Unit 3 Anatomy Physiology Veterinary Medical Applications I

Unit 3: Anatomy & Physiology Veterinary Medical Applications I

Directional Terminology Unit 3: Anatomy & Physiology

Introduction • It is very important for the veterinary assistant to be familiar with basic anatomical terminology. • This knowledge helps to better understand medical conditions and treatments, follow instructions from the veterinarian, perform basic veterinary medical procedures Unit 3: Anatomy & Physiology

Anatomical Terminology • Being familiar with anatomical terminology is important, and the terms used here will be repeated throughout this and other units. • These terms will be used in the description of bones, the names of muscles, as well as in the description of clinical cases. Unit 3: Anatomy & Physiology

Anatomical Terms Unit 3: Anatomy & Physiology

ANTERIOR • The front of the animal Unit 3: Anatomy & Physiology

POSTERIOR • The rear of the animal Unit 3: Anatomy & Physiology

CRANIAL • Towards the head Unit 3: Anatomy & Physiology

CAUDAL • Towards the tail Unit 3: Anatomy & Physiology

DORSAL • Along the back or uppermost surface Unit 3: Anatomy & Physiology

VENTRAL • Along the belly or undermost surface Unit 3: Anatomy & Physiology

PROXIMAL • Part of the limb closest to the body Unit 3: Anatomy & Physiology

DISTAL • Part of the limb furthest from the body Unit 3: Anatomy & Physiology

Three-Dimension Planes Unit 3: Anatomy & Physiology

FRONTAL PLANE • Body plane that divides the animal into dorsal and ventral parts Unit 3: Anatomy & Physiology

MEDIAN PLANE • Body plane that divides the animal into equal, symmetrical right and left halves. Unit 3: Anatomy & Physiology

SAGITTAL PLANE • Any body plane that is parallel to the median plane. Unit 3: Anatomy & Physiology

TRANSVERSE PLANE • Body plane that divides the animal into cranial and caudal parts. Unit 3: Anatomy & Physiology

SUPERFICIAL • Closer to the surface Unit 3: Anatomy & Physiology

DEEP • Further from the surface – Example: superficial and deep flexor tendons Unit 3: Anatomy & Physiology

Skeletal System Unit 3: Anatomy & Physiology

Skeletal System • The skeleton is a framework of structures, made of bones and cartilage that support and protect the body. • Axial Skeleton: includes the skull, vertebrae, ribs, and sternum. • Appendicular Skeleton – the fore and hind limbs Unit 3: Anatomy & Physiology

Unit 3: Anatomy & Physiology

Appendicular: Forelimb Scapula – “shoulder blade” attached with muscle Clavicle – the cat is the only domestic animal with a clavicle! Humerus – forms the upper arm Ulna – forms the elbow joint, fused with the radius in herbivores Radius – forms the forearm Carpus – commonly called the “knee” in horses, the “wrist” in dogs and humans Metacarpals – commonly called the cannon region of the forelimb. Number depends on species: a) Humans: 5 b) Horses: 1 plus 2 accessory metacarpals, called “splint bones” c) Dogs and cats: 4 plus the dewclaw d) Cattle: 1 that splits at bottom into a cloven hoof and two dewclaws e) Pigs: 4 (2 toes and 2 dewclaws) Unit 3: Anatomy & Physiology

Appendicular: Forelimb Continued Proximal phalanx (P 1) – bones of the finger, hoof, and claw Intermediate phalanx (P 2) Distal phalanx (P 3) – the coffin bone in horses Proximal sesamoids – tucked in behind P 1 Distal sesamoid – tucked in underneath P 3 Unit 3: Anatomy & Physiology

Pelvis Appendicular: Hindlimb a) Tuber coxae – part of pelvis that forms the “point of hip” b) Ischiatic tuberosity- part of pelvis that forms the “seat bones” Femur Patella – forms the “stifle” joint in horses, sometimes called the “knee” in dogs, equivalent to the human knee Tibia – main bone of the gaskin of the horse Fibula – fused with the tibia & considered vestigial in herbivores Tarsus – commonly called the “hock”, equivalent to the human “ankle”. Metatarsal – cannon region in the hind limb. Number depends on species. Unit 3: Anatomy & Physiology

Classification of Bones • Short bone – cube shaped, i. e. carpus and tarsus • Flat bone – plate of bone, i. e. scapula, rib, skull • Irregular bone – complex shaped, i. e. vertebrae • Sesamoid – small, seed-shaped bone, i. e. proximal and distal sesamoids, patella • Long bone – bone is longer that it is wide, i. e. femur, tibia, humerus, etc. Unit 3: Anatomy & Physiology

Bone Anatomy Epiphysis Diaphysis Periosteum Medullary cavity Endosteum Bone marrow Metaphysis Unit 3: Anatomy & Physiology

Classifications of Fractures Fissured Unit 3: Anatomy & Physiology Greenstick Transverse 29 Comminuted

Muscular System Unit 3: Anatomy & Physiology

Types of Muscle • Skeletal muscle – allows for all voluntary movement, appears to be striated when looked at under a microscope. • Cardiac muscle – controls the involuntary beating of the heart, appears striated under a microscope. • Smooth muscle – responsible for all other involuntary movement, such as breathing, digestion, peristalsis, blinking, etc. Unit 3: Anatomy & Physiology

Muscle Movement • Ambulation: moving from one place to another • Abduction: moving away from the median plane • Adduction: moving towards the median plane • Flexion: moving the distal part of the limb towards the body • Extension: moving the distal part of the limb away from the body Unit 3: Anatomy & Physiology

Muscle Function • All muscles can do is CONTRACT or RELAX, so they generally work in pairs. For any particular action, the muscles involved can be classified as: • Agonist – prime mover of a joint • Antagonist – opposes movement of the agonist • Ex: for elbow flexion, the agonist is the bicep, and the antagonist is the tricep. For elbow extension, the agonist is the tricep, and the antagonist is the bicep. Unit 3: Anatomy & Physiology

Major Muscles Brachiocephalicus Masseter Trapezius Latissimus dorsi External abdominal oblique Gluteals Pectorals Semitendinous Deltoid Triceps brachii Unit 3: Anatomy & Physiology Gastrocnemius Intercostal 34 Biceps femoris

Description/Function of Muscles • Masseter – superficial muscle of the cheek • Trapezius – superficial triangular muscle of the shoulder • Latissimus dorsi – long, superficial, dorsal muscle that attaches the humerus to the lumbar region of the back • Abdominal obliques – large flat muscles that support digestive and reproductive organs • Gluteals – large muscle of the upper hindquarters • Biceps femoris – lateral superficial muscle, one of three which forms the “hamstrings” • Biceps brachii – primary flexor of the elbow joint • Triceps brachii – primary extensor of the elbow joint • Pectorals – primary adductors of the forelimbs • Serratus ventralis – attaches forelimb to trunk (no collarbone!) Unit 3: Anatomy & Physiology

Nervous System Unit 3: Anatomy & Physiology

Vocabulary Axon – sends impulses away from cell Brain – major organ of nervous system; contained within the skull Brainstem – connects the cerebrum with the spinal cord; contains the Medulla oblongata Central nervous system – contains brain and spinal cord Cerebellum – coordinates movement and muscle activity, balance Cerebrum – largest portion of brain; responsible for receiving and storing information and signaling for voluntary movement

Connecting neuron – carries impulses from one neuron to another Dendrites – branch-like; receive impulses Homeostasis – state of balance of the physiologic systems within the body Impulse – electrical signal that is transmitted through nervous tissue Medulla oblongata – part of the brain responsible for all life functions including: heart rate, breathing, and reflex actions (coughing, sneezing, swallowing, and vomiting) Meninges – protective layer covering the brain; has three layers Motor neuron – carries impulses from the brain towards the muscles and glands

Nerve – term for one or more bundles of nerve cells Neuron – nerve cells Neurotransmitter – chemical substance that allows impulses to travel Parasympathetic nervous system – maintains and restores normal body function Peripheral nervous system – consists of all nerves that lead to and from the spinal cord and brain, known as cranial and spinal nerves Sensory neuron – carries impulses towards the brain and spinal cord Soma – cell body that contains the nucleus Spinal cord – pathway for all impulses going to and from the brain, Sympathetic nervous system – responsible for stress and emergency responses; “fight or flight” Synapse – space between neurons that contains a neurotransmitter

Functions of the Nervous System • Detects and processes information and formulates responses; coordinates and controls all bodily activity. • The nervous system sends and receives impulses –electrical signals that travel though the nervous system and provide information to the brain.

Types of Neurons Sensory neurons – carry impulses towards the brain and spinal cord. Connecting neurons – carry impulses from one neuron to another. Motor neurons – carry impulses away from the brain and spinal cord to the body.

Parts of a Neuron Dendrite Cell body (soma) Myelin sheath Axon Synapse http: //safari. pisd. edu/? a=175072&s=00: 00: 00 &e=00: 49: 00&d=25344 AA

Parts of a Neuron 1. Cell Body – often called the soma. Contains the cell nucleus 2. Dendrite – branch-like, receives impulses 3. Axon – sends impulses away from the cell 4. Synapse – space in between neurons; contains a chemical substance called a neurotransmitter that helps impulses travel 5. Myelin – protective sheath around the neuron

Central Nervous System – consists of brain and spinal cord. 1. Brain – major organ of the nervous system. a. b. Meninges – three-layered protective covering of the brain. Cerebrum – largest part of the brain. It has four lobes that receive and store information And are responsible for giving signals for voluntary movement c. Cerebellum – coordinates all movement, muscle activity, and balance. d. Brainstem – connects the brain to the spinal cord and contains the medulla oblongata. e. Medulla oblongata - dictates all life functions including: heart rate, breathing, and reflex actions. f. Thalamus – a central relay system for all nerve impulses except smell. It receives the impulses and then directs them to the proper part of the brain. g. Hypothalamus – serves as a link between the nervous system and the endocrine system. h. Pituitary gland – secretes hormones important for reproduction and growth. 2. Spinal cord – pathway for all impulses going to and from the brain. Connects to the

Parts of the Brain Meninges Cerebrum Cerebellum Thalamus Spinal cord Hypothalamus Pituitary gland Brain stem Medulla oblongata

• Peripheral Nervous System – consists of nerves that relay information to and from the spinal cord. • Sympathetic Nervous System – Responsible for emergency and stress responses: “fight or flight”. • Parasympathetic Nervous System – Seeks to maintain and restore normal body function, often called Homeostasis: a state of balance of the physiologic systems within the body

Respiratory System Unit 3: Anatomy & Physiology

Vocabulary Alveoli – grape-like clusters at ends of bronchioles; where exchange of oxygen and carbon dioxide gases occur Apnea – not breathing Asphyxiation – suffocation; blockage of airflow that results in a lack of oxygen Bradypnea – abnormally slow respiratory rate Bronchi – paired terminal branches of the trachea contained within the lungs; singular: bronchus

Bronchial tree – term that describes how bronchi get continually smaller, like a tree branch Bronchioles – smallest branches of the bronchial tree Cilia – tiny hairs inside nostrils that help to filter air Diaphragm – Muscle located below the lungs; contraction causes the lungs to draw in a breath

Dyspnea – difficult breathing Epiglottis – flap that covers the larynx during swallowing Exhalation – release of a breath Inhalation – drawing in of a breath Larynx – ‘voice box’ that contains vocal cords

Lungs – paired major organs of respiration that contain bronchi and are divided into clearly defined lobes Mucous membrane – lining of respiratory tract that secretes mucus Mucus – slimy secretion that warms, moistens, and filters air

Pharynx – common passageway for both the respiratory and digestive systems Respiration – exchange of oxygen and carbon dioxide gases with cells Tachypnea – abnormally fast respiratory rate Trachea – windpipe; has distinct rings of cartilage