them, M�L
First, second, third, fourth , fifth (I, II, III, IV, V)

Digits

5 of them M�>L
I, II, III, IV, V***

What are three parts of each digit?

Proximal phalanx
Middle phalanx
Distal phalanx
****Thumb does not have middle

Distal phalanx. Name and describe 3 parts

1. Ungual Crest - thin shelf, circle around base
2. Ungual process- conical extension of distal phalanx
3. Extensor process- dorsal part of base, insertion site for common digital extensor muscle on digits (II-V)

Median Raphe of the Neck (location and function)

-longitudinal fibrous septum
-btwn right and left epaxial muscles
Fxn: serves as an attachment for many cervical muscles

Thoracolumbar Fascia (location and function)

-deep fascia of the trunk
-arises from supraspinous ligaments and spines of thoracic and lumbar vertebrae.
FXn: attachment for many muscles

Extrinsic Muscles of thoracic limb ( function and location)

FXN: joins to the trunk by *
SYNSARCOSIS
*, not conventional joint (no bones)
-walking and advancing the limb
-attach limb to axial skeleton
Location: originate on the neck and thorax and extends to the shoulder or brachium as far distally as the elbow.

extrinsic vs intrinsic

Extrinsic- attach limb to body/axial skeleton (no bone to bone)
Intrinsic - bone to bone attachment ( flex and extend)
-extend between bones that compose of limb

Define origins and insertions

Origins- proximal, move least
Insertions- Distal, move more

Superficial pectoral muscle (innervation and function / I & F)-2 components (descending and transverse)

I: Cranial pectoral n
Fxn: both components are adduction of forelimb

Deep pectoral muscle (I and fxn)

I: Caudal pectoral n
F: pulls the trunk cranial
-draw limb caudallly
-adduction
-flex shouolder

Brachiocephalicus muscle ( I and F)

I : 1. Accessory n and 2. Ventral branches of cervical spinal n
F: 1. Advances limb
2. Extends the shoulder joint
3. Draw head and neck to the side

Brachiocephalicus muscle has 3 parts , name and describe them

1. Cleidobrachialis muscle -humerus to clavicle (below tendon)
2. Cleidocephalicus muscle -clavicle to head (above tendon) then splits
A. Cleidocervicalis muscle (clavicle to neck) bottom
B. Cleidomastoideus muscle (clavicle to mastoid process (skull) top

Sternocephalicus muscle (I and F)

I: 1. Accessory n
2. Ventral branches of cervical spinal n
F: draw head and neck to side ( two parts-mastoid and occipital)
-looks like a *
V
* from sternum to head

Omotransversarius ( I and F)

I: Accessory n
F: advances limb and flex neck

Trapezius (I and F)

I: accessory n
F: elevates/abducts limb
(Superficial over scapula and have two parts cervical and thoracic **looks like triangle over shoulder)

Rhomboideus m (I and F)

I: ventral branches of cervical and thoracic spinal n
F:elevates limb/draws scapula against trunk
(Has 3 parts: Capitis , cervicis, thoracis)

Latissimus Dorsi m (I and F)

I: thoracodorsal n
F: digging/ flex shoulder

Serratus Ventralis m ( I and F)

I: Ventral branches of cervical spinal n and long thoracic n
Fxn: support the trunk and depress the scapula

Cutaneous trunci m ( I and F)

I: lateral thoracic n
F: twitches skin